/*
* \brief String utilities
* \author Norman Feske
* \author Sebastian Sumpf
* \date 2006-05-10
*/
/*
* Copyright (C) 2006-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__UTIL__STRING_H_
#define _INCLUDE__UTIL__STRING_H_
#include <base/stdint.h>
#include <util/misc_math.h>
#include <cpu/string.h>
namespace Genode {
class Number_of_bytes;
template <Genode::size_t> class String;
}
/**
* Wrapper of 'size_t' for selecting the 'ascii_to' function to parse byte values
*/
class Genode::Number_of_bytes
{
size_t _n;
public:
/**
* Default constructor
*/
Number_of_bytes() : _n(0) { }
/**
* Constructor, to be used implicitly via assignment operator
*/
Number_of_bytes(size_t n) : _n(n) { }
/**
* Convert number of bytes to 'size_t' value
*/
operator size_t() const { return _n; }
};
/***********************
** Utility functions **
***********************/
namespace Genode {
/**
* Return length of null-terminated string in bytes
*/
inline size_t strlen(const char *s)
{
size_t res = 0;
for (; s && *s; s++, res++);
return res;
}
/**
* Compare two strings
*
* \param len maximum number of characters to compare,
* default is unlimited
*
* \return 0 if both strings are equal, or
* a positive number if s1 is higher than s2, or
* a negative number if s1 is lower than s2
*/
inline int strcmp(const char *s1, const char *s2, size_t len = ~0UL)
{
for (; *s1 && *s1 == *s2 && len; s1++, s2++, len--) ;
return len ? *s1 - *s2 : 0;
}
/**
* Copy memory buffer to a potentially overlapping destination buffer
*
* \param dst destination memory block
* \param src source memory block
* \param size number of bytes to move
*
* \return pointer to destination memory block
*/
inline void *memmove(void *dst, const void *src, size_t size)
{
char *d = (char *)dst, *s = (char *)src;
size_t i;
if (s > d)
for (i = 0; i < size; i++, *d++ = *s++);
else
for (s += size - 1, d += size - 1, i = size; i-- > 0; *d-- = *s--);
return dst;
}
/**
* Copy memory buffer to a non-overlapping destination buffer
*
* \param dst destination memory block
* \param src source memory block
* \param size number of bytes to copy
*
* \return pointer to destination memory block
*/
inline void *memcpy(void *dst, const void *src, size_t size)
{
char *d = (char *)dst, *s = (char *)src;
size_t i;
/* check for overlap */
if ((d + size > s) && (s + size > d))
return memmove(dst, src, size);
/* try cpu specific version first */
if ((i = size - memcpy_cpu(dst, src, size)) == size)
return dst;
d += i; s += i; size -= i;
/* copy eight byte chunks */
for (i = size >> 3; i > 0; i--, *d++ = *s++,
*d++ = *s++,
*d++ = *s++,
*d++ = *s++,
*d++ = *s++,
*d++ = *s++,
*d++ = *s++,
*d++ = *s++);
/* copy left over */
for (i = 0; i < (size & 0x7); i++, *d++ = *s++);
return dst;
}
/**
* Copy string
*
* \param dst destination buffer
* \param src buffer holding the null-terminated source string
* \param size maximum number of characters to copy
* \return pointer to destination string
*
* Note that this function is not fully compatible to the C standard, in
* particular there is no zero-padding if the length of 'src' is smaller
* than 'size'. Furthermore, in contrast to the libc version, this function
* always produces a null-terminated string in the 'dst' buffer if the
* 'size' argument is greater than 0.
*/
inline char *strncpy(char *dst, const char *src, size_t size)
{
/* sanity check for corner case of a zero-size destination buffer */
if (size == 0) return dst;
/* backup original 'dst' for the use as return value */
char *orig_dst = dst;
/*
* Copy characters from 'src' to 'dst' respecting the 'size' limit.
* In each iteration, the 'size' variable holds the maximum remaining
* size. We have to leave at least one character free to add the null
* termination afterwards.
*/
while ((size-- > 1UL) && *src)
*dst++ = *src++;
/* append null termination to the destination buffer */
*dst = 0;
return orig_dst;
}
/**
* Compare memory blocks
*
* \return 0 if both memory blocks are equal, or
* a negative number if 'p0' is less than 'p1', or
* a positive number if 'p0' is greater than 'p1'
*/
inline int memcmp(const void *p0, const void *p1, size_t size)
{
const unsigned char *c0 = (const unsigned char *)p0;
const unsigned char *c1 = (const unsigned char *)p1;
size_t i;
for (i = 0; i < size; i++)
if (c0[i] != c1[i]) return c0[i] - c1[i];
return 0;
}
/**
* Fill destination buffer with given value
*
* \param dst destination buffer
* \param i byte value
* \param size buffer size in bytes
*/
inline void *memset(void *dst, int i, size_t size)
{
while (size--) ((char *)dst)[size] = i;
return dst;
}
/**
* Convert ASCII character to digit
*
* \param hex consider hexadecimals
* \return digit or -1 on error
*/
inline int digit(char c, bool hex = false)
{
if (c >= '0' && c <= '9') return c - '0';
if (hex && c >= 'a' && c <= 'f') return c - 'a' + 10;
if (hex && c >= 'A' && c <= 'F') return c - 'A' + 10;
return -1;
}
/**
* Return true if character is a letter
*/
inline bool is_letter(char c)
{
return (((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z')));
}
/**
* Return true if character is a digit
*/
inline bool is_digit(char c, bool hex = false)
{
return (digit(c, hex) >= 0);
}
/**
* Return true if character is whitespace
*/
inline bool is_whitespace(char c)
{
return (c == '\t' || c == ' ' || c == '\n');
}
/**
* Read unsigned long value from string
*
* \param s source string
* \param result destination variable
* \param base integer base
* \return number of consumed characters
*
* If the base argument is 0, the integer base is detected based on the
* characters in front of the number. If the number is prefixed with "0x",
* a base of 16 is used, otherwise a base of 10.
*/
inline size_t ascii_to_unsigned_long(const char *s, unsigned long &result,
unsigned base)
{
unsigned long i = 0, value = 0;
if (!*s) return i;
/* autodetect hexadecimal base, default is a base of 10 */
if (base == 0) {
/* read '0x' prefix */
if (*s == '0' && (s[1] == 'x' || s[1] == 'X')) {
s += 2; i += 2;
base = 16;
} else
base = 10;
}
/* read number */
for (int d; ; s++, i++) {
/* read digit, stop when hitting a non-digit character */
if ((d = digit(*s, base == 16)) < 0) break;
/* append digit to integer value */
value = value*base + d;
}
result = value;
return i;
}
/**
* Read unsigned long value from string
*
* \return number of consumed characters
*/
inline size_t ascii_to(const char *s, unsigned long &result)
{
return ascii_to_unsigned_long(s, result, 0);
}
/**
* Read unsigned int value from string
*
* \return number of consumed characters
*/
inline size_t ascii_to(const char *s, unsigned int &result)
{
unsigned long result_long = 0;
size_t ret = ascii_to_unsigned_long(s, result_long, 0);
result = result_long;
return ret;
}
/**
* Read signed long value from string
*
* \return number of consumed characters
*/
inline size_t ascii_to(const char *s, long &result)
{
int i = 0;
/* read sign */
int sign = (*s == '-') ? -1 : 1;
if (*s == '-' || *s == '+') { s++; i++; }
int j = 0;
unsigned long value = 0;
j = ascii_to_unsigned_long(s, value, 10);
if (!j) return i;
result = sign*value;
return i + j;
}
/**
* Read 'Number_of_bytes' value from string and handle the size suffixes
*
* This function scales the resulting size value according to the suffixes
* for G (2^30), M (2^20), and K (2^10) if present.
*
* \return number of consumed characters
*/
inline size_t ascii_to(const char *s, Number_of_bytes &result)
{
unsigned long res = 0;
/* convert numeric part of string */
int i = ascii_to_unsigned_long(s, res, 0);
/* handle suffixes */
if (i > 0)
switch (s[i]) {
case 'G': res *= 1024;
case 'M': res *= 1024;
case 'K': res *= 1024; i++;
default: break;
}
result = res;
return i;
}
/**
* Read double float value from string
*
* \return number of consumed characters
*/
inline size_t ascii_to(const char *s, double &result)
{
double v = 0.0; /* decimal part */
double d = 0.1; /* power of fractional digit */
bool neg = false; /* sign */
int i = 0; /* character counter */
if (s[i] == '-') {
neg = true;
i++;
}
/* parse decimal part of number */
for (; s[i] && is_digit(s[i]); i++)
v = 10*v + digit(s[i], false);
/* if no fractional part exists, return current value */
if (s[i] != '.') {
result = neg ? -v : v;
return i;
}
/* skip comma */
i++;
/* parse fractional part of number */
for (; s[i] && is_digit(s[i]); i++, d *= 0.1)
v += d*digit(s[i], false);
result = neg ? -v : v;
return i;
}
/**
* Check for end of quotation
*
* Checks if next character is non-backslashed quotation mark.
*/
inline bool end_of_quote(const char *s) {
return s[0] != '\\' && s[1] == '\"'; }
/**
* Unpack quoted string
*
* \param src source string including the quotation marks ("...")
* \param dst destination buffer
*
* \return number of characters or negative error code
*/
inline int unpack_string(const char *src, char *dst, int dst_len)
{
/* check if quoted string */
if (*src != '"') return -1;
src++;
int i = 0;
for (; *src && !end_of_quote(src - 1) && (i < dst_len - 1); i++) {
/* transform '\"' to '"' */
if (src[0] == '\\' && src[1] == '\"') {
*dst++ = '"';
src += 2;
} else
*dst++ = *src++;
}
/* write terminating null */
*dst = 0;
return i;
}
}
/**
* Buffer that contains a null-terminated string
*
* \param CAPACITY buffer size including the terminating zero
*/
template <Genode::size_t CAPACITY>
class Genode::String
{
private:
char _buf[CAPACITY];
size_t _length;
public:
constexpr static size_t size() { return CAPACITY; }
String() : _length(0) { }
String(char const *str, size_t len = ~0UL - 1)
:
_length(min(len + 1, min(strlen(str) + 1, CAPACITY)))
{
strncpy(_buf, str, _length);
}
size_t length() const { return _length; }
static constexpr size_t capacity() { return CAPACITY; }
bool valid() const {
return (_length <= CAPACITY) && (_length != 0) && (_buf[_length - 1] == '\0'); }
char const *string() const { return valid() ? _buf : ""; }
template <size_t OTHER_CAPACITY>
bool operator == (String<OTHER_CAPACITY> const &other) const
{
return strcmp(string(), other.string()) == 0;
}
template <size_t OTHER_CAPACITY>
bool operator != (String<OTHER_CAPACITY> const &other) const
{
return strcmp(string(), other.string()) != 0;
}
};
#endif /* _INCLUDE__UTIL__STRING_H_ */