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Split Attach and Copy Reset Strategies into Separate Implementation Functions

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This commit is contained in:
W. Felix Handte 2018-08-24 15:54:58 -07:00
parent a6d6bbeae1
commit 01ff945eae
1 changed files with 83 additions and 41 deletions
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124
lib/compress/zstd_compress.c
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@ -1334,35 +1334,27 @@ static int ZSTD_shouldAttachDict(ZSTD_CCtx* cctx,
cdict->matchState.cParams);
}
static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
static size_t ZSTD_resetCCtx_byAttachingCDict(ZSTD_CCtx* cctx,
const ZSTD_CDict* cdict,
ZSTD_CCtx_params params,
U64 pledgedSrcSize,
ZSTD_buffered_policy_e zbuff)
{
/* We have a choice between copying the dictionary context into the working
* context, or referencing the dictionary context from the working context
* in-place. We decide here which strategy to use. */
const ZSTD_compressionParameters *cdict_cParams = &cdict->matchState.cParams;
const int attachDict = ZSTD_shouldAttachDict(cctx, cdict, params, pledgedSrcSize);
DEBUGLOG(4, "ZSTD_resetCCtx_usingCDict (pledgedSrcSize=%u)", (U32)pledgedSrcSize);
{ unsigned const windowLog = params.cParams.windowLog;
{
const ZSTD_compressionParameters *cdict_cParams = &cdict->matchState.cParams;
unsigned const windowLog = params.cParams.windowLog;
assert(windowLog != 0);
/* Copy only compression parameters related to tables. */
params.cParams = *cdict_cParams;
params.cParams.windowLog = windowLog;
ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
attachDict ? ZSTDcrp_continue : ZSTDcrp_noMemset,
zbuff);
ZSTDcrp_continue, zbuff);
assert(cctx->appliedParams.cParams.strategy == cdict_cParams->strategy);
assert(cctx->appliedParams.cParams.hashLog == cdict_cParams->hashLog);
assert(cctx->appliedParams.cParams.chainLog == cdict_cParams->chainLog);
}
if (attachDict) {
{
const U32 cdictEnd = (U32)( cdict->matchState.window.nextSrc
- cdict->matchState.window.base);
const U32 cdictLen = cdictEnd - cdict->matchState.window.dictLimit;
@ -1382,33 +1374,6 @@ static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
}
cctx->blockState.matchState.loadedDictEnd = cctx->blockState.matchState.window.dictLimit;
}
} else {
DEBUGLOG(4, "copying dictionary into context");
/* copy tables */
{ size_t const chainSize = (cdict_cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cdict_cParams->chainLog);
size_t const hSize = (size_t)1 << cdict_cParams->hashLog;
size_t const tableSpace = (chainSize + hSize) * sizeof(U32);
assert((U32*)cctx->blockState.matchState.chainTable == (U32*)cctx->blockState.matchState.hashTable + hSize); /* chainTable must follow hashTable */
assert((U32*)cctx->blockState.matchState.hashTable3 == (U32*)cctx->blockState.matchState.chainTable + chainSize);
assert((U32*)cdict->matchState.chainTable == (U32*)cdict->matchState.hashTable + hSize); /* chainTable must follow hashTable */
assert((U32*)cdict->matchState.hashTable3 == (U32*)cdict->matchState.chainTable + chainSize);
memcpy(cctx->blockState.matchState.hashTable, cdict->matchState.hashTable, tableSpace); /* presumes all tables follow each other */
}
/* Zero the hashTable3, since the cdict never fills it */
{ size_t const h3Size = (size_t)1 << cctx->blockState.matchState.hashLog3;
assert(cdict->matchState.hashLog3 == 0);
memset(cctx->blockState.matchState.hashTable3, 0, h3Size * sizeof(U32));
}
/* copy dictionary offsets */
{ ZSTD_matchState_t const* srcMatchState = &cdict->matchState;
ZSTD_matchState_t* dstMatchState = &cctx->blockState.matchState;
dstMatchState->window = srcMatchState->window;
dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
dstMatchState->nextToUpdate3= srcMatchState->nextToUpdate3;
dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
}
}
cctx->dictID = cdict->dictID;
@ -1419,6 +1384,83 @@ static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
return 0;
}
static size_t ZSTD_resetCCtx_byCopyingCDict(ZSTD_CCtx* cctx,
const ZSTD_CDict* cdict,
ZSTD_CCtx_params params,
U64 pledgedSrcSize,
ZSTD_buffered_policy_e zbuff)
{
const ZSTD_compressionParameters *cdict_cParams = &cdict->matchState.cParams;
DEBUGLOG(4, "copying dictionary into context");
{ unsigned const windowLog = params.cParams.windowLog;
assert(windowLog != 0);
/* Copy only compression parameters related to tables. */
params.cParams = *cdict_cParams;
params.cParams.windowLog = windowLog;
ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
ZSTDcrp_noMemset, zbuff);
assert(cctx->appliedParams.cParams.strategy == cdict_cParams->strategy);
assert(cctx->appliedParams.cParams.hashLog == cdict_cParams->hashLog);
assert(cctx->appliedParams.cParams.chainLog == cdict_cParams->chainLog);
}
/* copy tables */
{ size_t const chainSize = (cdict_cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cdict_cParams->chainLog);
size_t const hSize = (size_t)1 << cdict_cParams->hashLog;
size_t const tableSpace = (chainSize + hSize) * sizeof(U32);
assert((U32*)cctx->blockState.matchState.chainTable == (U32*)cctx->blockState.matchState.hashTable + hSize); /* chainTable must follow hashTable */
assert((U32*)cctx->blockState.matchState.hashTable3 == (U32*)cctx->blockState.matchState.chainTable + chainSize);
assert((U32*)cdict->matchState.chainTable == (U32*)cdict->matchState.hashTable + hSize); /* chainTable must follow hashTable */
assert((U32*)cdict->matchState.hashTable3 == (U32*)cdict->matchState.chainTable + chainSize);
memcpy(cctx->blockState.matchState.hashTable, cdict->matchState.hashTable, tableSpace); /* presumes all tables follow each other */
}
/* Zero the hashTable3, since the cdict never fills it */
{ size_t const h3Size = (size_t)1 << cctx->blockState.matchState.hashLog3;
assert(cdict->matchState.hashLog3 == 0);
memset(cctx->blockState.matchState.hashTable3, 0, h3Size * sizeof(U32));
}
/* copy dictionary offsets */
{ ZSTD_matchState_t const* srcMatchState = &cdict->matchState;
ZSTD_matchState_t* dstMatchState = &cctx->blockState.matchState;
dstMatchState->window = srcMatchState->window;
dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
dstMatchState->nextToUpdate3= srcMatchState->nextToUpdate3;
dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
}
cctx->dictID = cdict->dictID;
/* copy block state */
memcpy(cctx->blockState.prevCBlock, &cdict->cBlockState, sizeof(cdict->cBlockState));
return 0;
}
/* We have a choice between copying the dictionary context into the working
* context, or referencing the dictionary context from the working context
* in-place. We decide here which strategy to use. */
static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
const ZSTD_CDict* cdict,
ZSTD_CCtx_params params,
U64 pledgedSrcSize,
ZSTD_buffered_policy_e zbuff)
{
DEBUGLOG(4, "ZSTD_resetCCtx_usingCDict (pledgedSrcSize=%u)", (U32)pledgedSrcSize);
if (ZSTD_shouldAttachDict(cctx, cdict, params, pledgedSrcSize)) {
return ZSTD_resetCCtx_byAttachingCDict(
cctx, cdict, params, pledgedSrcSize, zbuff);
} else {
return ZSTD_resetCCtx_byCopyingCDict(
cctx, cdict, params, pledgedSrcSize, zbuff);
}
}
/*! ZSTD_copyCCtx_internal() :
* Duplicate an existing context `srcCCtx` into another one `dstCCtx`.
* Only works during stage ZSTDcs_init (i.e. after creation, but before first call to ZSTD_compressContinue()).