feat(编辑压缩): 完善多文档字体压缩

ofdgo_compression_fonts.go

@@ -0,0 +1,100 @@
+// 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 (
+	"context"
+	"encoding/xml"
+	"maps"
+	"slices"
+	"strings"
+)
+
+// compressionFontBinding 保存资源索引中的字体标识、文件路径及可裁剪状态
+type compressionFontBinding struct {
+	id     string
+	file   string
+	unsafe bool
+}
+
+// compressionFontUsage 按文档解析字体引用，按文件路径合并共享字体的全部用字
+// 入参: ctx 取消上下文, parts 输出改动, generated 自产页面引用, documents 文档入口, resources 资源索引, references 各文件引用, read 输出文件读取方法
+// 返回: map[string]*editorFontUsage 各字体文件的用字，无法确定作用域时为空, error 读取或取消错误
+func (r *Reader) compressionFontUsage(ctx context.Context, parts map[string][]byte, generated map[string]editorGeneratedReferences, documents map[string]bool, resources []string, references map[string]*editorResourceRefs, read func(string) ([]byte, error)) (map[string]*editorFontUsage, error) {
+	bindings := make(map[string][]compressionFontBinding)
+	for _, name := range resources {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		data, err := read(name)
+		if err != nil {
+			return nil, err
+		}
+		root, err := parseEditorXML(data)
+		if err != nil {
+			return nil, err
+		}
+		fonts := root.child("Fonts")
+		if fonts == nil {
+			continue
+		}
+		for _, font := range fonts.children {
+			file := font.child("FontFile")
+			if file == nil {
+				continue
+			}
+			var value string
+			if err := xml.Unmarshal(data[file.start:file.end], &value); err != nil {
+				return nil, err
+			}
+			location := editorResourceLocation(name, root.attr("BaseLoc"), value)
+			id, charset := editorResourceID(font.attr("ID")), font.attr("Charset")
+			unsafe := id == "" || charset != "" && !strings.EqualFold(charset, "unicode") || location != cleanPackagePath(resolveResourcePath(name, root.attr("BaseLoc"), value))
+			bindings[name] = append(bindings[name], compressionFontBinding{id: id, file: location, unsafe: unsafe})
+		}
+	}
+	used := make(map[string]bool)
+	result := make(map[string]*editorFontUsage)
+	for _, entry := range slices.Sorted(maps.Keys(documents)) {
+		scope, err := r.versionFileDependencies(ctx, entry, parts, generated)
+		if err != nil {
+			return nil, err
+		}
+		refs := editorResourceRefs{fonts: make(map[string]*editorFontUsage)}
+		for name := range scope {
+			if source := references[name]; source != nil {
+				for id, usage := range source.fonts {
+					refs.fontUsage(id).merge(usage, false)
+				}
+				used[name] = true
+			}
+		}
+		for name := range scope {
+			for _, binding := range bindings[name] {
+				usage := refs.fonts[binding.id]
+				if result[binding.file] == nil {
+					result[binding.file] = newEditorFontUsage()
+				}
+				result[binding.file].merge(usage, binding.unsafe)
+			}
+		}
+	}
+	for name, refs := range references {
+		if !used[name] && (len(refs.fonts) != 0 || len(bindings[name]) != 0) {
+			return nil, nil
+		}
+	}
+	return result, ctx.Err()
+}

ofdgo_compression_resources.go

@@ -74,6 +74,10 @@ func (e *Editor) compressResourceReferences(parts map[string][]byte, reader *Rea
 		return reader.readFileView(name)
 	}
 	refs := editorResourceRefs{ids: make(map[string]bool), files: make(map[string]bool), fonts: make(map[string]*editorFontUsage)}
+	var fontReferences map[string]*editorResourceRefs
+	if reader != nil && reader.DocumentCount() > 1 && e.backends.FontResources != nil {
+		fontReferences = make(map[string]*editorResourceRefs)
+	}
 	var resources []string
 	actual := make(map[string]string)
 	for _, name := range slices.Sorted(maps.Keys(names)) {
@@ -94,6 +98,9 @@ func (e *Editor) compressResourceReferences(parts map[string][]byte, reader *Rea
 		data, replaced := parts[name]
 		if known, ok := generated[name]; ok && replaced && known.refs != nil && known.matches(data) {
 			refs.merge(known.refs)
+			if fontReferences != nil && len(known.refs.fonts) != 0 {
+				fontReferences[name] = known.refs
+			}
 			continue
 		}
 		var input io.ReadCloser
@@ -110,7 +117,11 @@ func (e *Editor) compressResourceReferences(parts map[string][]byte, reader *Rea
 				return err
 			}
 		}
-		resource, safe := refs.scan(imageInput{ReadCloser: input, context: e.output.ctx}, name)
+		scanned := &refs
+		if fontReferences != nil {
+			scanned = &editorResourceRefs{ids: make(map[string]bool), files: make(map[string]bool), fonts: make(map[string]*editorFontUsage)}
+		}
+		resource, safe := scanned.scan(imageInput{ReadCloser: input, context: e.output.ctx}, name)
 		input.Close()
 		if err := e.output.ctx.Err(); err != nil {
 			return err
@@ -118,6 +129,12 @@ func (e *Editor) compressResourceReferences(parts map[string][]byte, reader *Rea
 		if !safe {
 			return nil
 		}
+		if fontReferences != nil {
+			if resource || len(scanned.fonts) != 0 {
+				fontReferences[name] = scanned
+			}
+			refs.merge(scanned)
+		}
 		if resource {
 			resources = append(resources, name)
 		}
@@ -168,6 +185,13 @@ func (e *Editor) compressResourceReferences(parts map[string][]byte, reader *Rea
 			}
 		}
 	}
+	var fontUsage map[string]*editorFontUsage
+	if fontReferences != nil {
+		fontUsage, err = reader.compressionFontUsage(e.output.ctx, parts, generated, refs.documents, resources, fontReferences, read)
+		if err != nil {
+			return err
+		}
+	}
 	aliases := make(map[string]string)
 	locations := maps.Clone(actual)
 	reserved := make(map[string]bool, len(actual))
@@ -227,6 +251,17 @@ func (e *Editor) compressResourceReferences(parts map[string][]byte, reader *Rea
 				}
 				source.key.hash = sha256.Sum256(data)
 			}
+			if usage := fontUsage[key]; role == "FontFile" && usage != nil && !usage.unsafe {
+				candidate, err := e.backends.FontResources.SubsetSourceFont(data, FontUsage{Characters: slices.Sorted(maps.Keys(usage.chars)), Glyphs: slices.Sorted(maps.Keys(usage.glyphs))})
+				if err != nil {
+					return fmt.Errorf("subset font %s: %w", key, err)
+				}
+				if len(candidate) != 0 && len(candidate) < len(data) {
+					data = candidate
+					parts[actual[key]] = data
+					source.key.hash = sha256.Sum256(data)
+				}
+			}
 			if role == "MediaFile" {
 				options, demand := e.outputImageOptions(key)
 				cacheKey := outputImageKey{hash: source.key.hash, options: options, size: demand}

ofdgo_editor_reference.go

@@ -143,6 +143,12 @@ func (s *editorReferenceScan) accept(token xml.Token) bool {
 		}
 		if len(s.stack) == 0 {
 			s.seen = true
+			if token.Name.Local == "Document" {
+				if s.refs.documents == nil {
+					s.refs.documents = make(map[string]bool)
+				}
+				s.refs.documents[s.name] = true
+			}
 			s.resource = token.Name.Local == "Res"
 			if s.resource {
 				for _, attr := range token.Attr {
@@ -238,6 +244,12 @@ func (s *editorReferenceScan) accept(token xml.Token) bool {
 func (r *editorResourceRefs) merge(other *editorResourceRefs) {
 	maps.Copy(r.ids, other.ids)
 	maps.Copy(r.files, other.files)
+	if len(other.documents) != 0 {
+		if r.documents == nil {
+			r.documents = make(map[string]bool)
+		}
+		maps.Copy(r.documents, other.documents)
+	}
 	if len(other.versions) != 0 {
 		if r.versions == nil {
 			r.versions = make(map[string]bool)

ofdgo_editor_resources.go

@@ -41,6 +41,7 @@ type editorResourceRefs struct {
 	files     map[string]bool
 	fonts     map[string]*editorFontUsage
 	versions  map[string]bool
+	documents map[string]bool
 }
 
 // compactSourceReferences 合并自产页面引用，版本文档按当前版本范围扫描