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#ifndef __CSNAPPY_H__
#define __CSNAPPY_H__
/*
File modified for the Linux Kernel by
Zeev Tarantov <zeev.tarantov@gmail.com>
*/
#ifdef __cplusplus
extern "C" {
#endif
#define CSNAPPY_VERSION 5
#define CSNAPPY_WORKMEM_BYTES_POWER_OF_TWO 16
#define CSNAPPY_WORKMEM_BYTES (1 << CSNAPPY_WORKMEM_BYTES_POWER_OF_TWO)
#ifndef __GNUC__
#define __attribute__(x) /*NOTHING*/
#endif
#if defined(__SUNPRO_C) || defined(_AIX)
# include <inttypes.h>
#else
# include <stdint.h>
#endif
/*
* Returns the maximal size of the compressed representation of
* input data that is "source_len" bytes in length;
*/
uint32_t
csnappy_max_compressed_length(uint32_t source_len) __attribute__((const));
/*
* Flat array compression that does not emit the "uncompressed length"
* prefix. Compresses "input" array to the "output" array.
*
* REQUIRES: "input" is at most 32KiB long.
* REQUIRES: "output" points to an array of memory that is at least
* "csnappy_max_compressed_length(input_length)" in size.
* REQUIRES: working_memory has (1 << workmem_bytes_power_of_two) bytes.
* REQUIRES: 9 <= workmem_bytes_power_of_two <= 15.
*
* Returns an "end" pointer into "output" buffer.
* "end - output" is the compressed size of "input".
*/
char*
csnappy_compress_fragment(
const char *input,
const uint32_t input_length,
char *output,
void *working_memory,
const int workmem_bytes_power_of_two);
/*
* REQUIRES: "compressed" must point to an area of memory that is at
* least "csnappy_max_compressed_length(input_length)" bytes in length.
* REQUIRES: working_memory has (1 << workmem_bytes_power_of_two) bytes.
* REQUIRES: 9 <= workmem_bytes_power_of_two <= 15.
*
* Takes the data stored in "input[0..input_length-1]" and stores
* it in the array pointed to by "compressed".
*
* "*out_compressed_length" is set to the length of the compressed output.
*/
void
csnappy_compress(
const char *input,
uint32_t input_length,
char *compressed,
uint32_t *out_compressed_length,
void *working_memory,
const int workmem_bytes_power_of_two);
/*
* Reads header of compressed data to get stored length of uncompressed data.
* REQUIRES: start points to compressed data.
* REQUIRES: n is length of available compressed data.
*
* Returns SNAPPY_E_HEADER_BAD on error.
* Returns number of bytes read from input on success.
* Stores decoded length into *result.
*/
int
csnappy_get_uncompressed_length(
const char *start,
uint32_t n,
uint32_t *result);
/*
* Safely decompresses all data from array "src" of length "src_len" containing
* entire compressed stream (with header) into array "dst" of size "dst_len".
* REQUIRES: dst_len is at least csnappy_get_uncompressed_length(...).
*
* Iff successful, returns CSNAPPY_E_OK.
* If recorded length in header is greater than dst_len, returns
* CSNAPPY_E_OUTPUT_INSUF.
* If compressed data is malformed, does not write more than dst_len into dst.
*/
int
csnappy_decompress(
const char *src,
uint32_t src_len,
char *dst,
uint32_t dst_len);
/*
* Safely decompresses stream src_len bytes long read from src to dst.
* Amount of available space at dst must be provided in *dst_len by caller.
* If compressed stream needs more space, it will not overflow and return
* CSNAPPY_E_OUTPUT_OVERRUN.
* On success, sets *dst_len to actal number of bytes decompressed.
* Iff successful, returns CSNAPPY_E_OK.
*/
int
csnappy_decompress_noheader(
const char *src,
uint32_t src_len,
char *dst,
uint32_t *dst_len);
/*
* Return values (< 0 = Error)
*/
#define CSNAPPY_E_OK 0
#define CSNAPPY_E_HEADER_BAD (-1)
#define CSNAPPY_E_OUTPUT_INSUF (-2)
#define CSNAPPY_E_OUTPUT_OVERRUN (-3)
#define CSNAPPY_E_INPUT_NOT_CONSUMED (-4)
#define CSNAPPY_E_DATA_MALFORMED (-5)
#ifdef __cplusplus
}
#endif
#endif
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