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()
+}