optimize $hdiffz -m required memory size when oldData different newData; support lzma2 decompress by multi-thread

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 full changelog at: https://github.com/sisong/HDiffPatch/commits   
 
+## [v5.1.0](https://github.com/sisong/HDiffPatch/tree/v5.1.0) - 2026-07-14
+### Added
+* optimize `$hdiffz -m` required memory size when oldData different newData;
+   default opened by diff with -block or -cache opened;
+* add lzma2mtDecompressPlugin, support lzma2 decompress by multi-thread;
+
 ## [v5.0.0](https://github.com/sisong/HDiffPatch/tree/v5.0.0) - 2026-06-25
 ### Added
 * add new format Window Diff(`HDIFFW26`) for optimize patch speed, by `$hdiffz -WD[-stepSize]`;

Makefile

@@ -119,7 +119,8 @@ ifeq ($(LZMA),1)
   ifeq ($(MT),0)  
   else  
     HPATCH_OBJ+=$(LZMA_PATH)/MtDec.o \
-				$(LZMA_PATH)/Threads.o
+				$(LZMA_PATH)/Threads.o \
+				$(LZMA_PATH)/Lzma2DecMt.o
   endif
   HDIFF_OBJ  += $(LZMA_PATH)/LzFind.o \
   				$(LZMA_PATH)/LzFindOpt.o \

README.md

@@ -1,5 +1,5 @@
 # [HDiffPatch]
-[![release](https://img.shields.io/badge/release-v5.0.1-blue.svg)](https://github.com/sisong/HDiffPatch/releases) 
+[![release](https://img.shields.io/badge/release-v5.1.0-blue.svg)](https://github.com/sisong/HDiffPatch/releases) 
 [![license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/sisong/HDiffPatch/blob/master/LICENSE) 
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-blue.svg)](https://github.com/sisong/HDiffPatch/pulls)
 [![+issue Welcome](https://img.shields.io/github/issues-raw/sisong/HDiffPatch?color=green&label=%2Bissue%20welcome)](https://github.com/sisong/HDiffPatch/issues)   

README_cn.md

@@ -1,5 +1,5 @@
 # [HDiffPatch]
-[![release](https://img.shields.io/badge/release-v5.0.1-blue.svg)](https://github.com/sisong/HDiffPatch/releases) 
+[![release](https://img.shields.io/badge/release-v5.1.0-blue.svg)](https://github.com/sisong/HDiffPatch/releases) 
 [![license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/sisong/HDiffPatch/blob/master/LICENSE) 
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-blue.svg)](https://github.com/sisong/HDiffPatch/pulls)
 [![+issue Welcome](https://img.shields.io/github/issues-raw/sisong/HDiffPatch?color=green&label=%2Bissue%20welcome)](https://github.com/sisong/HDiffPatch/issues)   

bsdiff_wrapper/bsdiff_wrapper.cpp

@@ -57,7 +57,7 @@ namespace hdiff_private{
         :curPos(0),curi(0),bufi(0),covers(_covers){
             streamImport=this;
             read=_read;
-            streamSize=(covers.size()-1)*(hpatch_StreamPos_t)(3*8);
+            streamSize=(covers.size()>1)?((hpatch_StreamPos_t)covers.size()-1)*(3*8):0;
             buf.reserve(hdiff_kFileIOBufBestSize);
         }
     private:

builds/android_ndk_jni_mk/hpatch.c

@@ -37,15 +37,16 @@ void bz_internal_error(int errcode){
 
 int hpatchz(const char *oldFileName,const char *diffFileName,const char *outNewFileName,
             int64_t cacheMemory,size_t threadNum,hpatch_BOOL isChecksumNewData){
+    size_t dec_threadNum=1;//now only support lzma2 decompressor,& used large memory!
     TPatchChecksumSet checksumSet={0,hpatch_FALSE,isChecksumNewData,isChecksumNewData,hpatch_FALSE};
 #if (_IS_NEED_DIR_DIFF_PATCH)
     const hpatch_BOOL isDirDiff=getIsDirDiffFile(diffFileName);
     if (isDirDiff){
         return hpatch_dir(oldFileName,diffFileName,outNewFileName,
                           hpatch_FALSE,limitCacheMemory(cacheMemory),kMaxOpenFileNumber_default_patch,
-                          &checksumSet,&defaultPatchDirlistener,0,0,threadNum);
+                          &checksumSet,&defaultPatchDirlistener,0,0,threadNum,dec_threadNum);
     } else
 #endif
         return hpatch(oldFileName,diffFileName,outNewFileName,
-                      hpatch_FALSE,limitCacheMemory(cacheMemory),0,0,&checksumSet,threadNum);
+                      hpatch_FALSE,limitCacheMemory(cacheMemory),0,0,&checksumSet,threadNum,dec_threadNum);
 }

compress_plugin_demo.h

@@ -812,11 +812,15 @@ int _default_setParallelThreadNumber(hdiff_TCompress* compressPlugin,int threadN
 #ifdef  _CompressPlugin_lzma2
 #if (_IsNeedIncludeDefaultCompressHead)
 #   include "MtCoder.h" // "lzma/C/MtCoder.h"   for MTCODER__THREADS_MAX
+#endif
+#ifndef LZMA2DECMT_OUT_BLOCK_MAX_DEFAULT
+#   define LZMA2DECMT_OUT_BLOCK_MAX_DEFAULT  (1<<28) // 256M
 #endif
     struct TCompressPlugin_lzma2{
         hdiff_TCompress base;
         int             compress_level; //0..9
         UInt32          dict_size;      //patch decompress need 4?*lzma_dictSize memory
+        UInt32          block_size;     //1M--256M; 0=AUTO, LZMA2 chunk size, affects decompress parallelism
         int             thread_num;     //1..(64?)
     };
     static int _lzma2_setThreadNumber(hdiff_TCompress* compressPlugin,int threadNum){
@@ -848,7 +852,8 @@ int _default_setParallelThreadNumber(hdiff_TCompress* compressPlugin,int threadN
         props.lzmaProps.level=plugin->compress_level;
         props.lzmaProps.dictSize=dictSize;
         props.lzmaProps.reduceSize=in_data->streamSize;
-        props.blockSize=LZMA2_ENC_PROPS_BLOCK_SIZE_AUTO;
+        props.blockSize=(plugin->block_size==0)?LZMA2_ENC_PROPS_BLOCK_SIZE_AUTO:
+                          (plugin->block_size<LZMA2DECMT_OUT_BLOCK_MAX_DEFAULT)?plugin->block_size:LZMA2DECMT_OUT_BLOCK_MAX_DEFAULT;
         props.numTotalThreads=plugin->thread_num;
         Lzma2EncProps_Normalize(&props);
         if (SZ_OK!=Lzma2Enc_SetProps(s,&props)) _compress_error_return("Lzma2Enc_SetProps()");
@@ -885,7 +890,7 @@ int _default_setParallelThreadNumber(hdiff_TCompress* compressPlugin,int threadN
     _def_fun_compressType(_lzma2_compressType,"lzma2");
     static const TCompressPlugin_lzma2 lzma2CompressPlugin={
         {_lzma2_compressType,_default_maxCompressedSize,_lzma2_setThreadNumber,_lzma2_compress},
-        7,(1<<23),kDefaultCompressThreadNumber};
+        7,(1<<23),0,kDefaultCompressThreadNumber};
 #endif//_CompressPlugin_lzma2
 
 #ifdef  _CompressPlugin_7zXZ