lib/zstd
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Address @terrelln's comments

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This commit is contained in:
Sean Purcell
2017-04-13 17:47:55 -07:00
parent 2785b28e05
commit 9626cf1ac6
4 changed files with 109 additions and 80 deletions
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49
contrib/seekable_format/zstdseek_decompress.c
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@ -13,9 +13,20 @@
#define XXH_NAMESPACE ZSTD_
#include "xxhash.h"
#include "zstd_internal.h" /* includes zstd.h */
#define ZSTD_STATIC_LINKING_ONLY
#include "zstd.h"
#include "zstd_errors.h"
#include "mem.h" /* includes zstd.h */
#include "zstd_seekable.h"
#undef ERROR
#define ERROR(name) ((size_t)-ZSTD_error_##name)
#undef MIN
#undef MAX
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define MAX(a, b) ((a) > (b) ? (a) : (b))
typedef struct {
U64 cOffset;
U64 dOffset;
@ -107,11 +118,8 @@ size_t ZSTD_seekable_loadSeekTable(ZSTD_seekable_DStream* zds, const void* src,
{
const BYTE* ip = (const BYTE*)src + srcSize;
U32 numFrames;
int checksumFlag;
U32 sizePerEntry;
/* footer is fixed size */
if (srcSize < ZSTD_seekTableFooterSize)
return ZSTD_seekTableFooterSize;
@ -129,10 +137,9 @@ size_t ZSTD_seekable_loadSeekTable(ZSTD_seekable_DStream* zds, const void* src,
}
}
numFrames = MEM_readLE32(ip-9);
sizePerEntry = 8 + (checksumFlag?4:0);
{ U32 const tableSize = sizePerEntry * numFrames;
{ U32 const numFrames = MEM_readLE32(ip-9);
U32 const sizePerEntry = 8 + (checksumFlag?4:0);
U32 const tableSize = sizePerEntry * numFrames;
U32 const frameSize = tableSize + ZSTD_seekTableFooterSize + ZSTD_skippableHeaderSize;
const BYTE* base = ip - frameSize;
@ -148,7 +155,8 @@ size_t ZSTD_seekable_loadSeekTable(ZSTD_seekable_DStream* zds, const void* src,
{ /* Allocate an extra entry at the end so that we can do size
* computations on the last element without special case */
seekEntry_t* entries = malloc(sizeof(seekEntry_t) * (numFrames + 1));
seekEntry_t* entries =
(seekEntry_t*)malloc(sizeof(seekEntry_t) * (numFrames + 1));
const BYTE* tableBase = base + ZSTD_skippableHeaderSize;
U32 idx;
@ -167,8 +175,10 @@ size_t ZSTD_seekable_loadSeekTable(ZSTD_seekable_DStream* zds, const void* src,
entries[idx].cOffset = cOffset;
entries[idx].dOffset = dOffset;
cOffset += MEM_readLE32(tableBase + pos); pos += 4;
dOffset += MEM_readLE32(tableBase + pos); pos += 4;
cOffset += MEM_readLE32(tableBase + pos);
pos += 4;
dOffset += MEM_readLE32(tableBase + pos);
pos += 4;
if (checksumFlag) {
entries[idx].checksum = MEM_readLE32(tableBase + pos);
pos += 4;
@ -188,18 +198,17 @@ size_t ZSTD_seekable_loadSeekTable(ZSTD_seekable_DStream* zds, const void* src,
size_t ZSTD_seekable_initDStream(ZSTD_seekable_DStream* zds, U64 rangeStart, U64 rangeEnd)
{
/* restrict range to the end of the file, of non-negative size */
rangeStart = MIN(rangeStart, zds->seekTable.entries[zds->seekTable.tableLen].dOffset);
rangeEnd = MIN(rangeEnd, zds->seekTable.entries[zds->seekTable.tableLen].dOffset);
rangeEnd = MAX(rangeEnd, rangeStart);
rangeStart = MIN(rangeStart, rangeEnd);
zds->targetStart = rangeStart;
zds->targetEnd = rangeEnd;
zds->stage = zsds_seek;
/* force a seek first */
zds->curFrame = (U32) -1;
zds->compressedOffset = (U64) -1;
zds->decompressedOffset = (U64) -1;
zds->curFrame = (U32)-1;
zds->compressedOffset = (U64)-1;
zds->decompressedOffset = (U64)-1;
if (zds->seekTable.checksumFlag) {
XXH64_reset(&zds->xxhState, 0);
@ -247,9 +256,7 @@ size_t ZSTD_seekable_decompressStream(ZSTD_seekable_DStream* zds, ZSTD_outBuffer
size_t const prevInputPos = input->pos;
ZSTD_outBuffer outTmp = {
.dst = outBase,
.size = (size_t)MIN((U64)outLen, toDecompress),
.pos = 0};
outBase, (size_t)MIN((U64)outLen, toDecompress), 0};
size_t const ret =
ZSTD_decompressStream(zds->dstream, &outTmp, input);
@ -286,9 +293,7 @@ size_t ZSTD_seekable_decompressStream(ZSTD_seekable_DStream* zds, ZSTD_outBuffer
size_t const prevInputPos = input->pos;
ZSTD_outBuffer outTmp = {
.dst = outBase,
.size = (size_t)MIN((U64)outLen, toDecompress),
.pos = 0};
outBase, (size_t)MIN((U64)outLen, toDecompress), 0};
size_t const ret =
ZSTD_decompressStream(zds->dstream, &outTmp, input);