updated ZSTD_estimate?DictSize() to pass parameter byReference

resulting ?Dict object is smaller when created byReference.
Seems better than a documentation note.

lib/compress/zstd_compress.c

@@ -3237,10 +3237,11 @@ size_t ZSTD_compress(void* dst, size_t dstCapacity, const void* src, size_t srcS
 
 /*! ZSTD_estimateCDictSize() :
  *  Estimate amount of memory that will be needed to create a dictionary with following arguments */
-size_t ZSTD_estimateCDictSize(ZSTD_compressionParameters cParams, size_t dictSize)
+size_t ZSTD_estimateCDictSize(ZSTD_compressionParameters cParams, size_t dictSize, unsigned byReference)
 {
     cParams = ZSTD_adjustCParams(cParams, 0, dictSize);
-    return sizeof(ZSTD_CDict) + dictSize + ZSTD_estimateCCtxSize(cParams);
+    return sizeof(ZSTD_CDict) + ZSTD_estimateCCtxSize(cParams)
+           + (byReference ? 0 : dictSize);
 }
 
 size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict)

lib/decompress/zstd_decompress.c

@@ -2053,10 +2053,10 @@ size_t ZSTD_freeDDict(ZSTD_DDict* ddict)
 
 /*! ZSTD_estimateDDictSize() :
  *  Estimate amount of memory that will be needed to create a dictionary for decompression.
- *  Note : if dictionary is created "byReference", reduce this amount by dictSize */
-size_t ZSTD_estimateDDictSize(size_t dictSize)
+ *  Note : dictionary created "byReference" are smaller */
+size_t ZSTD_estimateDDictSize(size_t dictSize, unsigned byReference)
 {
-    return dictSize + sizeof(ZSTD_DDict);
+    return sizeof(ZSTD_DDict) + (byReference ? 0 : dictSize);
 }
 
 size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict)

lib/zstd.h

@@ -345,8 +345,6 @@ ZSTDLIB_API size_t ZSTD_DStreamOutSize(void);   /*!< recommended size for output
 #endif  /* ZSTD_H_235446 */
 
 
-#if defined(ZSTD_STATIC_LINKING_ONLY) && !defined(ZSTD_H_ZSTD_STATIC_LINKING_ONLY)
-#define ZSTD_H_ZSTD_STATIC_LINKING_ONLY
 
 /****************************************************************************************
  * START OF ADVANCED AND EXPERIMENTAL FUNCTIONS
@@ -356,6 +354,9 @@ ZSTDLIB_API size_t ZSTD_DStreamOutSize(void);   /*!< recommended size for output
  * Use them only in association with static linking.
  * ***************************************************************************************/
 
+#if defined(ZSTD_STATIC_LINKING_ONLY) && !defined(ZSTD_H_ZSTD_STATIC_LINKING_ONLY)
+#define ZSTD_H_ZSTD_STATIC_LINKING_ONLY
+
 /* --- Constants ---*/
 #define ZSTD_MAGICNUMBER            0xFD2FB528   /* >= v0.8.0 */
 #define ZSTD_MAGIC_SKIPPABLE_START  0x184D2A50U
@@ -500,9 +501,9 @@ ZSTDLIB_API size_t ZSTD_estimateCStreamSize(ZSTD_compressionParameters cParams);
 ZSTDLIB_API size_t ZSTD_estimateDStreamSize(ZSTD_frameHeader fHeader);
 
 /*! ZSTD_estimate?DictSize() :
- *  Note : if dictionary is created "byReference", reduce estimation by dictSize */
-ZSTDLIB_API size_t ZSTD_estimateCDictSize(ZSTD_compressionParameters cParams, size_t dictSize);
-ZSTDLIB_API size_t ZSTD_estimateDDictSize(size_t dictSize);
+ *  Note : dictionary created "byReference" are smaller */
+ZSTDLIB_API size_t ZSTD_estimateCDictSize(ZSTD_compressionParameters cParams, size_t dictSize, unsigned byReference);
+ZSTDLIB_API size_t ZSTD_estimateDDictSize(size_t dictSize, unsigned byReference);
 
 
 /***************************************
@@ -842,6 +843,21 @@ ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, siz
 ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize,
                                                   unsigned byReference, ZSTD_customMem customMem);
 
+/*! ZSTD_initStaticDDict() :
+ *  Generate a digested dictionary in provided memory area.
+ *  workspace: The memory area to emplace the dictionary into.
+ *             Provided pointer must 8-bytes aligned.
+ *             It must outlive dictionary usage.
+ *  workspaceSize: Use ZSTD_estimateDDictSize()
+ *                 to determine how large workspace must be.
+ * @return : pointer to ZSTD_DDict*, or NULL if error (size too small)
+ *  Note : there is no corresponding "free" function.
+ *         Since workspace was allocated externally, it must be freed externally.
+ */
+ZSTDLIB_API ZSTD_DDict* ZSTD_initStaticDDict(void* workspace, size_t workspaceSize,
+                                             const void* dict, size_t dictSize,
+                                             unsigned byReference);
+
 /*! ZSTD_getDictID_fromDict() :
  *  Provides the dictID stored within dictionary.
  *  if @return == 0, the dictionary is not conformant with Zstandard specification.