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fix extended case combining stableInBuffer with continue() and flush() modes

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This commit is contained in:
Yann Collet
2022-01-24 22:57:55 -08:00
parent 270f9bf005
commit c1668a00d2
4 changed files with 65 additions and 29 deletions
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78
lib/compress/zstd_compress.c
View File

@ -5316,9 +5316,14 @@ size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel)
static size_t ZSTD_nextInputSizeHint(const ZSTD_CCtx* cctx)
{
size_t hintInSize = cctx->inBuffTarget - cctx->inBuffPos;
if (hintInSize==0) hintInSize = cctx->blockSize;
return hintInSize;
if (cctx->appliedParams.inBufferMode == ZSTD_bm_stable) {
return cctx->blockSize - cctx->stableIn_notConsumed;
}
assert(cctx->appliedParams.inBufferMode == ZSTD_bm_buffered);
{ size_t hintInSize = cctx->inBuffTarget - cctx->inBuffPos;
if (hintInSize==0) hintInSize = cctx->blockSize;
return hintInSize;
}
}
/** ZSTD_compressStream_generic():
@ -5329,16 +5334,23 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
ZSTD_inBuffer* input,
ZSTD_EndDirective const flushMode)
{
const char* const istart = (const char*)input->src;
const char* const istart = (assert(input != NULL), (const char*)input->src);
const char* const iend = (istart != NULL) ? istart + input->size : istart;
const char* ip = (istart != NULL) ? istart + input->pos : istart;
char* const ostart = (char*)output->dst;
char* const ostart = (assert(output != NULL), (char*)output->dst);
char* const oend = (ostart != NULL) ? ostart + output->size : ostart;
char* op = (ostart != NULL) ? ostart + output->pos : ostart;
U32 someMoreWork = 1;
/* check expectations */
DEBUGLOG(5, "ZSTD_compressStream_generic, flush=%i", (int)flushMode);
DEBUGLOG(5, "ZSTD_compressStream_generic, flush=%i, srcSize = %zu", (int)flushMode, input->size - input->pos);
assert(zcs != NULL);
if (zcs->appliedParams.inBufferMode == ZSTD_bm_stable) {
assert(input->pos >= zcs->stableIn_notConsumed);
input->pos -= zcs->stableIn_notConsumed;
ip -= zcs->stableIn_notConsumed;
zcs->stableIn_notConsumed = 0;
}
if (zcs->appliedParams.inBufferMode == ZSTD_bm_buffered) {
assert(zcs->inBuff != NULL);
assert(zcs->inBuffSize > 0);
@ -5347,8 +5359,10 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
assert(zcs->outBuff != NULL);
assert(zcs->outBuffSize > 0);
}
assert(output->pos <= output->size);
if (input->src == NULL) assert(input->size == 0);
assert(input->pos <= input->size);
if (output->dst == NULL) assert(output->size == 0);
assert(output->pos <= output->size);
assert((U32)flushMode <= (U32)ZSTD_e_end);
while (someMoreWork) {
@ -5380,8 +5394,7 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
zcs->inBuff + zcs->inBuffPos, toLoad,
ip, iend-ip);
zcs->inBuffPos += loaded;
if (loaded != 0)
ip += loaded;
if (ip) ip += loaded;
if ( (flushMode == ZSTD_e_continue)
&& (zcs->inBuffPos < zcs->inBuffTarget) ) {
/* not enough input to fill full block : stop here */
@ -5392,6 +5405,20 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
/* empty */
someMoreWork = 0; break;
}
} else {
assert(zcs->appliedParams.inBufferMode == ZSTD_bm_stable);
if ( (flushMode == ZSTD_e_continue)
&& ( (size_t)(iend - ip) < zcs->blockSize) ) {
/* can't compress a full block : stop here */
zcs->stableIn_notConsumed = (size_t)(iend - ip);
ip = iend; /* pretend to have consumed input */
someMoreWork = 0; break;
}
if ( (flushMode == ZSTD_e_flush)
&& (ip == iend) ) {
/* empty */
someMoreWork = 0; break;
}
}
/* compress current block (note : this stage cannot be stopped in the middle) */
DEBUGLOG(5, "stream compression stage (flushMode==%u)", flushMode);
@ -5399,9 +5426,8 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
void* cDst;
size_t cSize;
size_t oSize = oend-op;
size_t const iSize = inputBuffered
? zcs->inBuffPos - zcs->inToCompress
: MIN((size_t)(iend - ip), zcs->blockSize);
size_t const iSize = inputBuffered ? zcs->inBuffPos - zcs->inToCompress
: MIN((size_t)(iend - ip), zcs->blockSize);
if (oSize >= ZSTD_compressBound(iSize) || zcs->appliedParams.outBufferMode == ZSTD_bm_stable)
cDst = op; /* compress into output buffer, to skip flush stage */
else
@ -5425,17 +5451,15 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
assert(zcs->inBuffTarget <= zcs->inBuffSize);
zcs->inToCompress = zcs->inBuffPos;
} else { /* !inputBuffered, hence ZSTD_bm_stable */
unsigned const lastBlock = (ip + iSize == iend);
unsigned const lastBlock = (flushMode == ZSTD_e_end) && (ip + iSize == iend);
cSize = lastBlock ?
ZSTD_compressEnd(zcs, cDst, oSize, ip, iSize) :
ZSTD_compressContinue(zcs, cDst, oSize, ip, iSize);
/* Consume the input prior to error checking to mirror buffered mode. */
if (iSize > 0)
ip += iSize;
if (ip) ip += iSize;
FORWARD_IF_ERROR(cSize, "%s", lastBlock ? "ZSTD_compressEnd failed" : "ZSTD_compressContinue failed");
zcs->frameEnded = lastBlock;
if (lastBlock)
assert(ip == iend);
if (lastBlock) assert(ip == iend);
}
if (cDst == op) { /* no need to flush */
op += cSize;
@ -5514,6 +5538,7 @@ size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuf
static void
ZSTD_setBufferExpectations(ZSTD_CCtx* cctx, const ZSTD_outBuffer* output, const ZSTD_inBuffer* input)
{
DEBUGLOG(5, "ZSTD_setBufferExpectations (for advanced stable in/out modes)");
if (cctx->appliedParams.inBufferMode == ZSTD_bm_stable) {
cctx->expectedInBuffer = *input;
}
@ -5647,27 +5672,25 @@ size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
/* transparent initialization stage */
if (cctx->streamStage == zcss_init) {
size_t const inputSize = input->size - input->pos; /* no obligation to start from pos==0 */
size_t const totalInputSize = (cctx->savedInPosPlusOne == 0) ? inputSize : input->size - (cctx->savedInPosPlusOne - 1);
size_t const totalInputSize = inputSize + cctx->stableIn_notConsumed;
if ( (cctx->requestedParams.inBufferMode == ZSTD_bm_stable) /* input is presumed stable, across invocations */
&& (endOp == ZSTD_e_continue) /* no flush requested, more input to come */
&& (totalInputSize < ZSTD_BLOCKSIZE_MAX) ) { /* not even reached one block yet */
if (cctx->savedInPosPlusOne) { /* not the first time */
if (cctx->stableIn_notConsumed) { /* not the first time */
/* check stable source guarantees */
assert(input->src == cctx->expectedInBuffer.src);
assert(input->pos == cctx->expectedInBuffer.size);
}
/* keep track of first position */
if (cctx->savedInPosPlusOne == 0) cctx->savedInPosPlusOne = input->pos + 1;
cctx->expectedInBuffer = *input;
/* pretend input was consumed, to give a sense forward progress */
input->pos = input->size;
/* save stable inBuffer, for later control, and flush/end */
cctx->expectedInBuffer = *input;
/* but actually input wasn't consumed, so keep track of position from where compression shall resume */
cctx->expectedInBuffer.pos = cctx->savedInPosPlusOne - 1;
cctx->stableIn_notConsumed += inputSize;
/* don't initialize yet, wait for the first block of flush() order, for better parameters adaptation */
return ZSTD_FRAMEHEADERSIZE_MIN(cctx->requestedParams.format); /* at least some header to produce */
}
FORWARD_IF_ERROR(ZSTD_CCtx_init_compressStream2(cctx, endOp, totalInputSize), "compressStream2 initialization failed");
cctx->savedInPosPlusOne = 0;
ZSTD_setBufferExpectations(cctx, output, input); /* Set initial buffer expectations now that we've initialized */
}
/* end of transparent initialization stage */
@ -5681,6 +5704,13 @@ size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
ZSTDMT_updateCParams_whileCompressing(cctx->mtctx, &cctx->requestedParams);
cctx->cParamsChanged = 0;
}
if (cctx->stableIn_notConsumed) {
assert(cctx->appliedParams.inBufferMode == ZSTD_bm_stable);
/* some early data was skipped - make it available for consumption */
assert(input->pos >= cctx->stableIn_notConsumed);
input->pos -= cctx->stableIn_notConsumed;
cctx->stableIn_notConsumed = 0;
}
for (;;) {
size_t const ipos = input->pos;
size_t const opos = output->pos;

2
lib/compress/zstd_compress_internal.h
View File

@ -410,8 +410,8 @@ struct ZSTD_CCtx_s {
/* Stable in/out buffer verification */
ZSTD_inBuffer expectedInBuffer;
size_t stableIn_notConsumed; /* nb bytes within stable input buffer that are said to be consumed but are not */
size_t expectedOutBufferSize;
size_t savedInPosPlusOne; /* 0 == no savedInPos */
/* Dictionary */
ZSTD_localDict localDict;

2
tests/fuzzer.c
View File

@ -1206,7 +1206,7 @@ static int basicUnitTests(U32 const seed, double compressibility)
DISPLAYLEVEL(3, "test%3i : compress a NULL input with each level : ", testNb++);
{ int level = -1;
ZSTD_CCtx* cctx = ZSTD_createCCtx();
ZSTD_CCtx* const cctx = ZSTD_createCCtx();
if (!cctx) goto _output_error;
for (level = -1; level <= ZSTD_maxCLevel(); ++level) {
CHECK_Z( ZSTD_compress(compressedBuffer, compressedBufferSize, NULL, 0, level) );

12
tests/zstreamtest.c
View File

@ -878,20 +878,26 @@ static int basicUnitTests(U32 seed, double compressibility)
CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_stableInBuffer, 1) );
{ ZSTD_inBuffer inBuf;
ZSTD_outBuffer outBuf;
const size_t inputSize = 500;
inBuf.src = CNBuffer;
inBuf.size = 100;
inBuf.pos = 0;
outBuf.dst = (char*)(compressedBuffer)+cSize;
outBuf.size = ZSTD_compressBound(500);
outBuf.size = ZSTD_compressBound(inputSize);
outBuf.pos = 0;
CHECK_Z( ZSTD_compressStream(cctx, &outBuf, &inBuf) );
inBuf.size = 200;
CHECK_Z( ZSTD_compressStream(cctx, &outBuf, &inBuf) );
CHECK_Z( ZSTD_flushStream(cctx, &outBuf) );
inBuf.size = 300;
inBuf.size = inputSize;
CHECK_Z( ZSTD_compressStream(cctx, &outBuf, &inBuf) );
CHECK(ZSTD_endStream(cctx, &outBuf) != 0, "compression should be successful and fully flushed");
}
{ void* const verifBuf = (char*)outBuf.dst + outBuf.pos;
const size_t decSize = ZSTD_decompress(verifBuf, inputSize, outBuf.dst, outBuf.pos);
CHECK_Z(decSize);
CHECK(decSize != inputSize, "regenerated %zu bytes, instead of %zu", decSize, inputSize);
CHECK(memcmp(inBuf.src, verifBuf, inputSize) != 0, "regenerated data different from original");
} }
DISPLAYLEVEL(3, "OK \n");
DISPLAYLEVEL(3, "test%3i : ZSTD_compressStream2() with ZSTD_c_stableInBuffer: context size : ", testNb++);