mirror of
https://github.com/genodelabs/genode.git
synced 2025-01-19 03:06:39 +00:00
Noux: speed up tar record lookup
Currently the lookup of a specific record in a tar archive may take a long time, because the records get searched in sequence. With this patch a tree structure representing the directory layout gets created when loading the tar file for speeding up record lookups. Fixes #491.
This commit is contained in:
Christian Prochaska
Norman Feske
parent
bb33c9f3cf
commit
fb216f370b
@ -109,7 +109,7 @@ namespace Noux {
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public:
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Tar_vfs_handle(File_system *fs, int status_flags, Record *record)
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Tar_vfs_handle(File_system *fs, int status_flags, Record const *record)
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: Vfs_handle(fs, fs, status_flags), _record(record)
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{ }
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@ -117,85 +117,189 @@ namespace Noux {
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};
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struct Lookup_criterion { virtual bool match(char const *path) = 0; };
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/**
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* Return portion of 'path' without leading slashes and dots
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* path element token
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*/
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static char const *_skip_leading_slashes_dots(char const *path)
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struct Scanner_policy_path_element
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{
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while (*path == '.' || *path == '/')
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path++;
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return path;
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}
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static void _remove_trailing_slashes(char *str)
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{
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size_t len = 0;
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while ((len = strlen(str)) && (str[len - 1] == '/'))
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str[len - 1] = 0;
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}
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struct Lookup_exact : public Lookup_criterion
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{
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Absolute_path _match_path;
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Lookup_exact(char const *match_path)
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: _match_path(match_path)
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static bool identifier_char(char c, unsigned /* i */)
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{
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_match_path.remove_trailing('/');
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}
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bool match(char const *path)
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{
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Absolute_path test_path(path);
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test_path.remove_trailing('/');
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return _match_path.equals(test_path);
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return (c != '/') && (c != 0);
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}
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};
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/**
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* Lookup the Nth record in the specified path
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*/
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struct Lookup_member_of_path : public Lookup_criterion
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typedef Genode::Token<Scanner_policy_path_element> Path_element_token;
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struct Node : List<Node>, List<Node>::Element
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{
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Absolute_path _dir_path;
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int const index;
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int cnt;
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char const *name;
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Record const *record;
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Lookup_member_of_path(char const *dir_path, int index)
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: _dir_path(dir_path), index(index), cnt(0)
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Node(char const *name, Record const *record) : name(name), record(record) { }
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Node *lookup(char const *name)
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{
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_dir_path.remove_trailing('/');
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Absolute_path lookup_path(name);
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if (verbose)
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PDBG("lookup_path = %s", lookup_path.base());
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Node *parent_node = this;
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Node *child_node;
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Path_element_token t(lookup_path.base());
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while (t) {
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if (t.type() != Path_element_token::IDENT) {
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t = t.next();
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continue;
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}
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char path_element[Sysio::MAX_PATH_LEN];
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t.string(path_element, sizeof(path_element));
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if (verbose)
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PDBG("path_element = %s", path_element);
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for (child_node = parent_node->first(); child_node; child_node = child_node->next()) {
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if (verbose)
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PDBG("comparing with node %s", child_node->name);
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if (strcmp(child_node->name, path_element) == 0) {
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if (verbose)
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PDBG("found matching child node");
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parent_node = child_node;
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break;
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}
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}
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if (!child_node)
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return 0;
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t = t.next();
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}
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return parent_node;
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}
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bool match(char const *path)
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Node *lookup_child(int index)
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{
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Absolute_path test_path(path);
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for (Node *child_node = first(); child_node; child_node = child_node->next(), index--) {
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if (index == 0)
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return child_node;
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}
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if (!test_path.strip_prefix(_dir_path.base()))
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return false;
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if (!test_path.has_single_element())
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return false;
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cnt++;
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/* match only if index is reached */
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if (cnt - 1 != index)
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return false;
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return true;
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return 0;
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}
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size_t num_dirent()
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{
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size_t count = 0;
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for (Node *child_node = first(); child_node; child_node = child_node->next(), count++) ;
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return count;
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}
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} _root_node;
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/*
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* Create a Node for a tar record and insert it into the node list
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*/
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class Add_node_action
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{
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private:
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Node &_root_node;
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public:
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Add_node_action(Node &root_node) : _root_node(root_node) { }
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void operator()(Record const *record)
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{
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Absolute_path current_path(record->name());
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if (verbose)
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PDBG("current_path = %s", current_path.base());
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char path_element[Sysio::MAX_PATH_LEN];
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Path_element_token t(current_path.base());
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Node *parent_node = &_root_node;
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Node *child_node;
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while(t) {
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if (t.type() != Path_element_token::IDENT) {
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t = t.next();
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continue;
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}
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Absolute_path remaining_path(t.start());
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t.string(path_element, sizeof(path_element));
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for (child_node = parent_node->first(); child_node; child_node = child_node->next()) {
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if (strcmp(child_node->name, path_element) == 0)
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break;
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}
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if (child_node) {
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if (verbose)
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PDBG("found node for %s", path_element);
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if (remaining_path.has_single_element()) {
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/* Found a node for the record to be inserted.
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* This is usually a directory node without
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* record. */
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child_node->record = record;
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}
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} else {
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if (remaining_path.has_single_element()) {
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if (verbose)
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PDBG("creating node for %s", path_element);
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/*
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* TODO: find 'path_element' in 'record->name'
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* and use the location in the record as name
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* pointer to save some memory
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*/
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size_t name_size = strlen(path_element) + 1;
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char *name = (char*)env()->heap()->alloc(name_size);
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strncpy(name, path_element, name_size);
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child_node = new (env()->heap()) Node(name, record);
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} else {
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if (verbose)
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PDBG("creating node without record for %s", path_element);
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/* create a directory node without record */
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size_t name_size = strlen(path_element) + 1;
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char *name = (char*)env()->heap()->alloc(name_size);
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strncpy(name, path_element, name_size);
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child_node = new (env()->heap()) Node(name, 0);
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}
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parent_node->insert(child_node);
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}
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parent_node = child_node;
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t = t.next();
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}
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}
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};
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Record *_lookup(Lookup_criterion *criterion)
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template <typename Tar_record_action>
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void _for_each_tar_record_do(Tar_record_action tar_record_action)
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{
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/* measure size of archive in blocks */
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unsigned block_id = 0, block_cnt = _tar_size/Record::BLOCK_LEN;
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@ -205,9 +309,7 @@ namespace Noux {
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Record *record = (Record *)(_tar_base + block_id*Record::BLOCK_LEN);
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/* get infos about current file */
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if (criterion->match(record->name()))
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return record;
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tar_record_action(record);
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size_t file_size = record->size();
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@ -226,21 +328,19 @@ namespace Noux {
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if (*(_tar_base + (block_id*Record::BLOCK_LEN + 1)) == 0x00)
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break;
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}
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return 0;
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}
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struct Num_dirent_cache
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{
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Lock lock;
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Tar_file_system &tar_fs;
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Node &root_node;
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bool valid; /* true after first lookup */
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char key[256]; /* key used for lookup */
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size_t cached_num_dirent; /* cached value */
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Num_dirent_cache(Tar_file_system &tar_fs)
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: tar_fs(tar_fs), valid(false), cached_num_dirent(0) { }
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Num_dirent_cache(Node &root_node)
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: root_node(root_node), valid(false), cached_num_dirent(0) { }
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size_t num_dirent(char const *path)
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{
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@ -248,11 +348,11 @@ namespace Noux {
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/* check for cache miss */
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if (!valid || strcmp(path, key) != 0) {
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Lookup_member_of_path lookup_criterion(path, ~0);
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tar_fs._lookup(&lookup_criterion);
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Node *node = root_node.lookup(path);
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if (!node)
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return 0;
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strncpy(key, path, sizeof(key));
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cached_num_dirent = lookup_criterion.cnt;
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cached_num_dirent = node->num_dirent();
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valid = true;
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}
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return cached_num_dirent;
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@ -267,10 +367,13 @@ namespace Noux {
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_rom_name(config), _rom(_rom_name.name),
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_tar_base(env()->rm_session()->attach(_rom.dataspace())),
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_tar_size(Dataspace_client(_rom.dataspace()).size()),
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_cached_num_dirent(*this)
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_root_node("", 0),
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_cached_num_dirent(_root_node)
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{
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PINF("tar archive '%s' local at %p, size is %zd",
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_rom_name.name, _tar_base, _tar_size);
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_for_each_tar_record_do(Add_node_action(_root_node));
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}
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@ -283,23 +386,31 @@ namespace Noux {
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/*
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* Walk hardlinks until we reach a file
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*/
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Record *record = 0;
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Record const *record = 0;
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for (;;) {
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Lookup_exact lookup_criterion(path);
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record = _lookup(&lookup_criterion);
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if (!record)
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Node *node = _root_node.lookup(path);
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if (!node)
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return Dataspace_capability();
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if (record->type() == Record::TYPE_HARDLINK) {
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path = record->linked_name();
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continue;
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record = node->record;
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if (record) {
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if (record->type() == Record::TYPE_HARDLINK) {
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path = record->linked_name();
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continue;
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}
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if (record->type() == Record::TYPE_FILE)
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break;
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PERR("TAR record \"%s\" has unsupported type %d",
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record->name(), record->type());
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}
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if (record->type() == Record::TYPE_FILE)
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break;
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PERR("TAR record \"%s\" has unsupported type %d",
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record->name(), record->type());
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path, Record::TYPE_DIR);
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return Dataspace_capability();
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}
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@ -325,31 +436,45 @@ namespace Noux {
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bool stat(Sysio *sysio, char const *path)
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{
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Lookup_exact lookup_criterion(path);
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Record *record = _lookup(&lookup_criterion);
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if (!record) {
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if (verbose)
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PDBG("path = %s", path);
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Node *node = _root_node.lookup(path);
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if (!node) {
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sysio->error.stat = Sysio::STAT_ERR_NO_ENTRY;
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return false;
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}
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/* convert TAR record modes to stat modes */
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unsigned mode = record->mode();
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switch (record->type()) {
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case Record::TYPE_FILE: mode |= Sysio::STAT_MODE_FILE; break;
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case Record::TYPE_SYMLINK: mode |= Sysio::STAT_MODE_SYMLINK; break;
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case Record::TYPE_DIR: mode |= Sysio::STAT_MODE_DIRECTORY; break;
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memset(&sysio->stat_out.st, 0, sizeof(sysio->stat_out.st));
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default:
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Record const *record = node->record;
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if (record) {
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/* convert TAR record modes to stat modes */
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unsigned mode = record->mode();
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switch (record->type()) {
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case Record::TYPE_FILE: mode |= Sysio::STAT_MODE_FILE; break;
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case Record::TYPE_SYMLINK: mode |= Sysio::STAT_MODE_SYMLINK; break;
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case Record::TYPE_DIR: mode |= Sysio::STAT_MODE_DIRECTORY; break;
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default:
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if (verbose)
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PDBG("unhandled record type %d", record->type());
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}
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sysio->stat_out.st.mode = mode;
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sysio->stat_out.st.size = record->size();
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sysio->stat_out.st.uid = record->uid();
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sysio->stat_out.st.gid = record->gid();
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} else {
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if (verbose)
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PDBG("unhandled record type %d", record->type());
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PDBG("found a virtual directoty node");
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sysio->stat_out.st.mode = Sysio::STAT_MODE_DIRECTORY;
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}
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memset(&sysio->stat_out.st, 0, sizeof(sysio->stat_out.st));
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sysio->stat_out.st.mode = mode;
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sysio->stat_out.st.size = record->size();
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sysio->stat_out.st.uid = record->uid();
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sysio->stat_out.st.gid = record->gid();
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sysio->stat_out.st.inode = (unsigned long)record;
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sysio->stat_out.st.inode = (unsigned long)node;
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return true;
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}
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@ -357,32 +482,37 @@ namespace Noux {
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{
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Lock::Guard guard(_lock);
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Lookup_member_of_path lookup_criterion(path, index);
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Record *record = _lookup(&lookup_criterion);
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if (!record) {
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Node *node = _root_node.lookup(path);
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if (!node)
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return false;
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node = node->lookup_child(index);
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if (!node) {
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sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_END;
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return true;
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}
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sysio->dirent_out.entry.fileno = (unsigned long)record;
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sysio->dirent_out.entry.fileno = (unsigned long)node;
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switch (record->type()) {
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case 0: sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_FILE; break;
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case 2: sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_SYMLINK; break;
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case 5: sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_DIRECTORY; break;
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Record const *record = node->record;
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default:
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if (verbose)
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PDBG("unhandled record type %d", record->type());
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if (record) {
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switch (record->type()) {
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case 0: sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_FILE; break;
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case 2: sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_SYMLINK; break;
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case 5: sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_DIRECTORY; break;
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default:
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if (verbose)
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PDBG("unhandled record type %d", record->type());
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}
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}
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Absolute_path absolute_path(record->name());
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absolute_path.keep_only_last_element();
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absolute_path.remove_trailing('/');
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strncpy(sysio->dirent_out.entry.name,
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absolute_path.base() + 1,
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sizeof(sysio->dirent_out.entry.name));
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node->name,
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sizeof(sysio->dirent_out.entry.name));
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return true;
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}
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@ -391,9 +521,8 @@ namespace Noux {
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bool readlink(Sysio *sysio, char const *path)
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{
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Lookup_exact lookup_criterion(path);
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Record *record = _lookup(&lookup_criterion);
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Node *node = _root_node.lookup(path);
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Record const *record = node ? node->record : 0;
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if (!record || (record->type() != Record::TYPE_SYMLINK)) {
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sysio->error.readlink = Sysio::READLINK_ERR_NO_ENTRY;
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@ -424,9 +553,14 @@ namespace Noux {
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bool is_directory(char const *path)
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{
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Lookup_exact lookup_criterion(path);
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Record const * record = _lookup(&lookup_criterion);
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return record && (record->type() == Record::TYPE_DIR);
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Node *node = _root_node.lookup(path);
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if (!node)
|
||||
return false;
|
||||
|
||||
Record const *record = node->record;
|
||||
|
||||
return record ? (record->type() == Record::TYPE_DIR) : true;
|
||||
}
|
||||
|
||||
char const *leaf_path(char const *path)
|
||||
@ -436,20 +570,18 @@ namespace Noux {
|
||||
* case, return the whole path, which is relative to the root
|
||||
* of this file system.
|
||||
*/
|
||||
Lookup_exact lookup_criterion(path);
|
||||
Record const * record = _lookup(&lookup_criterion);
|
||||
return record ? path : 0;
|
||||
Node *node = _root_node.lookup(path);
|
||||
return node ? path : 0;
|
||||
}
|
||||
|
||||
Vfs_handle *open(Sysio *sysio, char const *path)
|
||||
{
|
||||
Lock::Guard guard(_lock);
|
||||
|
||||
Lookup_exact lookup_criterion(path);
|
||||
Record *record = 0;
|
||||
if ((record = _lookup(&lookup_criterion)))
|
||||
Node *node = _root_node.lookup(path);
|
||||
if (node)
|
||||
return new (env()->heap())
|
||||
Tar_vfs_handle(this, 0, record);
|
||||
Tar_vfs_handle(this, 0, node->record);
|
||||
|
||||
sysio->error.open = Sysio::OPEN_ERR_UNACCESSIBLE;
|
||||
return 0;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user