From: inikep <inikep@gmail.com>
Date: Tue, 31 May 2016 17:36:51 +0000 (+0200)
Subject: fixed skippable frame
X-Git-Tag: v0.7.0^2~37^2~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=43aa9fe8b3f6b48e1ab5ad4da7d8b8a28b47d181;p=thirdparty%2Fzstd.git

fixed skippable frame
---

diff --git a/lib/decompress/zbuff_decompress.c b/lib/decompress/zbuff_decompress.c
index e785e9ec3..72456fd5f 100644
--- a/lib/decompress/zbuff_decompress.c
+++ b/lib/decompress/zbuff_decompress.c
@@ -224,13 +224,7 @@ size_t ZBUFF_decompressContinue(ZBUFF_DCtx* zbd,
                         ip, neededInSize);
                     if (ZSTD_isError(decodedSize)) return decodedSize;
                     ip += neededInSize;
-                    if (!decodedSize)  {
-                        if (isSkipFrame) {
-                           zbd->stage = ZBUFFds_loadHeader;
-                           zbd->lhSize = 0;
-                        }
-                        break;   /* this was just a header */
-                    }
+                    if (!decodedSize && !isSkipFrame) break;   /* this was just a header */
                     zbd->outEnd = zbd->outStart +  decodedSize;
                     zbd->stage = ZBUFFds_flush;
                     break;
@@ -256,15 +250,7 @@ size_t ZBUFF_decompressContinue(ZBUFF_DCtx* zbd,
                         zbd->inBuff, neededInSize);
                     if (ZSTD_isError(decodedSize)) return decodedSize;
                     zbd->inPos = 0;   /* input is consumed */
-                    if (!decodedSize) {
-                        if (isSkipFrame) {
-                           zbd->stage = ZBUFFds_loadHeader;
-                           zbd->lhSize = 0;
-                           break; 
-                        }
-                        zbd->stage = ZBUFFds_read; /* this was just a header */
-                        break; 
-                    }
+                    if (!decodedSize && !isSkipFrame) { zbd->stage = ZBUFFds_read; break; }   /* this was just a header */
                     zbd->outEnd = zbd->outStart +  decodedSize;
                     zbd->stage = ZBUFFds_flush;
                     // break; /* ZBUFFds_flush follows */
@@ -292,7 +278,7 @@ size_t ZBUFF_decompressContinue(ZBUFF_DCtx* zbd,
     *srcSizePtr = ip-istart;
     *dstCapacityPtr = op-ostart;
     {   size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zbd->zd);
-        if (nextSrcSizeHint > ZSTD_blockHeaderSize) nextSrcSizeHint+= ZSTD_blockHeaderSize;   /* get following block header too */
+//        if (nextSrcSizeHint > ZSTD_blockHeaderSize) nextSrcSizeHint+= ZSTD_blockHeaderSize;   /* get following block header too */
         nextSrcSizeHint -= zbd->inPos;   /* already loaded*/
         return nextSrcSizeHint;
     }
diff --git a/lib/decompress/zstd_decompress.c b/lib/decompress/zstd_decompress.c
index 64be8fb56..75e91e81c 100644
--- a/lib/decompress/zstd_decompress.c
+++ b/lib/decompress/zstd_decompress.c
@@ -1090,7 +1090,7 @@ size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, c
             return 0;
         }
     case ZSTDds_skipFrame:
-        {   dctx->expected = ZSTD_frameHeaderSize_min;
+        {   dctx->expected = 0;
             dctx->stage = ZSTDds_getFrameHeaderSize;
             return 0;
         }
diff --git a/programs/zbufftest.c b/programs/zbufftest.c
index 6e5b74394..5b172d23e 100644
--- a/programs/zbufftest.c
+++ b/programs/zbufftest.c
@@ -151,7 +151,7 @@ static int basicUnitTests(U32 seed, double compressibility, ZSTD_customMem custo
     void* compressedBuffer = malloc(compressedBufferSize);
     size_t const decodedBufferSize = CNBufferSize;
     void* decodedBuffer = malloc(decodedBufferSize);
-    size_t result, cSize, readSize, genSize;
+    size_t result, cSize, readSize, readSkipSize, genSize;
     U32 testNb=0;
     ZBUFF_CCtx* zc = ZBUFF_createCCtx_advanced(customMem);
     ZBUFF_DCtx* zd = ZBUFF_createDCtx_advanced(customMem);
@@ -185,12 +185,17 @@ static int basicUnitTests(U32 seed, double compressibility, ZSTD_customMem custo
     /* Basic decompression test */
     DISPLAYLEVEL(4, "test%3i : decompress %u bytes : ", testNb++, COMPRESSIBLE_NOISE_LENGTH);
     ZBUFF_decompressInitDictionary(zd, CNBuffer, 128 KB);
-    readSize = cSize;
+    readSkipSize = cSize;
     genSize = CNBufferSize;
-    result = ZBUFF_decompressContinue(zd, decodedBuffer, &genSize, compressedBuffer, &readSize);
+    result = ZBUFF_decompressContinue(zd, decodedBuffer, &genSize, compressedBuffer, &readSkipSize);
+    if (genSize != 0) goto _output_error;   /* skippable frame */
+    ZBUFF_decompressInitDictionary(zd, CNBuffer, 128 KB);
+    readSize = cSize - readSkipSize;
+    genSize = CNBufferSize;
+    result = ZBUFF_decompressContinue(zd, decodedBuffer, &genSize, compressedBuffer+readSkipSize, &readSize);
     if (result != 0) goto _output_error;  /* should reach end of frame == 0; otherwise, some data left, or an error */
     if (genSize != CNBufferSize) goto _output_error;   /* should regenerate the same amount */
-    if (readSize != cSize) goto _output_error;   /* should have read the entire frame */
+    if (readSize+readSkipSize != cSize) goto _output_error;   /* should have read the entire frame */
     DISPLAYLEVEL(4, "OK \n");
 
     /* check regenerated data is byte exact */
@@ -204,17 +209,20 @@ static int basicUnitTests(U32 seed, double compressibility, ZSTD_customMem custo
 
     /* Byte-by-byte decompression test */
     DISPLAYLEVEL(4, "test%3i : decompress byte-by-byte : ", testNb++);
-    ZBUFF_decompressInitDictionary(zd, CNBuffer, 128 KB);
-    {   size_t r = 1, pIn=0, pOut=0;
-        while (r) {
-            size_t inS = 1;
-            size_t outS = 1;
-            r = ZBUFF_decompressContinue(zd, ((BYTE*)decodedBuffer)+pOut, &outS, ((BYTE*)compressedBuffer)+pIn, &inS);
-            pIn += inS;
-            pOut += outS;
-        }
-        readSize = pIn;
-        genSize = pOut;
+    {   size_t r, pIn=0, pOut=0;
+        do 
+        {   ZBUFF_decompressInitDictionary(zd, CNBuffer, 128 KB);
+            r = 1;
+            while (r) {
+                size_t inS = 1;
+                size_t outS = 1;
+                r = ZBUFF_decompressContinue(zd, ((BYTE*)decodedBuffer)+pOut, &outS, ((BYTE*)compressedBuffer)+pIn, &inS);
+                pIn += inS;
+                pOut += outS;
+            }
+            readSize = pIn;
+            genSize = pOut;
+        } while (genSize==0);
     }
     if (genSize != CNBufferSize) goto _output_error;   /* should regenerate the same amount */
     if (readSize != cSize) goto _output_error;   /* should have read the entire frame */