From: Yann Collet <yann.collet.73@gmail.com>
Date: Wed, 18 May 2016 10:06:33 +0000 (+0200)
Subject: reverted default compression level to 1
X-Git-Tag: v0.7.0^2~73
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=236d94fa9a4ff8723922971274a119c6084d5dbc;p=thirdparty%2Fzstd.git

reverted default compression level to 1
---

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 1bb75c68c..ceaff74e0 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -2432,7 +2432,7 @@ size_t ZSTD_compress(void* dst, size_t dstCapacity, const void* src, size_t srcS
 
 /*-=====  Pre-defined compression levels  =====-*/
 
-#define ZSTD_DEFAULT_CLEVEL 5
+#define ZSTD_DEFAULT_CLEVEL 1
 #define ZSTD_MAX_CLEVEL     22
 unsigned ZSTD_maxCLevel(void) { return ZSTD_MAX_CLEVEL; }
 
@@ -2543,17 +2543,16 @@ static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEV
 },
 };
 
-/*! ZSTD_getParams() :
-*   @return ZSTD_parameters structure for a selected compression level and srcSize.
-*   `srcSize` value is optional, select 0 if not known */
+/*! ZSTD_getCParams() :
+*   @return ZSTD_compressionParameters structure for a selected compression level, `srcSize` and `dictSize`.
+*   Size values are optional, provide 0 if not known or unused */
 ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, U64 srcSize, size_t dictSize)
 {
     ZSTD_compressionParameters cp;
     size_t const addedSize = srcSize ? 0 : 500;
     U64 const rSize = srcSize+dictSize ? srcSize+dictSize+addedSize : (U64)-1;
     U32 const tableID = (rSize <= 256 KB) + (rSize <= 128 KB) + (rSize <= 16 KB);   /* intentional underflow for srcSizeHint == 0 */
-    if (compressionLevel < 0) compressionLevel = ZSTD_DEFAULT_CLEVEL;
-    if (compressionLevel==0) compressionLevel = 1;
+    if (compressionLevel <= 0) compressionLevel = ZSTD_DEFAULT_CLEVEL;   /* 0 == default; no negative compressionLevel yet */
     if (compressionLevel > ZSTD_MAX_CLEVEL) compressionLevel = ZSTD_MAX_CLEVEL;
     cp = ZSTD_defaultCParameters[tableID][compressionLevel];
     if (MEM_32bits()) {   /* auto-correction, for 32-bits mode */