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feat(电子公文): 完善标引注释，优化资源处理
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xiaoqidun committed 2026-10-13 08:30:03 +08:00
1 parent 3f797e656b
commit 91e5b57e24
43 files changed
+2018 -384
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ofdgo_image_tiff.go
+94 -15
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@@ -28,18 +28,26 @@ import (
// errTIFFRandomAccess 表示目录链需要回读，仅流式输入需重新打开资源
var errTIFFRandomAccess = errors.New("TIFF directory requires random access")
// tiffImageLayout 保存单页TIFF的尺寸、方向、采样及压缩参数
// tiffImageLayout 保存TIFF目录的图像布局及关联透明蒙版
type tiffImageLayout struct {
width, height int
tileWidth int
tileHeight int
orientation int
offset, next uint32
reduced, mask bool
planar bool
auxiliary bool
samples uint32
depth uint32
fillOrder uint32
compression uint32
predictor uint32
photometric uint32
profileOffset uint32
profileSize uint32
t4, t6 uint32
transparency *tiffImageLayout
}
// tiffDirectoryInput 只替换解码视图中的首目录偏移，不复制或改写原始资源
@@ -62,11 +70,21 @@ func isTIFFData(data []byte) bool {
return len(data) >= 4 && (string(data[:4]) == "II\x2a\x00" || string(data[:4]) == "MM\x00\x2a")
}
// readTIFFLayout 选择单页TIFF的主图，允许缩略图目录并拒绝循环和多个主图
// readTIFFLayout 选择主图及其蒙版，允许缩略图并拒绝循环和多个主图
// 入参: input 从文件头开始的输入流
// 返回: tiffImageLayout 存储尺寸与方向, error 文件结构或方向错误
func readTIFFLayout(input io.Reader) (tiffImageLayout, error) {
return readTIFFLayoutContext(context.Background(), input)
}
// readTIFFLayoutContext 扫描目录链并选择主图，读取期间响应取消
// 入参: ctx 取消上下文, input 从文件头开始的输入流
// 返回: tiffImageLayout 存储尺寸与方向, error 结构、读取或取消错误
func readTIFFLayoutContext(ctx context.Context, input io.Reader) (tiffImageLayout, error) {
var result tiffImageLayout
if err := ctx.Err(); err != nil {
return result, err
}
var header [8]byte
if _, err := io.ReadFull(input, header[:]); err != nil {
return result, err
@@ -81,18 +99,23 @@ func readTIFFLayout(input io.Reader) (tiffImageLayout, error) {
offset := int64(order.Uint32(header[4:]))
position := int64(8)
var seen map[uint32]bool
var transparency *tiffImageLayout
for offset != 0 {
if seen != nil && seen[uint32(offset)] {
return result, fmt.Errorf("cyclic TIFF directory chain")
}
layout, end, err := readTIFFDirectory(input, order, offset, position)
layout, end, err := readTIFFDirectory(ctx, input, order, offset, position)
if err != nil {
return result, err
}
if layout.mask {
return result, fmt.Errorf("TIFF transparency mask directories are not supported")
}
if !layout.reduced || layout.next == 0 && seen == nil {
if !layout.reduced {
if transparency != nil {
return result, fmt.Errorf("multiple TIFF transparency masks")
}
transparency = &layout
}
} else if !layout.reduced || layout.next == 0 && seen == nil {
if result.offset != 0 {
return result, fmt.Errorf("multiple TIFF pages are not supported in OFD resources")
}
@@ -106,17 +129,30 @@ func readTIFFLayout(input io.Reader) (tiffImageLayout, error) {
}
offset, position = int64(layout.next), end
}
if err := ctx.Err(); err != nil {
return tiffImageLayout{}, err
}
if result.offset == 0 {
return result, fmt.Errorf("missing TIFF main image")
}
result.transparency = transparency
if transparency != nil {
size := result.displaySize()
if size.X > int(^uint(0)>>1)/8/size.Y {
return tiffImageLayout{}, fmt.Errorf("TIFF mask image dimensions exceed capacity")
}
}
return result, nil
}
// readTIFFDirectory 读取目录中的图像布局和子文件类型，不读取像素
// 入参: input 输入流, order 字节序, offset 目录偏移, position 当前流位置
// 返回: tiffImageLayout 目录布局, int64 读取后的流位置, error 结构或读取错误
func readTIFFDirectory(input io.Reader, order binary.ByteOrder, offset, position int64) (tiffImageLayout, int64, error) {
// 入参: ctx 取消上下文, input 输入流, order 字节序, offset 目录偏移, position 当前流位置
// 返回: tiffImageLayout 目录布局, int64 读取后的流位置, error 结构、读取或取消错误
func readTIFFDirectory(ctx context.Context, input io.Reader, order binary.ByteOrder, offset, position int64) (tiffImageLayout, int64, error) {
var result tiffImageLayout
if err := ctx.Err(); err != nil {
return result, position, err
}
var header [4]byte
if offset < 8 {
return result, position, fmt.Errorf("invalid TIFF directory offset")
@@ -129,7 +165,8 @@ func readTIFFDirectory(input io.Reader, order binary.ByteOrder, offset, position
if offset < position {
return result, position, errTIFFRandomAccess
}
if _, err := io.CopyN(io.Discard, input, offset-position); err != nil {
reader := imageInput{ReadCloser: io.NopCloser(input), context: ctx}
if _, err := io.CopyN(io.Discard, reader, offset-position); err != nil {
return result, position, err
}
}
@@ -140,11 +177,16 @@ func readTIFFDirectory(input io.Reader, order binary.ByteOrder, offset, position
result.orientation, result.offset, result.samples, result.fillOrder = 1, uint32(offset), 1, 1
result.depth = 1
result.compression = 1
result.predictor = 1
var entry [12]byte
var previous uint16
var subfile, legacy uint32
var hasSubfile bool
var invalidMaskDepth bool
for i := range count {
if err := ctx.Err(); err != nil {
return result, position, err
}
if _, err := io.ReadFull(input, entry[:]); err != nil {
return result, position, err
}
@@ -153,20 +195,33 @@ func readTIFFDirectory(input io.Reader, order binary.ByteOrder, offset, position
return result, position, fmt.Errorf("invalid TIFF directory order")
}
previous = tag
if tag == 258 && kind == 3 && number == 1 {
result.depth = uint32(order.Uint16(entry[8:10]))
if tag == 338 {
result.auxiliary = kind != 3 || number != 1 || order.Uint16(entry[8:]) == 0
}
if tag != 254 && tag != 255 && tag != 256 && tag != 257 && tag != 259 && tag != 262 && tag != 266 && tag != 274 && tag != 277 && tag != 284 && tag != 292 && tag != 293 {
if tag == 34675 {
if kind != 7 || number < 132 {
return result, position, fmt.Errorf("invalid TIFF color profile")
}
result.profileOffset, result.profileSize = order.Uint32(entry[8:]), number
continue
}
if number != 1 || kind != 3 && kind != 4 || (tag == 255 || tag == 259 || tag == 262 || tag == 266 || tag == 274 || tag == 277 || tag == 284) && kind != 3 || (tag == 254 || tag == 292 || tag == 293) && kind != 4 {
if tag == 258 {
invalidMaskDepth = kind != 3 || number != 1
if !invalidMaskDepth {
result.depth = uint32(order.Uint16(entry[8:10]))
}
}
if tag != 254 && tag != 255 && tag != 256 && tag != 257 && tag != 259 && tag != 262 && tag != 266 && tag != 274 && tag != 277 && tag != 284 && tag != 292 && tag != 293 && tag != 317 && tag != 322 && tag != 323 {
continue
}
if number != 1 || kind != 3 && kind != 4 || (tag == 255 || tag == 259 || tag == 262 || tag == 266 || tag == 274 || tag == 277 || tag == 284 || tag == 317) && kind != 3 || (tag == 254 || tag == 292 || tag == 293) && kind != 4 {
return result, position, fmt.Errorf("invalid TIFF image layout")
}
value := uint64(order.Uint32(entry[8:12]))
if kind == 3 {
value = uint64(order.Uint16(entry[8:10]))
}
if (tag == 256 || tag == 257) && (value == 0 || value > uint64(int(^uint(0)>>1))) {
if (tag == 256 || tag == 257 || tag == 322 || tag == 323) && (value == 0 || value > uint64(int(^uint(0)>>1))) {
return result, position, fmt.Errorf("invalid TIFF dimensions")
}
switch tag {
@@ -181,6 +236,7 @@ func readTIFFDirectory(input io.Reader, order binary.ByteOrder, offset, position
case 259:
result.compression = uint32(value)
case 262:
result.photometric = uint32(value)
result.mask = value == 4
case 266:
if value != 1 && value != 2 {
@@ -206,6 +262,12 @@ func readTIFFDirectory(input io.Reader, order binary.ByteOrder, offset, position
result.t4 = uint32(value)
case 293:
result.t6 = uint32(value)
case 317:
result.predictor = uint32(value)
case 322:
result.tileWidth = int(value)
case 323:
result.tileHeight = int(value)
}
}
if _, err := io.ReadFull(input, header[:4]); err != nil {
@@ -220,6 +282,12 @@ func readTIFFDirectory(input io.Reader, order binary.ByteOrder, offset, position
if result.width == 0 || result.height == 0 {
return result, position, fmt.Errorf("missing TIFF dimensions")
}
if (result.tileWidth == 0) != (result.tileHeight == 0) || result.tileWidth%16 != 0 || result.tileHeight%16 != 0 {
return result, position, fmt.Errorf("invalid TIFF tile dimensions")
}
if result.mask && (invalidMaskDepth || result.photometric != 4 || result.samples != 1 || result.depth != 1) {
return result, position, fmt.Errorf("invalid TIFF transparency mask")
}
return result, offset + 6 + int64(count)*12, nil
}
@@ -285,6 +353,17 @@ func (l tiffImageLayout) size() image.Point {
return image.Pt(l.width, l.height)
}
// displaySize 返回同时保留主图和透明蒙版分辨率的显示尺寸
// 返回: image.Point 保留高分辨率蒙版边缘的像素宽高
func (l tiffImageLayout) displaySize() image.Point {
size := l.size()
if l.transparency != nil {
mask := l.transparency.size()
size.X, size.Y = max(size.X, mask.X), max(size.Y, mask.Y)
}
return size
}
// Bounds 返回从零开始的显示区域
// 返回: image.Rectangle 显示区域
func (s *orientedTIFFImage) Bounds() image.Rectangle {