FreeBSD/Linux Kernel Cross Reference
sys/contrib/zstd/lib/legacy/zstd_v05.h

     /*
      * Copyright (c) Yann Collet, Facebook, Inc.
      * 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).
      * You may select, at your option, one of the above-listed licenses.
      */
    
    #ifndef ZSTDv05_H
    #define ZSTDv05_H
    
    #if defined (__cplusplus)
    extern "C" {
    #endif
    
    /*-*************************************
    *  Dependencies
    ***************************************/
    #include <stddef.h>   /* size_t */
    #include "../common/mem.h"      /* U64, U32 */
    
    
    /* *************************************
    *  Simple functions
    ***************************************/
    /*! ZSTDv05_decompress() :
        `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail.
        `dstCapacity` must be large enough, equal or larger than originalSize.
        @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
                  or an errorCode if it fails (which can be tested using ZSTDv05_isError()) */
    size_t ZSTDv05_decompress( void* dst, size_t dstCapacity,
                         const void* src, size_t compressedSize);
    
     /**
     ZSTDv05_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.5.x format
         srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
         cSize (output parameter)  : the number of bytes that would be read to decompress this frame
                                     or an error code if it fails (which can be tested using ZSTDv01_isError())
         dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
                                     or ZSTD_CONTENTSIZE_ERROR if an error occurs
    
        note : assumes `cSize` and `dBound` are _not_ NULL.
     */
    void ZSTDv05_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
                                         size_t* cSize, unsigned long long* dBound);
    
    /* *************************************
    *  Helper functions
    ***************************************/
    /* Error Management */
    unsigned    ZSTDv05_isError(size_t code);          /*!< tells if a `size_t` function result is an error code */
    const char* ZSTDv05_getErrorName(size_t code);     /*!< provides readable string for an error code */
    
    
    /* *************************************
    *  Explicit memory management
    ***************************************/
    /** Decompression context */
    typedef struct ZSTDv05_DCtx_s ZSTDv05_DCtx;
    ZSTDv05_DCtx* ZSTDv05_createDCtx(void);
    size_t ZSTDv05_freeDCtx(ZSTDv05_DCtx* dctx);      /*!< @return : errorCode */
    
    /** ZSTDv05_decompressDCtx() :
    *   Same as ZSTDv05_decompress(), but requires an already allocated ZSTDv05_DCtx (see ZSTDv05_createDCtx()) */
    size_t ZSTDv05_decompressDCtx(ZSTDv05_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
    
    
    /*-***********************
    *  Simple Dictionary API
    *************************/
    /*! ZSTDv05_decompress_usingDict() :
    *   Decompression using a pre-defined Dictionary content (see dictBuilder).
    *   Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted.
    *   Note : dict can be NULL, in which case, it's equivalent to ZSTDv05_decompressDCtx() */
    size_t ZSTDv05_decompress_usingDict(ZSTDv05_DCtx* dctx,
                                                void* dst, size_t dstCapacity,
                                          const void* src, size_t srcSize,
                                          const void* dict,size_t dictSize);
    
    /*-************************
    *  Advanced Streaming API
    ***************************/
    typedef enum { ZSTDv05_fast, ZSTDv05_greedy, ZSTDv05_lazy, ZSTDv05_lazy2, ZSTDv05_btlazy2, ZSTDv05_opt, ZSTDv05_btopt } ZSTDv05_strategy;
    typedef struct {
        U64 srcSize;
        U32 windowLog;     /* the only useful information to retrieve */
        U32 contentLog; U32 hashLog; U32 searchLog; U32 searchLength; U32 targetLength; ZSTDv05_strategy strategy;
    } ZSTDv05_parameters;
    size_t ZSTDv05_getFrameParams(ZSTDv05_parameters* params, const void* src, size_t srcSize);
    
    size_t ZSTDv05_decompressBegin_usingDict(ZSTDv05_DCtx* dctx, const void* dict, size_t dictSize);
    void   ZSTDv05_copyDCtx(ZSTDv05_DCtx* dstDCtx, const ZSTDv05_DCtx* srcDCtx);
    size_t ZSTDv05_nextSrcSizeToDecompress(ZSTDv05_DCtx* dctx);
    size_t ZSTDv05_decompressContinue(ZSTDv05_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
    
    
    /*-***********************
   *  ZBUFF API
   *************************/
   typedef struct ZBUFFv05_DCtx_s ZBUFFv05_DCtx;
   ZBUFFv05_DCtx* ZBUFFv05_createDCtx(void);
   size_t         ZBUFFv05_freeDCtx(ZBUFFv05_DCtx* dctx);
   
   size_t ZBUFFv05_decompressInit(ZBUFFv05_DCtx* dctx);
   size_t ZBUFFv05_decompressInitDictionary(ZBUFFv05_DCtx* dctx, const void* dict, size_t dictSize);
   
   size_t ZBUFFv05_decompressContinue(ZBUFFv05_DCtx* dctx,
                                               void* dst, size_t* dstCapacityPtr,
                                         const void* src, size_t* srcSizePtr);
   
   /*-***************************************************************************
   *  Streaming decompression
   *
   *  A ZBUFFv05_DCtx object is required to track streaming operations.
   *  Use ZBUFFv05_createDCtx() and ZBUFFv05_freeDCtx() to create/release resources.
   *  Use ZBUFFv05_decompressInit() to start a new decompression operation,
   *   or ZBUFFv05_decompressInitDictionary() if decompression requires a dictionary.
   *  Note that ZBUFFv05_DCtx objects can be reused multiple times.
   *
   *  Use ZBUFFv05_decompressContinue() 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 present remaining input again.
   *  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 help latency)
   *            or 0 when a frame is completely decoded
   *            or an error code, which can be tested using ZBUFFv05_isError().
   *
   *  Hint : recommended buffer sizes (not compulsory) : ZBUFFv05_recommendedDInSize() / ZBUFFv05_recommendedDOutSize()
   *  output : ZBUFFv05_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
   *  input  : ZBUFFv05_recommendedDInSize==128Kb+3; just follow indications from ZBUFFv05_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
   * *******************************************************************************/
   
   
   /* *************************************
   *  Tool functions
   ***************************************/
   unsigned ZBUFFv05_isError(size_t errorCode);
   const char* ZBUFFv05_getErrorName(size_t errorCode);
   
   /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
   *   These sizes are just hints, and tend to offer better latency */
   size_t ZBUFFv05_recommendedDInSize(void);
   size_t ZBUFFv05_recommendedDOutSize(void);
   
   
   
   /*-*************************************
   *  Constants
   ***************************************/
   #define ZSTDv05_MAGICNUMBER 0xFD2FB525   /* v0.5 */
   
   
   
   
   #if defined (__cplusplus)
   }
   #endif
   
   #endif  /* ZSTDv0505_H */

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