separate DDict logic into its own module

created zstd_ddict.c within lib/decompress

build/VS2008/fullbench/fullbench.vcproj

@@ -380,6 +380,10 @@
 				RelativePath="..\..\..\lib\decompress\zstd_decompress.c"
 				>
 			</File>
+			<File
+				RelativePath="..\..\..\lib\decompress\zstd_ddict.c"
+				>
+			</File>
 			<File
 				RelativePath="..\..\..\lib\decompress\huf_decompress.c"
 				>

build/VS2008/fuzzer/fuzzer.vcproj

@@ -412,6 +412,10 @@
 				RelativePath="..\..\..\lib\decompress\zstd_decompress.c"
 				>
 			</File>
+			<File
+				RelativePath="..\..\..\lib\decompress\zstd_ddict.c"
+				>
+			</File>
 			<File
 				RelativePath="..\..\..\lib\compress\zstd_fast.c"
 				>

build/VS2008/zstd/zstd.vcproj

@@ -420,6 +420,10 @@
 				RelativePath="..\..\..\lib\decompress\zstd_decompress.c"
 				>
 			</File>
+			<File
+				RelativePath="..\..\..\lib\decompress\zstd_ddict.c"
+				>
+			</File>
 			<File
 				RelativePath="..\..\..\lib\legacy\zstd_v01.c"
 				>

build/VS2008/zstdlib/zstdlib.vcproj

@@ -420,6 +420,10 @@
 				RelativePath="..\..\..\lib\decompress\zstd_decompress.c"
 				>
 			</File>
+			<File
+				RelativePath="..\..\..\lib\decompress\zstd_ddict.c"
+				>
+			</File>
 			<File
 				RelativePath="..\..\..\lib\legacy\zstd_v01.c"
 				>

build/VS2010/fullbench/fullbench.vcxproj

@@ -176,6 +176,7 @@
     <ClCompile Include="..\..\..\lib\compress\zstd_ldm.c" />
     <ClCompile Include="..\..\..\lib\decompress\huf_decompress.c" />
     <ClCompile Include="..\..\..\lib\decompress\zstd_decompress.c" />
+    <ClCompile Include="..\..\..\lib\decompress\zstd_ddict.c" />
     <ClCompile Include="..\..\..\programs\datagen.c" />
     <ClCompile Include="..\..\..\programs\bench.c" />
     <ClCompile Include="..\..\..\tests\fullbench.c" />
@@ -196,6 +197,7 @@
     <ClInclude Include="..\..\..\lib\compress\zstd_opt.h" />
     <ClInclude Include="..\..\..\lib\compress\zstd_ldm.h" />
     <ClInclude Include="..\..\..\lib\compress\zstdmt_compress.h" />
+    <ClCompile Include="..\..\..\lib\decompress\zstd_ddict.h" />
     <ClInclude Include="..\..\..\lib\legacy\zstd_legacy.h" />
     <ClInclude Include="..\..\..\programs\datagen.h" />
     <ClInclude Include="..\..\..\programs\util.h" />

build/VS2010/fuzzer/fuzzer.vcxproj

@@ -175,6 +175,7 @@
     <ClCompile Include="..\..\..\lib\compress\zstdmt_compress.c" />
     <ClCompile Include="..\..\..\lib\decompress\huf_decompress.c" />
     <ClCompile Include="..\..\..\lib\decompress\zstd_decompress.c" />
+    <ClCompile Include="..\..\..\lib\decompress\zstd_ddict.c" />
     <ClCompile Include="..\..\..\lib\dictBuilder\cover.c" />
     <ClCompile Include="..\..\..\lib\dictBuilder\fastcover.c" />
     <ClCompile Include="..\..\..\lib\dictBuilder\divsufsort.c" />
@@ -199,6 +200,7 @@
     <ClInclude Include="..\..\..\lib\compress\zstd_opt.h" />
     <ClInclude Include="..\..\..\lib\compress\zstd_ldm.h" />
     <ClInclude Include="..\..\..\lib\compress\zstdmt_compress.h" />
+    <ClCompile Include="..\..\..\lib\decompress\zstd_ddict.h" />
     <ClInclude Include="..\..\..\lib\dictBuilder\divsufsort.h" />
     <ClInclude Include="..\..\..\lib\dictBuilder\zdict.h" />
     <ClInclude Include="..\..\..\lib\dictBuilder\cover.h" />

build/VS2010/libzstd-dll/libzstd-dll.vcxproj

@@ -39,6 +39,7 @@
     <ClCompile Include="..\..\..\lib\compress\zstdmt_compress.c" />
     <ClCompile Include="..\..\..\lib\decompress\huf_decompress.c" />
     <ClCompile Include="..\..\..\lib\decompress\zstd_decompress.c" />
+    <ClCompile Include="..\..\..\lib\decompress\zstd_ddict.c" />
     <ClCompile Include="..\..\..\lib\deprecated\zbuff_common.c" />
     <ClCompile Include="..\..\..\lib\deprecated\zbuff_compress.c" />
     <ClCompile Include="..\..\..\lib\deprecated\zbuff_decompress.c" />
@@ -82,6 +83,7 @@
     <ClInclude Include="..\..\..\lib\compress\zstd_opt.h" />
     <ClInclude Include="..\..\..\lib\compress\zstd_ldm.h" />
     <ClInclude Include="..\..\..\lib\compress\zstdmt_compress.h" />
+    <ClCompile Include="..\..\..\lib\decompress\zstd_ddict.h" />
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="libzstd-dll.rc" />

build/VS2010/libzstd/libzstd.vcxproj

@@ -39,6 +39,7 @@
     <ClCompile Include="..\..\..\lib\compress\zstdmt_compress.c" />
     <ClCompile Include="..\..\..\lib\decompress\huf_decompress.c" />
     <ClCompile Include="..\..\..\lib\decompress\zstd_decompress.c" />
+    <ClCompile Include="..\..\..\lib\decompress\zstd_ddict.c" />
     <ClCompile Include="..\..\..\lib\deprecated\zbuff_common.c" />
     <ClCompile Include="..\..\..\lib\deprecated\zbuff_compress.c" />
     <ClCompile Include="..\..\..\lib\deprecated\zbuff_decompress.c" />
@@ -82,6 +83,7 @@
     <ClInclude Include="..\..\..\lib\compress\zstd_opt.h" />
     <ClInclude Include="..\..\..\lib\compress\zstd_ldm.h" />
     <ClInclude Include="..\..\..\lib\compress\zstdmt_compress.h" />
+    <ClCompile Include="..\..\..\lib\decompress\zstd_ddict.h" />
   </ItemGroup>
   <PropertyGroup Label="Globals">
     <ProjectGuid>{8BFD8150-94D5-4BF9-8A50-7BD9929A0850}</ProjectGuid>

build/VS2010/zstd/zstd.vcxproj

@@ -39,6 +39,7 @@
     <ClCompile Include="..\..\..\lib\compress\zstd_ldm.c" />
     <ClCompile Include="..\..\..\lib\decompress\huf_decompress.c" />
     <ClCompile Include="..\..\..\lib\decompress\zstd_decompress.c" />
+    <ClCompile Include="..\..\..\lib\decompress\zstd_ddict.c" />
     <ClCompile Include="..\..\..\lib\dictBuilder\cover.c" />
     <ClCompile Include="..\..\..\lib\dictBuilder\fastcover.c" />
     <ClCompile Include="..\..\..\lib\dictBuilder\divsufsort.c" />
@@ -76,6 +77,7 @@
     <ClInclude Include="..\..\..\lib\compress\zstd_lazy.h" />
     <ClInclude Include="..\..\..\lib\compress\zstd_opt.h" />
     <ClInclude Include="..\..\..\lib\compress\zstd_ldm.h" />
+    <ClCompile Include="..\..\..\lib\decompress\zstd_ddict.h" />
     <ClInclude Include="..\..\..\lib\legacy\zstd_legacy.h" />
     <ClInclude Include="..\..\..\lib\legacy\zstd_v01.h" />
     <ClInclude Include="..\..\..\lib\legacy\zstd_v02.h" />

build/cmake/contrib/pzstd/CMakeLists.txt

@@ -17,7 +17,7 @@ SET(PROGRAMS_DIR ${ZSTD_SOURCE_DIR}/programs)
 SET(PZSTD_DIR ${ZSTD_SOURCE_DIR}/contrib/pzstd)
 INCLUDE_DIRECTORIES(${PROGRAMS_DIR} ${LIBRARY_DIR} ${LIBRARY_DIR}/common ${PZSTD_DIR})
 
-ADD_EXECUTABLE(pzstd ${PZSTD_DIR}/main.cpp ${PZSTD_DIR}/Options.cpp ${PZSTD_DIR}/Pzstd.cpp ${PZSTD_DIR}/SkippableFrame.cpp)
+ADD_EXECUTABLE(pzstd ${PROGRAMS_DIR}/util.c ${PZSTD_DIR}/main.cpp ${PZSTD_DIR}/Options.cpp ${PZSTD_DIR}/Pzstd.cpp ${PZSTD_DIR}/SkippableFrame.cpp)
 SET_PROPERTY(TARGET pzstd APPEND PROPERTY COMPILE_DEFINITIONS "NDEBUG")
 SET_PROPERTY(TARGET pzstd APPEND PROPERTY COMPILE_OPTIONS "-Wno-shadow")
 

build/cmake/lib/CMakeLists.txt

@@ -46,6 +46,7 @@ SET(Sources
         ${LIBRARY_DIR}/compress/zstd_ldm.c
         ${LIBRARY_DIR}/decompress/huf_decompress.c
         ${LIBRARY_DIR}/decompress/zstd_decompress.c
+        ${LIBRARY_DIR}/decompress/zstd_ddict.c
         ${LIBRARY_DIR}/dictBuilder/cover.c
         ${LIBRARY_DIR}/dictBuilder/fastcover.c
         ${LIBRARY_DIR}/dictBuilder/divsufsort.c
@@ -74,6 +75,8 @@ SET(Headers
         ${LIBRARY_DIR}/compress/zstd_opt.h
         ${LIBRARY_DIR}/compress/zstd_ldm.h
         ${LIBRARY_DIR}/compress/zstdmt_compress.h
+        ${LIBRARY_DIR}/decompress/zstd_ddict.h
+        ${LIBRARY_DIR}/decompress/zstd_decompress_internal.h
         ${LIBRARY_DIR}/dictBuilder/zdict.h
         ${LIBRARY_DIR}/dictBuilder/cover.h
         ${LIBRARY_DIR}/deprecated/zbuff.h)

build/cmake/tests/CMakeLists.txt

@@ -43,13 +43,13 @@ INCLUDE_DIRECTORIES(${TESTS_DIR} ${PROGRAMS_DIR} ${LIBRARY_DIR} ${LIBRARY_DIR}/c
 ADD_EXECUTABLE(datagen ${PROGRAMS_DIR}/datagen.c ${TESTS_DIR}/datagencli.c)
 TARGET_LINK_LIBRARIES(datagen libzstd_static)
 
-ADD_EXECUTABLE(fullbench ${PROGRAMS_DIR}/datagen.c ${PROGRAMS_DIR}/bench.c ${TESTS_DIR}/fullbench.c)
+ADD_EXECUTABLE(fullbench ${PROGRAMS_DIR}/datagen.c ${PROGRAMS_DIR}/util.c ${PROGRAMS_DIR}/bench.c ${TESTS_DIR}/fullbench.c)
 TARGET_LINK_LIBRARIES(fullbench libzstd_static)
 
-ADD_EXECUTABLE(fuzzer ${PROGRAMS_DIR}/datagen.c ${TESTS_DIR}/fuzzer.c)
+ADD_EXECUTABLE(fuzzer ${PROGRAMS_DIR}/datagen.c ${PROGRAMS_DIR}/util.c ${TESTS_DIR}/fuzzer.c)
 TARGET_LINK_LIBRARIES(fuzzer libzstd_static)
 
 IF (UNIX)
-    ADD_EXECUTABLE(paramgrill ${PROGRAMS_DIR}/bench.c ${PROGRAMS_DIR}/datagen.c ${TESTS_DIR}/paramgrill.c)
+    ADD_EXECUTABLE(paramgrill ${PROGRAMS_DIR}/bench.c ${PROGRAMS_DIR}/datagen.c ${PROGRAMS_DIR}/util.c ${TESTS_DIR}/paramgrill.c)
     TARGET_LINK_LIBRARIES(paramgrill libzstd_static m) #m is math library
 ENDIF (UNIX)

lib/common/zstd_common.c

@@ -30,8 +30,10 @@ const char* ZSTD_versionString(void) { return ZSTD_VERSION_STRING; }
 /*-****************************************
 *  ZSTD Error Management
 ******************************************/
+#undef ZSTD_isError   /* defined within zstd_internal.h */
 /*! ZSTD_isError() :
- *  tells if a return value is an error code */
+ *  tells if a return value is an error code
+ *  symbol is required for external callers */
 unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
 
 /*! ZSTD_getErrorName() :

lib/common/zstd_internal.h

@@ -41,6 +41,9 @@ extern "C" {
 
 /* ---- static assert (debug) --- */
 #define ZSTD_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)
+#define ZSTD_isError ERR_isError   /* for inlining */
+#define FSE_isError  ERR_isError
+#define HUF_isError  ERR_isError
 
 
 /*-*************************************

lib/decompress/zstd_ddict.c

@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2016-present, 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.
+ */
+
+/* zstd_ddict.c :
+ * concentrates all logic that needs to know the internals of ZSTD_DDict object */
+
+/*-*******************************************************
+*  Dependencies
+*********************************************************/
+#include <string.h>      /* memcpy, memmove, memset */
+#include "compiler.h"    /* prefetch */
+#include "cpu.h"         /* bmi2 */
+#include "mem.h"         /* low level memory routines */
+#define FSE_STATIC_LINKING_ONLY
+#include "fse.h"
+#define HUF_STATIC_LINKING_ONLY
+#include "huf.h"
+#include "zstd_decompress_internal.h"
+#include "zstd_ddict.h"
+
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
+#  include "zstd_legacy.h"
+#endif
+
+
+
+/*-*******************************************************
+*  Types
+*********************************************************/
+struct ZSTD_DDict_s {
+    void* dictBuffer;
+    const void* dictContent;
+    size_t dictSize;
+    ZSTD_entropyDTables_t entropy;
+    U32 dictID;
+    U32 entropyPresent;
+    ZSTD_customMem cMem;
+};  /* typedef'd to ZSTD_DDict within "zstd.h" */
+
+const void* ZSTD_DDict_dictContent(const ZSTD_DDict* ddict)
+{
+    assert(ddict != NULL);
+    return ddict->dictContent;
+}
+
+size_t ZSTD_DDict_dictSize(const ZSTD_DDict* ddict)
+{
+    assert(ddict != NULL);
+    return ddict->dictSize;
+}
+
+void ZSTD_copyDDictParameters(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
+{
+    DEBUGLOG(4, "ZSTD_copyDDictParameters");
+    assert(dctx != NULL);
+    assert(ddict != NULL);
+    dctx->dictID = ddict->dictID;
+    dctx->prefixStart = ddict->dictContent;
+    dctx->virtualStart = ddict->dictContent;
+    dctx->dictEnd = (const BYTE*)ddict->dictContent + ddict->dictSize;
+    dctx->previousDstEnd = dctx->dictEnd;
+    if (ddict->entropyPresent) {
+        dctx->litEntropy = 1;
+        dctx->fseEntropy = 1;
+        dctx->LLTptr = ddict->entropy.LLTable;
+        dctx->MLTptr = ddict->entropy.MLTable;
+        dctx->OFTptr = ddict->entropy.OFTable;
+        dctx->HUFptr = ddict->entropy.hufTable;
+        dctx->entropy.rep[0] = ddict->entropy.rep[0];
+        dctx->entropy.rep[1] = ddict->entropy.rep[1];
+        dctx->entropy.rep[2] = ddict->entropy.rep[2];
+    } else {
+        dctx->litEntropy = 0;
+        dctx->fseEntropy = 0;
+    }
+}
+
+
+static size_t
+ZSTD_loadEntropy_intoDDict(ZSTD_DDict* ddict,
+                           ZSTD_dictContentType_e dictContentType)
+{
+    ddict->dictID = 0;
+    ddict->entropyPresent = 0;
+    if (dictContentType == ZSTD_dct_rawContent) return 0;
+
+    if (ddict->dictSize < 8) {
+        if (dictContentType == ZSTD_dct_fullDict)
+            return ERROR(dictionary_corrupted);   /* only accept specified dictionaries */
+        return 0;   /* pure content mode */
+    }
+    {   U32 const magic = MEM_readLE32(ddict->dictContent);
+        if (magic != ZSTD_MAGIC_DICTIONARY) {
+            if (dictContentType == ZSTD_dct_fullDict)
+                return ERROR(dictionary_corrupted);   /* only accept specified dictionaries */
+            return 0;   /* pure content mode */
+        }
+    }
+    ddict->dictID = MEM_readLE32((const char*)ddict->dictContent + ZSTD_FRAMEIDSIZE);
+
+    /* load entropy tables */
+    CHECK_E( ZSTD_loadDEntropy(&ddict->entropy,
+                                ddict->dictContent, ddict->dictSize),
+             dictionary_corrupted );
+    ddict->entropyPresent = 1;
+    return 0;
+}
+
+
+static size_t ZSTD_initDDict_internal(ZSTD_DDict* ddict,
+                                      const void* dict, size_t dictSize,
+                                      ZSTD_dictLoadMethod_e dictLoadMethod,
+                                      ZSTD_dictContentType_e dictContentType)
+{
+    if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dict) || (!dictSize)) {
+        ddict->dictBuffer = NULL;
+        ddict->dictContent = dict;
+        if (!dict) dictSize = 0;
+    } else {
+        void* const internalBuffer = ZSTD_malloc(dictSize, ddict->cMem);
+        ddict->dictBuffer = internalBuffer;
+        ddict->dictContent = internalBuffer;
+        if (!internalBuffer) return ERROR(memory_allocation);
+        memcpy(internalBuffer, dict, dictSize);
+    }
+    ddict->dictSize = dictSize;
+    ddict->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001);  /* cover both little and big endian */
+
+    /* parse dictionary content */
+    CHECK_F( ZSTD_loadEntropy_intoDDict(ddict, dictContentType) );
+
+    return 0;
+}
+
+ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize,
+                                      ZSTD_dictLoadMethod_e dictLoadMethod,
+                                      ZSTD_dictContentType_e dictContentType,
+                                      ZSTD_customMem customMem)
+{
+    if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
+
+    {   ZSTD_DDict* const ddict = (ZSTD_DDict*) ZSTD_malloc(sizeof(ZSTD_DDict), customMem);
+        if (ddict == NULL) return NULL;
+        ddict->cMem = customMem;
+        {   size_t const initResult = ZSTD_initDDict_internal(ddict,
+                                            dict, dictSize,
+                                            dictLoadMethod, dictContentType);
+            if (ZSTD_isError(initResult)) {
+                ZSTD_freeDDict(ddict);
+                return NULL;
+        }   }
+        return ddict;
+    }
+}
+
+/*! ZSTD_createDDict() :
+*   Create a digested dictionary, to start decompression without startup delay.
+*   `dict` content is copied inside DDict.
+*   Consequently, `dict` can be released after `ZSTD_DDict` creation */
+ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize)
+{
+    ZSTD_customMem const allocator = { NULL, NULL, NULL };
+    return ZSTD_createDDict_advanced(dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto, allocator);
+}
+
+/*! ZSTD_createDDict_byReference() :
+ *  Create a digested dictionary, to start decompression without startup delay.
+ *  Dictionary content is simply referenced, it will be accessed during decompression.
+ *  Warning : dictBuffer must outlive DDict (DDict must be freed before dictBuffer) */
+ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize)
+{
+    ZSTD_customMem const allocator = { NULL, NULL, NULL };
+    return ZSTD_createDDict_advanced(dictBuffer, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto, allocator);
+}
+
+
+const ZSTD_DDict* ZSTD_initStaticDDict(
+                                void* sBuffer, size_t sBufferSize,
+                                const void* dict, size_t dictSize,
+                                ZSTD_dictLoadMethod_e dictLoadMethod,
+                                ZSTD_dictContentType_e dictContentType)
+{
+    size_t const neededSpace = sizeof(ZSTD_DDict)
+                             + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
+    ZSTD_DDict* const ddict = (ZSTD_DDict*)sBuffer;
+    assert(sBuffer != NULL);
+    assert(dict != NULL);
+    if ((size_t)sBuffer & 7) return NULL;   /* 8-aligned */
+    if (sBufferSize < neededSpace) return NULL;
+    if (dictLoadMethod == ZSTD_dlm_byCopy) {
+        memcpy(ddict+1, dict, dictSize);  /* local copy */
+        dict = ddict+1;
+    }
+    if (ZSTD_isError( ZSTD_initDDict_internal(ddict,
+                                              dict, dictSize,
+                                              ZSTD_dlm_byRef, dictContentType) ))
+        return NULL;
+    return ddict;
+}
+
+
+size_t ZSTD_freeDDict(ZSTD_DDict* ddict)
+{
+    if (ddict==NULL) return 0;   /* support free on NULL */
+    {   ZSTD_customMem const cMem = ddict->cMem;
+        ZSTD_free(ddict->dictBuffer, cMem);
+        ZSTD_free(ddict, cMem);
+        return 0;
+    }
+}
+
+/*! ZSTD_estimateDDictSize() :
+ *  Estimate amount of memory that will be needed to create a dictionary for decompression.
+ *  Note : dictionary created by reference using ZSTD_dlm_byRef are smaller */
+size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod)
+{
+    return sizeof(ZSTD_DDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
+}
+
+size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict)
+{
+    if (ddict==NULL) return 0;   /* support sizeof on NULL */
+    return sizeof(*ddict) + (ddict->dictBuffer ? ddict->dictSize : 0) ;
+}
+
+/*! ZSTD_getDictID_fromDDict() :
+ *  Provides the dictID of the dictionary loaded into `ddict`.
+ *  If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
+ *  Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
+unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict)
+{
+    if (ddict==NULL) return 0;
+    return ZSTD_getDictID_fromDict(ddict->dictContent, ddict->dictSize);
+}

lib/decompress/zstd_ddict.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2016-present, 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.
+ */
+
+ /*-*******************************************************
+ *  Dependencies
+ *********************************************************/
+#include <stddef.h>   /* size_t */
+#include "zstd.h"     /* ZSTD_DDict */
+
+
+/*-*******************************************************
+*  Interface
+*********************************************************/
+
+const void* ZSTD_DDict_dictContent(const ZSTD_DDict* ddict);
+size_t ZSTD_DDict_dictSize(const ZSTD_DDict* ddict);
+
+void ZSTD_copyDDictParameters(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);

lib/decompress/zstd_decompress.c

@@ -64,22 +64,13 @@
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #include "zstd_internal.h"
+#include "zstd_decompress_internal.h"   /* ZSTD_DCtx */
+#include "zstd_ddict.h"  /* ZSTD_DDictDictContent */
 
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
 #  include "zstd_legacy.h"
 #endif
 
-static const void* ZSTD_DDictDictContent(const ZSTD_DDict* ddict);
-static size_t ZSTD_DDictDictSize(const ZSTD_DDict* ddict);
-
-
-/*-*************************************
-*  Errors
-***************************************/
-#define ZSTD_isError ERR_isError   /* for inlining */
-#define FSE_isError  ERR_isError
-#define HUF_isError  ERR_isError
-
 
 /*_*******************************************************
 *  Memory operations
@@ -90,94 +81,11 @@ static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
 /*-*************************************************************
 *   Context management
 ***************************************************************/
-typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader,
-               ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock,
-               ZSTDds_decompressLastBlock, ZSTDds_checkChecksum,
-               ZSTDds_decodeSkippableHeader, ZSTDds_skipFrame } ZSTD_dStage;
-
-typedef enum { zdss_init=0, zdss_loadHeader,
-               zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage;
-
-
 typedef struct {
     U32 fastMode;
     U32 tableLog;
 } ZSTD_seqSymbol_header;
 
-typedef struct {
-    U16  nextState;
-    BYTE nbAdditionalBits;
-    BYTE nbBits;
-    U32  baseValue;
-} ZSTD_seqSymbol;
-
-#define SEQSYMBOL_TABLE_SIZE(log)   (1 + (1 << (log)))
-
-typedef struct {
-    ZSTD_seqSymbol LLTable[SEQSYMBOL_TABLE_SIZE(LLFSELog)];    /* Note : Space reserved for FSE Tables */
-    ZSTD_seqSymbol OFTable[SEQSYMBOL_TABLE_SIZE(OffFSELog)];   /* is also used as temporary workspace while building hufTable during DDict creation */
-    ZSTD_seqSymbol MLTable[SEQSYMBOL_TABLE_SIZE(MLFSELog)];    /* and therefore must be at least HUF_DECOMPRESS_WORKSPACE_SIZE large */
-    HUF_DTable hufTable[HUF_DTABLE_SIZE(HufLog)];  /* can accommodate HUF_decompress4X */
-    U32 rep[ZSTD_REP_NUM];
-} ZSTD_entropyDTables_t;
-
-struct ZSTD_DCtx_s
-{
-    const ZSTD_seqSymbol* LLTptr;
-    const ZSTD_seqSymbol* MLTptr;
-    const ZSTD_seqSymbol* OFTptr;
-    const HUF_DTable* HUFptr;
-    ZSTD_entropyDTables_t entropy;
-    U32 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];   /* space needed when building huffman tables */
-    const void* previousDstEnd;   /* detect continuity */
-    const void* prefixStart;      /* start of current segment */
-    const void* virtualStart;     /* virtual start of previous segment if it was just before current one */
-    const void* dictEnd;          /* end of previous segment */
-    size_t expected;
-    ZSTD_frameHeader fParams;
-    U64 decodedSize;
-    blockType_e bType;            /* used in ZSTD_decompressContinue(), store blockType between block header decoding and block decompression stages */
-    ZSTD_dStage stage;
-    U32 litEntropy;
-    U32 fseEntropy;
-    XXH64_state_t xxhState;
-    size_t headerSize;
-    ZSTD_format_e format;
-    const BYTE* litPtr;
-    ZSTD_customMem customMem;
-    size_t litSize;
-    size_t rleSize;
-    size_t staticSize;
-    int bmi2;                     /* == 1 if the CPU supports BMI2 and 0 otherwise. CPU support is determined dynamically once per context lifetime. */
-
-    /* dictionary */
-    ZSTD_DDict* ddictLocal;
-    const ZSTD_DDict* ddict;     /* set by ZSTD_initDStream_usingDDict(), or ZSTD_DCtx_refDDict() */
-    U32 dictID;
-    int ddictIsCold;             /* if == 1 : dictionary is "new" for working context, and presumed "cold" (not in cpu cache) */
-
-    /* streaming */
-    ZSTD_dStreamStage streamStage;
-    char*  inBuff;
-    size_t inBuffSize;
-    size_t inPos;
-    size_t maxWindowSize;
-    char*  outBuff;
-    size_t outBuffSize;
-    size_t outStart;
-    size_t outEnd;
-    size_t lhSize;
-    void* legacyContext;
-    U32 previousLegacyVersion;
-    U32 legacyVersion;
-    U32 hostageByte;
-    int noForwardProgress;
-
-    /* workspace */
-    BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH];
-    BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
-};  /* typedef'd to ZSTD_DCtx within "zstd.h" */
-
 size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx)
 {
     if (dctx==NULL) return 0;   /* support sizeof NULL */
@@ -1946,8 +1854,8 @@ static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx,
     assert(dict==NULL || ddict==NULL);  /* either dict or ddict set, not both */
 
     if (ddict) {
-        dict = ZSTD_DDictDictContent(ddict);
+        dict = ZSTD_DDict_dictContent(ddict);
-        dictSize = ZSTD_DDictDictSize(ddict);
+        dictSize = ZSTD_DDict_dictSize(ddict);
     }
 
     while (srcSize >= ZSTD_frameHeaderSize_prefix) {
@@ -2238,11 +2146,12 @@ static size_t ZSTD_refDictContent(ZSTD_DCtx* dctx, const void* dict, size_t dict
     return 0;
 }
 
-/*! ZSTD_loadEntropy() :
+/*! ZSTD_loadDEntropy() :
  *  dict : must point at beginning of a valid zstd dictionary.
  * @return : size of entropy tables read */
-static size_t ZSTD_loadEntropy(ZSTD_entropyDTables_t* entropy,
+size_t
-                         const void* const dict, size_t const dictSize)
+ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy,
+                  const void* const dict, size_t const dictSize)
 {
     const BYTE* dictPtr = (const BYTE*)dict;
     const BYTE* const dictEnd = dictPtr + dictSize;
@@ -2324,7 +2233,7 @@ static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict
     dctx->dictID = MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
 
     /* load entropy tables */
-    {   size_t const eSize = ZSTD_loadEntropy(&dctx->entropy, dict, dictSize);
+    {   size_t const eSize = ZSTD_loadDEntropy(&dctx->entropy, dict, dictSize);
         if (ZSTD_isError(eSize)) return ERROR(dictionary_corrupted);
         dict = (const char*)dict + eSize;
         dictSize -= eSize;
@@ -2368,209 +2277,25 @@ size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t
 
 /* ======   ZSTD_DDict   ====== */
 
-struct ZSTD_DDict_s {
-    void* dictBuffer;
-    const void* dictContent;
-    size_t dictSize;
-    ZSTD_entropyDTables_t entropy;
-    U32 dictID;
-    U32 entropyPresent;
-    ZSTD_customMem cMem;
-};  /* typedef'd to ZSTD_DDict within "zstd.h" */
-
-static const void* ZSTD_DDictDictContent(const ZSTD_DDict* ddict)
-{
-    assert(ddict != NULL);
-    return ddict->dictContent;
-}
-
-static size_t ZSTD_DDictDictSize(const ZSTD_DDict* ddict)
-{
-    assert(ddict != NULL);
-    return ddict->dictSize;
-}
-
 size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
 {
     DEBUGLOG(4, "ZSTD_decompressBegin_usingDDict");
     assert(dctx != NULL);
     if (ddict) {
-        dctx->ddictIsCold = (dctx->dictEnd != (const char*)ddict->dictContent + ddict->dictSize);
+        const char* const dictStart = (const char*)ZSTD_DDict_dictContent(ddict);
+        size_t const dictSize = ZSTD_DDict_dictSize(ddict);
+        const void* const dictEnd = dictStart + dictSize;
+        dctx->ddictIsCold = (dctx->dictEnd != dictEnd);
         DEBUGLOG(4, "DDict is %s",
                     dctx->ddictIsCold ? "~cold~" : "hot!");
     }
     CHECK_F( ZSTD_decompressBegin(dctx) );
     if (ddict) {   /* NULL ddict is equivalent to no dictionary */
-        dctx->dictID = ddict->dictID;
+        ZSTD_copyDDictParameters(dctx, ddict);
-        dctx->prefixStart = ddict->dictContent;
-        dctx->virtualStart = ddict->dictContent;
-        dctx->dictEnd = (const BYTE*)ddict->dictContent + ddict->dictSize;
-        dctx->previousDstEnd = dctx->dictEnd;
-        if (ddict->entropyPresent) {
-            dctx->litEntropy = 1;
-            dctx->fseEntropy = 1;
-            dctx->LLTptr = ddict->entropy.LLTable;
-            dctx->MLTptr = ddict->entropy.MLTable;
-            dctx->OFTptr = ddict->entropy.OFTable;
-            dctx->HUFptr = ddict->entropy.hufTable;
-            dctx->entropy.rep[0] = ddict->entropy.rep[0];
-            dctx->entropy.rep[1] = ddict->entropy.rep[1];
-            dctx->entropy.rep[2] = ddict->entropy.rep[2];
-        } else {
-            dctx->litEntropy = 0;
-            dctx->fseEntropy = 0;
-        }
     }
     return 0;
 }
 
-static size_t
-ZSTD_loadEntropy_inDDict(ZSTD_DDict* ddict,
-                         ZSTD_dictContentType_e dictContentType)
-{
-    ddict->dictID = 0;
-    ddict->entropyPresent = 0;
-    if (dictContentType == ZSTD_dct_rawContent) return 0;
-
-    if (ddict->dictSize < 8) {
-        if (dictContentType == ZSTD_dct_fullDict)
-            return ERROR(dictionary_corrupted);   /* only accept specified dictionaries */
-        return 0;   /* pure content mode */
-    }
-    {   U32 const magic = MEM_readLE32(ddict->dictContent);
-        if (magic != ZSTD_MAGIC_DICTIONARY) {
-            if (dictContentType == ZSTD_dct_fullDict)
-                return ERROR(dictionary_corrupted);   /* only accept specified dictionaries */
-            return 0;   /* pure content mode */
-        }
-    }
-    ddict->dictID = MEM_readLE32((const char*)ddict->dictContent + ZSTD_FRAMEIDSIZE);
-
-    /* load entropy tables */
-    CHECK_E( ZSTD_loadEntropy(&ddict->entropy,
-                              ddict->dictContent, ddict->dictSize),
-             dictionary_corrupted );
-    ddict->entropyPresent = 1;
-    return 0;
-}
-
-
-static size_t ZSTD_initDDict_internal(ZSTD_DDict* ddict,
-                                      const void* dict, size_t dictSize,
-                                      ZSTD_dictLoadMethod_e dictLoadMethod,
-                                      ZSTD_dictContentType_e dictContentType)
-{
-    if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dict) || (!dictSize)) {
-        ddict->dictBuffer = NULL;
-        ddict->dictContent = dict;
-        if (!dict) dictSize = 0;
-    } else {
-        void* const internalBuffer = ZSTD_malloc(dictSize, ddict->cMem);
-        ddict->dictBuffer = internalBuffer;
-        ddict->dictContent = internalBuffer;
-        if (!internalBuffer) return ERROR(memory_allocation);
-        memcpy(internalBuffer, dict, dictSize);
-    }
-    ddict->dictSize = dictSize;
-    ddict->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001);  /* cover both little and big endian */
-
-    /* parse dictionary content */
-    CHECK_F( ZSTD_loadEntropy_inDDict(ddict, dictContentType) );
-
-    return 0;
-}
-
-ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize,
-                                      ZSTD_dictLoadMethod_e dictLoadMethod,
-                                      ZSTD_dictContentType_e dictContentType,
-                                      ZSTD_customMem customMem)
-{
-    if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
-
-    {   ZSTD_DDict* const ddict = (ZSTD_DDict*) ZSTD_malloc(sizeof(ZSTD_DDict), customMem);
-        if (ddict == NULL) return NULL;
-        ddict->cMem = customMem;
-        {   size_t const initResult = ZSTD_initDDict_internal(ddict,
-                                            dict, dictSize,
-                                            dictLoadMethod, dictContentType);
-            if (ZSTD_isError(initResult)) {
-                ZSTD_freeDDict(ddict);
-                return NULL;
-        }   }
-        return ddict;
-    }
-}
-
-/*! ZSTD_createDDict() :
-*   Create a digested dictionary, to start decompression without startup delay.
-*   `dict` content is copied inside DDict.
-*   Consequently, `dict` can be released after `ZSTD_DDict` creation */
-ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize)
-{
-    ZSTD_customMem const allocator = { NULL, NULL, NULL };
-    return ZSTD_createDDict_advanced(dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto, allocator);
-}
-
-/*! ZSTD_createDDict_byReference() :
- *  Create a digested dictionary, to start decompression without startup delay.
- *  Dictionary content is simply referenced, it will be accessed during decompression.
- *  Warning : dictBuffer must outlive DDict (DDict must be freed before dictBuffer) */
-ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize)
-{
-    ZSTD_customMem const allocator = { NULL, NULL, NULL };
-    return ZSTD_createDDict_advanced(dictBuffer, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto, allocator);
-}
-
-
-const ZSTD_DDict* ZSTD_initStaticDDict(
-                                void* sBuffer, size_t sBufferSize,
-                                const void* dict, size_t dictSize,
-                                ZSTD_dictLoadMethod_e dictLoadMethod,
-                                ZSTD_dictContentType_e dictContentType)
-{
-    size_t const neededSpace = sizeof(ZSTD_DDict)
-                             + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
-    ZSTD_DDict* const ddict = (ZSTD_DDict*)sBuffer;
-    assert(sBuffer != NULL);
-    assert(dict != NULL);
-    if ((size_t)sBuffer & 7) return NULL;   /* 8-aligned */
-    if (sBufferSize < neededSpace) return NULL;
-    if (dictLoadMethod == ZSTD_dlm_byCopy) {
-        memcpy(ddict+1, dict, dictSize);  /* local copy */
-        dict = ddict+1;
-    }
-    if (ZSTD_isError( ZSTD_initDDict_internal(ddict,
-                                              dict, dictSize,
-                                              ZSTD_dlm_byRef, dictContentType) ))
-        return NULL;
-    return ddict;
-}
-
-
-size_t ZSTD_freeDDict(ZSTD_DDict* ddict)
-{
-    if (ddict==NULL) return 0;   /* support free on NULL */
-    {   ZSTD_customMem const cMem = ddict->cMem;
-        ZSTD_free(ddict->dictBuffer, cMem);
-        ZSTD_free(ddict, cMem);
-        return 0;
-    }
-}
-
-/*! ZSTD_estimateDDictSize() :
- *  Estimate amount of memory that will be needed to create a dictionary for decompression.
- *  Note : dictionary created by reference using ZSTD_dlm_byRef are smaller */
-size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod)
-{
-    return sizeof(ZSTD_DDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
-}
-
-size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict)
-{
-    if (ddict==NULL) return 0;   /* support sizeof on NULL */
-    return sizeof(*ddict) + (ddict->dictBuffer ? ddict->dictSize : 0) ;
-}
-
 /*! ZSTD_getDictID_fromDict() :
  *  Provides the dictID stored within dictionary.
  *  if @return == 0, the dictionary is not conformant with Zstandard specification.
@@ -2582,16 +2307,6 @@ unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize)
     return MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
 }
 
-/*! ZSTD_getDictID_fromDDict() :
- *  Provides the dictID of the dictionary loaded into `ddict`.
- *  If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
- *  Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
-unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict)
-{
-    if (ddict==NULL) return 0;
-    return ZSTD_getDictID_fromDict(ddict->dictContent, ddict->dictSize);
-}
-
 /*! ZSTD_getDictID_fromFrame() :
  *  Provides the dictID required to decompresse frame stored within `src`.
  *  If @return == 0, the dictID could not be decoded.
@@ -2872,8 +2587,8 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
                     U32 const legacyVersion = ZSTD_isLegacy(istart, iend-istart);
                     if (legacyVersion) {
-                        const void* const dict = zds->ddict ? zds->ddict->dictContent : NULL;
+                        const void* const dict = zds->ddict ? ZSTD_DDict_dictContent(zds->ddict) : NULL;
-                        size_t const dictSize = zds->ddict ? zds->ddict->dictSize : 0;
+                        size_t const dictSize = zds->ddict ? ZSTD_DDict_dictSize(zds->ddict) : 0;
                         DEBUGLOG(5, "ZSTD_decompressStream: detected legacy version v0.%u", legacyVersion);
                         /* legacy support is incompatible with static dctx */
                         if (zds->staticSize) return ERROR(memory_allocation);

lib/decompress/zstd_decompress_internal.h

@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2016-present, 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.
+ */
+
+
+/* zstd_decompress_internal:
+ * objects and definitions shared within lib/decompress modules */
+
+
+/*-*******************************************************
+ *  Dependencies
+ *********************************************************/
+#include "mem.h"             /* BYTE, U16, U32 */
+#include "zstd_internal.h"   /* ZSTD_seqSymbol */
+
+
+/*-*******************************************************
+ *  Decompression types
+ *********************************************************/
+ typedef struct {
+     U16  nextState;
+     BYTE nbAdditionalBits;
+     BYTE nbBits;
+     U32  baseValue;
+ } ZSTD_seqSymbol;
+
+ #define SEQSYMBOL_TABLE_SIZE(log)   (1 + (1 << (log)))
+
+typedef struct {
+    ZSTD_seqSymbol LLTable[SEQSYMBOL_TABLE_SIZE(LLFSELog)];    /* Note : Space reserved for FSE Tables */
+    ZSTD_seqSymbol OFTable[SEQSYMBOL_TABLE_SIZE(OffFSELog)];   /* is also used as temporary workspace while building hufTable during DDict creation */
+    ZSTD_seqSymbol MLTable[SEQSYMBOL_TABLE_SIZE(MLFSELog)];    /* and therefore must be at least HUF_DECOMPRESS_WORKSPACE_SIZE large */
+    HUF_DTable hufTable[HUF_DTABLE_SIZE(HufLog)];  /* can accommodate HUF_decompress4X */
+    U32 rep[ZSTD_REP_NUM];
+} ZSTD_entropyDTables_t;
+
+typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader,
+               ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock,
+               ZSTDds_decompressLastBlock, ZSTDds_checkChecksum,
+               ZSTDds_decodeSkippableHeader, ZSTDds_skipFrame } ZSTD_dStage;
+
+typedef enum { zdss_init=0, zdss_loadHeader,
+               zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage;
+
+struct ZSTD_DCtx_s
+{
+    const ZSTD_seqSymbol* LLTptr;
+    const ZSTD_seqSymbol* MLTptr;
+    const ZSTD_seqSymbol* OFTptr;
+    const HUF_DTable* HUFptr;
+    ZSTD_entropyDTables_t entropy;
+    U32 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];   /* space needed when building huffman tables */
+    const void* previousDstEnd;   /* detect continuity */
+    const void* prefixStart;      /* start of current segment */
+    const void* virtualStart;     /* virtual start of previous segment if it was just before current one */
+    const void* dictEnd;          /* end of previous segment */
+    size_t expected;
+    ZSTD_frameHeader fParams;
+    U64 decodedSize;
+    blockType_e bType;            /* used in ZSTD_decompressContinue(), store blockType between block header decoding and block decompression stages */
+    ZSTD_dStage stage;
+    U32 litEntropy;
+    U32 fseEntropy;
+    XXH64_state_t xxhState;
+    size_t headerSize;
+    ZSTD_format_e format;
+    const BYTE* litPtr;
+    ZSTD_customMem customMem;
+    size_t litSize;
+    size_t rleSize;
+    size_t staticSize;
+    int bmi2;                     /* == 1 if the CPU supports BMI2 and 0 otherwise. CPU support is determined dynamically once per context lifetime. */
+
+    /* dictionary */
+    ZSTD_DDict* ddictLocal;
+    const ZSTD_DDict* ddict;     /* set by ZSTD_initDStream_usingDDict(), or ZSTD_DCtx_refDDict() */
+    U32 dictID;
+    int ddictIsCold;             /* if == 1 : dictionary is "new" for working context, and presumed "cold" (not in cpu cache) */
+
+    /* streaming */
+    ZSTD_dStreamStage streamStage;
+    char*  inBuff;
+    size_t inBuffSize;
+    size_t inPos;
+    size_t maxWindowSize;
+    char*  outBuff;
+    size_t outBuffSize;
+    size_t outStart;
+    size_t outEnd;
+    size_t lhSize;
+    void* legacyContext;
+    U32 previousLegacyVersion;
+    U32 legacyVersion;
+    U32 hostageByte;
+    int noForwardProgress;
+
+    /* workspace */
+    BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH];
+    BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
+};  /* typedef'd to ZSTD_DCtx within "zstd.h" */
+
+
+/*-*******************************************************
+ *  Shared internal functions
+ *********************************************************/
+
+ /*! ZSTD_loadDEntropy() :
+  *  dict : must point at beginning of a valid zstd dictionary.
+  * @return : size of entropy tables read */
+ size_t ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy,
+                    const void* const dict, size_t const dictSize);