refactor(重构提升): 优化转换渲染与资源压缩

ofdgo_reader_dependencies.go

@@ -0,0 +1,149 @@
+// 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 (
+	"bufio"
+	"bytes"
+	"context"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"strings"
+)
+
+// documentFiles 按标准路径遍历独立文档依赖，签名摘要引用不作为内容依赖
+// 入参: ctx 取消上下文, index 文档索引
+// 返回: map[string]bool 大小写折叠的文件路径, error 读取或取消错误
+func (r *Reader) documentFiles(ctx context.Context, index int) (map[string]bool, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if index < 0 || index >= r.DocumentCount() {
+		return nil, fmt.Errorf("document index out of range: %d", index)
+	}
+	queue := []string{cleanPackagePath(r.OFD.DocBody[index].DocRoot)}
+	data, err := r.readFile("OFD.xml")
+	if err != nil {
+		return nil, err
+	}
+	root, err := parseEditorXML(data)
+	if err != nil {
+		return nil, err
+	}
+	body := root.childAt("DocBody", index)
+	if body == nil {
+		return nil, fmt.Errorf("document body not found: %d", index)
+	}
+	var collect func(*editorXML)
+	collect = func(node *editorXML) {
+		if node.name.Local == "Cover" || node.name.Local == "Signatures" || node.name.Local == "DocRoot" {
+			if value := strings.TrimSpace(editorImportText(data, node)); value != "" {
+				queue = append(queue, resolveResourcePath("OFD.xml", "", value))
+			}
+		}
+		if node.name.Local == "Version" && node.attr("BaseLoc") != "" {
+			queue = append(queue, resolveResourcePath("OFD.xml", "", node.attr("BaseLoc")))
+		}
+		for _, child := range node.children {
+			collect(child)
+		}
+	}
+	collect(body)
+	seen := make(map[string]bool)
+	for len(queue) > 0 {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		name := queue[0]
+		queue = queue[1:]
+		key := strings.ToLower(name)
+		if seen[key] {
+			continue
+		}
+		seen[key] = true
+		actual, exists := r.fileNamesFold[key]
+		if !exists {
+			continue
+		}
+		input, err := r.openFile(actual)
+		if err != nil {
+			return nil, err
+		}
+		buffer := bufio.NewReader(imageInput{ReadCloser: input, context: ctx})
+		if prefix, _ := buffer.Peek(3); bytes.Equal(prefix, []byte{0xef, 0xbb, 0xbf}) {
+			buffer.Discard(3)
+		}
+		header, _ := buffer.Peek(128)
+		for len(header) > 0 && len(bytes.TrimSpace(header)) == 0 {
+			buffer.Discard(len(header))
+			header, _ = buffer.Peek(128)
+		}
+		if !bytes.HasPrefix(bytes.TrimSpace(header), []byte("<")) {
+			input.Close()
+			continue
+		}
+		decoder := xml.NewDecoder(buffer)
+		base, resource, depth := "", false, 0
+		var text strings.Builder
+		for {
+			token, err := decoder.Token()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				input.Close()
+				return nil, err
+			}
+			switch node := token.(type) {
+			case xml.StartElement:
+				if depth == 0 && node.Name.Space != "" && node.Name.Space != ofdNamespace && node.Name.Space != "http://www.ofdspec.org" {
+					input.Close()
+					goto nextFile
+				}
+				if node.Name.Space != "" && node.Name.Space != ofdNamespace && node.Name.Space != "http://www.ofdspec.org" {
+					input.Close()
+					return nil, fmt.Errorf("cannot determine document dependencies in %s", actual)
+				}
+				if depth == 0 {
+					resource = node.Name.Local == "Res"
+				}
+				for _, attr := range node.Attr {
+					if resource && depth == 0 && attr.Name.Local == "BaseLoc" {
+						base = attr.Value
+					} else if attr.Name.Local == "BaseLoc" || attr.Name.Local == "FileLoc" || node.Name.Local == "DrawParam" && attr.Name.Local == "Link" || node.Name.Local == "ColorSpace" && attr.Name.Local == "Profile" {
+						queue = append(queue, resolveResourcePath(actual, base, attr.Value))
+					}
+				}
+				depth++
+				text.Reset()
+			case xml.CharData:
+				text.Write(node)
+			case xml.EndElement:
+				switch node.Name.Local {
+				case "DocRoot", "Signatures", "Cover", "PublicRes", "DocumentRes", "PageRes", "Annotations", "Attachments", "FileLoc", "Profile", "SignedValue", "SchemaLoc", "ExtendData", "File", "FontFile", "MediaFile", "CustomTags", "Extensions":
+					if value := strings.TrimSpace(text.String()); value != "" {
+						queue = append(queue, resolveResourcePath(actual, base, value))
+					}
+				}
+				depth--
+				text.Reset()
+			}
+		}
+		input.Close()
+	nextFile:
+	}
+	return seen, ctx.Err()
+}