implemented dictionary compression in lz4frame

note : only compression API is implemented and tested
still to do : decompression API

1 files changed, 44 insertions, 0 deletions

diff --git a/lib/lz4frame_static.h b/lib/lz4frame_static.h
index d3bae82..5f22aed 100644
--- a/lib/lz4frame_static.h
+++ b/lib/lz4frame_static.h
@@ -82,6 +82,50 @@ typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM) } LZ4F_errorCodes;
 LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult);
 
 
+
+/**********************************
+ *  Bulk processing dictionary API
+ *********************************/
+typedef struct LZ4F_CDict_s LZ4F_CDict;
+
+/*! LZ4_createCDict() :
+ *  When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
+ *  LZ4_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
+ *  LZ4_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
+ *  `dictBuffer` can be released after LZ4_CDict creation, since its content is copied within CDict */
+LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize);
+void        LZ4F_freeCDict(LZ4F_CDict* CDict);
+
+/*! LZ4_compressFrame_usingCDict() :
+ *  Compress an entire srcBuffer into a valid LZ4 frame using a digested Dictionary.
+ *  If cdict==NULL, compress without a dictionary.
+ *  dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
+ *  If this condition is not respected, function will fail (@return an errorCode).
+ *  The LZ4F_preferences_t structure is optional : you may provide NULL as argument,
+ *  but it's not recommended, as it's the only way to provide dictID in the frame header.
+ * @return : number of bytes written into dstBuffer.
+ *           or an error code if it fails (can be tested using LZ4F_isError())
+ */
+size_t LZ4F_compressFrame_usingCDict(void* dst, size_t dstCapacity,
+                               const void* src, size_t srcSize,
+                               const LZ4F_CDict* cdict,
+                               const LZ4F_preferences_t* preferencesPtr);
+
+
+/*! LZ4F_compressBegin_usingCDict() :
+ *  Inits streaming dictionary compression, and writes the frame header into dstBuffer.
+ *  dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
+ * `prefsPtr` is optional : you may provide NULL as argument,
+ *  however, it's the only way to provide dictID in the frame header.
+ * @return : number of bytes written into dstBuffer for the header,
+ *           or an error code (which can be tested using LZ4F_isError())
+ */
+size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctx,
+                                     void* dstBuffer, size_t dstCapacity,
+                                     const LZ4F_CDict* cdict,
+                                     const LZ4F_preferences_t* prefsPtr);
+
+
 #if defined (__cplusplus)
 }
 #endif