minor comment changes

lib/common/entropy_common.c

@@ -173,7 +173,7 @@ size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
     size_t iSize = ip[0];
     size_t oSize;
 
-    //memset(huffWeight, 0, hwSize);   /* is not necessary, even though some analyzer complain ... */
+    /* memset(huffWeight, 0, hwSize);   *//* is not necessary, even though some analyzer complain ... */
 
     if (iSize >= 128) {  /* special header */
         if (iSize >= (242)) {  /* RLE */
@@ -181,8 +181,7 @@ size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
             oSize = l[iSize-242];
             memset(huffWeight, 1, hwSize);
             iSize = 0;
-        }
+        } else {   /* Incompressible */
-        else {   /* Incompressible */
             oSize = iSize - 127;
             iSize = ((oSize+1)/2);
             if (iSize+1 > srcSize) return ERROR(srcSize_wrong);

lib/compress/huf_compress.c

@@ -174,7 +174,7 @@ size_t HUF_readCTable (HUF_CElt* CTable, U32 maxSymbolValue, const void* src, si
     U32 tableLog = 0;
     size_t readSize;
     U32 nbSymbols = 0;
-    //memset(huffWeight, 0, sizeof(huffWeight));   /* is not necessary, even though some analyzer complain ... */
+    /*memset(huffWeight, 0, sizeof(huffWeight));*/   /* is not necessary, even though some analyzer complain ... */
 
     /* get symbol weights */
     readSize = HUF_readStats(huffWeight, HUF_SYMBOLVALUE_MAX+1, rankVal, &nbSymbols, &tableLog, src, srcSize);
@@ -196,7 +196,7 @@ size_t HUF_readCTable (HUF_CElt* CTable, U32 maxSymbolValue, const void* src, si
     {   U32 n; for (n=0; n<nbSymbols; n++) {
             const U32 w = huffWeight[n];
             CTable[n].nbBits = (BYTE)(tableLog + 1 - w);
-    }}
+    }   }
 
     /* fill val */
     {   U16 nbPerRank[HUF_TABLELOG_MAX+1] = {0};
@@ -535,7 +535,6 @@ static size_t HUF_compress_internal (
     {   size_t const hSize = HUF_writeCTable (op, dstSize, CTable, maxSymbolValue, huffLog);
         if (HUF_isError(hSize)) return hSize;
         if (hSize + 12 >= srcSize) return 0;   /* not useful to try compression */
-        //static U64 totalHSize = 0; static U32 nbHSize = 0; totalHSize += hSize; nbHSize++; if ((nbHSize & 63) == 1) printf("average : %6.3f \n", (double)totalHSize / nbHSize);
         op += hSize;
     }
 

lib/decompress/zstd_decompress.c

@@ -194,117 +194,7 @@ void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
 *   Decompression section
 ***************************************************************/
 
-/* Frame format description
+/* See compression format details in : zstd_compression_format.md */
-   Frame Header -  [ Block Header - Block ] - Frame End
-   1) Frame Header
-      - 4 bytes - Magic Number : ZSTD_MAGICNUMBER (defined within zstd.h)
-      - 1 byte  - Frame Descriptor
-   2) Block Header
-      - 3 bytes, starting with a 2-bits descriptor
-                 Uncompressed, Compressed, Frame End, unused
-   3) Block
-      See Block Format Description
-   4) Frame End
-      - 3 bytes, compatible with Block Header
-*/
-
-
-/* Frame Header :
-
-   1 byte - FrameHeaderDescription :
-   bit 0-1 : dictID (0, 1, 2 or 4 bytes)
-   bit 2   : checksumFlag
-   bit 3   : reserved (must be zero)
-   bit 4   : reserved (unused, can be any value)
-   bit 5   : Single Segment (if 1, WindowLog byte is not present)
-   bit 6-7 : FrameContentFieldSize (0, 2, 4, or 8)
-             if (SkippedWindowLog && !FrameContentFieldsize) FrameContentFieldsize=1;
-
-   Optional : WindowLog (0 or 1 byte)
-   bit 0-2 : octal Fractional (1/8th)
-   bit 3-7 : Power of 2, with 0 = 1 KB (up to 2 TB)
-
-   Optional : dictID (0, 1, 2 or 4 bytes)
-   Automatic adaptation
-   0 : no dictID
-   1 : 1 - 255
-   2 : 256 - 65535
-   4 : all other values
-
-   Optional : content size (0, 1, 2, 4 or 8 bytes)
-   0 : unknown          (fcfs==0 and swl==0)
-   1 : 0-255 bytes      (fcfs==0 and swl==1)
-   2 : 256 - 65535+256  (fcfs==1)
-   4 : 0 - 4GB-1        (fcfs==2)
-   8 : 0 - 16EB-1       (fcfs==3)
-*/
-
-
-/* Compressed Block, format description
-
-   Block = Literal Section - Sequences Section
-   Prerequisite : size of (compressed) block, maximum size of regenerated data
-
-   1) Literal Section
-
-   1.1) Header : 1-5 bytes
-        flags: 2 bits
-            00 compressed by Huff0
-            01 unused
-            10 is Raw (uncompressed)
-            11 is Rle
-            Note : using 01 => Huff0 with precomputed table ?
-            Note : delta map ? => compressed ?
-
-   1.1.1) Huff0-compressed literal block : 3-5 bytes
-            srcSize < 1 KB => 3 bytes (2-2-10-10) => single stream
-            srcSize < 1 KB => 3 bytes (2-2-10-10)
-            srcSize < 16KB => 4 bytes (2-2-14-14)
-            else           => 5 bytes (2-2-18-18)
-            big endian convention
-
-   1.1.2) Raw (uncompressed) literal block header : 1-3 bytes
-        size :  5 bits: (IS_RAW<<6) + (0<<4) + size
-               12 bits: (IS_RAW<<6) + (2<<4) + (size>>8)
-                        size&255
-               20 bits: (IS_RAW<<6) + (3<<4) + (size>>16)
-                        size>>8&255
-                        size&255
-
-   1.1.3) Rle (repeated single byte) literal block header : 1-3 bytes
-        size :  5 bits: (IS_RLE<<6) + (0<<4) + size
-               12 bits: (IS_RLE<<6) + (2<<4) + (size>>8)
-                        size&255
-               20 bits: (IS_RLE<<6) + (3<<4) + (size>>16)
-                        size>>8&255
-                        size&255
-
-   1.1.4) Huff0-compressed literal block, using precomputed CTables : 3-5 bytes
-            srcSize < 1 KB => 3 bytes (2-2-10-10) => single stream
-            srcSize < 1 KB => 3 bytes (2-2-10-10)
-            srcSize < 16KB => 4 bytes (2-2-14-14)
-            else           => 5 bytes (2-2-18-18)
-            big endian convention
-
-        1- CTable available (stored into workspace ?)
-        2- Small input (fast heuristic ? Full comparison ? depend on clevel ?)
-
-
-   1.2) Literal block content
-
-   1.2.1) Huff0 block, using sizes from header
-        See Huff0 format
-
-   1.2.2) Huff0 block, using prepared table
-
-   1.2.3) Raw content
-
-   1.2.4) single byte
-
-
-   2) Sequences section
-      TO DO
-*/
 
 /** ZSTD_frameHeaderSize() :
 *   srcSize must be >= ZSTD_frameHeaderSize_min.