genode/repos/os/include/ram_fs/chunk.h

449 lines
10 KiB
C
Raw Normal View History

File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/*
* \brief Data structure for storing sparse files in RAM
* \author Norman Feske
* \date 2012-04-18
*/
/*
* Copyright (C) 2012-2017 Genode Labs GmbH
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
*/
#ifndef _INCLUDE__RAM_FS__CHUNK_H_
#define _INCLUDE__RAM_FS__CHUNK_H_
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/* Genode includes */
#include <util/noncopyable.h>
#include <base/allocator.h>
#include <util/string.h>
#include <file_system_session/file_system_session.h>
namespace File_system {
using namespace Genode;
using Genode::Noncopyable;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
class Chunk_base;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
template <unsigned> class Chunk;
template <unsigned, typename> class Chunk_index;
}
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/**
* Common base class of both 'Chunk' and 'Chunk_index'
*/
class File_system::Chunk_base : Noncopyable
{
public:
class Index_out_of_range { };
protected:
seek_off_t const _base_offset;
size_t _num_entries; /* corresponds to last used entry */
/**
* Test if specified range lies within the chunk
*/
void assert_valid_range(seek_off_t start, size_t len,
file_size_t chunk_size) const
{
if (zero()) return;
if (start < _base_offset)
throw Index_out_of_range();
if (start + len > _base_offset + chunk_size)
throw Index_out_of_range();
}
Chunk_base(seek_off_t base_offset)
: _base_offset(base_offset), _num_entries(0) { }
/**
* Construct zero chunk
*
* A zero chunk is a chunk that cannot be written to. When reading
* from it, it returns zeros. Because there is a single zero chunk
* for each chunk type, the base offset is meaningless. We use a
* base offset of ~0 as marker to identify zero chunks.
*/
Chunk_base() : _base_offset(~0L), _num_entries(0) { }
public:
/**
* Return absolute base offset of chunk in bytes
*/
seek_off_t base_offset() const { return _base_offset; }
/**
* Return true if chunk is a read-only zero chunk
*/
bool zero() const { return _base_offset == (seek_off_t)(~0L); }
/**
* Return true if chunk has no allocated sub chunks
*/
bool empty() const { return _num_entries == 0; }
};
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/**
* Chunk of bytes used as leaf in hierarchy of chunk indices
*/
template <unsigned CHUNK_SIZE>
class File_system::Chunk : public Chunk_base
{
private:
char _data[CHUNK_SIZE];
public:
enum { SIZE = CHUNK_SIZE };
/**
* Construct byte chunk
*
* \param base_offset absolute offset of chunk in bytes
*
* The first argument is unused. Its mere purpose is to make the
* signature of the constructor compatible to the constructor
* of 'Chunk_index'.
*/
Chunk(Allocator &, seek_off_t base_offset)
:
Chunk_base(base_offset)
{
memset(_data, 0, CHUNK_SIZE);
}
/**
* Construct zero chunk
*/
Chunk() { }
/**
* Return number of used entries
*
* The returned value corresponds to the index of the last used
* entry + 1. It does not correlate to the number of actually
* allocated entries (there may be ranges of zero blocks).
*/
file_size_t used_size() const { return _num_entries; }
void write(char const *src, size_t len, seek_off_t seek_offset)
{
assert_valid_range(seek_offset, len, SIZE);
/* offset relative to this chunk */
seek_off_t const local_offset = seek_offset - base_offset();
memcpy(&_data[local_offset], src, len);
_num_entries = max(_num_entries, local_offset + len);
}
void read(char *dst, size_t len, seek_off_t seek_offset) const
{
assert_valid_range(seek_offset, len, SIZE);
memcpy(dst, &_data[seek_offset - base_offset()], len);
}
void truncate(file_size_t size)
{
assert_valid_range(size, 0, SIZE);
/*
* Offset of the first free position (relative to the beginning
* this chunk).
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
*/
seek_off_t const local_offset = size - base_offset();
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
if (local_offset >= _num_entries)
return;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
memset(&_data[local_offset], 0, _num_entries - local_offset);
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
_num_entries = local_offset;
}
};
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
template <unsigned NUM_ENTRIES, typename ENTRY_TYPE>
class File_system::Chunk_index : public Chunk_base
{
public:
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
typedef ENTRY_TYPE Entry;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
enum { ENTRY_SIZE = ENTRY_TYPE::SIZE,
SIZE = ENTRY_SIZE*NUM_ENTRIES };
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
private:
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
Allocator &_alloc;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
Entry * _entries[NUM_ENTRIES];
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/**
* Return instance of a zero sub chunk
*/
static Entry const &_zero_chunk()
{
static Entry zero_chunk;
return zero_chunk;
}
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/**
* Return sub chunk at given index
*
* If there is no sub chunk at the specified index, this function
* transparently allocates one. Hence, the returned sub chunk
* is ready to be written to.
*/
Entry &_entry_for_writing(unsigned index)
{
if (index >= NUM_ENTRIES)
throw Index_out_of_range();
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
if (_entries[index])
return *_entries[index];
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
seek_off_t entry_offset = base_offset() + index*ENTRY_SIZE;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
_entries[index] = new (&_alloc) Entry(_alloc, entry_offset);
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
_num_entries = max(_num_entries, index + 1);
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
return *_entries[index];
}
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/**
* Return sub chunk at given index (for reading only)
*
* This function transparently provides a zero sub chunk for any
* index that is not populated by a real chunk.
*/
Entry const &_entry_for_reading(unsigned index) const
{
if (index >= NUM_ENTRIES)
throw Index_out_of_range();
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
if (_entries[index])
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
return *_entries[index];
return _zero_chunk();
}
/**
* Return index of entry located at specified byte offset
*
* The caller of this function must make sure that the offset
* parameter is within the bounds of the chunk.
*/
unsigned _index_by_offset(seek_off_t offset) const
{
return (offset - base_offset()) / ENTRY_SIZE;
}
/**
* Apply operation 'func' to a range of entries
*/
template <typename THIS, typename DATA, typename FUNC>
static void _range_op(THIS &obj, DATA *data, size_t len,
seek_off_t seek_offset, FUNC const &func)
{
/*
* Depending on whether this function is called for reading
* (const function) or writing (non-const function), the
* operand type is const or non-const Entry. The correct type
* is embedded as a trait in the 'FUNC' functor type.
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
*/
typedef typename FUNC::Entry Const_qualified_entry;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
obj.assert_valid_range(seek_offset, len, SIZE);
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
while (len > 0) {
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
unsigned const index = obj._index_by_offset(seek_offset);
Const_qualified_entry &entry = FUNC::lookup(obj, index);
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/*
* Calculate byte offset relative to the chunk
*
* We cannot use 'entry.base_offset()' for this calculation
* because in the const case, the lookup might return a
* zero chunk, which has no defined base offset. Therefore,
* we calculate the base offset via index*ENTRY_SIZE.
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
*/
seek_off_t const local_seek_offset =
seek_offset - obj.base_offset() - index*ENTRY_SIZE;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/* available capacity at 'entry' starting at seek offset */
seek_off_t const capacity = ENTRY_SIZE - local_seek_offset;
seek_off_t const curr_len = min(len, capacity);
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/* apply functor (read or write) to entry */
func(entry, data, curr_len, seek_offset);
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
/* advance to next entry */
len -= curr_len;
data += curr_len;
seek_offset += curr_len;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
}
}
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
struct Write_func
{
typedef ENTRY_TYPE Entry;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
static Entry &lookup(Chunk_index &chunk, unsigned i) {
return chunk._entry_for_writing(i); }
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
void operator () (Entry &entry, char const *src, size_t len,
seek_off_t seek_offset) const
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
{
entry.write(src, len, seek_offset);
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
}
};
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
struct Read_func
{
typedef ENTRY_TYPE const Entry;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
static Entry &lookup(Chunk_index const &chunk, unsigned i) {
return chunk._entry_for_reading(i); }
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
void operator () (Entry &entry, char *dst, size_t len,
seek_off_t seek_offset) const
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
{
if (entry.zero())
memset(dst, 0, len);
else
entry.read(dst, len, seek_offset);
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
}
};
void _init_entries()
{
for (unsigned i = 0; i < NUM_ENTRIES; i++)
_entries[i] = 0;
}
void _destroy_entry(unsigned i)
{
if (_entries[i] && (i < _num_entries)) {
destroy(&_alloc, _entries[i]);
_entries[i] = 0;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
}
}
public:
/**
* Constructor
*
* \param alloc allocator to use for allocating sub-chunk
* indices and chunks
* \param base_offset absolute offset of the chunk in bytes
*/
Chunk_index(Allocator &alloc, seek_off_t base_offset)
: Chunk_base(base_offset), _alloc(alloc) { _init_entries(); }
/**
* Construct zero chunk
*/
Chunk_index() : _alloc(*(Allocator *)0) { }
/**
* Destructor
*/
~Chunk_index()
{
for (unsigned i = 0; i < NUM_ENTRIES; i++)
_destroy_entry(i);
}
/**
* Return size of chunk in bytes
*
* The returned value corresponds to the position after the highest
* offset that was written to.
*/
file_size_t used_size() const
{
if (_num_entries == 0)
return 0;
/* size of entries that lie completely within the used range */
file_size_t const size_whole_entries = ENTRY_SIZE*(_num_entries - 1);
Entry *last_entry = _entries[_num_entries - 1];
if (!last_entry)
return size_whole_entries;
return size_whole_entries + last_entry->used_size();
}
/**
* Write data to chunk
*/
void write(char const *src, size_t len, seek_off_t seek_offset)
{
_range_op(*this, src, len, seek_offset, Write_func());
}
/**
* Read data from chunk
*/
void read(char *dst, size_t len, seek_off_t seek_offset) const
{
_range_op(*this, dst, len, seek_offset, Read_func());
}
/**
* Truncate chunk to specified size in bytes
*
* This function can be used to shrink a chunk only. Specifying a
* 'size' larger than 'used_size' has no effect. The value returned
* by 'used_size' refers always to the position of the last byte
* written to the chunk.
*/
void truncate(file_size_t size)
{
unsigned const trunc_index = _index_by_offset(size);
if (trunc_index >= _num_entries)
return;
for (unsigned i = trunc_index + 1; i < _num_entries; i++)
_destroy_entry(i);
/* traverse into sub chunks */
if (_entries[trunc_index])
_entries[trunc_index]->truncate(size);
_num_entries = trunc_index + 1;
/*
* If the truncated at a chunk boundary, we can release the
* empty trailing chunk at 'trunc_index'.
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
*/
if (_entries[trunc_index] && _entries[trunc_index]->empty()) {
_destroy_entry(trunc_index);
_num_entries--;
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
}
}
File-system interface, ram_fs, libc-fs This patch introduces the file-system-session interface, provides an implementation of this interface in the form of an in-memory file system, and enables the libc to use the new file-system facility. The new interface resides in 'os/include/file_system_session/'. It uses synchronous RPC calls for functions referring to directory and meta-data handling. For transferring payload from/to files, the packet-stream interface is used. I envision that the asynchronous design of the packet-stream interface fits well will the block-session interface. Compared to Unix-like file-system APIs, Genode's file-system session interface is much simpler. In particular, it does not support per-file permissions. On Genode, we facilitate binding policy (such as write-permission) is sessions rather than individual file objects. As a reference implementation of the new interface, there is the new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse files in memory. At the startup, 'ram_fs' is able to populate the file-system content with directories and ROM modules as specified in its configuration. To enable libc-using programs to access the new file-system interface, there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this plugin, files stored on a native Genode file system can be accessed using the traditional POSIX file API. To see how the three parts described above fit together, the test case at 'libports/run/libc_fs' can be taken as reference. It reuses the original 'libc_ffat' test to exercise several file operations on a RAM file-system using the libc API. :Known limitations: The current state should be regarded as work in progress. In particular the error handling is not complete yet. Not all of the session functions return the proper exceptions in the event of an error. I plan to successively refine the interface while advancing the file-system implementations. Also the support for truncating files and symlink handling are not yet implemented. Furthermore, there is much room for optimization, in particular for the handling of directory entries. Currently, we communicate only one dir entry at a time, which is bad when traversing large trees. However, I decided to focus on functionality first and defer optimizations (such as batching dir entries) to a later stage. The current implementation does not handle file modification times at all, which may be a severe limitation for tools that depend on this information such as GNU make. Support for time will be added after we have revisited Genode's timer-session interface (issue #1). Fixes #54 Fixes #171
2012-04-11 13:46:33 +00:00
};
#endif /* _INCLUDE__RAM_FS__CHUNK_H_ */