size_t ZBUFF_decompressContinue(ZBUFF_DCtx* zbc, void* dst, size_t* maxDstSizePtr, const void* src, size_t* srcSizePtr)
{
const char* const istart = (const char*)src;
const char* ip = istart;
const char* const iend = istart + *srcSizePtr;
char* const ostart = (char*)dst;
char* op = ostart;
char* const oend = ostart + *maxDstSizePtr;
U32 notDone = 1;
while (notDone)
{
switch(zbc->stage)
{
case ZBUFFds_init :
return ERROR(init_missing);
case ZBUFFds_readHeader :
/* read header from src */
{
size_t headerSize = ZSTD_getFrameParams(&(zbc->params), src, *srcSizePtr);
if (ZSTD_isError(headerSize)) return headerSize;
if (headerSize)
{
/* not enough input to decode header : tell how many bytes would be necessary */
memcpy(zbc->headerBuffer+zbc->hPos, src, *srcSizePtr);
zbc->hPos += *srcSizePtr;
*maxDstSizePtr = 0;
zbc->stage = ZBUFFds_loadHeader;
return headerSize - zbc->hPos;
}
zbc->stage = ZBUFFds_decodeHeader;
break;
}
case ZBUFFds_loadHeader:
/* complete header from src */
{
size_t headerSize = ZBUFF_limitCopy(
zbc->headerBuffer + zbc->hPos, ZSTD_frameHeaderSize_max - zbc->hPos,
src, *srcSizePtr);
zbc->hPos += headerSize;
ip += headerSize;
headerSize = ZSTD_getFrameParams(&(zbc->params), zbc->headerBuffer, zbc->hPos);
if (ZSTD_isError(headerSize)) return headerSize;
if (headerSize)
{
/* not enough input to decode header : tell how many bytes would be necessary */
*maxDstSizePtr = 0;
return headerSize - zbc->hPos;
}
// zbc->stage = ZBUFFds_decodeHeader; break; /* useless : stage follows */
}
case ZBUFFds_decodeHeader:
/* apply header to create / resize buffers */
{
size_t neededOutSize = (size_t)1 << zbc->params.windowLog;
size_t neededInSize = BLOCKSIZE; /* a block is never > BLOCKSIZE */
if (zbc->inBuffSize < neededInSize)
{
free(zbc->inBuff);
zbc->inBuffSize = neededInSize;
zbc->inBuff = (char*)malloc(neededInSize);
if (zbc->inBuff == NULL) return ERROR(memory_allocation);
}
if (zbc->outBuffSize < neededOutSize)
{
free(zbc->outBuff);
zbc->outBuffSize = neededOutSize;
zbc->outBuff = (char*)malloc(neededOutSize);
if (zbc->outBuff == NULL) return ERROR(memory_allocation);
}
}
if (zbc->dictSize)
ZSTD_decompress_insertDictionary(zbc->zc, zbc->dict, zbc->dictSize);
if (zbc->hPos)
{
/* some data already loaded into headerBuffer : transfer into inBuff */
memcpy(zbc->inBuff, zbc->headerBuffer, zbc->hPos);
zbc->inPos = zbc->hPos;
zbc->hPos = 0;
zbc->stage = ZBUFFds_load;
break;
}
zbc->stage = ZBUFFds_read;
case ZBUFFds_read:
{
size_t neededInSize = ZSTD_nextSrcSizeToDecompress(zbc->zc);
if (neededInSize==0) /* end of frame */
{
zbc->stage = ZBUFFds_init;
notDone = 0;
break;
}
if ((size_t)(iend-ip) >= neededInSize)
{
/* directly decode from src */
size_t decodedSize = ZSTD_decompressContinue(zbc->zc,
zbc->outBuff + zbc->outStart, zbc->outBuffSize - zbc->outStart,
ip, neededInSize);
if (ZSTD_isError(decodedSize)) return decodedSize;
ip += neededInSize;
if (!decodedSize) break; /* this was just a header */
zbc->outEnd = zbc->outStart + decodedSize;
zbc->stage = ZBUFFds_flush;
break;
}
if (ip==iend) { notDone = 0; break; } /* no more input */
zbc->stage = ZBUFFds_load;
}
case ZBUFFds_load:
{
size_t neededInSize = ZSTD_nextSrcSizeToDecompress(zbc->zc);
size_t toLoad = neededInSize - zbc->inPos; /* should always be <= remaining space within inBuff */
size_t loadedSize;
if (toLoad > zbc->inBuffSize - zbc->inPos) return ERROR(corruption_detected); /* should never happen */
loadedSize = ZBUFF_limitCopy(zbc->inBuff + zbc->inPos, toLoad, ip, iend-ip);
ip += loadedSize;
zbc->inPos += loadedSize;
if (loadedSize < toLoad) { notDone = 0; break; } /* not enough input, wait for more */
{
size_t decodedSize = ZSTD_decompressContinue(zbc->zc,
zbc->outBuff + zbc->outStart, zbc->outBuffSize - zbc->outStart,
zbc->inBuff, neededInSize);
if (ZSTD_isError(decodedSize)) return decodedSize;
zbc->inPos = 0; /* input is consumed */
if (!decodedSize) { zbc->stage = ZBUFFds_read; break; } /* this was just a header */
zbc->outEnd = zbc->outStart + decodedSize;
zbc->stage = ZBUFFds_flush;
// break; /* ZBUFFds_flush follows */
}
}
case ZBUFFds_flush:
{
size_t toFlushSize = zbc->outEnd - zbc->outStart;
size_t flushedSize = ZBUFF_limitCopy(op, oend-op, zbc->outBuff + zbc->outStart, toFlushSize);
op += flushedSize;
zbc->outStart += flushedSize;
if (flushedSize == toFlushSize)
{
zbc->stage = ZBUFFds_read;
if (zbc->outStart + BLOCKSIZE > zbc->outBuffSize)
zbc->outStart = zbc->outEnd = 0;
break;
}
/* cannot flush everything */
notDone = 0;
break;
}
}
}
*srcSizePtr = ip-istart;
*maxDstSizePtr = op-ostart;
{
size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zbc->zc);
if (nextSrcSizeHint > 3) nextSrcSizeHint+= 3; /* get the next block header while at it */
nextSrcSizeHint -= zbc->inPos; /* already loaded*/
return nextSrcSizeHint;
}
}
size_t ZBUFF_decompressContinue(ZBUFF_DCtx* zbd,
void* dst, size_t* dstCapacityPtr,
const void* src, size_t* srcSizePtr)
{
const char* const istart = (const char*)src;
const char* const iend = istart + *srcSizePtr;
const char* ip = istart;
char* const ostart = (char*)dst;
char* const oend = ostart + *dstCapacityPtr;
char* op = ostart;
U32 notDone = 1;
while (notDone) {
switch(zbd->stage)
{
case ZBUFFds_init :
return ERROR(init_missing);
case ZBUFFds_loadHeader :
{ size_t const hSize = ZSTD_getFrameParams(&(zbd->fParams), zbd->headerBuffer, zbd->lhSize);
if (hSize != 0) {
size_t const toLoad = hSize - zbd->lhSize; /* if hSize!=0, hSize > zbd->lhSize */
if (ZSTD_isError(hSize)) return hSize;
if (toLoad > (size_t)(iend-ip)) { /* not enough input to load full header */
memcpy(zbd->headerBuffer + zbd->lhSize, ip, iend-ip);
zbd->lhSize += iend-ip; ip = iend; notDone = 0;
*dstCapacityPtr = 0;
return (hSize - zbd->lhSize) + ZSTD_blockHeaderSize; /* remaining header bytes + next block header */
}
memcpy(zbd->headerBuffer + zbd->lhSize, ip, toLoad); zbd->lhSize = hSize; ip += toLoad;
break;
} }
/* Consume header */
{ size_t const h1Size = ZSTD_nextSrcSizeToDecompress(zbd->zd); /* == ZSTD_frameHeaderSize_min */
size_t const h1Result = ZSTD_decompressContinue(zbd->zd, NULL, 0, zbd->headerBuffer, h1Size);
if (ZSTD_isError(h1Result)) return h1Result;
if (h1Size < zbd->lhSize) { /* long header */
size_t const h2Size = ZSTD_nextSrcSizeToDecompress(zbd->zd);
size_t const h2Result = ZSTD_decompressContinue(zbd->zd, NULL, 0, zbd->headerBuffer+h1Size, h2Size);
if (ZSTD_isError(h2Result)) return h2Result;
} }
/* Frame header instruct buffer sizes */
{ size_t const blockSize = MIN(1 << zbd->fParams.windowLog, ZSTD_BLOCKSIZE_MAX);
zbd->blockSize = blockSize;
if (zbd->inBuffSize < blockSize) {
free(zbd->inBuff);
zbd->inBuffSize = blockSize;
zbd->inBuff = (char*)malloc(blockSize);
if (zbd->inBuff == NULL) return ERROR(memory_allocation);
}
{ size_t const neededOutSize = ((size_t)1 << zbd->fParams.windowLog) + blockSize;
if (zbd->outBuffSize < neededOutSize) {
free(zbd->outBuff);
zbd->outBuffSize = neededOutSize;
zbd->outBuff = (char*)malloc(neededOutSize);
if (zbd->outBuff == NULL) return ERROR(memory_allocation);
} } }
zbd->stage = ZBUFFds_read;
case ZBUFFds_read:
{ size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zbd->zd);
if (neededInSize==0) { /* end of frame */
zbd->stage = ZBUFFds_init;
notDone = 0;
break;
}
if ((size_t)(iend-ip) >= neededInSize) { /* decode directly from src */
size_t const decodedSize = ZSTD_decompressContinue(zbd->zd,
zbd->outBuff + zbd->outStart, zbd->outBuffSize - zbd->outStart,
ip, neededInSize);
if (ZSTD_isError(decodedSize)) return decodedSize;
ip += neededInSize;
if (!decodedSize) break; /* this was just a header */
zbd->outEnd = zbd->outStart + decodedSize;
zbd->stage = ZBUFFds_flush;
break;
}
if (ip==iend) { notDone = 0; break; } /* no more input */
zbd->stage = ZBUFFds_load;
}
case ZBUFFds_load:
{ size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zbd->zd);
size_t const toLoad = neededInSize - zbd->inPos; /* should always be <= remaining space within inBuff */
size_t loadedSize;
if (toLoad > zbd->inBuffSize - zbd->inPos) return ERROR(corruption_detected); /* should never happen */
loadedSize = ZBUFF_limitCopy(zbd->inBuff + zbd->inPos, toLoad, ip, iend-ip);
ip += loadedSize;
zbd->inPos += loadedSize;
if (loadedSize < toLoad) { notDone = 0; break; } /* not enough input, wait for more */
/* decode loaded input */
{ size_t const decodedSize = ZSTD_decompressContinue(zbd->zd,
zbd->outBuff + zbd->outStart, zbd->outBuffSize - zbd->outStart,
zbd->inBuff, neededInSize);
if (ZSTD_isError(decodedSize)) return decodedSize;
zbd->inPos = 0; /* input is consumed */
if (!decodedSize) { zbd->stage = ZBUFFds_read; break; } /* this was just a header */
zbd->outEnd = zbd->outStart + decodedSize;
zbd->stage = ZBUFFds_flush;
// break; /* ZBUFFds_flush follows */
} }
case ZBUFFds_flush:
{ size_t const toFlushSize = zbd->outEnd - zbd->outStart;
size_t const flushedSize = ZBUFF_limitCopy(op, oend-op, zbd->outBuff + zbd->outStart, toFlushSize);
op += flushedSize;
zbd->outStart += flushedSize;
if (flushedSize == toFlushSize) {
zbd->stage = ZBUFFds_read;
if (zbd->outStart + zbd->blockSize > zbd->outBuffSize)
zbd->outStart = zbd->outEnd = 0;
break;
}
/* cannot flush everything */
notDone = 0;
break;
}
default: return ERROR(GENERIC); /* impossible */
} }
/* result */
*srcSizePtr = ip-istart;
*dstCapacityPtr = op-ostart;
{ size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zbd->zd);
if (nextSrcSizeHint > ZSTD_blockHeaderSize) nextSrcSizeHint+= ZSTD_blockHeaderSize; /* get following block header too */
nextSrcSizeHint -= zbd->inPos; /* already loaded*/
return nextSrcSizeHint;
}
}
