feat(文件拆分): 拆分PDF格式适配模块

ofdgo_pdf_clip.go

@@ -15,11 +15,9 @@
 package ofdgo
 
 import (
-	"context"
-	"crypto/sha256"
-	"encoding/binary"
 	"math"
 
+	codecpdf "github.com/xiaoqidun/ofdgo/internal/codec/pdf"
 	"github.com/xiaoqidun/pdfgo"
 )
 
@@ -79,54 +77,11 @@ func pdfClipContainsBoundary(path pdfgo.Path, matrix pdfgo.Matrix, boundary Box)
 	return left < right && top < bottom && boundary.X >= left && boundary.Y >= top && boundary.X+boundary.W <= right && boundary.Y+boundary.H <= bottom
 }
 
-// pdfClipPathKey 按路径完整内容与变换生成键，不依赖可变切片的地址
-// 入参: ctx 取消上下文, path 裁剪路径, matrix 页面变换
-// 返回: [32]byte 内容摘要, error 取消错误
-func pdfClipPathKey(ctx context.Context, path pdfgo.Path, matrix pdfgo.Matrix) ([32]byte, error) {
-	hash := sha256.New()
-	var value [16]byte
-	for _, number := range matrix {
-		binary.LittleEndian.PutUint64(value[:8], math.Float64bits(number))
-		hash.Write(value[:8])
-	}
-	binary.LittleEndian.PutUint64(value[:8], uint64(len(path.Segments)))
-	value[8] = 0
-	if path.EvenOdd {
-		value[8] = 1
-	}
-	hash.Write(value[:9])
-	for _, segment := range path.Segments {
-		if err := ctx.Err(); err != nil {
-			return [32]byte{}, err
-		}
-		binary.LittleEndian.PutUint64(value[:8], uint64(len(segment.Operator)))
-		binary.LittleEndian.PutUint64(value[8:], uint64(len(segment.Points)))
-		hash.Write(value[:])
-		hash.Write([]byte(segment.Operator))
-		for index, point := range segment.Points {
-			if index&255 == 0 {
-				if err := ctx.Err(); err != nil {
-					return [32]byte{}, err
-				}
-			}
-			binary.LittleEndian.PutUint64(value[:8], math.Float64bits(point.X))
-			binary.LittleEndian.PutUint64(value[8:], math.Float64bits(point.Y))
-			hash.Write(value[:])
-		}
-	}
-	if err := ctx.Err(); err != nil {
-		return [32]byte{}, err
-	}
-	var key [32]byte
-	hash.Sum(key[:0])
-	return key, nil
-}
-
 // clipPath 复用页面内重复路径编码，按估算字节预算淘汰且不缓存错误
 // 入参: path 裁剪路径
 // 返回: pdfClipPath 变换后的边界及编码, error 取消错误
 func (p *pdfImporter) clipPath(path pdfgo.Path) (pdfClipPath, error) {
-	key, err := pdfClipPathKey(p.ctx, path, p.matrix)
+	key, err := codecpdf.ClipPathKey(p.ctx, path, p.matrix)
 	if err != nil {
 		return pdfClipPath{}, err
 	}