support custom block sizes

3 files changed, 33 insertions, 10 deletions

diff --git a/programs/lz4cli.c b/programs/lz4cli.c
index 46a95cd6..759f3363 100644
--- a/programs/lz4cli.c
+++ b/programs/lz4cli.c
@@ -134,7 +134,8 @@ static int usage_advanced(const char* exeName)
     DISPLAY( " -r     : operate recursively on directories (sets also -m) \n");
 #endif
     DISPLAY( " -l     : compress using Legacy format (Linux kernel compression)\n");
-    DISPLAY( " -B#    : Block size [4-7] (default : 7) \n");
+    DISPLAY( " -B#    : cut file into independent blocks of size # bytes [32+] \n");
+    DISPLAY( "                     or predefined block size [4-7] (default: 7) \n");
     DISPLAY( " -BD    : Block dependency (improve compression ratio) \n");
     DISPLAY( " -BX    : enable block checksum (default:disabled) \n");
     DISPLAY( "--no-frame-crc : disable stream checksum (default:enabled) \n");
@@ -146,8 +147,6 @@ static int usage_advanced(const char* exeName)
     DISPLAY( " -b#    : benchmark file(s), using # compression level (default : 1) \n");
     DISPLAY( " -e#    : test all compression levels from -bX to # (default : 1)\n");
     DISPLAY( " -i#    : minimum evaluation time in seconds (default : 3s) \n");
-    DISPLAY( " -B#    : cut file into independent blocks of size # bytes [32+] \n");
-    DISPLAY( "                     or predefined block size [4-7] (default: 7) \n");
     if (g_lz4c_legacy_commands) {
         DISPLAY( "Legacy arguments : \n");
         DISPLAY( " -c0    : fast compression \n");
@@ -497,11 +496,12 @@ int main(int argc, const char** argv)
                                     DISPLAYLEVEL(2, "using blocks of size %u KB \n", (U32)(blockSize>>10));
                                 } else {
                                     if (B < 32) badusage(exeName);
-                                    BMK_setBlockSize(B);
-                                    if (B >= 1024) {
-                                        DISPLAYLEVEL(2, "bench: using blocks of size %u KB \n", (U32)(B>>10));
+                                    blockSize = LZ4IO_setBlockSize(B);
+                                    BMK_setBlockSize(blockSize);
+                                    if (blockSize >= 1024) {
+                                        DISPLAYLEVEL(2, "using blocks of size %u KB \n", (U32)(blockSize>>10));
                                     } else {
-                                        DISPLAYLEVEL(2, "bench: using blocks of size %u bytes \n", (U32)(B));
+                                        DISPLAYLEVEL(2, "using blocks of size %u bytes \n", (U32)(blockSize));
                                     }
                                 }
                                 break;
diff --git a/programs/lz4io.c b/programs/lz4io.c
index cdc4c27f..17ff9a1d 100644
--- a/programs/lz4io.c
+++ b/programs/lz4io.c
@@ -110,6 +110,7 @@ static clock_t g_time = 0;
 static int g_overwrite = 1;
 static int g_testMode = 0;
 static int g_blockSizeId = LZ4IO_BLOCKSIZEID_DEFAULT;
+static int g_blockSize = 0;
 static int g_blockChecksum = 0;
 static int g_streamChecksum = 1;
 static int g_blockIndependence = 1;
@@ -178,7 +179,25 @@ size_t LZ4IO_setBlockSizeID(unsigned bsid)
     static const unsigned maxBlockSizeID = 7;
     if ((bsid < minBlockSizeID) || (bsid > maxBlockSizeID)) return 0;
     g_blockSizeId = bsid;
-    return blockSizeTable[g_blockSizeId-minBlockSizeID];
+    g_blockSize = blockSizeTable[g_blockSizeId-minBlockSizeID];
+    return g_blockSize;
+}
+
+size_t LZ4IO_setBlockSize(size_t blockSize)
+{
+    static const size_t minBlockSize = 32;
+    static const size_t maxBlockSize = 4 MB;
+    unsigned bsid = 0;
+    if (blockSize < minBlockSize) blockSize = minBlockSize;
+    if (blockSize > maxBlockSize) blockSize = maxBlockSize;
+    g_blockSize = blockSize;
+    blockSize--;
+    /* find which of { 64k, 256k, 1MB, 4MB } is closest to blockSize */
+    while (blockSize >>= 2)
+        bsid++;
+    if (bsid < 7) bsid = 7;
+    g_blockSizeId = bsid-3;
+    return g_blockSize;
 }
 
 int LZ4IO_setBlockMode(LZ4IO_blockMode_t blockMode)
@@ -499,7 +518,7 @@ static LZ4F_CDict* LZ4IO_createCDict(void) {
 
 static cRess_t LZ4IO_createCResources(void)
 {
-    const size_t blockSize = (size_t)LZ4IO_GetBlockSize_FromBlockId (g_blockSizeId);
+    const size_t blockSize = g_blockSize;
     cRess_t ress;
 
     LZ4F_errorCode_t const errorCode = LZ4F_createCompressionContext(&(ress.ctx), LZ4F_VERSION);
@@ -543,7 +562,7 @@ static int LZ4IO_compressFilename_extRess(cRess_t ress, const char* srcFileName,
     void* const srcBuffer = ress.srcBuffer;
     void* const dstBuffer = ress.dstBuffer;
     const size_t dstBufferSize = ress.dstBufferSize;
-    const size_t blockSize = (size_t)LZ4IO_GetBlockSize_FromBlockId (g_blockSizeId);
+    const size_t blockSize = g_blockSize;
     size_t readSize;
     LZ4F_compressionContext_t ctx = ress.ctx;   /* just a pointer */
     LZ4F_preferences_t prefs;
diff --git a/programs/lz4io.h b/programs/lz4io.h
index 22c5e3e6..33de41fe 100644
--- a/programs/lz4io.h
+++ b/programs/lz4io.h
@@ -78,6 +78,10 @@ int LZ4IO_setTestMode(int yes);
    return : 0 if error, blockSize if OK */
 size_t LZ4IO_setBlockSizeID(unsigned blockSizeID);
 
+/* blockSize : valid values : 32 -> 4MB
+   return : 0 if error, actual blocksize if OK */
+size_t LZ4IO_setBlockSize(size_t blockSize);
+
 /* Default setting : independent blocks */
 typedef enum { LZ4IO_blockLinked=0, LZ4IO_blockIndependent} LZ4IO_blockMode_t;
 int LZ4IO_setBlockMode(LZ4IO_blockMode_t blockMode);