resource: Fix multi-threaded image processing issue - hugo - [fork] hugo port for 9front
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---
(DIR) commit d8fdffb55268464d54558d6f9cd3874b612dc7c7
(DIR) parent 2851af0225cdf6c4e47058979cd22949ed6d1fc0
(HTM) Author: Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com>
Date: Tue, 13 Feb 2018 21:45:51 +0100
resource: Fix multi-threaded image processing issue
When doing something like this with the same image from a partial used in, say, both the home page and the single page:
```bash
{{ with $img }}
{{ $big := .Fill "1024x512 top" }}
{{ $small := $big.Resize "512x" }}
{{ end }}
```
There would be timing issues making Hugo in some cases try to process the same image with the same instructions in parallel.
You would experience errors of type:
```bash
png: invalid format: not enough pixel data
```
This commit works around that by adding a mutex per image. This should also improve the performance, sligthly, as it avoids duplicate work.
The current workaround before this fix is to always operate on the original:
```bash
{{ with $img }}
{{ $big := .Fill "1024x512 top" }}
{{ $small := .Fill "512x256 top" }}
{{ end }}
```
Fixes #4404
Diffstat:
M resource/image.go | 3 +++
M resource/image_cache.go | 8 +++++++-
M resource/image_test.go | 68 +++++++++++++++++++++++++++++++
M resource/testhelpers_test.go | 46 ++++++++++++++++++++++++++++---
4 files changed, 120 insertions(+), 5 deletions(-)
---
(DIR) diff --git a/resource/image.go b/resource/image.go
@@ -112,6 +112,9 @@ type Image struct {
copyToDestinationInit sync.Once
+ // Lock used when creating alternate versions of this image.
+ createMu sync.Mutex
+
imaging *Imaging
hash string
(DIR) diff --git a/resource/image_cache.go b/resource/image_cache.go
@@ -28,7 +28,8 @@ type imageCache struct {
absCacheDir string
pathSpec *helpers.PathSpec
mu sync.RWMutex
- store map[string]*Image
+
+ store map[string]*Image
}
func (c *imageCache) isInCache(key string) bool {
@@ -69,6 +70,11 @@ func (c *imageCache) getOrCreate(
}
// Now look in the file cache.
+ // Multiple Go routines can invoke same operation on the same image, so
+ // we need to make sure this is serialized per source image.
+ parent.createMu.Lock()
+ defer parent.createMu.Unlock()
+
cacheFilename := filepath.Join(c.absCacheDir, key)
// The definition of this counter is not that we have processed that amount
(DIR) diff --git a/resource/image_test.go b/resource/image_test.go
@@ -15,8 +15,12 @@ package resource
import (
"fmt"
+ "math/rand"
+ "strconv"
"testing"
+ "sync"
+
"github.com/stretchr/testify/require"
)
@@ -141,6 +145,51 @@ func TestImageTransformLongFilename(t *testing.T) {
assert.Equal("/a/_hu59e56ffff1bc1d8d122b1403d34e039f_90587_c876768085288f41211f768147ba2647.jpg", resized.RelPermalink())
}
+func TestImageTransformConcurrent(t *testing.T) {
+
+ var wg sync.WaitGroup
+
+ assert := require.New(t)
+
+ spec := newTestResourceOsFs(assert)
+
+ image := fetchImageForSpec(spec, assert, "sunset.jpg")
+
+ for i := 0; i < 4; i++ {
+ wg.Add(1)
+ go func(id int) {
+ defer wg.Done()
+ for j := 0; j < 5; j++ {
+ img := image
+ for k := 0; k < 2; k++ {
+ r1, err := img.Resize(fmt.Sprintf("%dx", id-k))
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ if r1.Width() != id-k {
+ t.Fatalf("Width: %d:%d", r1.Width(), j)
+ }
+
+ r2, err := r1.Resize(fmt.Sprintf("%dx", id-k-1))
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ _, err = r2.decodeSource()
+ if err != nil {
+ t.Fatal("Err decode:", err)
+ }
+
+ img = r1
+ }
+ }
+ }(i + 20)
+ }
+
+ wg.Wait()
+}
+
func TestDecodeImaging(t *testing.T) {
assert := require.New(t)
m := map[string]interface{}{
@@ -208,3 +257,22 @@ func TestImageWithMetadata(t *testing.T) {
assert.Equal("Sunset #1", resized.Name())
}
+
+func BenchmarkResizeParallel(b *testing.B) {
+ assert := require.New(b)
+ img := fetchSunset(assert)
+
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ w := rand.Intn(10) + 10
+ resized, err := img.Resize(strconv.Itoa(w) + "x")
+ if err != nil {
+ b.Fatal(err)
+ }
+ _, err = resized.Resize(strconv.Itoa(w-1) + "x")
+ if err != nil {
+ b.Fatal(err)
+ }
+ }
+ })
+}
(DIR) diff --git a/resource/testhelpers_test.go b/resource/testhelpers_test.go
@@ -6,8 +6,11 @@ import (
"image"
"io"
+ "io/ioutil"
"os"
"path"
+ "runtime"
+ "strings"
"github.com/gohugoio/hugo/helpers"
"github.com/gohugoio/hugo/hugofs"
@@ -45,17 +48,53 @@ func newTestResourceSpecForBaseURL(assert *require.Assertions, baseURL string) *
return spec
}
+func newTestResourceOsFs(assert *require.Assertions) *Spec {
+ cfg := viper.New()
+ cfg.Set("baseURL", "https://example.com")
+
+ workDir, err := ioutil.TempDir("", "hugores")
+
+ if runtime.GOOS == "darwin" && !strings.HasPrefix(workDir, "/private") {
+ // To get the entry folder in line with the rest. This its a little bit
+ // mysterious, but so be it.
+ workDir = "/private" + workDir
+ }
+
+ contentDir := "base"
+ cfg.Set("workingDir", workDir)
+ cfg.Set("contentDir", contentDir)
+ cfg.Set("resourceDir", filepath.Join(workDir, "res"))
+
+ fs := hugofs.NewFrom(hugofs.Os, cfg)
+ fs.Destination = &afero.MemMapFs{}
+
+ s, err := helpers.NewPathSpec(fs, cfg)
+
+ assert.NoError(err)
+
+ spec, err := NewSpec(s, media.DefaultTypes)
+ assert.NoError(err)
+ return spec
+
+}
+
func fetchSunset(assert *require.Assertions) *Image {
return fetchImage(assert, "sunset.jpg")
}
func fetchImage(assert *require.Assertions, name string) *Image {
+ spec := newTestResourceSpec(assert)
+ return fetchImageForSpec(spec, assert, name)
+}
+
+func fetchImageForSpec(spec *Spec, assert *require.Assertions, name string) *Image {
src, err := os.Open("testdata/" + name)
assert.NoError(err)
- spec := newTestResourceSpec(assert)
+ workingDir := spec.Cfg.GetString("workingDir")
+ f := filepath.Join(workingDir, name)
- out, err := spec.Fs.Source.Create("/b/" + name)
+ out, err := spec.Fs.Source.Create(f)
assert.NoError(err)
_, err = io.Copy(out, src)
out.Close()
@@ -66,11 +105,10 @@ func fetchImage(assert *require.Assertions, name string) *Image {
return path.Join("/a", s)
}
- r, err := spec.NewResourceFromFilename(factory, "/public", "/b/"+name, name)
+ r, err := spec.NewResourceFromFilename(factory, "/public", f, name)
assert.NoError(err)
assert.IsType(&Image{}, r)
return r.(*Image)
-
}
func assertFileCache(assert *require.Assertions, fs *hugofs.Fs, filename string, width, height int) {