Files
CBZOptimizer/pkg/converter/webp/webp_converter_test.go
Copilot e535809e74 fix: Fix deadlock in ConvertChapter when context cancelled during page processing (#152)
* Initial plan

* Fix deadlock in ConvertChapter when context is cancelled after wgConvertedPages.Add

Co-authored-by: Belphemur <197810+Belphemur@users.noreply.github.com>

* Fix test comments to remove placeholder issue references

Co-authored-by: Belphemur <197810+Belphemur@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Belphemur <197810+Belphemur@users.noreply.github.com>
2025-12-20 14:26:33 -05:00

596 lines
16 KiB
Go

package webp
import (
"bytes"
"context"
"fmt"
"image"
"image/color"
"image/gif"
"image/jpeg"
"image/png"
"sync"
"testing"
"time"
_ "golang.org/x/image/webp"
"github.com/belphemur/CBZOptimizer/v2/internal/manga"
"github.com/belphemur/CBZOptimizer/v2/pkg/converter/constant"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func createTestImage(width, height int, format string) (image.Image, error) {
img := image.NewRGBA(image.Rect(0, 0, width, height))
// Create a gradient pattern to ensure we have actual image data
for y := 0; y < height; y++ {
for x := 0; x < width; x++ {
img.Set(x, y, color.RGBA{
R: uint8((x * 255) / width),
G: uint8((y * 255) / height),
B: 100,
A: 255,
})
}
}
return img, nil
}
func encodeImage(img image.Image, format string) (*bytes.Buffer, string, error) {
buf := new(bytes.Buffer)
switch format {
case "jpeg", "jpg":
if err := jpeg.Encode(buf, img, &jpeg.Options{Quality: 85}); err != nil {
return nil, "", err
}
return buf, ".jpg", nil
case "gif":
if err := gif.Encode(buf, img, nil); err != nil {
return nil, "", err
}
return buf, ".gif", nil
case "webp":
PrepareEncoder()
if err := Encode(buf, img, 80); err != nil {
return nil, "", err
}
return buf, ".webp", nil
case "png":
fallthrough
default:
if err := png.Encode(buf, img); err != nil {
return nil, "", err
}
return buf, ".png", nil
}
}
func createTestPage(t *testing.T, index int, width, height int, format string) *manga.Page {
img, err := createTestImage(width, height, format)
require.NoError(t, err)
buf, ext, err := encodeImage(img, format)
require.NoError(t, err)
return &manga.Page{
Index: uint16(index),
Contents: buf,
Extension: ext,
Size: uint64(buf.Len()),
}
}
func validateConvertedImage(t *testing.T, page *manga.Page) {
require.NotNil(t, page.Contents)
require.Greater(t, page.Contents.Len(), 0)
// Try to decode the image
img, format, err := image.Decode(bytes.NewReader(page.Contents.Bytes()))
require.NoError(t, err, "Failed to decode converted image")
if page.Extension == ".webp" {
assert.Equal(t, "webp", format, "Expected WebP format")
}
require.NotNil(t, img)
bounds := img.Bounds()
assert.Greater(t, bounds.Dx(), 0, "Image width should be positive")
assert.Greater(t, bounds.Dy(), 0, "Image height should be positive")
}
// TestConverter_ConvertChapter tests the ConvertChapter method of the WebP converter.
// It verifies various scenarios including:
// - Converting single normal images
// - Converting multiple normal images
// - Converting tall images with split enabled
// - Handling tall images that exceed maximum height
//
// For each test case it validates:
// - Proper error handling
// - Expected number of output pages
// - Correct page ordering
// - Split page handling and indexing
// - Progress callback behavior
//
// The test uses different image dimensions and split settings to ensure
// the converter handles all cases correctly while maintaining proper
// progress reporting and page ordering.
func TestConverter_ConvertChapter(t *testing.T) {
tests := []struct {
name string
pages []*manga.Page
split bool
expectSplit bool
expectError bool
numExpected int
}{
{
name: "Single normal image",
pages: []*manga.Page{createTestPage(t, 1, 800, 1200, "jpeg")},
split: false,
expectSplit: false,
numExpected: 1,
},
{
name: "Multiple normal images",
pages: []*manga.Page{
createTestPage(t, 1, 800, 1200, "png"),
createTestPage(t, 2, 800, 1200, "jpeg"),
createTestPage(t, 3, 800, 1200, "gif"),
},
split: false,
expectSplit: false,
numExpected: 3,
},
{
name: "Multiple normal images with webp",
pages: []*manga.Page{
createTestPage(t, 1, 800, 1200, "png"),
createTestPage(t, 2, 800, 1200, "jpeg"),
createTestPage(t, 3, 800, 1200, "gif"),
createTestPage(t, 4, 800, 1200, "webp"),
},
split: false,
expectSplit: false,
numExpected: 4,
},
{
name: "Tall image with split enabled",
pages: []*manga.Page{createTestPage(t, 1, 800, 5000, "jpeg")},
split: true,
expectSplit: true,
numExpected: 3, // Based on cropHeight of 2000
},
{
name: "Tall image without split",
pages: []*manga.Page{createTestPage(t, 1, 800, webpMaxHeight+100, "png")},
split: false,
expectError: true,
numExpected: 1,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
converter := New()
err := converter.PrepareConverter()
require.NoError(t, err)
chapter := &manga.Chapter{
Pages: tt.pages,
}
var progressMutex sync.Mutex
var lastProgress uint32
progress := func(message string, current uint32, total uint32) {
progressMutex.Lock()
defer progressMutex.Unlock()
assert.GreaterOrEqual(t, current, lastProgress, "Progress should never decrease")
lastProgress = current
assert.LessOrEqual(t, current, total, "Current progress should not exceed total")
}
convertedChapter, err := converter.ConvertChapter(context.Background(), chapter, 80, tt.split, progress)
if tt.expectError {
assert.Error(t, err)
if convertedChapter != nil {
assert.LessOrEqual(t, len(convertedChapter.Pages), tt.numExpected)
}
return
}
require.NoError(t, err)
require.NotNil(t, convertedChapter)
assert.Len(t, convertedChapter.Pages, tt.numExpected)
// Validate all converted images
for _, page := range convertedChapter.Pages {
validateConvertedImage(t, page)
}
// Verify page order
for i := 1; i < len(convertedChapter.Pages); i++ {
prevPage := convertedChapter.Pages[i-1]
currPage := convertedChapter.Pages[i]
if prevPage.Index == currPage.Index {
assert.Less(t, prevPage.SplitPartIndex, currPage.SplitPartIndex,
"Split parts should be in ascending order for page %d", prevPage.Index)
} else {
assert.Less(t, prevPage.Index, currPage.Index,
"Pages should be in ascending order")
}
}
if tt.expectSplit {
splitFound := false
for _, page := range convertedChapter.Pages {
if page.IsSplitted {
splitFound = true
break
}
}
assert.True(t, splitFound, "Expected to find at least one split page")
}
})
}
}
func TestConverter_convertPage(t *testing.T) {
converter := New()
err := converter.PrepareConverter()
require.NoError(t, err)
tests := []struct {
name string
format string
isToBeConverted bool
expectWebP bool
expectError bool
}{
{
name: "Convert PNG to WebP",
format: "png",
isToBeConverted: true,
expectWebP: true,
expectError: false,
},
{
name: "Convert GIF to WebP",
format: "gif",
isToBeConverted: true,
expectWebP: true,
expectError: false,
},
{
name: "Already WebP",
format: "webp",
isToBeConverted: true,
expectWebP: true,
expectError: false,
},
{
name: "Skip conversion",
format: "png",
isToBeConverted: false,
expectWebP: false,
expectError: false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
page := createTestPage(t, 1, 100, 100, tt.format)
img, err := createTestImage(100, 100, tt.format)
require.NoError(t, err)
container := manga.NewContainer(page, img, tt.format, tt.isToBeConverted)
converted, err := converter.convertPage(container, 80)
if tt.expectError {
assert.Error(t, err)
assert.Nil(t, converted)
} else {
require.NoError(t, err)
assert.NotNil(t, converted)
if tt.expectWebP {
assert.Equal(t, ".webp", converted.Page.Extension)
validateConvertedImage(t, converted.Page)
} else {
assert.NotEqual(t, ".webp", converted.Page.Extension)
}
}
})
}
}
func TestConverter_convertPage_EncodingError(t *testing.T) {
converter := New()
err := converter.PrepareConverter()
require.NoError(t, err)
// Create a test case with nil image to test encoding error path
// when isToBeConverted is true but the image is nil, simulating a failure in the encoding step
corruptedPage := &manga.Page{
Index: 1,
Contents: &bytes.Buffer{}, // Empty buffer
Extension: ".png",
Size: 0,
}
container := manga.NewContainer(corruptedPage, nil, "png", true)
converted, err := converter.convertPage(container, 80)
// This should return nil container and error because encoding will fail with nil image
assert.Error(t, err)
assert.Nil(t, converted)
}
func TestConverter_checkPageNeedsSplit(t *testing.T) {
converter := New()
tests := []struct {
name string
imageHeight int
split bool
expectSplit bool
expectError bool
}{
{
name: "Normal height",
imageHeight: 1000,
split: true,
expectSplit: false,
},
{
name: "Height exceeds max with split enabled",
imageHeight: 5000,
split: true,
expectSplit: true,
},
{
name: "Height exceeds webp max without split",
imageHeight: webpMaxHeight + 100,
split: false,
expectError: true,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
page := createTestPage(t, 1, 800, tt.imageHeight, "jpeg")
needsSplit, img, format, err := converter.checkPageNeedsSplit(page, tt.split)
if tt.expectError {
assert.Error(t, err)
return
}
require.NoError(t, err)
assert.NotNil(t, img)
assert.NotEmpty(t, format)
assert.Equal(t, tt.expectSplit, needsSplit)
})
}
}
func TestConverter_Format(t *testing.T) {
converter := New()
assert.Equal(t, constant.WebP, converter.Format())
}
func TestConverter_ConvertChapter_Timeout(t *testing.T) {
converter := New()
err := converter.PrepareConverter()
require.NoError(t, err)
// Create a test chapter with a few pages
pages := []*manga.Page{
createTestPage(t, 1, 800, 1200, "jpeg"),
createTestPage(t, 2, 800, 1200, "png"),
createTestPage(t, 3, 800, 1200, "gif"),
}
chapter := &manga.Chapter{
FilePath: "/test/chapter.cbz",
Pages: pages,
}
var progressMutex sync.Mutex
var lastProgress uint32
progress := func(message string, current uint32, total uint32) {
progressMutex.Lock()
defer progressMutex.Unlock()
assert.GreaterOrEqual(t, current, lastProgress, "Progress should never decrease")
lastProgress = current
assert.LessOrEqual(t, current, total, "Current progress should not exceed total")
}
// Test with very short timeout (1 nanosecond)
ctx, cancel := context.WithTimeout(context.Background(), 1)
defer cancel()
convertedChapter, err := converter.ConvertChapter(ctx, chapter, 80, false, progress)
// Should return context error due to timeout
assert.Error(t, err)
assert.Nil(t, convertedChapter)
assert.Equal(t, context.DeadlineExceeded, err)
}
// TestConverter_ConvertChapter_ManyPages_NoDeadlock tests that converting chapters with many pages
// does not cause a deadlock. This test reproduces the scenario where processing
// many files with context cancellation could cause "all goroutines are asleep - deadlock!" error.
// The fix ensures that wgConvertedPages.Done() is called when context is cancelled after Add(1).
func TestConverter_ConvertChapter_ManyPages_NoDeadlock(t *testing.T) {
converter := New()
err := converter.PrepareConverter()
require.NoError(t, err)
// Create a chapter with many pages to increase the chance of hitting the race condition
numPages := 50
pages := make([]*manga.Page, numPages)
for i := 0; i < numPages; i++ {
pages[i] = createTestPage(t, i+1, 100, 100, "jpeg")
}
chapter := &manga.Chapter{
FilePath: "/test/chapter_many_pages.cbz",
Pages: pages,
}
progress := func(message string, current uint32, total uint32) {
// No-op progress callback
}
// Run multiple iterations to increase the chance of hitting the race condition
for iteration := 0; iteration < 10; iteration++ {
t.Run(fmt.Sprintf("iteration_%d", iteration), func(t *testing.T) {
// Use a very short timeout to trigger context cancellation during processing
ctx, cancel := context.WithTimeout(context.Background(), time.Nanosecond)
defer cancel()
// This should NOT deadlock - it should return quickly with context error
done := make(chan struct{})
var convertErr error
go func() {
defer close(done)
_, convertErr = converter.ConvertChapter(ctx, chapter, 80, false, progress)
}()
// Wait with a reasonable timeout - if it takes longer than 5 seconds, we have a deadlock
select {
case <-done:
// Expected - conversion should complete (with error) quickly
assert.Error(t, convertErr, "Expected context error")
case <-time.After(5 * time.Second):
t.Fatal("Deadlock detected: ConvertChapter did not return within 5 seconds")
}
})
}
}
// TestConverter_ConvertChapter_ManyPages_WithSplit_NoDeadlock tests that converting chapters
// with many pages and split enabled does not cause a deadlock.
func TestConverter_ConvertChapter_ManyPages_WithSplit_NoDeadlock(t *testing.T) {
converter := New()
err := converter.PrepareConverter()
require.NoError(t, err)
// Create pages with varying heights, some requiring splits
numPages := 30
pages := make([]*manga.Page, numPages)
for i := 0; i < numPages; i++ {
height := 1000 // Normal height
if i%5 == 0 {
height = 5000 // Tall image that will be split
}
pages[i] = createTestPage(t, i+1, 100, height, "png")
}
chapter := &manga.Chapter{
FilePath: "/test/chapter_split_test.cbz",
Pages: pages,
}
progress := func(message string, current uint32, total uint32) {
// No-op progress callback
}
// Run multiple iterations with short timeouts
for iteration := 0; iteration < 10; iteration++ {
t.Run(fmt.Sprintf("iteration_%d", iteration), func(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), time.Nanosecond)
defer cancel()
done := make(chan struct{})
var convertErr error
go func() {
defer close(done)
_, convertErr = converter.ConvertChapter(ctx, chapter, 80, true, progress) // split=true
}()
select {
case <-done:
assert.Error(t, convertErr, "Expected context error")
case <-time.After(5 * time.Second):
t.Fatal("Deadlock detected: ConvertChapter with split did not return within 5 seconds")
}
})
}
}
// TestConverter_ConvertChapter_ConcurrentChapters_NoDeadlock simulates the scenario from the
// original bug report where multiple chapters are processed in parallel with parallelism > 1.
// This test ensures no deadlock occurs when multiple goroutines are converting chapters concurrently.
func TestConverter_ConvertChapter_ConcurrentChapters_NoDeadlock(t *testing.T) {
converter := New()
err := converter.PrepareConverter()
require.NoError(t, err)
// Create multiple chapters, each with many pages
numChapters := 20
pagesPerChapter := 30
chapters := make([]*manga.Chapter, numChapters)
for c := 0; c < numChapters; c++ {
pages := make([]*manga.Page, pagesPerChapter)
for i := 0; i < pagesPerChapter; i++ {
pages[i] = createTestPage(t, i+1, 100, 100, "jpeg")
}
chapters[c] = &manga.Chapter{
FilePath: fmt.Sprintf("/test/chapter_%d.cbz", c+1),
Pages: pages,
}
}
progress := func(message string, current uint32, total uint32) {}
// Process chapters concurrently with short timeouts (simulating parallelism flag)
parallelism := 4
var wg sync.WaitGroup
semaphore := make(chan struct{}, parallelism)
// Overall test timeout
testCtx, testCancel := context.WithTimeout(context.Background(), 30*time.Second)
defer testCancel()
for _, chapter := range chapters {
wg.Add(1)
semaphore <- struct{}{} // Acquire
go func(ch *manga.Chapter) {
defer wg.Done()
defer func() { <-semaphore }() // Release
// Use very short timeout to trigger cancellation
ctx, cancel := context.WithTimeout(context.Background(), time.Nanosecond)
defer cancel()
// This should not deadlock
_, _ = converter.ConvertChapter(ctx, ch, 80, false, progress)
}(chapter)
}
// Wait for all conversions with a timeout
done := make(chan struct{})
go func() {
wg.Wait()
close(done)
}()
select {
case <-done:
// All goroutines completed successfully
case <-testCtx.Done():
t.Fatal("Deadlock detected: Concurrent chapter conversions did not complete within 30 seconds")
}
}