tor/src/common/compress.h

91 lines
3.1 KiB
C

/* Copyright (c) 2003, Roger Dingledine
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2017, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file compress.h
* \brief Headers for compress.c
**/
#ifndef TOR_COMPRESS_H
#define TOR_COMPRESS_H
/** Enumeration of what kind of compression to use. Only ZLIB_METHOD and
* GZIP_METHOD is guaranteed to be supported by the compress/uncompress
* functions here. Call tor_compress_supports_method() to check if a given
* compression schema is supported by Tor. */
typedef enum {
NO_METHOD=0, // This method must be first.
GZIP_METHOD=1,
ZLIB_METHOD=2,
LZMA_METHOD=3,
ZSTD_METHOD=4,
UNKNOWN_METHOD=5, // This method must be last. Add new ones in the middle.
} compress_method_t;
/**
* Enumeration to define tradeoffs between memory usage and compression level.
* BEST_COMPRESSION saves the most bandwidth; LOW_COMPRESSION saves the most
* memory.
**/
typedef enum {
BEST_COMPRESSION, HIGH_COMPRESSION, MEDIUM_COMPRESSION, LOW_COMPRESSION
} compression_level_t;
int tor_compress(char **out, size_t *out_len,
const char *in, size_t in_len,
compress_method_t method);
int tor_uncompress(char **out, size_t *out_len,
const char *in, size_t in_len,
compress_method_t method,
int complete_only,
int protocol_warn_level);
compress_method_t detect_compression_method(const char *in, size_t in_len);
MOCK_DECL(int,tor_compress_is_compression_bomb,(size_t size_in,
size_t size_out));
int tor_compress_supports_method(compress_method_t method);
unsigned tor_compress_get_supported_method_bitmask(void);
const char *compression_method_get_name(compress_method_t method);
const char *compression_method_get_human_name(compress_method_t method);
compress_method_t compression_method_get_by_name(const char *name);
const char *tor_compress_version_str(compress_method_t method);
const char *tor_compress_header_version_str(compress_method_t method);
size_t tor_compress_get_total_allocation(void);
/** Return values from tor_compress_process; see that function's documentation
* for details. */
typedef enum {
TOR_COMPRESS_OK,
TOR_COMPRESS_DONE,
TOR_COMPRESS_BUFFER_FULL,
TOR_COMPRESS_ERROR
} tor_compress_output_t;
/** Internal state for an incremental compression/decompression. */
typedef struct tor_compress_state_t tor_compress_state_t;
tor_compress_state_t *tor_compress_new(int compress,
compress_method_t method,
compression_level_t level);
tor_compress_output_t tor_compress_process(tor_compress_state_t *state,
char **out, size_t *out_len,
const char **in, size_t *in_len,
int finish);
void tor_compress_free(tor_compress_state_t *state);
size_t tor_compress_state_size(const tor_compress_state_t *state);
void tor_compress_init(void);
#endif /* !defined(TOR_COMPRESS_H) */