added : ZSTD_createCDict_byReference()

lib/zstd.h

@@ -173,8 +173,8 @@ typedef struct ZSTD_CDict_s ZSTD_CDict;
 *   When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
 *   ZSTD_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
 *   ZSTD_CDict can be created once and used by multiple threads concurrently, as its usage is read-only.
-*   `dict` can be released after ZSTD_CDict creation. */
-ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict(const void* dict, size_t dictSize, int compressionLevel);
+*   `dictBuffer` can be released after ZSTD_CDict creation, as its content is copied within CDict */
+ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict(const void* dictBuffer, size_t dictSize, int compressionLevel);
 
 /*! ZSTD_freeCDict() :
 *   Function frees memory allocated by ZSTD_createCDict(). */
@@ -400,9 +400,15 @@ ZSTDLIB_API ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem);
  *  Gives the amount of memory used by a given ZSTD_CCtx */
 ZSTDLIB_API size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
 
+/*! ZSTD_createCDict_byReference() :
+ *  Create a digested dictionary for compression
+ *  Dictionary content is simply referenced, and therefore stays in dictBuffer.
+ *  It is important that dictBuffer outlives CDict, it must remain read accessible throughout the lifetime of CDict */
+ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict_byReference(const void* dictBuffer, size_t dictSize, int compressionLevel);
+
 /*! ZSTD_createCDict_advanced() :
  *  Create a ZSTD_CDict using external alloc and free, and customized compression parameters */
-ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize,
+ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize, unsigned byReference,
                                                   ZSTD_parameters params, ZSTD_customMem customMem);
 
 /*! ZSTD_sizeof_CDict() :