From: Yann Collet <yann.collet.73@gmail.com>
Date: Thu, 14 Jul 2016 15:05:38 +0000 (+0200)
Subject: simplified ZSTD_estimateCCtxSize()
X-Git-Tag: v0.7.4^2~16
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8847238cac146b8642a5c4e944de8221c025b739;p=thirdparty%2Fzstd.git

simplified ZSTD_estimateCCtxSize()
---

diff --git a/lib/common/zstd.h b/lib/common/zstd.h
index f30e76cc3..b52b1de64 100644
--- a/lib/common/zstd.h
+++ b/lib/common/zstd.h
@@ -215,7 +215,7 @@ ZSTDLIB_API size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
 #define ZSTD_HASHLOG_MAX       ZSTD_WINDOWLOG_MAX
 #define ZSTD_HASHLOG_MIN       12
 #define ZSTD_HASHLOG3_MAX      17
-#define ZSTD_HASHLOG3_MIN      15
+//#define ZSTD_HASHLOG3_MIN      15
 #define ZSTD_SEARCHLOG_MAX    (ZSTD_WINDOWLOG_MAX-1)
 #define ZSTD_SEARCHLOG_MIN      1
 #define ZSTD_SEARCHLENGTH_MAX   7
@@ -265,7 +265,7 @@ typedef struct { ZSTD_allocFunction customAlloc; ZSTD_freeFunction customFree; v
 /*! ZSTD_estimateCCtxSize() :
  *  Gives the amount of memory allocated for a ZSTD_CCtx given a set of compression parameters.
  *  `frameContentSize` is an optional parameter, provide `0` if unknown */
-ZSTDLIB_API size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams, unsigned long long frameContentSize);
+ZSTDLIB_API size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams);
 
 /*! ZSTD_createCCtx_advanced() :
  *  Create a ZSTD compression context using external alloc and free functions */
diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index a53c172f6..c42f56ebc 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -249,7 +249,7 @@ ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, u
 }
 
 
-size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams, unsigned long long frameContentSize)
+size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams)
 {
     const size_t blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << cParams.windowLog);
     const U32    divider = (cParams.searchLength==3) ? 3 : 4;
@@ -258,9 +258,7 @@ size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams, unsigned long l
 
     const size_t chainSize = (cParams.strategy == ZSTD_fast) ? 0 : (1 << cParams.chainLog);
     const size_t hSize = ((size_t)1) << cParams.hashLog;
-    const U32 hashLog3 = (cParams.searchLength>3) ? 0 :
-                        ( (!frameContentSize || frameContentSize >= 8192) ? ZSTD_HASHLOG3_MAX :
-                          ((frameContentSize >= 2048) ? ZSTD_HASHLOG3_MIN + 1 : ZSTD_HASHLOG3_MIN) );
+    const U32 hashLog3 = (cParams.searchLength>3) ? 0 : MIN(ZSTD_HASHLOG3_MAX, cParams.windowLog);
     const size_t h3Size = ((size_t)1) << hashLog3;
     const size_t tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
 
@@ -283,9 +281,7 @@ static size_t ZSTD_resetCCtx_advanced (ZSTD_CCtx* zc,
     const size_t tokenSpace = blockSize + 11*maxNbSeq;
     const size_t chainSize = (params.cParams.strategy == ZSTD_fast) ? 0 : (1 << params.cParams.chainLog);
     const size_t hSize = ((size_t)1) << params.cParams.hashLog;
-    const U32 hashLog3 = (params.cParams.searchLength>3) ? 0 :
-                        ( (!frameContentSize || frameContentSize >= 8192) ? ZSTD_HASHLOG3_MAX :
-                          ((frameContentSize >= 2048) ? ZSTD_HASHLOG3_MIN + 1 : ZSTD_HASHLOG3_MIN) );
+    const U32 hashLog3 = (params.cParams.searchLength>3) ? 0 : MIN(ZSTD_HASHLOG3_MAX, params.cParams.windowLog);
     const size_t h3Size = ((size_t)1) << hashLog3;
     const size_t tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);