contrib/python-zstandard/zstd/compress/zbuff_compress.c
changeset 30822 b54a2984cdd4
parent 30821 7005c03f7387
child 30823 806a830e6612
--- a/contrib/python-zstandard/zstd/compress/zbuff_compress.c	Sat Jan 14 20:05:15 2017 +0530
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,319 +0,0 @@
-/**
- * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- */
-
-
-
-/* *************************************
-*  Dependencies
-***************************************/
-#include <stdlib.h>
-#include "error_private.h"
-#include "zstd_internal.h"  /* MIN, ZSTD_BLOCKHEADERSIZE, defaultCustomMem */
-#define ZBUFF_STATIC_LINKING_ONLY
-#include "zbuff.h"
-
-
-/* *************************************
-*  Constants
-***************************************/
-static size_t const ZBUFF_endFrameSize = ZSTD_BLOCKHEADERSIZE;
-
-
-/*-***********************************************************
-*  Streaming compression
-*
-*  A ZBUFF_CCtx object is required to track streaming operation.
-*  Use ZBUFF_createCCtx() and ZBUFF_freeCCtx() to create/release resources.
-*  Use ZBUFF_compressInit() to start a new compression operation.
-*  ZBUFF_CCtx objects can be reused multiple times.
-*
-*  Use ZBUFF_compressContinue() repetitively to consume your input.
-*  *srcSizePtr and *dstCapacityPtr can be any size.
-*  The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
-*  Note that it may not consume the entire input, in which case it's up to the caller to call again the function with remaining input.
-*  The content of dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change dst .
-*  @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to improve latency)
-*            or an error code, which can be tested using ZBUFF_isError().
-*
-*  ZBUFF_compressFlush() can be used to instruct ZBUFF to compress and output whatever remains within its buffer.
-*  Note that it will not output more than *dstCapacityPtr.
-*  Therefore, some content might still be left into its internal buffer if dst buffer is too small.
-*  @return : nb of bytes still present into internal buffer (0 if it's empty)
-*            or an error code, which can be tested using ZBUFF_isError().
-*
-*  ZBUFF_compressEnd() instructs to finish a frame.
-*  It will perform a flush and write frame epilogue.
-*  Similar to ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content if *dstCapacityPtr is too small.
-*  @return : nb of bytes still present into internal buffer (0 if it's empty)
-*            or an error code, which can be tested using ZBUFF_isError().
-*
-*  Hint : recommended buffer sizes (not compulsory)
-*  input : ZSTD_BLOCKSIZE_MAX (128 KB), internal unit size, it improves latency to use this value.
-*  output : ZSTD_compressBound(ZSTD_BLOCKSIZE_MAX) + ZSTD_blockHeaderSize + ZBUFF_endFrameSize : ensures it's always possible to write/flush/end a full block at best speed.
-* ***********************************************************/
-
-typedef enum { ZBUFFcs_init, ZBUFFcs_load, ZBUFFcs_flush, ZBUFFcs_final } ZBUFF_cStage;
-
-/* *** Resources *** */
-struct ZBUFF_CCtx_s {
-    ZSTD_CCtx* zc;
-    char*  inBuff;
-    size_t inBuffSize;
-    size_t inToCompress;
-    size_t inBuffPos;
-    size_t inBuffTarget;
-    size_t blockSize;
-    char*  outBuff;
-    size_t outBuffSize;
-    size_t outBuffContentSize;
-    size_t outBuffFlushedSize;
-    ZBUFF_cStage stage;
-    U32    checksum;
-    U32    frameEnded;
-    ZSTD_customMem customMem;
-};   /* typedef'd tp ZBUFF_CCtx within "zbuff.h" */
-
-ZBUFF_CCtx* ZBUFF_createCCtx(void)
-{
-    return ZBUFF_createCCtx_advanced(defaultCustomMem);
-}
-
-ZBUFF_CCtx* ZBUFF_createCCtx_advanced(ZSTD_customMem customMem)
-{
-    ZBUFF_CCtx* zbc;
-
-    if (!customMem.customAlloc && !customMem.customFree)
-        customMem = defaultCustomMem;
-
-    if (!customMem.customAlloc || !customMem.customFree)
-        return NULL;
-
-    zbc = (ZBUFF_CCtx*)customMem.customAlloc(customMem.opaque, sizeof(ZBUFF_CCtx));
-    if (zbc==NULL) return NULL;
-    memset(zbc, 0, sizeof(ZBUFF_CCtx));
-    memcpy(&zbc->customMem, &customMem, sizeof(ZSTD_customMem));
-    zbc->zc = ZSTD_createCCtx_advanced(customMem);
-    if (zbc->zc == NULL) { ZBUFF_freeCCtx(zbc); return NULL; }
-    return zbc;
-}
-
-size_t ZBUFF_freeCCtx(ZBUFF_CCtx* zbc)
-{
-    if (zbc==NULL) return 0;   /* support free on NULL */
-    ZSTD_freeCCtx(zbc->zc);
-    if (zbc->inBuff) zbc->customMem.customFree(zbc->customMem.opaque, zbc->inBuff);
-    if (zbc->outBuff) zbc->customMem.customFree(zbc->customMem.opaque, zbc->outBuff);
-    zbc->customMem.customFree(zbc->customMem.opaque, zbc);
-    return 0;
-}
-
-
-/* ======   Initialization   ====== */
-
-size_t ZBUFF_compressInit_advanced(ZBUFF_CCtx* zbc,
-                                   const void* dict, size_t dictSize,
-                                   ZSTD_parameters params, unsigned long long pledgedSrcSize)
-{
-    /* allocate buffers */
-    {   size_t const neededInBuffSize = (size_t)1 << params.cParams.windowLog;
-        if (zbc->inBuffSize < neededInBuffSize) {
-            zbc->inBuffSize = neededInBuffSize;
-            zbc->customMem.customFree(zbc->customMem.opaque, zbc->inBuff);   /* should not be necessary */
-            zbc->inBuff = (char*)zbc->customMem.customAlloc(zbc->customMem.opaque, neededInBuffSize);
-            if (zbc->inBuff == NULL) return ERROR(memory_allocation);
-        }
-        zbc->blockSize = MIN(ZSTD_BLOCKSIZE_ABSOLUTEMAX, neededInBuffSize);
-    }
-    if (zbc->outBuffSize < ZSTD_compressBound(zbc->blockSize)+1) {
-        zbc->outBuffSize = ZSTD_compressBound(zbc->blockSize)+1;
-        zbc->customMem.customFree(zbc->customMem.opaque, zbc->outBuff);   /* should not be necessary */
-        zbc->outBuff = (char*)zbc->customMem.customAlloc(zbc->customMem.opaque, zbc->outBuffSize);
-        if (zbc->outBuff == NULL) return ERROR(memory_allocation);
-    }
-
-    { size_t const errorCode = ZSTD_compressBegin_advanced(zbc->zc, dict, dictSize, params, pledgedSrcSize);
-      if (ZSTD_isError(errorCode)) return errorCode; }
-
-    zbc->inToCompress = 0;
-    zbc->inBuffPos = 0;
-    zbc->inBuffTarget = zbc->blockSize;
-    zbc->outBuffContentSize = zbc->outBuffFlushedSize = 0;
-    zbc->stage = ZBUFFcs_load;
-    zbc->checksum = params.fParams.checksumFlag > 0;
-    zbc->frameEnded = 0;
-    return 0;   /* ready to go */
-}
-
-
-size_t ZBUFF_compressInitDictionary(ZBUFF_CCtx* zbc, const void* dict, size_t dictSize, int compressionLevel)
-{
-    ZSTD_parameters const params = ZSTD_getParams(compressionLevel, 0, dictSize);
-    return ZBUFF_compressInit_advanced(zbc, dict, dictSize, params, 0);
-}
-
-size_t ZBUFF_compressInit(ZBUFF_CCtx* zbc, int compressionLevel)
-{
-    return ZBUFF_compressInitDictionary(zbc, NULL, 0, compressionLevel);
-}
-
-
-/* internal util function */
-MEM_STATIC size_t ZBUFF_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
-{
-    size_t const length = MIN(dstCapacity, srcSize);
-    memcpy(dst, src, length);
-    return length;
-}
-
-
-/* ======   Compression   ====== */
-
-typedef enum { zbf_gather, zbf_flush, zbf_end } ZBUFF_flush_e;
-
-static size_t ZBUFF_compressContinue_generic(ZBUFF_CCtx* zbc,
-                              void* dst, size_t* dstCapacityPtr,
-                        const void* src, size_t* srcSizePtr,
-                              ZBUFF_flush_e const flush)
-{
-    U32 someMoreWork = 1;
-    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;
-
-    while (someMoreWork) {
-        switch(zbc->stage)
-        {
-        case ZBUFFcs_init: return ERROR(init_missing);   /* call ZBUFF_compressInit() first ! */
-
-        case ZBUFFcs_load:
-            /* complete inBuffer */
-            {   size_t const toLoad = zbc->inBuffTarget - zbc->inBuffPos;
-                size_t const loaded = ZBUFF_limitCopy(zbc->inBuff + zbc->inBuffPos, toLoad, ip, iend-ip);
-                zbc->inBuffPos += loaded;
-                ip += loaded;
-                if ( (zbc->inBuffPos==zbc->inToCompress) || (!flush && (toLoad != loaded)) ) {
-                    someMoreWork = 0; break;  /* not enough input to get a full block : stop there, wait for more */
-            }   }
-            /* compress current block (note : this stage cannot be stopped in the middle) */
-            {   void* cDst;
-                size_t cSize;
-                size_t const iSize = zbc->inBuffPos - zbc->inToCompress;
-                size_t oSize = oend-op;
-                if (oSize >= ZSTD_compressBound(iSize))
-                    cDst = op;   /* compress directly into output buffer (avoid flush stage) */
-                else
-                    cDst = zbc->outBuff, oSize = zbc->outBuffSize;
-                cSize = (flush == zbf_end) ?
-                        ZSTD_compressEnd(zbc->zc, cDst, oSize, zbc->inBuff + zbc->inToCompress, iSize) :
-                        ZSTD_compressContinue(zbc->zc, cDst, oSize, zbc->inBuff + zbc->inToCompress, iSize);
-                if (ZSTD_isError(cSize)) return cSize;
-                if (flush == zbf_end) zbc->frameEnded = 1;
-                /* prepare next block */
-                zbc->inBuffTarget = zbc->inBuffPos + zbc->blockSize;
-                if (zbc->inBuffTarget > zbc->inBuffSize)
-                    zbc->inBuffPos = 0, zbc->inBuffTarget = zbc->blockSize;   /* note : inBuffSize >= blockSize */
-                zbc->inToCompress = zbc->inBuffPos;
-                if (cDst == op) { op += cSize; break; }   /* no need to flush */
-                zbc->outBuffContentSize = cSize;
-                zbc->outBuffFlushedSize = 0;
-                zbc->stage = ZBUFFcs_flush;   /* continue to flush stage */
-            }
-
-        case ZBUFFcs_flush:
-            {   size_t const toFlush = zbc->outBuffContentSize - zbc->outBuffFlushedSize;
-                size_t const flushed = ZBUFF_limitCopy(op, oend-op, zbc->outBuff + zbc->outBuffFlushedSize, toFlush);
-                op += flushed;
-                zbc->outBuffFlushedSize += flushed;
-                if (toFlush!=flushed) { someMoreWork = 0; break; } /* dst too small to store flushed data : stop there */
-                zbc->outBuffContentSize = zbc->outBuffFlushedSize = 0;
-                zbc->stage = ZBUFFcs_load;
-                break;
-            }
-
-        case ZBUFFcs_final:
-            someMoreWork = 0;   /* do nothing */
-            break;
-
-        default:
-            return ERROR(GENERIC);   /* impossible */
-        }
-    }
-
-    *srcSizePtr = ip - istart;
-    *dstCapacityPtr = op - ostart;
-    if (zbc->frameEnded) return 0;
-    {   size_t hintInSize = zbc->inBuffTarget - zbc->inBuffPos;
-        if (hintInSize==0) hintInSize = zbc->blockSize;
-        return hintInSize;
-    }
-}
-
-size_t ZBUFF_compressContinue(ZBUFF_CCtx* zbc,
-                              void* dst, size_t* dstCapacityPtr,
-                        const void* src, size_t* srcSizePtr)
-{
-    return ZBUFF_compressContinue_generic(zbc, dst, dstCapacityPtr, src, srcSizePtr, zbf_gather);
-}
-
-
-
-/* ======   Finalize   ====== */
-
-size_t ZBUFF_compressFlush(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
-{
-    size_t srcSize = 0;
-    ZBUFF_compressContinue_generic(zbc, dst, dstCapacityPtr, &srcSize, &srcSize, zbf_flush);  /* use a valid src address instead of NULL */
-    return zbc->outBuffContentSize - zbc->outBuffFlushedSize;
-}
-
-
-size_t ZBUFF_compressEnd(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
-{
-    BYTE* const ostart = (BYTE*)dst;
-    BYTE* const oend = ostart + *dstCapacityPtr;
-    BYTE* op = ostart;
-
-    if (zbc->stage != ZBUFFcs_final) {
-        /* flush whatever remains */
-        size_t outSize = *dstCapacityPtr;
-        size_t srcSize = 0;
-        size_t const notEnded = ZBUFF_compressContinue_generic(zbc, dst, &outSize, &srcSize, &srcSize, zbf_end);  /* use a valid address instead of NULL */
-        size_t const remainingToFlush = zbc->outBuffContentSize - zbc->outBuffFlushedSize;
-        op += outSize;
-        if (remainingToFlush) {
-            *dstCapacityPtr = op-ostart;
-            return remainingToFlush + ZBUFF_endFrameSize + (zbc->checksum * 4);
-        }
-        /* create epilogue */
-        zbc->stage = ZBUFFcs_final;
-        zbc->outBuffContentSize = !notEnded ? 0 :
-            ZSTD_compressEnd(zbc->zc, zbc->outBuff, zbc->outBuffSize, NULL, 0);  /* write epilogue into outBuff */
-    }
-
-    /* flush epilogue */
-    {   size_t const toFlush = zbc->outBuffContentSize - zbc->outBuffFlushedSize;
-        size_t const flushed = ZBUFF_limitCopy(op, oend-op, zbc->outBuff + zbc->outBuffFlushedSize, toFlush);
-        op += flushed;
-        zbc->outBuffFlushedSize += flushed;
-        *dstCapacityPtr = op-ostart;
-        if (toFlush==flushed) zbc->stage = ZBUFFcs_init;  /* end reached */
-        return toFlush - flushed;
-    }
-}
-
-
-
-/* *************************************
-*  Tool functions
-***************************************/
-size_t ZBUFF_recommendedCInSize(void)  { return ZSTD_BLOCKSIZE_ABSOLUTEMAX; }
-size_t ZBUFF_recommendedCOutSize(void) { return ZSTD_compressBound(ZSTD_BLOCKSIZE_ABSOLUTEMAX) + ZSTD_blockHeaderSize + ZBUFF_endFrameSize; }