From: Yann Collet <yann.collet.73@gmail.com>
Date: Mon, 4 Apr 2016 11:28:28 +0000 (+0200)
Subject: reduced memory usage of very hich compression levels in 32-bits mode
X-Git-Tag: v0.6.0^2~17^2~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1005fc1276347d6661de79a0edeba28006a9a7de;p=thirdparty%2Fzstd.git

reduced memory usage of very hich compression levels in 32-bits mode
---

diff --git a/lib/zstd_compress.c b/lib/zstd_compress.c
index 6905dcbf6..da5192012 100644
--- a/lib/zstd_compress.c
+++ b/lib/zstd_compress.c
@@ -226,7 +226,7 @@ static size_t ZSTD_resetCCtx_advanced (ZSTD_CCtx* zc,
     {   size_t const optSpace = ((MaxML+1) + (MaxLL+1) + (1<<Offbits) + (1<<Litbits))*sizeof(U32)
                               + (ZSTD_OPT_NUM+1)*(sizeof(ZSTD_match_t) + sizeof(ZSTD_optimal_t));
         size_t const neededSpace = tableSpace + (256*sizeof(U32)) /* huffTable */ + tokenSpace
-                           + ((params.cParams.strategy == ZSTD_btopt) ? optSpace : 0);
+                              + ((params.cParams.strategy == ZSTD_btopt) ? optSpace : 0);
         if (zc->workSpaceSize < neededSpace) {
             free(zc->workSpace);
             zc->workSpace = malloc(neededSpace);
@@ -2525,7 +2525,7 @@ static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEV
 ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, U64 srcSize, size_t dictSize)
 {
     ZSTD_compressionParameters cp;
-    size_t addedSize = srcSize ? 0 : 500;
+    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 = 1;
@@ -2534,6 +2534,10 @@ ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, U64 srcSize, si
     tableID=0;
 #endif
     cp = ZSTD_defaultCParameters[tableID][compressionLevel];
-    if (cp.windowLog > ZSTD_WINDOWLOG_MAX) cp.windowLog = ZSTD_WINDOWLOG_MAX;   /* auto-correction, for 32-bits mode */
+    if (MEM_32bits()) {   /* auto-correction, for 32-bits mode */
+        if (cp.windowLog > ZSTD_WINDOWLOG_MAX) cp.windowLog = ZSTD_WINDOWLOG_MAX;
+        if (cp.contentLog > ZSTD_CONTENTLOG_MAX) cp.contentLog = ZSTD_CONTENTLOG_MAX;
+        if (cp.hashLog > ZSTD_HASHLOG_MAX) cp.hashLog = ZSTD_HASHLOG_MAX;
+    }
     return cp;
 }
diff --git a/lib/zstd_static.h b/lib/zstd_static.h
index ecc5ff58b..acf9791ea 100644
--- a/lib/zstd_static.h
+++ b/lib/zstd_static.h
@@ -61,9 +61,9 @@ extern "C" {
 #define ZSTD_WINDOWLOG_MIN     18
 #define ZSTD_CONTENTLOG_MAX   (ZSTD_WINDOWLOG_MAX+1)
 #define ZSTD_CONTENTLOG_MIN     4
-#define ZSTD_HASHLOG_MAX       28
+#define ZSTD_HASHLOG_MAX       ZSTD_WINDOWLOG_MAX
 #define ZSTD_HASHLOG_MIN       12
-#define ZSTD_SEARCHLOG_MAX    (ZSTD_CONTENTLOG_MAX-1)
+#define ZSTD_SEARCHLOG_MAX    (ZSTD_WINDOWLOG_MAX-1)
 #define ZSTD_SEARCHLOG_MIN      1
 #define ZSTD_SEARCHLENGTH_MAX   7
 #define ZSTD_SEARCHLENGTH_MIN   3