Fix use of infra image to clarify default

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

1 files changed, 49 insertions, 13 deletions

diff --git a/vendor/github.com/klauspost/compress/flate/deflate.go b/vendor/github.com/klauspost/compress/flate/deflate.go
index b27f5a93b..bffa2f332 100644
--- a/vendor/github.com/klauspost/compress/flate/deflate.go
+++ b/vendor/github.com/klauspost/compress/flate/deflate.go
@@ -10,9 +10,6 @@ import (
 	"fmt"
 	"io"
 	"math"
-	"math/bits"
-
-	comp "github.com/klauspost/compress"
 )
 
 const (
@@ -76,8 +73,8 @@ var levels = []compressionLevel{
 	{0, 0, 0, 0, 0, 6},
 	// Levels 7-9 use increasingly more lazy matching
 	// and increasingly stringent conditions for "good enough".
-	{6, 10, 12, 16, skipNever, 7},
-	{10, 24, 32, 64, skipNever, 8},
+	{8, 12, 16, 24, skipNever, 7},
+	{16, 30, 40, 64, skipNever, 8},
 	{32, 258, 258, 1024, skipNever, 9},
 }
 
@@ -110,6 +107,7 @@ type advancedState struct {
 type compressor struct {
 	compressionLevel
 
+	h *huffmanEncoder
 	w *huffmanBitWriter
 
 	// compression algorithm
@@ -271,7 +269,7 @@ func (d *compressor) fillWindow(b []byte) {
 // Try to find a match starting at index whose length is greater than prevSize.
 // We only look at chainCount possibilities before giving up.
 // pos = s.index, prevHead = s.chainHead-s.hashOffset, prevLength=minMatchLength-1, lookahead
-func (d *compressor) findMatch(pos int, prevHead int, lookahead, bpb int) (length, offset int, ok bool) {
+func (d *compressor) findMatch(pos int, prevHead int, lookahead int) (length, offset int, ok bool) {
 	minMatchLook := maxMatchLength
 	if lookahead < minMatchLook {
 		minMatchLook = lookahead
@@ -297,14 +295,46 @@ func (d *compressor) findMatch(pos int, prevHead int, lookahead, bpb int) (lengt
 	}
 	offset = 0
 
+	cGain := 0
+	if d.chain < 100 {
+		for i := prevHead; tries > 0; tries-- {
+			if wEnd == win[i+length] {
+				n := matchLen(win[i:i+minMatchLook], wPos)
+				if n > length {
+					length = n
+					offset = pos - i
+					ok = true
+					if n >= nice {
+						// The match is good enough that we don't try to find a better one.
+						break
+					}
+					wEnd = win[pos+n]
+				}
+			}
+			if i <= minIndex {
+				// hashPrev[i & windowMask] has already been overwritten, so stop now.
+				break
+			}
+			i = int(d.state.hashPrev[i&windowMask]) - d.state.hashOffset
+			if i < minIndex {
+				break
+			}
+		}
+		return
+	}
+
+	// Some like it higher (CSV), some like it lower (JSON)
+	const baseCost = 6
 	// Base is 4 bytes at with an additional cost.
 	// Matches must be better than this.
-	cGain := minMatchLength*bpb - 12
 	for i := prevHead; tries > 0; tries-- {
 		if wEnd == win[i+length] {
 			n := matchLen(win[i:i+minMatchLook], wPos)
 			if n > length {
-				newGain := n*bpb - bits.Len32(uint32(pos-i))
+				// Calculate gain. Estimate
+				newGain := d.h.bitLengthRaw(wPos[:n]) - int(offsetExtraBits[offsetCode(uint32(pos-i))]) - baseCost - int(lengthExtraBits[lengthCodes[(n-3)&255]])
+
+				//fmt.Println(n, "gain:", newGain, "prev:", cGain, "raw:", d.h.bitLengthRaw(wPos[:n]))
 				if newGain > cGain {
 					length = n
 					offset = pos - i
@@ -389,10 +419,16 @@ func (d *compressor) deflateLazy() {
 	if d.windowEnd-s.index < minMatchLength+maxMatchLength && !d.sync {
 		return
 	}
-	s.estBitsPerByte = 8
-	if !d.sync {
-		s.estBitsPerByte = comp.ShannonEntropyBits(d.window[s.index:d.windowEnd])
-		s.estBitsPerByte = int(1 + float64(s.estBitsPerByte)/float64(d.windowEnd-s.index))
+	if d.windowEnd != s.index && d.chain > 100 {
+		// Get literal huffman coder.
+		if d.h == nil {
+			d.h = newHuffmanEncoder(maxFlateBlockTokens)
+		}
+		var tmp [256]uint16
+		for _, v := range d.window[s.index:d.windowEnd] {
+			tmp[v]++
+		}
+		d.h.generate(tmp[:], 15)
 	}
 
 	s.maxInsertIndex = d.windowEnd - (minMatchLength - 1)
@@ -446,7 +482,7 @@ func (d *compressor) deflateLazy() {
 		}
 
 		if s.chainHead-s.hashOffset >= minIndex && lookahead > prevLength && prevLength < d.lazy {
-			if newLength, newOffset, ok := d.findMatch(s.index, s.chainHead-s.hashOffset, lookahead, s.estBitsPerByte); ok {
+			if newLength, newOffset, ok := d.findMatch(s.index, s.chainHead-s.hashOffset, lookahead); ok {
 				s.length = newLength
 				s.offset = newOffset
 			}