Files
ofdgo/ofdgo_compression_resources.go
T
2026-10-18 01:48:36 +08:00

473 lines
14 KiB
Go

// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package ofdgo
import (
"bytes"
"context"
"crypto/sha256"
"encoding/xml"
"fmt"
"image"
"io"
"maps"
"path"
"slices"
"strings"
)
// outputImageKey 区分相同图像的压缩配置和像素需求,不跨写出保留状态
type outputImageKey struct {
hash [32]byte
options CompressionOptions
size image.Point
}
// compressResourceParts 优化输出图片并合并相同资源文件,保留资源标识及各自属性
// 入参: parts 输出改动, reader 原包,可为空, removed 已移除条目
// 返回: error 读取或取消错误
func (e *Editor) compressResourceParts(parts map[string][]byte, reader *Reader, removed map[string]bool) error {
if reader == nil && e.output != nil && e.output.options.Mode != CompressionUnchanged && !e.output.protected {
unused, err := e.compactResourceReferences(parts, nil, editorProgress(e.OnWriteProgress), nil, nil)
if err != nil {
return err
}
maps.Copy(removed, unused)
}
return e.compressResourceReferences(parts, reader, removed, nil)
}
// compressResourceReferences 优化资源,复用自产页面引用并流式读取暂存页面
// 版本文件隔离当前入口,其他文档仅优化未受版本保护的资源;结果仅在本次写出内复用
// 入参: parts 输出改动, reader 原包, removed 已移除条目, generated 本次自产页面及引用
// 返回: error 读取或取消错误
func (e *Editor) compressResourceReferences(parts map[string][]byte, reader *Reader, removed map[string]bool, generated map[string]editorGeneratedReferences) error {
if e.output == nil || e.output.options.Mode == CompressionUnchanged || e.output.protected {
return nil
}
generated = e.generatedVectorReferences(parts, generated)
selected, scope, err := reader.versionResourceFiles(e.output.ctx, parts, generated)
if err != nil {
return err
}
names := make(map[string]bool)
if reader != nil {
for name := range reader.fileIndex {
names[name] = true
}
for name := range reader.files {
names[name] = true
}
}
for name := range parts {
names[name] = true
}
read := func(name string) ([]byte, error) {
if err := e.output.ctx.Err(); err != nil {
return nil, err
}
if data, ok := parts[name]; ok {
return data, nil
}
return reader.readFileViewContext(e.output.ctx, name)
}
actual := make(map[string]string)
for _, name := range slices.Sorted(maps.Keys(names)) {
if err := e.output.ctx.Err(); err != nil {
return err
}
key := cleanPackagePath(name)
if removed[key] || strings.HasSuffix(name, "/") {
delete(names, name)
continue
}
if prior, ok := actual[key]; ok && prior != name {
return nil
}
actual[key] = name
if scope != nil && !scope[key] {
delete(names, name)
continue
}
}
collect := reader != nil && reader.DocumentCount() > 1 && e.backends.FontResources != nil
refs, resources, references, safe, err := scanEditorResources(e.output.ctx, reader, parts, generated, names, nil, collect)
if err != nil || !safe {
return err
}
if selected != nil && reader.DocumentCount() > 1 {
preserved, err := reader.versionPreservedFiles(e.output.ctx)
if err != nil {
return err
}
for name := range preserved {
if !selected[name] {
refs.files[name], refs.versions[name] = true, true
}
}
}
type resourceFile struct{ key, role string }
type resourceScope struct {
role string
selected bool
}
type resourceSize struct {
role string
size uint64
}
files := make(map[resourceFile]bool)
for _, name := range resources {
data, err := read(name)
if err != nil {
return err
}
root, err := parseEditorXMLContext(e.output.ctx, data)
if err != nil {
return err
}
preserved := refs.versions[cleanPackagePath(name)]
for _, group := range root.children {
for _, node := range group.children {
if err := e.output.ctx.Err(); err != nil {
return err
}
field := ""
if group.name.Local == "Fonts" && node.name.Local == "Font" {
field = "FontFile"
}
if group.name.Local == "MultiMedias" && node.name.Local == "MultiMedia" {
field = "MediaFile"
}
if field == "" {
continue
}
file := node.child(field)
if file == nil {
continue
}
var value string
if err := xml.Unmarshal(data[file.start:file.end], &value); err != nil {
return err
}
key := editorResourceLocation(name, root.attr("BaseLoc"), value)
if selected != nil && !selected[cleanPackagePath(name)] && selected[key] {
continue
}
if preserved || field == "MediaFile" && node.attr("Type") != "Image" {
refs.files[key] = true
continue
}
if key != cleanPackagePath(resolveResourcePath(name, root.attr("BaseLoc"), value)) {
return nil
}
if actual[key] != "" && !refs.files[key] {
files[resourceFile{key, field}] = true
}
}
}
}
var fontUsage map[string]*editorFontUsage
if references != nil {
fontUsage, err = reader.compressionFontUsage(e.output.ctx, refs.documents, resources, references, read)
if err != nil {
return err
}
}
aliases := make(map[string]string)
locations := maps.Clone(actual)
reserved := make(map[string]bool, len(actual))
for key := range actual {
reserved[key] = true
}
formats := make(map[string]string)
seen := make(map[resourceScope]map[[32]byte]string)
imageResults := make(map[outputImageKey][]byte)
imageDigests := make(map[outputImageKey][32]byte)
imageSources := make(map[string]outputImageSource)
ordered := slices.Sorted(maps.Keys(actual))
sizes := make(map[string]uint64, len(files))
largeCounts := make(map[resourceSize]int)
var imageKeys []string
for _, key := range ordered {
if err := e.output.ctx.Err(); err != nil {
return err
}
font, media := files[resourceFile{key, "FontFile"}], files[resourceFile{key, "MediaFile"}]
if refs.files[key] || font == media {
continue
}
size, err := outputResourceSize(reader, parts, actual[key])
if err != nil {
return err
}
sizes[key] = size
if size > outputOptimizationBufferLimit {
role := "MediaFile"
if font {
role = "FontFile"
}
largeCounts[resourceSize{role, size}]++
} else if media {
imageKeys = append(imageKeys, key)
}
}
load := func(key string) ([]byte, error) {
if sizes[key] > outputOptimizationBufferLimit {
return nil, nil
}
return read(actual[key])
}
if err := e.prepareOutputImages(imageKeys, load, imageResults, imageSources); err != nil {
return err
}
var fontCache editorSourceFontCache
var hashBuffer []byte
for _, key := range ordered {
if refs.files[key] || files[resourceFile{key, "FontFile"}] && files[resourceFile{key, "MediaFile"}] {
continue
}
for _, role := range []string{"FontFile", "MediaFile"} {
if !files[resourceFile{key, role}] {
continue
}
if err := editorProgress(e.OnWriteProgress).withContext(e.output.ctx).report("compress", e.output.completed, 0); err != nil {
return err
}
if size := sizes[key]; size > outputOptimizationBufferLimit && largeCounts[resourceSize{role, size}] < 2 {
continue
}
source, prefetched := imageSources[key]
usage := fontUsage[key]
subset := role == "FontFile" && usage != nil && !usage.unsafe && e.backends.FontResources != nil
var data []byte
optimizable := prefetched
if !prefetched {
var err error
if role == "MediaFile" || subset {
data, err = load(key)
if err != nil {
return err
}
}
optimizable = data != nil
if optimizable {
source.key.hash = sha256.Sum256(data)
} else {
if hashBuffer == nil {
hashBuffer = make([]byte, 32*1024)
}
source.key.hash, err = outputResourceDigest(e.output.ctx, reader, parts, actual[key], hashBuffer)
if err != nil {
return err
}
}
}
if optimizable && subset {
candidate, err := fontCache.subset(e.output.ctx, e.backends.FontResources, data, usage)
if err != nil {
return fmt.Errorf("subset font %s: %w", key, err)
}
if err := e.output.ctx.Err(); err != nil {
return err
}
if len(candidate) != 0 && len(candidate) < len(data) {
data = candidate
parts[actual[key]] = data
source.key.hash = sha256.Sum256(data)
}
}
if role == "MediaFile" && optimizable {
options, demand := e.outputImageOptions(key)
cacheKey := outputImageKey{hash: source.key.hash, options: options, size: demand}
candidate, cached := imageResults[cacheKey]
var err error
if !cached {
candidate, err = optimizeOutputImage(e.output.ctx, outputImageJob{data: data, key: outputImageKey{options: options, size: demand}})
if err := e.output.ctx.Err(); err != nil {
return err
}
imageResults[cacheKey] = nil
if err == nil && len(candidate) < len(data) {
imageResults[cacheKey] = candidate
} else {
candidate = nil
}
}
if candidate != nil {
data = candidate
parts[actual[key]] = data
digest, ok := imageDigests[cacheKey]
if !ok {
digest = sha256.Sum256(data)
imageDigests[cacheKey] = digest
}
source.key.hash = digest
}
if data != nil {
source.format = outputImageFormat(data)
}
if source.format != "" {
formats[key] = source.format
suffix := ".png"
if source.format == "JPEG" {
suffix = ".jpg"
}
ext := path.Ext(actual[key])
if !strings.EqualFold(ext, suffix) && !(source.format == "JPEG" && strings.EqualFold(ext, ".jpeg")) {
if data == nil {
data, err = read(actual[key])
if err != nil {
return err
}
}
stem := strings.TrimSuffix(actual[key], ext)
name := stem + suffix
for n := 1; reserved[name]; n++ {
name = fmt.Sprintf("%s-%d%s", stem, n, suffix)
}
reserved[name] = true
locations[key] = name
parts[name] = data
delete(parts, actual[key])
removed[key] = true
}
}
}
scope := resourceScope{role, selected[key]}
if seen[scope] == nil {
seen[scope] = make(map[[32]byte]string)
}
hash := source.key.hash
if first, ok := seen[scope][hash]; ok {
aliases[key] = first
removed[key] = true
if locations[key] != actual[key] {
delete(parts, locations[key])
}
} else {
seen[scope][hash] = key
}
}
}
if len(aliases) == 0 && len(formats) == 0 {
return e.output.ctx.Err()
}
for _, name := range resources {
if refs.versions[cleanPackagePath(name)] {
continue
}
data, err := read(name)
if err != nil {
return err
}
root, err := parseEditorXMLContext(e.output.ctx, data)
if err != nil {
return err
}
var patches []editorXMLPatch
for _, group := range root.children {
for _, node := range group.children {
if err := e.output.ctx.Err(); err != nil {
return err
}
for _, field := range []string{"FontFile", "MediaFile"} {
file := node.child(field)
if file == nil {
continue
}
var value string
if err := xml.Unmarshal(data[file.start:file.end], &value); err != nil {
return err
}
key := editorResourceLocation(name, root.attr("BaseLoc"), value)
if selected != nil && !selected[cleanPackagePath(name)] && selected[key] {
continue
}
location := locations[key]
if first, ok := aliases[key]; ok {
location = locations[first]
}
if location != "" && location != actual[key] {
var escaped bytes.Buffer
xml.EscapeText(&escaped, []byte("/"+location))
patches = append(patches, editorXMLContent(data, file, escaped.Bytes()))
}
if field == "MediaFile" && formats[key] != "" && node.attr("Format") != formats[key] {
patch, err := editorXMLAttributePatch(data, node, "Format", formats[key])
if err != nil {
return err
}
patches = append(patches, patch)
}
}
}
}
if len(patches) > 0 {
parts[name] = editorPatchXML(data, patches)
}
}
return e.output.ctx.Err()
}
// outputResourceSize 获取资源的实际输出大小,优先使用本次改动及已加载数据
// 入参: reader 原包,可为空, parts 输出改动, name 资源路径
// 返回: uint64 未压缩字节数, error 文件不存在
func outputResourceSize(reader *Reader, parts map[string][]byte, name string) (uint64, error) {
if data, ok := parts[name]; ok {
return uint64(len(data)), nil
}
if reader != nil {
if data, ok := reader.files[cleanPackagePath(name)]; ok {
return uint64(len(data)), nil
}
if file, ok := reader.packageFile(name); ok {
return file.UncompressedSize64, nil
}
}
return 0, fmt.Errorf("file not found: %s", name)
}
// outputResourceDigest 流式计算资源摘要,不将原包中的大文件加载到内存
// 入参: ctx 取消上下文, reader 原包,可为空, parts 输出改动, name 资源路径, buffer 复用缓冲
// 返回: [32]byte 内容摘要, error 读取或取消错误
func outputResourceDigest(ctx context.Context, reader *Reader, parts map[string][]byte, name string, buffer []byte) ([32]byte, error) {
if err := ctx.Err(); err != nil {
return [32]byte{}, err
}
var input io.ReadCloser
if data, ok := parts[name]; ok {
input = io.NopCloser(bytes.NewReader(data))
} else {
if reader == nil {
return [32]byte{}, fmt.Errorf("file not found: %s", name)
}
var err error
input, err = reader.openFile(name)
if err != nil {
return [32]byte{}, err
}
}
hash := sha256.New()
_, err := io.CopyBuffer(hash, imageInput{ReadCloser: input, context: ctx}, buffer)
closeErr := input.Close()
if err != nil {
return [32]byte{}, err
}
if closeErr != nil {
return [32]byte{}, closeErr
}
return [32]byte(hash.Sum(nil)), ctx.Err()
}