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/* CC0 (Public domain) - see LICENSE file for details */
#ifndef CCAN_MEM_H
#define CCAN_MEM_H
#include "config.h"
#include "compiler.h"
#include <string.h>
#include <stdbool.h>
#if !HAVE_MEMMEM
PURE_FUNCTION
void *memmem(const void *haystack, size_t haystacklen,
const void *needle, size_t needlelen);
#endif
#if !HAVE_MEMRCHR
PURE_FUNCTION
void *memrchr(const void *s, int c, size_t n);
#endif
/**
* mempbrkm - locates the first occurrence in @data of any bytes in @accept
* @data: where we search
* @len: length of data in bytes
* @accept: array of bytes we search for
* @accept_len: # of bytes in accept
*
* Returns a pointer to the byte in @data that matches one of the bytes in
* @accept, or NULL if no such byte is found.
*
* Example:
* char otherbytes[] = "Hello \0world";
* size_t otherbytes_len = sizeof(otherbytes) - 1;
* char *r = mempbrkm(otherbytes, otherbytes_len, "\0b", 2);
* if (r) {
* printf("Found %c\n", *r);
* } else {
* printf("Nada\n");
* }
*
*/
PURE_FUNCTION
void *mempbrkm(const void *data, size_t len, const void *accept, size_t accept_len);
/**
* mempbrk - locates the first occurrence in @data of any bytes in @accept
* @data: where we search
* @len: length of data in bytes
* @accept: NUL terminated string containing the bytes we search for
*
* Returns a pointer to the byte in @data that matches one of the bytes in
* @accept, or NULL if no such byte is found.
*
* Example:
*
* r = mempbrk(otherbytes, otherbytes_len, "abcde");
* if (r) {
* printf("Found %c\n", *r);
* } else {
* printf("Nada\n");
* }
*/
PURE_FUNCTION
static inline char *mempbrk(const void *data, size_t len, const char *accept)
{
return mempbrkm(data, len, accept, strlen(accept));
}
/**
* memcchr - scan memory until a character does _not_ match
* @data: pointer to memory to scan
* @data_len: length of data
* @c: character to scan for
*
* The complement of memchr().
*
* Returns a pointer to the first character which is _not_ @c. If all memory in
* @data is @c, returns NULL.
*
* Example:
* char somebytes[] = "HI By\0e";
* size_t bytes_len = sizeof(somebytes) - 1;
* r = memcchr(somebytes, ' ', bytes_len);
* if (r) {
* printf("Found %c after trimming spaces\n", *r);
* }
*/
PURE_FUNCTION
void *memcchr(void const *data, int c, size_t data_len);
/**
* memeq - Are two byte arrays equal?
* @a: first array
* @al: bytes in first array
* @b: second array
* @bl: bytes in second array
*
* Example:
* if (memeq(somebytes, bytes_len, otherbytes, otherbytes_len)) {
* printf("memory blocks are the same!\n");
* }
*/
PURE_FUNCTION
static inline bool memeq(const void *a, size_t al, const void *b, size_t bl)
{
return al == bl && !memcmp(a, b, bl);
}
/**
* memstarts - determine if @data starts with @prefix
* @data: does this begin with @prefix?
* @data_len: bytes in @data
* @prefix: does @data begin with these bytes?
* @prefix_len: bytes in @prefix
*
* Returns true if @data starts with @prefix, otherwise return false.
*
* Example:
* if (memstarts(somebytes, bytes_len, otherbytes, otherbytes_len)) {
* printf("somebytes starts with otherbytes!\n");
* }
*/
PURE_FUNCTION
static inline bool memstarts(void const *data, size_t data_len,
void const *prefix, size_t prefix_len)
{
if (prefix_len > data_len)
return false;
return memeq(data, prefix_len, prefix, prefix_len);
}
/**
* memeqstr - Is a byte array equal to a NUL terminated string?
* @data: byte array
* @length: length of @data in bytes
* @string: NUL terminated string
*
* The '\0' byte is ignored when checking if @bytes == @string.
*
* Example:
* if (memeqstr(somebytes, bytes_len, "foo")) {
* printf("somebytes == 'foo'!\n");
* }
*/
PURE_FUNCTION
static inline bool memeqstr(const void *data, size_t length, const char *string)
{
return memeq(data, length, string, strlen(string));
}
/**
* memeqzero - Is a byte array all zeroes?
* @data: byte array
* @length: length of @data in bytes
*
* Example:
* if (memeqzero(somebytes, bytes_len)) {
* printf("somebytes == 0!\n");
* }
*/
PURE_FUNCTION
bool memeqzero(const void *data, size_t length);
/**
* memstarts_str - Does this byte array start with a string prefix?
* @a: byte array
* @al: length in bytes
* @s: string prefix
*
* Example:
* if (memstarts_str(somebytes, bytes_len, "It")) {
* printf("somebytes starts with 'It'\n");
* }
*/
PURE_FUNCTION
static inline bool memstarts_str(const void *a, size_t al, const char *s)
{
return memstarts(a, al, s, strlen(s));
}
/**
* memends - Does this byte array end with a given byte-array suffix?
* @s: byte array
* @s_len: length in bytes
* @suffix: byte array suffix
* @suffix_len: length of suffix in bytes
*
* Returns true if @suffix appears as a substring at the end of @s,
* false otherwise.
*/
PURE_FUNCTION
static inline bool memends(const void *s, size_t s_len, const void *suffix, size_t suffix_len)
{
return (s_len >= suffix_len) && (memcmp((const char *)s + s_len - suffix_len,
suffix, suffix_len) == 0);
}
/**
* memends_str - Does this byte array end with a string suffix?
* @a: byte array
* @al: length in bytes
* @s: string suffix
*
* Example:
* if (memends_str(somebytes, bytes_len, "It")) {
* printf("somebytes ends with with 'It'\n");
* }
*/
PURE_FUNCTION
static inline bool memends_str(const void *a, size_t al, const char *s)
{
return memends(a, al, s, strlen(s));
}
/**
* memoverlaps - Do two memory ranges overlap?
* @a: pointer to first memory range
* @al: length of first memory range
* @b: pointer to second memory range
* @al: length of second memory range
*/
CONST_FUNCTION
static inline bool memoverlaps(const void *a_, size_t al,
const void *b_, size_t bl)
{
const char *a = a_;
const char *b = b_;
return (a < (b + bl)) && (b < (a + al));
}
/*
* memswap - Exchange two memory regions
* @a: first region
* @b: second region
* @n: length of the regions
*
* Undefined results if the two memory regions overlap.
*/
void memswap(void *a, void *b, size_t n);
#if HAVE_VALGRIND_MEMCHECK_H
#include <valgrind/memcheck.h>
static inline void *memcheck_(const void *data, size_t len)
{
VALGRIND_CHECK_MEM_IS_DEFINED(data, len);
return (void *)data;
}
#else
static inline void *memcheck_(const void *data, size_t len)
{
(void)len;
return (void *)data;
}
#endif
#if HAVE_TYPEOF
/**
* memcheck - check that a memory region is initialized
* @data: start of region
* @len: length in bytes
*
* When running under valgrind, this causes an error to be printed
* if the entire region is not defined. Otherwise valgrind only
* reports an error when an undefined value is used for a branch, or
* written out.
*
* Example:
* // Search for space, but make sure it's all initialized.
* if (memchr(memcheck(somebytes, bytes_len), ' ', bytes_len)) {
* printf("space was found!\n");
* }
*/
#define memcheck(data, len) ((__typeof__((data)+0))memcheck_((data), (len)))
#else
#define memcheck(data, len) memcheck_((data), (len))
#endif
/**
* memtaint - mark a memory region unused
* @data: start of region
* @len: length in bytes
*
* This writes an "0xdeadbeef" eyecatcher repeatedly to the memory.
* When running under valgrind, it also tells valgrind that the memory is
* uninitialized, triggering valgrind errors if it is used for branches
* or written out (or passed to memcheck!) in future.
*
* Example:
* // We'll reuse this buffer later, but be sure we don't access it.
* memtaint(somebytes, bytes_len);
*/
void memtaint(void *data, size_t len);
#endif /* CCAN_MEM_H */