From: senhuang42 <senhuang96@fb.com>
Date: Mon, 21 Dec 2020 16:33:41 +0000 (-0500)
Subject: Use pre-defined constants
X-Git-Tag: v1.4.9^2~39^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5c41490bfe8149933213a1245acff586fb65e587;p=thirdparty%2Fzstd.git

Use pre-defined constants
---

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 3e6bf7464..2e0edaf99 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -2954,16 +2954,16 @@ static size_t ZSTD_writeFrameHeader(void* dst, size_t dstCapacity,
     return pos;
 }
 
-/* ZSTD_generateSkippableFrame_advanced() :
+/* ZSTD_writeSkippableFrame_advanced() :
  * Writes out a skippable frame with the specified magic number variant (16 are supported), 
  * from ZSTD_MAGIC_SKIPPABLE_START to ZSTD_MAGIC_SKIPPABLE_START+15, and the desired source data.
  * 
  * Returns the total number of bytes written, or a ZSTD error code.
  */
-size_t ZSTD_generateSkippableFrame_advanced(void* dst, size_t dstCapacity,
-                                            const void* src, size_t srcSize, U32 magicVariant) {
-    BYTE* op = dst;
-    RETURN_ERROR_IF(dstCapacity < srcSize + 8 /* Skippable frame overhead */,
+size_t ZSTD_writeSkippableFrame(void* dst, size_t dstCapacity,
+                                const void* src, size_t srcSize, unsigned magicVariant) {
+    BYTE* op = (BYTE*)dst;
+    RETURN_ERROR_IF(dstCapacity < srcSize + ZSTD_SKIPPABLEHEADERSIZE /* Skippable frame overhead */,
                     dstSize_tooSmall, "Not enough room for skippable frame");
     RETURN_ERROR_IF(srcSize > (unsigned)0xFFFFFFFF, srcSize_wrong, "Src size too large for skippable frame");
     RETURN_ERROR_IF(magicVariant > 15, parameter_outOfBound, "Skippable frame magic number variant not supported");
@@ -2971,7 +2971,7 @@ size_t ZSTD_generateSkippableFrame_advanced(void* dst, size_t dstCapacity,
     MEM_writeLE32(op, (U32)(ZSTD_MAGIC_SKIPPABLE_START + magicVariant));
     MEM_writeLE32(op+4, (U32)srcSize);
     ZSTD_memcpy(op+8, src, srcSize);
-    return srcSize + 8;
+    return srcSize + ZSTD_SKIPPABLEHEADERSIZE;
 }
 
 /* ZSTD_writeLastEmptyBlock() :
diff --git a/lib/zstd.h b/lib/zstd.h
index c34b43976..61e118647 100644
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -1372,20 +1372,21 @@ ZSTDLIB_API size_t ZSTD_compressSequences(ZSTD_CCtx* const cctx, void* dst, size
                                   const void* src, size_t srcSize);
 
 
-/*! ZSTD_generateSkippableFrame() :
+/*! ZSTD_writeSkippableFrame() :
  * Generates a zstd skippable frame containing data given by src, and writes it to dst buffer.
  * 
- * Skippable frames have a 4-byte magic number, which can range from ZSTD_MAGIC_SKIPPABLE_START to ZSTD_MAGIC_SKIPPABLE_START+15.
+ * Skippable frames begin with a a 4-byte magic number. There are 16 possible choices of magic number,
+ * ranging from ZSTD_MAGIC_SKIPPABLE_START to ZSTD_MAGIC_SKIPPABLE_START+15.
  * As such, the parameter magicVariant controls the exact skippable frame magic number variant used, so
- * the final magic number will be ZSTD_MAGIC_SKIPPABLE_START + magicVariant.
+ * the magic number used will be ZSTD_MAGIC_SKIPPABLE_START + magicVariant.
  * 
  * Returns an error if destination buffer is not large enough, if the source size is not representable
- * with a 4-byte unsigned int, or if the magicVariant is greater than 15.
+ * with a 4-byte unsigned int, or if the parameter magicVariant is greater than 15 (and therefore invalid).
  * 
  * @return : number of bytes written or a ZSTD error.
  */
-ZSTDLIB_API size_t ZSTD_generateSkippableFrame(void* dst, size_t dstCapacity,
-                                               const void* src, size_t srcSize, unsigned magicVariant);
+ZSTDLIB_API size_t ZSTD_writeSkippableFrame(void* dst, size_t dstCapacity,
+                                            const void* src, size_t srcSize, unsigned magicVariant);
 
 
 /***************************************
diff --git a/tests/fuzzer.c b/tests/fuzzer.c
index eb84dbfa2..71ed3e0b8 100644
--- a/tests/fuzzer.c
+++ b/tests/fuzzer.c
@@ -1583,7 +1583,7 @@ static int basicUnitTests(U32 const seed, double compressibility)
             off += r;
             if (i == segs/2) {
                 /* insert skippable frame */
-                skippableSize = ZSTD_generateSkippableFrame(compressedBuffer + off, compressedBufferSize, skipBuff, skipLen, seed % 15);
+                skippableSize = ZSTD_writeSkippableFrame(compressedBuffer + off, compressedBufferSize, skipBuff, skipLen, seed % 15);
                 CHECK_Z(skippableSize);
                 off += skippableSize;
             }