ddidderr/zstd-rs
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

implemented ZSTD_refPrefix()

Browse Source
This commit is contained in:
Yann Collet
2017-06-27 15:49:12 -07:00
parent 7d3816183f
commit b7372933b8
4 changed files with 61 additions and 57 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/compress/zstd_compress.c
+35 -21
View File
@@ -88,8 +88,6 @@ struct ZSTD_CCtx_s {
U32 hashLog3; /* dispatch table : larger == faster, more memory */
U32 loadedDictEnd; /* index of end of dictionary */
U32 forceWindow; /* force back-references to respect limit of 1<<wLog, even for dictionary */
ZSTD_dictMode_e dictMode; /* select restricting dictionary to "rawContent" or "fullDict" only */
U32 dictContentByRef;
ZSTD_compressionStage_e stage;
U32 rep[ZSTD_REP_NUM];
U32 repToConfirm[ZSTD_REP_NUM];
@@ -119,8 +117,6 @@ struct ZSTD_CCtx_s {
unsigned* entropyScratchSpace;
/* streaming */
ZSTD_CDict* cdictLocal;
const ZSTD_CDict* cdict;
char* inBuff;
size_t inBuffSize;
size_t inToCompress;
@@ -133,6 +129,14 @@ struct ZSTD_CCtx_s {
ZSTD_cStreamStage streamStage;
U32 frameEnded;
/* Dictionary */
ZSTD_dictMode_e dictMode; /* select restricting dictionary to "rawContent" or "fullDict" only */
U32 dictContentByRef;
ZSTD_CDict* cdictLocal;
const ZSTD_CDict* cdict;
const void* prefix;
size_t prefixSize;
/* Multi-threading */
U32 nbThreads;
ZSTDMT_CCtx* mtctx;
@@ -427,19 +431,22 @@ ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, s
return 0;
}
/* Not ready yet ! */
size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize)
{
(void)cctx; (void)prefix; (void)prefixSize; /* to be done later */
if (cctx->streamStage != zcss_init) return ERROR(stage_wrong);
return ERROR(compressionParameter_unsupported);
}
size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
{
if (cctx->streamStage != zcss_init) return ERROR(stage_wrong);
cctx->cdict = cdict;
return ERROR(compressionParameter_unsupported);
cctx->prefix = NULL; /* exclusive */
cctx->prefixSize = 0;
return 0;
}
size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize)
{
if (cctx->streamStage != zcss_init) return ERROR(stage_wrong);
cctx->cdict = NULL; /* prefix discards any prior cdict */
cctx->prefix = prefix;
cctx->prefixSize = prefixSize;
return 0;
}
static void ZSTD_startNewCompression(ZSTD_CCtx* cctx)
@@ -3622,14 +3629,17 @@ size_t ZSTD_CStreamOutSize(void)
}
static size_t ZSTD_resetCStream_internal(ZSTD_CStream* zcs,
ZSTD_parameters params,
unsigned long long pledgedSrcSize)
const void* dict, size_t dictSize, const ZSTD_CDict* cdict,
ZSTD_parameters params, unsigned long long pledgedSrcSize)
{
DEBUGLOG(5, "ZSTD_resetCStream_internal");
/* params are supposed to be fully validated at this point */
assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
assert(!((dict) && (cdict))); /* either dict or cdict, not both */
CHECK_F( ZSTD_compressBegin_internal(zcs,
NULL, 0, ZSTD_dm_auto,
zcs->cdict,
dict, dictSize, ZSTD_dm_auto, /* <========= Todo : make dictMode controllable ! */
cdict,
params, pledgedSrcSize,
ZSTDb_buffered) );
@@ -3650,10 +3660,11 @@ size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize)
if (zcs->compressionLevel != ZSTD_CLEVEL_CUSTOM) {
params.cParams = ZSTD_getCParams(zcs->compressionLevel, pledgedSrcSize, 0 /* dictSize */);
}
return ZSTD_resetCStream_internal(zcs, params, pledgedSrcSize);
return ZSTD_resetCStream_internal(zcs, NULL, 0, zcs->cdict, params, pledgedSrcSize);
}
/*! ZSTD_initCStream_internal() :
* Note : not static, but hidden (not exposed). Used by zstdmt_compress.c
* Assumption 1 : params are valid
* Assumption 2 : either dict, or cdict, is defined, not both */
size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
@@ -3672,7 +3683,7 @@ size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
}
ZSTD_freeCDict(zcs->cdictLocal);
zcs->cdictLocal = ZSTD_createCDict_advanced(dict, dictSize,
0 /* byReference */, ZSTD_dm_auto,
0 /* byReference */, ZSTD_dm_auto, /* <======== Todo : make dictMode controllable */
params.cParams, zcs->customMem);
zcs->cdict = zcs->cdictLocal;
if (zcs->cdictLocal == NULL) return ERROR(memory_allocation);
@@ -3688,7 +3699,7 @@ size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
zcs->requestedParams = params;
zcs->compressionLevel = ZSTD_CLEVEL_CUSTOM;
return ZSTD_resetCStream_internal(zcs, params, pledgedSrcSize);
return ZSTD_resetCStream_internal(zcs, NULL, 0, zcs->cdict, params, pledgedSrcSize);
}
/* ZSTD_initCStream_usingCDict_advanced() :
@@ -3925,7 +3936,10 @@ size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
} else
#endif
{
CHECK_F( ZSTD_resetCStream_internal(cctx, params, cctx->pledgedSrcSizePlusOne-1) );
const void* const prefix = cctx->prefix;
size_t const prefixSize = cctx->prefixSize;
cctx->prefix = NULL; cctx->prefixSize = 0; /* single usage */
CHECK_F( ZSTD_resetCStream_internal(cctx, prefix, prefixSize, cctx->cdict, params, cctx->pledgedSrcSizePlusOne-1) );
} }
#ifdef ZSTD_MULTITHREAD
lib/zstd.h
+11 -16
View File
@@ -947,20 +947,13 @@ typedef enum {
* The higher the value of selected strategy, the more complex it is,
* resulting in stronger and slower compression.
* Special: value 0 means "do not change strategy". */
#if 0
ZSTD_p_windowSize, /* Maximum allowed back-reference distance.
* Can be set to a more precise value than windowLog.
* Will be transparently reduced to closest possible inferior value
* (see Zstandard compression format) */
/* Not ready yet ! */
#endif
/* frame parameters */
ZSTD_p_contentSizeFlag=200, /* Content size is written into frame header _whenever known_ (default:1) */
ZSTD_p_checksumFlag, /* A 32-bits checksum of content is written at end of frame (default:0) */
ZSTD_p_dictIDFlag, /* When applicable, dictID of dictionary is provided in frame header (default:1) */
/* dictionary parameters (must be set before loading) */
/* dictionary parameters (must be set before ZSTD_CCtx_loadDictionary) */
ZSTD_p_dictMode=300, /* Select how dictionary content must be interpreted. Value must be from type ZSTD_dictMode_e.
* default : 0==auto : dictionary will be "full" if it respects specification, otherwise it will be "rawContent" */
ZSTD_p_refDictContent, /* Dictionary content will be referenced, instead of copied (default:0==byCopy).
@@ -1018,7 +1011,7 @@ ZSTDLIB_API size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long lo
ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
/*! ZSTD_CCtx_refCDict() :
* Ref a prepared dictionary, to be used for all next compression jobs.
* Reference a prepared dictionary, to be used for all next compression jobs.
* Note that compression parameters are enforced from within CDict,
* and supercede any compression parameter previously set within CCtx.
* The dictionary will remain valid for future compression jobs using same CCtx.
@@ -1031,16 +1024,18 @@ ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, s
ZSTDLIB_API size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
/*! ZSTD_CCtx_refPrefix() :
* Reference a prefix (raw-content dictionary) for next compression job.
* Decompression will have to use same prefix.
* Prefix is only used once. Tables are discarded at end of compression job.
* If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_CDict.
* Reference a prefix (single-usage dictionary) for next compression job.
* Decompression need same prefix to properly regenerate data.
* Prefix is **only used once**. Tables are discarded at end of compression job.
* Subsequent compression jobs will be done without prefix (if none is explicitly referenced).
* If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_CDict instead.
* @result : 0, or an error code (which can be tested with ZSTD_isError()).
* Special : Adding a NULL (or 0-size) dictionary invalidates any previous prefix, meaning "return to no-dictionary mode".
* Special : Adding any prefix (including NULL) invalidates any previous prefix or dictionary
* Note 1 : Prefix buffer is referenced. It must outlive compression job.
* Note 2 : Referencing a prefix involves building tables, which are dependent on compression parameters.
* It's a CPU-heavy operation, with non-negligible impact on latency. */
ZSTDLIB_API size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize); /* Not ready yet ! <===================================== */
* It's a CPU-heavy operation, with non-negligible impact on latency.
* Note 3 : it's possible to alter ZSTD_p_dictMode using ZSTD_CCtx_setParameter() */
ZSTDLIB_API size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize);