/* following error codes are not stable and may be removed or changed in a future version */
case PREFIX(frameIndex_tooLarge): return "Frame index is too large";
case PREFIX(seekableIO): return "An I/O error occurred when reading/seeking";
+ case PREFIX(dstBuffer_wrong): return "Destination buffer is wrong";
case PREFIX(maxCode):
default: return notErrorCode;
}
/* following error codes are __NOT STABLE__, they can be removed or changed in future versions */
ZSTD_error_frameIndex_tooLarge = 100,
ZSTD_error_seekableIO = 102,
+ ZSTD_error_dstBuffer_wrong = 104,
ZSTD_error_maxCode = 120 /* never EVER use this value directly, it can change in future versions! Use ZSTD_isError() instead */
} ZSTD_ErrorCode;
dctx->noForwardProgress = 0;
dctx->oversizedDuration = 0;
dctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
+ dctx->outBufferMode = ZSTD_obm_buffered;
}
ZSTD_DCtx* ZSTD_initStaticDCtx(void *workspace, size_t workspaceSize)
bounds.upperBound = (int)ZSTD_f_zstd1_magicless;
ZSTD_STATIC_ASSERT(ZSTD_f_zstd1 < ZSTD_f_zstd1_magicless);
return bounds;
+ case ZSTD_d_stableOutBuffer:
+ bounds.lowerBound = (int)ZSTD_obm_buffered;
+ bounds.upperBound = (int)ZSTD_obm_stable;
+ return bounds;
default:;
}
bounds.error = ERROR(parameter_unsupported);
CHECK_DBOUNDS(ZSTD_d_format, value);
dctx->format = (ZSTD_format_e)value;
return 0;
+ case ZSTD_d_stableOutBuffer:
+ CHECK_DBOUNDS(ZSTD_d_stableOutBuffer, value);
+ dctx->outBufferMode = (ZSTD_outBufferMode_e)value;
+ return 0;
default:;
}
RETURN_ERROR(parameter_unsupported);
return zds->oversizedDuration >= ZSTD_WORKSPACETOOLARGE_MAXDURATION;
}
+static size_t ZSTD_checkOutBuffer(ZSTD_DStream const* zds, ZSTD_outBuffer const* output)
+{
+ ZSTD_outBuffer const expect = zds->expectedOutBuffer;
+ /* No requirement when ZSTD_obm_stable is not enabled. */
+ if (zds->outBufferMode != ZSTD_obm_stable)
+ return 0;
+ /* Any buffer is allowed in zdss_init, this must be the same for every other call until
+ * the context is reset.
+ */
+ if (zds->streamStage == zdss_init)
+ return 0;
+ /* The buffer must match our expectation exactly. */
+ if (expect.dst == output->dst && expect.pos == output->pos && expect.size == output->size)
+ return 0;
+ RETURN_ERROR(dstBuffer_wrong, "ZSTD_obm_stable enabled but output differs!");
+}
+
+static size_t ZSTD_decompressContinueStream(
+ ZSTD_DStream* zds, char** op, char* oend,
+ void const* src, size_t srcSize) {
+ int const isSkipFrame = ZSTD_isSkipFrame(zds);
+ if (zds->outBufferMode == ZSTD_obm_buffered) {
+ size_t const dstSize = isSkipFrame ? 0 : zds->outBuffSize - zds->outStart;
+ size_t const decodedSize = ZSTD_decompressContinue(zds,
+ zds->outBuff + zds->outStart, dstSize, src, srcSize);
+ FORWARD_IF_ERROR(decodedSize);
+ if (!decodedSize && !isSkipFrame) {
+ zds->streamStage = zdss_read;
+ } else {
+ zds->outEnd = zds->outStart + decodedSize;
+ zds->streamStage = zdss_flush;
+ }
+ } else {
+ size_t const dstSize = isSkipFrame ? 0 : oend - *op;
+ size_t const decodedSize = ZSTD_decompressContinue(zds, *op, dstSize, src, srcSize);
+ FORWARD_IF_ERROR(decodedSize);
+ *op += decodedSize;
+ zds->streamStage = zdss_read;
+ assert(*op <= oend);
+ assert(zds->outBufferMode == ZSTD_obm_stable);
+ }
+ return 0;
+}
+
size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
{
const char* const src = (const char*)input->src;
"forbidden. out: pos: %u vs size: %u",
(U32)output->pos, (U32)output->size);
DEBUGLOG(5, "input size : %u", (U32)(input->size - input->pos));
+ FORWARD_IF_ERROR(ZSTD_checkOutBuffer(zds, output));
while (someMoreWork) {
switch(zds->streamStage)
zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
zds->legacyVersion = 0;
zds->hostageByte = 0;
+ zds->expectedOutBuffer = *output;
/* fall-through */
case zdss_loadHeader :
break;
} }
+ /* Check output buffer is large enough for ZSTD_odm_stable. */
+ if (zds->outBufferMode == ZSTD_obm_stable
+ && zds->fParams.frameType != ZSTD_skippableFrame
+ && zds->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
+ && (U64)(size_t)(oend-op) < zds->fParams.frameContentSize) {
+ RETURN_ERROR(dstSize_tooSmall, "ZSTD_obm_stable passed but ZSTD_outBuffer is too small");
+ }
+
/* Consume header (see ZSTDds_decodeFrameHeader) */
DEBUGLOG(4, "Consume header");
FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(zds, ZSTD_getDDict(zds)));
/* Adapt buffer sizes to frame header instructions */
{ size_t const neededInBuffSize = MAX(zds->fParams.blockSizeMax, 4 /* frame checksum */);
- size_t const neededOutBuffSize = ZSTD_decodingBufferSize_min(zds->fParams.windowSize, zds->fParams.frameContentSize);
+ size_t const neededOutBuffSize = zds->outBufferMode == ZSTD_obm_buffered
+ ? ZSTD_decodingBufferSize_min(zds->fParams.windowSize, zds->fParams.frameContentSize)
+ : 0;
ZSTD_DCtx_updateOversizedDuration(zds, neededInBuffSize, neededOutBuffSize);
break;
}
if ((size_t)(iend-ip) >= neededInSize) { /* decode directly from src */
- int const isSkipFrame = ZSTD_isSkipFrame(zds);
- size_t const decodedSize = ZSTD_decompressContinue(zds,
- zds->outBuff + zds->outStart, (isSkipFrame ? 0 : zds->outBuffSize - zds->outStart),
- ip, neededInSize);
- if (ZSTD_isError(decodedSize)) return decodedSize;
+ FORWARD_IF_ERROR(ZSTD_decompressContinueStream(zds, &op, oend, ip, neededInSize));
ip += neededInSize;
- if (!decodedSize && !isSkipFrame) break; /* this was just a header */
- zds->outEnd = zds->outStart + decodedSize;
- zds->streamStage = zdss_flush;
+ /* Function modifies the stage so we must break */
break;
} }
if (ip==iend) { someMoreWork = 0; break; } /* no more input */
if (loadedSize < toLoad) { someMoreWork = 0; break; } /* not enough input, wait for more */
/* decode loaded input */
- { size_t const decodedSize = ZSTD_decompressContinue(zds,
- zds->outBuff + zds->outStart, zds->outBuffSize - zds->outStart,
- zds->inBuff, neededInSize);
- if (ZSTD_isError(decodedSize)) return decodedSize;
- zds->inPos = 0; /* input is consumed */
- if (!decodedSize && !isSkipFrame) { zds->streamStage = zdss_read; break; } /* this was just a header */
- zds->outEnd = zds->outStart + decodedSize;
- } }
- zds->streamStage = zdss_flush;
- /* fall-through */
-
+ zds->inPos = 0; /* input is consumed */
+ FORWARD_IF_ERROR(ZSTD_decompressContinueStream(zds, &op, oend, zds->inBuff, neededInSize));
+ /* Function modifies the stage so we must break */
+ break;
+ }
case zdss_flush:
{ size_t const toFlushSize = zds->outEnd - zds->outStart;
size_t const flushedSize = ZSTD_limitCopy(op, oend-op, zds->outBuff + zds->outStart, toFlushSize);
/* result */
input->pos = (size_t)(ip - (const char*)(input->src));
output->pos = (size_t)(op - (char*)(output->dst));
+
+ /* Update the expected output buffer for ZSTD_obm_stable. */
+ zds->expectedOutBuffer = *output;
+
if ((ip==istart) && (op==ostart)) { /* no forward progress */
zds->noForwardProgress ++;
if (zds->noForwardProgress >= ZSTD_NO_FORWARD_PROGRESS_MAX) {
ZSTD_use_once = 1 /* Use the dictionary once and set to ZSTD_dont_use */
} ZSTD_dictUses_e;
+typedef enum {
+ ZSTD_obm_buffered = 0, /* Buffer the output */
+ ZSTD_obm_stable = 1 /* ZSTD_outBuffer is stable */
+} ZSTD_outBufferMode_e;
+
struct ZSTD_DCtx_s
{
const ZSTD_seqSymbol* LLTptr;
U32 legacyVersion;
U32 hostageByte;
int noForwardProgress;
+ ZSTD_outBufferMode_e outBufferMode;
+ ZSTD_outBuffer expectedOutBuffer;
/* workspace */
BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH];
* within the experimental section of the API.
* At the time of this writing, they include :
* ZSTD_d_format
+ * ZSTD_d_stableOutBuffer
* Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them.
* note : never ever use experimentalParam? names directly
*/
- ZSTD_d_experimentalParam1=1000
+ ZSTD_d_experimentalParam1=1000,
+ ZSTD_d_experimentalParam2=1001
} ZSTD_dParameter;
* allowing selection between ZSTD_format_e input compression formats
*/
#define ZSTD_d_format ZSTD_d_experimentalParam1
+/* ZSTD_d_stableOutBuffer
+ * Experimental parameter.
+ * Default is 0 == disabled. Set to 1 to enable.
+ *
+ * Tells the decompressor that the ZSTD_outBuffer will ALWAYS be the same
+ * between calls, except for the modifications that zstd makes to pos (the
+ * caller must not modify pos). This is checked by the decompressor, and
+ * decompression will fail if it ever changes. Therefore the ZSTD_outBuffer
+ * MUST be large enough to fit the entire decompressed frame. This will be
+ * checked when the frame content size is known.
+ *
+ * When this flags is enabled zstd won't allocate an output buffer, because
+ * it can write directly to the ZSTD_outBuffer, but it will still allocate
+ * an input buffer large enough to fit any compressed block. This will also
+ * avoid the memcpy() from the internal output buffer to the ZSTD_outBuffer.
+ * If you need to avoid the input buffer allocation use the buffer-less
+ * streaming API.
+ *
+ * NOTE: So long as the ZSTD_outBuffer always points to valid memory, using
+ * this flag is ALWAYS memory safe, and will never access out-of-bounds
+ * memory. However, decompression WILL fail if you violate the preconditions.
+ */
+#define ZSTD_d_stableOutBuffer ZSTD_d_experimentalParam2
/*! ZSTD_DCtx_setFormat() :
* Instruct the decoder context about what kind of data to decode next.
}
DISPLAYLEVEL(3, "OK \n");
+ /* Decompression with ZSTD_d_stableOutBuffer */
+ cSize = ZSTD_compress(compressedBuffer, compressedBufferSize, CNBuffer, CNBufferSize, 1);
+ CHECK_Z(cSize);
+ { ZSTD_DCtx* dctx = ZSTD_createDCtx();
+ size_t const dctxSize0 = ZSTD_sizeof_DCtx(dctx);
+ size_t dctxSize1;
+ CHECK_Z(ZSTD_DCtx_setParameter(dctx, ZSTD_d_stableOutBuffer, 1));
+
+ outBuff.dst = decodedBuffer;
+ outBuff.pos = 0;
+ outBuff.size = CNBufferSize;
+
+ DISPLAYLEVEL(3, "test%3i : ZSTD_decompressStream() single pass : ", testNb++);
+ inBuff.src = compressedBuffer;
+ inBuff.size = cSize;
+ inBuff.pos = 0;
+ { size_t const r = ZSTD_decompressStream(dctx, &outBuff, &inBuff);
+ CHECK_Z(r);
+ CHECK(r != 0, "Entire frame must be decompressed");
+ CHECK(outBuff.pos != CNBufferSize, "Wrong size!");
+ CHECK(memcmp(CNBuffer, outBuff.dst, CNBufferSize) != 0, "Corruption!");
+ }
+ CHECK(dctxSize0 != ZSTD_sizeof_DCtx(dctx), "No buffers allocated");
+ DISPLAYLEVEL(3, "OK \n");
+
+ DISPLAYLEVEL(3, "test%3i : ZSTD_decompressStream() stable out buffer : ", testNb++);
+ outBuff.pos = 0;
+ inBuff.pos = 0;
+ inBuff.size = 0;
+ while (inBuff.pos < cSize) {
+ inBuff.size += MIN(cSize - inBuff.pos, 1 + (FUZ_rand(&coreSeed) & 15));
+ CHECK_Z(ZSTD_decompressStream(dctx, &outBuff, &inBuff));
+ }
+ CHECK(outBuff.pos != CNBufferSize, "Wrong size!");
+ CHECK(memcmp(CNBuffer, outBuff.dst, CNBufferSize) != 0, "Corruption!");
+ dctxSize1 = ZSTD_sizeof_DCtx(dctx);
+ CHECK(!(dctxSize0 < dctxSize1), "Input buffer allocated");
+ DISPLAYLEVEL(3, "OK \n");
+
+ DISPLAYLEVEL(3, "test%3i : ZSTD_decompressStream() stable out buffer too small : ", testNb++);
+ ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only);
+ CHECK_Z(ZSTD_DCtx_setParameter(dctx, ZSTD_d_stableOutBuffer, 1));
+ inBuff.src = compressedBuffer;
+ inBuff.size = cSize;
+ inBuff.pos = 0;
+ outBuff.pos = 0;
+ outBuff.size = CNBufferSize - 1;
+ { size_t const r = ZSTD_decompressStream(dctx, &outBuff, &inBuff);
+ CHECK(ZSTD_getErrorCode(r) != ZSTD_error_dstSize_tooSmall, "Must error but got %s", ZSTD_getErrorName(r));
+ }
+ DISPLAYLEVEL(3, "OK \n");
+
+ DISPLAYLEVEL(3, "test%3i : ZSTD_decompressStream() stable out buffer modified : ", testNb++);
+ ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only);
+ CHECK_Z(ZSTD_DCtx_setParameter(dctx, ZSTD_d_stableOutBuffer, 1));
+ inBuff.src = compressedBuffer;
+ inBuff.size = cSize - 1;
+ inBuff.pos = 0;
+ outBuff.pos = 0;
+ outBuff.size = CNBufferSize;
+ CHECK_Z(ZSTD_decompressStream(dctx, &outBuff, &inBuff));
+ ++inBuff.size;
+ outBuff.pos = 0;
+ { size_t const r = ZSTD_decompressStream(dctx, &outBuff, &inBuff);
+ CHECK(ZSTD_getErrorCode(r) != ZSTD_error_dstBuffer_wrong, "Must error but got %s", ZSTD_getErrorName(r));
+ }
+ DISPLAYLEVEL(3, "OK \n");
+
+ DISPLAYLEVEL(3, "test%3i : ZSTD_decompressStream() buffered output : ", testNb++);
+ ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only);
+ CHECK_Z(ZSTD_DCtx_setParameter(dctx, ZSTD_d_stableOutBuffer, 0));
+ outBuff.pos = 0;
+ inBuff.pos = 0;
+ inBuff.size = 0;
+ while (inBuff.pos < cSize) {
+ inBuff.size += MIN(cSize - inBuff.pos, 1 + (FUZ_rand(&coreSeed) & 15));
+ CHECK_Z(ZSTD_decompressStream(dctx, &outBuff, &inBuff));
+ }
+ CHECK(outBuff.pos != CNBufferSize, "Wrong size!");
+ CHECK(memcmp(CNBuffer, outBuff.dst, CNBufferSize) != 0, "Corruption!");
+ CHECK(!(dctxSize1 < ZSTD_sizeof_DCtx(dctx)), "Output buffer allocated");
+ DISPLAYLEVEL(3, "OK \n");
+
+ ZSTD_freeDCtx(dctx);
+ }
+
/* CDict scenario */
DISPLAYLEVEL(3, "test%3i : digested dictionary : ", testNb++);
{ ZSTD_CDict* const cdict = ZSTD_createCDict(dictionary.start, dictionary.filled, 1 /*byRef*/ );
projects / thirdparty / zstd.git / commitdiff
