X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fmem%2Fmem.h;h=f2c3d5c7a6f795e2e091df8a545992c6533b50ec;hp=dcb44b86c59779c0990b47c72ff037b6b67daea4;hb=a934320836ffaad26be1e3160df30ef7350c39d5;hpb=40b45c4cfbf110a8e790366302ff43fa94dc8daa diff --git a/ccan/mem/mem.h b/ccan/mem/mem.h index dcb44b86..f2c3d5c7 100644 --- a/ccan/mem/mem.h +++ b/ccan/mem/mem.h @@ -3,16 +3,292 @@ #define CCAN_MEM_H #include "config.h" +#include #include +#include #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 @c + * @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 +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) +{ + 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 */