Clear the Dictionary When Sliding the Window

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index e05882684023fab3f0d7516724955e463bbcf920..9f488b9ac12cdcf7bad8e8abccb89b63b14086dc 100644 (file)
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -1240,6 +1240,7 @@ static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
                 - cdict->matchState.window.base);
             ZSTD_window_clear(&cctx->blockState.matchState.window);
         }
+        cctx->blockState.matchState.loadedDictEnd = cctx->blockState.matchState.window.dictLimit;
     } else {
         DEBUGLOG(4, "copying dictionary into context");
         /* copy tables */
@@ -2313,8 +2314,9 @@ static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
             if (ms->nextToUpdate < correction) ms->nextToUpdate = 0;
             else ms->nextToUpdate -= correction;
             ms->loadedDictEnd = 0;
+            ms->dictMatchState = NULL;
         }
-        ZSTD_window_enforceMaxDist(&ms->window, ip + blockSize, maxDist, &ms->loadedDictEnd);
+        ZSTD_window_enforceMaxDist(&ms->window, ip + blockSize, maxDist, &ms->loadedDictEnd, &ms->dictMatchState);
         if (ms->nextToUpdate < ms->window.lowLimit) ms->nextToUpdate = ms->window.lowLimit;
 
         {   size_t cSize = ZSTD_compressBlock_internal(cctx,

diff --git a/lib/compress/zstd_compress_internal.h b/lib/compress/zstd_compress_internal.h
index 80c03433f4a0ae58704cce3718187e9b6194de57..a61fc374297212ae60bcb8b17d66fb14006cb8b6 100644 (file)
--- a/lib/compress/zstd_compress_internal.h
+++ b/lib/compress/zstd_compress_internal.h
@@ -520,10 +520,10 @@ MEM_STATIC U32 ZSTD_window_hasExtDict(ZSTD_window_t const window)
  */
 MEM_STATIC ZSTD_dictMode_e ZSTD_matchState_dictMode(const ZSTD_matchState_t *ms)
 {
-    return ms->dictMatchState != NULL ?
-        ZSTD_dictMatchState :
-        ZSTD_window_hasExtDict(ms->window) ?
-            ZSTD_extDict :
+    return ZSTD_window_hasExtDict(ms->window) ?
+        ZSTD_extDict :
+        ms->dictMatchState != NULL ?
+            ZSTD_dictMatchState :
             ZSTD_noDict;
 }
 
@@ -605,7 +605,8 @@ MEM_STATIC U32 ZSTD_window_correctOverflow(ZSTD_window_t* window, U32 cycleLog,
  */
 MEM_STATIC void ZSTD_window_enforceMaxDist(ZSTD_window_t* window,
                                            void const* srcEnd, U32 maxDist,
-                                           U32* loadedDictEndPtr)
+                                           U32* loadedDictEndPtr,
+                                           const ZSTD_matchState_t** dictMatchStatePtr)
 {
     U32 const current = (U32)((BYTE const*)srcEnd - window->base);
     U32 loadedDictEnd = loadedDictEndPtr != NULL ? *loadedDictEndPtr : 0;
@@ -619,6 +620,8 @@ MEM_STATIC void ZSTD_window_enforceMaxDist(ZSTD_window_t* window,
         }
         if (loadedDictEndPtr)
             *loadedDictEndPtr = 0;
+        if (dictMatchStatePtr)
+            *dictMatchStatePtr = NULL;
     }
 }
 

diff --git a/lib/compress/zstd_ldm.c b/lib/compress/zstd_ldm.c
index b0c5d06541c39d3c7bcb78c9023380ecdfec783c..03d1f54c46113aee8e7af789d9bc566a74866940 100644 (file)
--- a/lib/compress/zstd_ldm.c
+++ b/lib/compress/zstd_ldm.c
@@ -508,7 +508,7 @@ size_t ZSTD_ldm_generateSequences(
          *       * Try invalidation after the sequence generation and test the
          *         the offset against maxDist directly.
          */
-        ZSTD_window_enforceMaxDist(&ldmState->window, chunkEnd, maxDist, NULL);
+        ZSTD_window_enforceMaxDist(&ldmState->window, chunkEnd, maxDist, NULL, NULL);
         /* 3. Generate the sequences for the chunk, and get newLeftoverSize. */
         newLeftoverSize = ZSTD_ldm_generateSequences_internal(
             ldmState, sequences, params, chunkStart, chunkSize);