Removed unnecessary general code.

common/basetilecreator.go

@@ -5,7 +5,6 @@
 package common
 
 import (
-	"image"
 	"image/color"
 	"io/ioutil"
 	"log"
@@ -50,7 +49,7 @@ var tileDepths = [...][2]int16{
 
 var BackgroundColor = color.RGBA{R: 0xff, G: 0xff, B: 0xff, A: 0xff}
 
-type BaseTileUpdateFunc func(x, y int, img image.Image) bool
+type BaseTileUpdateFunc func(x, y int, hash []byte) bool
 
 type BaseTileCreator struct {
 	client     *RedisClient
@@ -165,7 +164,7 @@ func (btc *BaseTileCreator) CreateTile(x, z int16, i, j int) (bool, error) {
 		return true, SaveAsPNG(path, image)
 	}
 
-	if btc.update(i, j, image) {
+	if btc.update(i, j, SHA1Image(image)) {
 		log.Printf("Writing (%d, %d) to file %s.\n", x, z, path)
 		return true, SaveAsPNGAtomic(path, image)
 	}

common/basetilehash.go

@@ -6,7 +6,6 @@ package common
 
 import (
 	"bytes"
-	"image"
 	"sync"
 )
 
@@ -20,8 +19,7 @@ func NewBaseTileHash() *BaseTileHash {
 	return &BaseTileHash{hashes: map[struct{ x, y int }][]byte{}}
 }
 
-func (bth *BaseTileHash) Update(x, y int, img image.Image) bool {
-	hash := SHA1Image(img)
+func (bth *BaseTileHash) Update(x, y int, hash []byte) bool {
 	key := struct{ x, y int }{x, y}
 	bth.Lock()
 	defer bth.Unlock()

common/image.go

@@ -112,7 +112,8 @@ func LoadPNG(path string, bg color.RGBA) image.Image {
 	return img
 }
 
-func sha1rgba(img *image.RGBA) []byte {
+func SHA1Image(img *image.RGBA) []byte {
+
 	hash := sha1.New()
 	w, h := img.Rect.Dx()*4, img.Rect.Dy()
 
@@ -124,39 +125,3 @@ func sha1rgba(img *image.RGBA) []byte {
 
 	return hash.Sum(nil)
 }
-
-func sha1uniform(img *image.Uniform) []byte {
-	r, g, b, a := img.C.RGBA()
-	return sha1.New().Sum([]byte{
-		byte(r >> 16),
-		byte(g >> 16),
-		byte(b >> 16),
-		byte(a >> 16)})
-}
-
-func SHA1Image(img image.Image) []byte {
-
-	switch i := img.(type) {
-	case *image.RGBA:
-		return sha1rgba(i)
-	case *image.Uniform:
-		return sha1uniform(i)
-	}
-
-	log.Println("WARN: slow path for SHA1Image")
-
-	hash := sha1.New()
-	bounds := img.Bounds()
-	var pix [4]byte
-	for x := bounds.Min.X; x <= bounds.Max.X; x++ {
-		for y := bounds.Min.Y; y <= bounds.Max.Y; y++ {
-			r, g, b, a := img.At(x, y).RGBA()
-			pix[0] = byte(r >> 16)
-			pix[1] = byte(g >> 16)
-			pix[2] = byte(b >> 16)
-			pix[3] = byte(a >> 16)
-			hash.Write(pix[:])
-		}
-	}
-	return hash.Sum(nil)
-}