--- /dev/null
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+
+#include <stdlib.h> /* malloc, free */
+#include <limits.h> /* UINT_MAX */
+#include <assert.h>
+
+#define XXH_STATIC_LINKING_ONLY
+#include "xxhash.h"
+
+#define ZSTD_STATIC_LINKING_ONLY
+#include "zstd.h"
+#include "zstd_errors.h"
+#include "mem.h"
+
+#include "zstd_seekable.h"
+
+#define CHECK_Z(f) { size_t const ret = (f); if (ret != 0) return ret; }
+
+#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 {
+ U32 cSize;
+ U32 dSize;
+ U32 checksum;
+} framelogEntry_t;
+
+struct ZSTD_frameLog_s {
+ framelogEntry_t* entries;
+ U32 size;
+ U32 capacity;
+
+ int checksumFlag;
+
+ /* for use when streaming out the seek table */
+ U32 seekTablePos;
+ U32 seekTableIndex;
+} framelog_t;
+
+struct ZSTD_seekable_CStream_s {
+ ZSTD_CStream* cstream;
+ ZSTD_frameLog framelog;
+
+ U32 frameCSize;
+ U32 frameDSize;
+
+ XXH64_state_t xxhState;
+
+ U32 maxFrameSize;
+
+ int writingSeekTable;
+};
+
+static size_t ZSTD_seekable_frameLog_allocVec(ZSTD_frameLog* fl)
+{
+ /* allocate some initial space */
+ size_t const FRAMELOG_STARTING_CAPACITY = 16;
+ fl->entries = (framelogEntry_t*)malloc(
+ sizeof(framelogEntry_t) * FRAMELOG_STARTING_CAPACITY);
+ if (fl->entries == NULL) return ERROR(memory_allocation);
+ fl->capacity = (U32)FRAMELOG_STARTING_CAPACITY;
+ return 0;
+}
+
+static size_t ZSTD_seekable_frameLog_freeVec(ZSTD_frameLog* fl)
+{
+ if (fl != NULL) free(fl->entries);
+ return 0;
+}
+
+ZSTD_frameLog* ZSTD_seekable_createFrameLog(int checksumFlag)
+{
+ ZSTD_frameLog* const fl = (ZSTD_frameLog*)malloc(sizeof(ZSTD_frameLog));
+ if (fl == NULL) return NULL;
+
+ if (ZSTD_isError(ZSTD_seekable_frameLog_allocVec(fl))) {
+ free(fl);
+ return NULL;
+ }
+
+ fl->checksumFlag = checksumFlag;
+ fl->seekTablePos = 0;
+ fl->seekTableIndex = 0;
+ fl->size = 0;
+
+ return fl;
+}
+
+size_t ZSTD_seekable_freeFrameLog(ZSTD_frameLog* fl)
+{
+ ZSTD_seekable_frameLog_freeVec(fl);
+ free(fl);
+ return 0;
+}
+
+ZSTD_seekable_CStream* ZSTD_seekable_createCStream(void)
+{
+ ZSTD_seekable_CStream* const zcs = (ZSTD_seekable_CStream*)malloc(sizeof(ZSTD_seekable_CStream));
+ if (zcs == NULL) return NULL;
+
+ memset(zcs, 0, sizeof(*zcs));
+
+ zcs->cstream = ZSTD_createCStream();
+ if (zcs->cstream == NULL) goto failed1;
+
+ if (ZSTD_isError(ZSTD_seekable_frameLog_allocVec(&zcs->framelog))) goto failed2;
+
+ return zcs;
+
+failed2:
+ ZSTD_freeCStream(zcs->cstream);
+failed1:
+ free(zcs);
+ return NULL;
+}
+
+size_t ZSTD_seekable_freeCStream(ZSTD_seekable_CStream* zcs)
+{
+ if (zcs == NULL) return 0; /* support free on null */
+ ZSTD_freeCStream(zcs->cstream);
+ ZSTD_seekable_frameLog_freeVec(&zcs->framelog);
+ free(zcs);
+ return 0;
+}
+
+size_t ZSTD_seekable_initCStream(ZSTD_seekable_CStream* zcs,
+ int compressionLevel,
+ int checksumFlag,
+ unsigned maxFrameSize)
+{
+ zcs->framelog.size = 0;
+ zcs->frameCSize = 0;
+ zcs->frameDSize = 0;
+
+ /* make sure maxFrameSize has a reasonable value */
+ if (maxFrameSize > ZSTD_SEEKABLE_MAX_FRAME_DECOMPRESSED_SIZE) {
+ return ERROR(frameParameter_unsupported);
+ }
+
+ zcs->maxFrameSize = maxFrameSize ?
+ maxFrameSize : ZSTD_SEEKABLE_MAX_FRAME_DECOMPRESSED_SIZE;
+
+ zcs->framelog.checksumFlag = checksumFlag;
+ if (zcs->framelog.checksumFlag) {
+ XXH64_reset(&zcs->xxhState, 0);
+ }
+
+ zcs->framelog.seekTablePos = 0;
+ zcs->framelog.seekTableIndex = 0;
+ zcs->writingSeekTable = 0;
+
+ return ZSTD_initCStream(zcs->cstream, compressionLevel);
+}
+
+size_t ZSTD_seekable_logFrame(ZSTD_frameLog* fl,
+ unsigned compressedSize,
+ unsigned decompressedSize,
+ unsigned checksum)
+{
+ if (fl->size == ZSTD_SEEKABLE_MAXFRAMES)
+ return ERROR(frameIndex_tooLarge);
+
+ /* grow the buffer if required */
+ if (fl->size == fl->capacity) {
+ /* exponential size increase for constant amortized runtime */
+ size_t const newCapacity = fl->capacity * 2;
+ framelogEntry_t* const newEntries = (framelogEntry_t*)realloc(fl->entries,
+ sizeof(framelogEntry_t) * newCapacity);
+
+ if (newEntries == NULL) return ERROR(memory_allocation);
+
+ fl->entries = newEntries;
+ assert(newCapacity <= UINT_MAX);
+ fl->capacity = (U32)newCapacity;
+ }
+
+ fl->entries[fl->size] = (framelogEntry_t){
+ compressedSize, decompressedSize, checksum
+ };
+ fl->size++;
+
+ return 0;
+}
+
+size_t ZSTD_seekable_endFrame(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output)
+{
+ size_t const prevOutPos = output->pos;
+ /* end the frame */
+ size_t ret = ZSTD_endStream(zcs->cstream, output);
+
+ zcs->frameCSize += (U32)(output->pos - prevOutPos);
+
+ /* need to flush before doing the rest */
+ if (ret) return ret;
+
+ /* frame done */
+
+ /* store the frame data for later */
+ ret = ZSTD_seekable_logFrame(
+ &zcs->framelog, zcs->frameCSize, zcs->frameDSize,
+ zcs->framelog.checksumFlag
+ ? XXH64_digest(&zcs->xxhState) & 0xFFFFFFFFU
+ : 0);
+ if (ret) return ret;
+
+ /* reset for the next frame */
+ zcs->frameCSize = 0;
+ zcs->frameDSize = 0;
+
+ ZSTD_CCtx_reset(zcs->cstream, ZSTD_reset_session_only);
+ if (zcs->framelog.checksumFlag) XXH64_reset(&zcs->xxhState, 0);
+
+ return 0;
+}
+
+size_t ZSTD_seekable_compressStream(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
+{
+ const BYTE* const inBase = (const BYTE*) input->src + input->pos;
+ size_t inLen = input->size - input->pos;
+
+ assert(zcs->maxFrameSize < INT_MAX);
+ ZSTD_CCtx_setParameter(zcs->cstream, ZSTD_c_srcSizeHint, (int)zcs->maxFrameSize);
+ inLen = MIN(inLen, (size_t)(zcs->maxFrameSize - zcs->frameDSize));
+
+ /* if we haven't finished flushing the last frame, don't start writing a new one */
+ if (inLen > 0) {
+ ZSTD_inBuffer inTmp = { inBase, inLen, 0 };
+ size_t const prevOutPos = output->pos;
+
+ size_t const ret = ZSTD_compressStream(zcs->cstream, output, &inTmp);
+
+ if (zcs->framelog.checksumFlag) {
+ XXH64_update(&zcs->xxhState, inBase, inTmp.pos);
+ }
+
+ zcs->frameCSize += (U32)(output->pos - prevOutPos);
+ zcs->frameDSize += (U32)inTmp.pos;
+
+ input->pos += inTmp.pos;
+
+ if (ZSTD_isError(ret)) return ret;
+ }
+
+ if (zcs->maxFrameSize == zcs->frameDSize) {
+ /* log the frame and start over */
+ size_t const ret = ZSTD_seekable_endFrame(zcs, output);
+ if (ZSTD_isError(ret)) return ret;
+
+ /* get the client ready for the next frame */
+ return (size_t)zcs->maxFrameSize;
+ }
+
+ return (size_t)(zcs->maxFrameSize - zcs->frameDSize);
+}
+
+static inline size_t ZSTD_seekable_seekTableSize(const ZSTD_frameLog* fl)
+{
+ size_t const sizePerFrame = 8 + (fl->checksumFlag?4:0);
+ size_t const seekTableLen = ZSTD_SKIPPABLEHEADERSIZE +
+ sizePerFrame * fl->size +
+ ZSTD_seekTableFooterSize;
+
+ return seekTableLen;
+}
+
+static inline size_t ZSTD_stwrite32(ZSTD_frameLog* fl,
+ ZSTD_outBuffer* output, U32 const value,
+ U32 const offset)
+{
+ if (fl->seekTablePos < offset + 4) {
+ BYTE tmp[4]; /* so that we can work with buffers too small to write a whole word to */
+ size_t const lenWrite =
+ MIN(output->size - output->pos, offset + 4 - fl->seekTablePos);
+ MEM_writeLE32(tmp, value);
+ memcpy((BYTE*)output->dst + output->pos,
+ tmp + (fl->seekTablePos - offset), lenWrite);
+ output->pos += lenWrite;
+ fl->seekTablePos += (U32)lenWrite;
+
+ if (lenWrite < 4) return ZSTD_seekable_seekTableSize(fl) - fl->seekTablePos;
+ }
+ return 0;
+}
+
+size_t ZSTD_seekable_writeSeekTable(ZSTD_frameLog* fl, ZSTD_outBuffer* output)
+{
+ /* seekTableIndex: the current index in the table and
+ * seekTableSize: the amount of the table written so far
+ *
+ * This function is written this way so that if it has to return early
+ * because of a small buffer, it can keep going where it left off.
+ */
+
+ size_t const sizePerFrame = 8 + (fl->checksumFlag?4:0);
+ size_t const seekTableLen = ZSTD_seekable_seekTableSize(fl);
+
+ CHECK_Z(ZSTD_stwrite32(fl, output, ZSTD_MAGIC_SKIPPABLE_START | 0xE, 0));
+ assert(seekTableLen <= (size_t)UINT_MAX);
+ CHECK_Z(ZSTD_stwrite32(fl, output, (U32)seekTableLen - ZSTD_SKIPPABLEHEADERSIZE, 4));
+
+ while (fl->seekTableIndex < fl->size) {
+ unsigned long long const start = ZSTD_SKIPPABLEHEADERSIZE + sizePerFrame * fl->seekTableIndex;
+ assert(start + 8 <= UINT_MAX);
+ CHECK_Z(ZSTD_stwrite32(fl, output,
+ fl->entries[fl->seekTableIndex].cSize,
+ (U32)start + 0));
+
+ CHECK_Z(ZSTD_stwrite32(fl, output,
+ fl->entries[fl->seekTableIndex].dSize,
+ (U32)start + 4));
+
+ if (fl->checksumFlag) {
+ CHECK_Z(ZSTD_stwrite32(
+ fl, output, fl->entries[fl->seekTableIndex].checksum,
+ (U32)start + 8));
+ }
+
+ fl->seekTableIndex++;
+ }
+
+ assert(seekTableLen <= UINT_MAX);
+ CHECK_Z(ZSTD_stwrite32(fl, output, fl->size,
+ (U32)seekTableLen - ZSTD_seekTableFooterSize));
+
+ if (output->size - output->pos < 1) return seekTableLen - fl->seekTablePos;
+ if (fl->seekTablePos < seekTableLen - 4) {
+ BYTE const sfd = (BYTE)((fl->checksumFlag) << 7);
+
+ ((BYTE*)output->dst)[output->pos] = sfd;
+ output->pos++;
+ fl->seekTablePos++;
+ }
+
+ CHECK_Z(ZSTD_stwrite32(fl, output, ZSTD_SEEKABLE_MAGICNUMBER,
+ (U32)seekTableLen - 4));
+
+ if (fl->seekTablePos != seekTableLen) return ERROR(GENERIC);
+ return 0;
+}
+
+size_t ZSTD_seekable_endStream(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output)
+{
+ if (!zcs->writingSeekTable) {
+ const size_t endFrame = ZSTD_seekable_endFrame(zcs, output);
+ if (ZSTD_isError(endFrame)) return endFrame;
+ /* return an accurate size hint */
+ if (endFrame) return endFrame + ZSTD_seekable_seekTableSize(&zcs->framelog);
+ }
+
+ zcs->writingSeekTable = 1;
+
+ return ZSTD_seekable_writeSeekTable(&zcs->framelog, output);
+}
notaz.gp2x.de / pcsx_rearmed.git / blobdiff