zstd: Fix incorrect hash table placement for dict encoding in default (…

…#606) Bonus: Load table values in same order they are used.
klauspost · May 30, 2022 · dab79ca · dab79ca
1 parent c4c3195
commit dab79ca
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Showing 2 changed files with 9 additions and 9 deletions.
diff --git a/zstd/enc_better.go b/zstd/enc_better.go
@@ -156,8 +156,8 @@ encodeLoop:
 				panic("offset0 was 0")
 			}
 
-			nextHashS := hashLen(cv, betterShortTableBits, betterShortLen)
 			nextHashL := hashLen(cv, betterLongTableBits, betterLongLen)
+			nextHashS := hashLen(cv, betterShortTableBits, betterShortLen)
 			candidateL := e.longTable[nextHashL]
 			candidateS := e.table[nextHashS]
 
@@ -518,8 +518,8 @@ encodeLoop:
 			}
 
 			// Store this, since we have it.
-			nextHashS := hashLen(cv, betterShortTableBits, betterShortLen)
 			nextHashL := hashLen(cv, betterLongTableBits, betterLongLen)
+			nextHashS := hashLen(cv, betterShortTableBits, betterShortLen)
 
 			// We have at least 4 byte match.
 			// No need to check backwards. We come straight from a match
@@ -674,8 +674,8 @@ encodeLoop:
 				panic("offset0 was 0")
 			}
 
-			nextHashS := hashLen(cv, betterShortTableBits, betterShortLen)
 			nextHashL := hashLen(cv, betterLongTableBits, betterLongLen)
+			nextHashS := hashLen(cv, betterShortTableBits, betterShortLen)
 			candidateL := e.longTable[nextHashL]
 			candidateS := e.table[nextHashS]
 
@@ -1047,8 +1047,8 @@ encodeLoop:
 			}
 
 			// Store this, since we have it.
-			nextHashS := hashLen(cv, betterShortTableBits, betterShortLen)
 			nextHashL := hashLen(cv, betterLongTableBits, betterLongLen)
+			nextHashS := hashLen(cv, betterShortTableBits, betterShortLen)
 
 			// We have at least 4 byte match.
 			// No need to check backwards. We come straight from a match

diff --git a/zstd/enc_dfast.go b/zstd/enc_dfast.go
@@ -127,8 +127,8 @@ encodeLoop:
 				panic("offset0 was 0")
 			}
 
-			nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen)
 			nextHashL := hashLen(cv, dFastLongTableBits, dFastLongLen)
+			nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen)
 			candidateL := e.longTable[nextHashL]
 			candidateS := e.table[nextHashS]
 
@@ -439,8 +439,8 @@ encodeLoop:
 		var t int32
 		for {
 
-			nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen)
 			nextHashL := hashLen(cv, dFastLongTableBits, dFastLongLen)
+			nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen)
 			candidateL := e.longTable[nextHashL]
 			candidateS := e.table[nextHashS]
 
@@ -785,8 +785,8 @@ encodeLoop:
 				panic("offset0 was 0")
 			}
 
-			nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen)
 			nextHashL := hashLen(cv, dFastLongTableBits, dFastLongLen)
+			nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen)
 			candidateL := e.longTable[nextHashL]
 			candidateS := e.table[nextHashS]
 
@@ -969,7 +969,7 @@ encodeLoop:
 		te0 := tableEntry{offset: index0 + e.cur, val: uint32(cv0)}
 		te1 := tableEntry{offset: index1 + e.cur, val: uint32(cv1)}
 		longHash1 := hashLen(cv0, dFastLongTableBits, dFastLongLen)
-		longHash2 := hashLen(cv0, dFastLongTableBits, dFastLongLen)
+		longHash2 := hashLen(cv1, dFastLongTableBits, dFastLongLen)
 		e.longTable[longHash1] = te0
 		e.longTable[longHash2] = te1
 		e.markLongShardDirty(longHash1)
@@ -1002,8 +1002,8 @@ encodeLoop:
 			}
 
 			// Store this, since we have it.
-			nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen)
 			nextHashL := hashLen(cv, dFastLongTableBits, dFastLongLen)
+			nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen)
 
 			// We have at least 4 byte match.
 			// No need to check backwards. We come straight from a match