From: W. Felix Handte <w@felixhandte.com>
Date: Fri, 25 May 2018 19:19:37 +0000 (-0400)
Subject: Allow Different Dict Attachment Cut-Offs for Different Strategies
X-Git-Tag: v1.3.5~3^2~37^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F1151%2Fhead;p=thirdparty%2Fzstd.git

Allow Different Dict Attachment Cut-Offs for Different Strategies
---

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 46a3fe541..68beea0c9 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -1207,7 +1207,18 @@ static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
     /* We have a choice between copying the dictionary context into the working
      * context, or referencing the dictionary context from the working context
      * in-place. We decide here which strategy to use. */
-    const int attachDict = ( pledgedSrcSize <= 8 KB
+    const U64 attachDictSizeCutoffs[(unsigned)ZSTD_btultra+1] = {
+        8 KB, /* unused */
+        8 KB, /* ZSTD_fast */
+        16 KB, /* ZSTD_dfast */
+        16 KB, /* ZSTD_greedy */
+        16 KB, /* ZSTD_lazy */
+        16 KB, /* ZSTD_lazy2 */
+        16 KB, /* ZSTD_btlazy2 */
+        16 KB, /* ZSTD_btopt */
+        16 KB /* ZSTD_btultra */
+    };
+    const int attachDict = ( pledgedSrcSize <= attachDictSizeCutoffs[cdict->cParams.strategy]
                           || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN )
                         && !params.forceWindow /* dictMatchState isn't correctly
                                                 * handled in _enforceMaxDist */