mirror of https://github.com/dsoprea/go-exif.git
ifd_builder: renamed builderTag to BuilderTag.
- It's probably a generally good idea.
- These are usually created by other methods, but they're regularly
interacted with when you want to make tag changes and by making them
private we can't public official, testable examples.
- Corrected names for new examples.
pull/3/head
Dustin Oprea
parent
81b804b70d
commit
570c4d582c
1403
ifd_builder.go
1403
ifd_builder.go
File diff suppressed because it is too large
Load Diff
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@ -1,199 +1,197 @@
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package exif
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import (
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"bytes"
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"fmt"
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"strings"
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"bytes"
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"fmt"
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"strings"
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"encoding/binary"
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"encoding/binary"
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"github.com/dsoprea/go-logging"
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"github.com/dsoprea/go-logging"
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)
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const (
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// Tag-ID + Tag-Type + Unit-Count + Value/Offset.
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IfdTagEntrySize = uint32(2 + 2 + 4 + 4)
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// Tag-ID + Tag-Type + Unit-Count + Value/Offset.
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IfdTagEntrySize = uint32(2 + 2 + 4 + 4)
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)
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type ByteWriter struct {
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b *bytes.Buffer
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byteOrder binary.ByteOrder
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b *bytes.Buffer
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byteOrder binary.ByteOrder
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}
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func NewByteWriter(b *bytes.Buffer, byteOrder binary.ByteOrder) (bw *ByteWriter) {
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return &ByteWriter{
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b: b,
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byteOrder: byteOrder,
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}
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return &ByteWriter{
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b: b,
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byteOrder: byteOrder,
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}
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}
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func (bw ByteWriter) writeAsBytes(value interface{}) (err error) {
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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err = binary.Write(bw.b, bw.byteOrder, value)
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log.PanicIf(err)
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err = binary.Write(bw.b, bw.byteOrder, value)
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log.PanicIf(err)
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return nil
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return nil
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}
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func (bw ByteWriter) WriteUint32(value uint32) (err error) {
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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err = bw.writeAsBytes(value)
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log.PanicIf(err)
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err = bw.writeAsBytes(value)
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log.PanicIf(err)
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return nil
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return nil
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}
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func (bw ByteWriter) WriteUint16(value uint16) (err error) {
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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err = bw.writeAsBytes(value)
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log.PanicIf(err)
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err = bw.writeAsBytes(value)
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log.PanicIf(err)
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return nil
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return nil
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}
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func (bw ByteWriter) WriteFourBytes(value []byte) (err error) {
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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len_ := len(value)
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if len_ != 4 {
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log.Panicf("value is not four-bytes: (%d)", len_)
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}
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len_ := len(value)
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if len_ != 4 {
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log.Panicf("value is not four-bytes: (%d)", len_)
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}
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_, err = bw.b.Write(value)
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log.PanicIf(err)
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_, err = bw.b.Write(value)
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log.PanicIf(err)
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return nil
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return nil
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}
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// ifdOffsetIterator keeps track of where the next IFD should be written by
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// keeping track of where the offsets start, the data that has been added, and
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// bumping the offset *when* the data is added.
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type ifdDataAllocator struct {
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offset uint32
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b bytes.Buffer
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offset uint32
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b bytes.Buffer
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}
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func newIfdDataAllocator(ifdDataAddressableOffset uint32) *ifdDataAllocator{
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return &ifdDataAllocator{
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offset: ifdDataAddressableOffset,
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}
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func newIfdDataAllocator(ifdDataAddressableOffset uint32) *ifdDataAllocator {
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return &ifdDataAllocator{
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offset: ifdDataAddressableOffset,
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}
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}
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func (ida *ifdDataAllocator) Allocate(value []byte) (offset uint32, err error) {
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_, err = ida.b.Write(value)
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log.PanicIf(err)
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_, err = ida.b.Write(value)
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log.PanicIf(err)
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offset = ida.offset
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ida.offset += uint32(len(value))
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offset = ida.offset
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ida.offset += uint32(len(value))
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return offset, nil
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return offset, nil
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}
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func (ida *ifdDataAllocator) NextOffset() uint32 {
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return ida.offset
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return ida.offset
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}
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func (ida *ifdDataAllocator) Bytes() []byte {
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return ida.b.Bytes()
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return ida.b.Bytes()
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}
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// IfdByteEncoder converts an IB to raw bytes (for writing) while also figuring
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// out all of the allocations and indirection that is required for extended
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// data.
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type IfdByteEncoder struct {
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// journal holds a list of actions taken while encoding.
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journal [][3]string
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// journal holds a list of actions taken while encoding.
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journal [][3]string
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}
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func NewIfdByteEncoder() (ibe *IfdByteEncoder) {
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return &IfdByteEncoder{
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journal: make([][3]string, 0),
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}
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return &IfdByteEncoder{
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journal: make([][3]string, 0),
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}
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}
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func (ibe *IfdByteEncoder) Journal() [][3]string {
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return ibe.journal
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return ibe.journal
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}
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func (ibe *IfdByteEncoder) TableSize(entryCount int) uint32 {
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// Tag-Count + (Entry-Size * Entry-Count) + Next-IFD-Offset.
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return uint32(2) + (IfdTagEntrySize * uint32(entryCount)) + uint32(4)
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// Tag-Count + (Entry-Size * Entry-Count) + Next-IFD-Offset.
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return uint32(2) + (IfdTagEntrySize * uint32(entryCount)) + uint32(4)
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}
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func (ibe *IfdByteEncoder) pushToJournal(where, direction, format string, args ...interface{}) {
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event := [3]string {
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direction,
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where,
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fmt.Sprintf(format, args...),
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}
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event := [3]string{
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direction,
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where,
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fmt.Sprintf(format, args...),
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}
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ibe.journal = append(ibe.journal, event)
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ibe.journal = append(ibe.journal, event)
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}
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// PrintJournal prints a hierarchical representation of the steps taken during
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// encoding.
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func (ibe *IfdByteEncoder) PrintJournal() {
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maxWhereLength := 0
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for _, event := range ibe.journal {
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where := event[1]
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maxWhereLength := 0
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for _, event := range ibe.journal {
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where := event[1]
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len_ := len(where)
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if len_ > maxWhereLength {
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maxWhereLength = len_
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}
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}
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len_ := len(where)
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if len_ > maxWhereLength {
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maxWhereLength = len_
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}
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}
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level := 0
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for i, event := range ibe.journal {
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direction := event[0]
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where := event[1]
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message := event[2]
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level := 0
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for i, event := range ibe.journal {
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direction := event[0]
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where := event[1]
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message := event[2]
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if direction != ">" && direction != "<" && direction != "-" {
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log.Panicf("journal operation not valid: [%s]", direction)
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}
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if direction != ">" && direction != "<" && direction != "-" {
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log.Panicf("journal operation not valid: [%s]", direction)
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}
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if direction == "<" {
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if level <= 0 {
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log.Panicf("journal operations unbalanced (too many closes)")
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}
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if direction == "<" {
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if level <= 0 {
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log.Panicf("journal operations unbalanced (too many closes)")
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}
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level--
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}
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level--
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}
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indent := strings.Repeat(" ", level)
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indent := strings.Repeat(" ", level)
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fmt.Printf("%3d %s%s %s: %s\n", i, indent, direction, where, message)
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fmt.Printf("%3d %s%s %s: %s\n", i, indent, direction, where, message)
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if direction == ">" {
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level++
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}
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}
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if direction == ">" {
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level++
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}
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}
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if level != 0 {
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log.Panicf("journal operations unbalanced (too many opens)")
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}
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if level != 0 {
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log.Panicf("journal operations unbalanced (too many opens)")
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}
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}
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// encodeTagToBytes encodes the given tag to a byte stream. If
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@ -201,103 +199,103 @@ func (ibe *IfdByteEncoder) PrintJournal() {
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// (`nextIfdOffsetToWrite` is required in order for them to know where the its
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// IFD data will be written, in order for them to know the offset of where
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// their allocated-data block will start, which follows right behind).
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func (ibe *IfdByteEncoder) encodeTagToBytes(ib *IfdBuilder, bt *builderTag, bw *ByteWriter, ida *ifdDataAllocator, nextIfdOffsetToWrite uint32) (childIfdBlock []byte, err error) {
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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func (ibe *IfdByteEncoder) encodeTagToBytes(ib *IfdBuilder, bt *BuilderTag, bw *ByteWriter, ida *ifdDataAllocator, nextIfdOffsetToWrite uint32) (childIfdBlock []byte, err error) {
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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// Write tag-ID.
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err = bw.WriteUint16(bt.tagId)
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log.PanicIf(err)
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// Write tag-ID.
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err = bw.WriteUint16(bt.tagId)
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log.PanicIf(err)
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// Works for both values and child IFDs (which have an official size of
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// LONG).
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err = bw.WriteUint16(bt.typeId)
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log.PanicIf(err)
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// Works for both values and child IFDs (which have an official size of
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// LONG).
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err = bw.WriteUint16(bt.typeId)
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log.PanicIf(err)
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// Write unit-count.
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// Write unit-count.
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if bt.value.IsBytes() == true {
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effectiveType := bt.typeId
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if bt.typeId == TypeUndefined {
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effectiveType = TypeByte
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}
|
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if bt.value.IsBytes() == true {
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effectiveType := bt.typeId
|
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if bt.typeId == TypeUndefined {
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effectiveType = TypeByte
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}
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|
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// It's a non-unknown value.Calculate the count of values of
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// the type that we're writing and the raw bytes for the whole list.
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// It's a non-unknown value.Calculate the count of values of
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// the type that we're writing and the raw bytes for the whole list.
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|
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typeSize := uint32(TagTypeSize(effectiveType))
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typeSize := uint32(TagTypeSize(effectiveType))
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|
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valueBytes := bt.value.Bytes()
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valueBytes := bt.value.Bytes()
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|
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len_ := len(valueBytes)
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unitCount := uint32(len_) / typeSize
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len_ := len(valueBytes)
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unitCount := uint32(len_) / typeSize
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|
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if _, found := tagsWithoutAlignment[bt.tagId]; found == false {
|
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remainder := uint32(len_) % typeSize
|
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if _, found := tagsWithoutAlignment[bt.tagId]; found == false {
|
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remainder := uint32(len_) % typeSize
|
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|
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if remainder > 0 {
|
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log.Panicf("tag (0x%04x) value of (%d) bytes not evenly divisible by type-size (%d)", bt.tagId, len_, typeSize)
|
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}
|
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}
|
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if remainder > 0 {
|
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log.Panicf("tag (0x%04x) value of (%d) bytes not evenly divisible by type-size (%d)", bt.tagId, len_, typeSize)
|
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}
|
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}
|
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|
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err = bw.WriteUint32(unitCount)
|
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log.PanicIf(err)
|
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err = bw.WriteUint32(unitCount)
|
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log.PanicIf(err)
|
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|
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// Write four-byte value/offset.
|
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// Write four-byte value/offset.
|
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|
||||
if len_ > 4 {
|
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offset, err := ida.Allocate(valueBytes)
|
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log.PanicIf(err)
|
||||
if len_ > 4 {
|
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offset, err := ida.Allocate(valueBytes)
|
||||
log.PanicIf(err)
|
||||
|
||||
err = bw.WriteUint32(offset)
|
||||
log.PanicIf(err)
|
||||
} else {
|
||||
fourBytes := make([]byte, 4)
|
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copy(fourBytes, valueBytes)
|
||||
err = bw.WriteUint32(offset)
|
||||
log.PanicIf(err)
|
||||
} else {
|
||||
fourBytes := make([]byte, 4)
|
||||
copy(fourBytes, valueBytes)
|
||||
|
||||
err = bw.WriteFourBytes(fourBytes)
|
||||
log.PanicIf(err)
|
||||
}
|
||||
} else {
|
||||
if bt.value.IsIb() == false {
|
||||
log.Panicf("tag value is not a byte-slice but also not a child IB: %v", bt)
|
||||
}
|
||||
err = bw.WriteFourBytes(fourBytes)
|
||||
log.PanicIf(err)
|
||||
}
|
||||
} else {
|
||||
if bt.value.IsIb() == false {
|
||||
log.Panicf("tag value is not a byte-slice but also not a child IB: %v", bt)
|
||||
}
|
||||
|
||||
// Write unit-count (one LONG representing one offset).
|
||||
err = bw.WriteUint32(1)
|
||||
log.PanicIf(err)
|
||||
// Write unit-count (one LONG representing one offset).
|
||||
err = bw.WriteUint32(1)
|
||||
log.PanicIf(err)
|
||||
|
||||
if nextIfdOffsetToWrite > 0 {
|
||||
var err error
|
||||
if nextIfdOffsetToWrite > 0 {
|
||||
var err error
|
||||
|
||||
ibe.pushToJournal("encodeTagToBytes", ">", "[%s]->[%s]", ib.ii.IfdName, bt.value.Ib().ii.IfdName)
|
||||
ibe.pushToJournal("encodeTagToBytes", ">", "[%s]->[%s]", ib.ii.IfdName, bt.value.Ib().ii.IfdName)
|
||||
|
||||
// Create the block of IFD data and everything it requires.
|
||||
childIfdBlock, err = ibe.encodeAndAttachIfd(bt.value.Ib(), nextIfdOffsetToWrite)
|
||||
log.PanicIf(err)
|
||||
// Create the block of IFD data and everything it requires.
|
||||
childIfdBlock, err = ibe.encodeAndAttachIfd(bt.value.Ib(), nextIfdOffsetToWrite)
|
||||
log.PanicIf(err)
|
||||
|
||||
ibe.pushToJournal("encodeTagToBytes", "<", "[%s]->[%s]", bt.value.Ib().ii.IfdName, ib.ii.IfdName)
|
||||
ibe.pushToJournal("encodeTagToBytes", "<", "[%s]->[%s]", bt.value.Ib().ii.IfdName, ib.ii.IfdName)
|
||||
|
||||
// Use the next-IFD offset for it. The IFD will actually get
|
||||
// attached after we return.
|
||||
err = bw.WriteUint32(nextIfdOffsetToWrite)
|
||||
log.PanicIf(err)
|
||||
// Use the next-IFD offset for it. The IFD will actually get
|
||||
// attached after we return.
|
||||
err = bw.WriteUint32(nextIfdOffsetToWrite)
|
||||
log.PanicIf(err)
|
||||
|
||||
} else {
|
||||
// No child-IFDs are to be allocated. Finish the entry with a NULL
|
||||
// pointer.
|
||||
} else {
|
||||
// No child-IFDs are to be allocated. Finish the entry with a NULL
|
||||
// pointer.
|
||||
|
||||
ibe.pushToJournal("encodeTagToBytes", "-", "*Not* descending to child: [%s]", bt.value.Ib().ii.IfdName)
|
||||
ibe.pushToJournal("encodeTagToBytes", "-", "*Not* descending to child: [%s]", bt.value.Ib().ii.IfdName)
|
||||
|
||||
err = bw.WriteUint32(0)
|
||||
log.PanicIf(err)
|
||||
}
|
||||
}
|
||||
err = bw.WriteUint32(0)
|
||||
log.PanicIf(err)
|
||||
}
|
||||
}
|
||||
|
||||
return childIfdBlock, nil
|
||||
return childIfdBlock, nil
|
||||
}
|
||||
|
||||
// encodeIfdToBytes encodes the given IB to a byte-slice. We are given the
|
||||
|
|
@ -310,255 +308,254 @@ func (ibe *IfdByteEncoder) encodeTagToBytes(ib *IfdBuilder, bt *builderTag, bw *
|
|||
// IFDs, we will not be able to allocate them without first knowing how much
|
||||
// data we need to allocate for the current IFD.
|
||||
func (ibe *IfdByteEncoder) encodeIfdToBytes(ib *IfdBuilder, ifdAddressableOffset uint32, nextIfdOffsetToWrite uint32, setNextIb bool) (data []byte, tableSize uint32, dataSize uint32, childIfdSizes []uint32, err error) {
|
||||
defer func() {
|
||||
if state := recover(); state != nil {
|
||||
err = log.Wrap(state.(error))
|
||||
}
|
||||
}()
|
||||
defer func() {
|
||||
if state := recover(); state != nil {
|
||||
err = log.Wrap(state.(error))
|
||||
}
|
||||
}()
|
||||
|
||||
ibe.pushToJournal("encodeIfdToBytes", ">", "%s", ib)
|
||||
ibe.pushToJournal("encodeIfdToBytes", ">", "%s", ib)
|
||||
|
||||
tableSize = ibe.TableSize(len(ib.tags))
|
||||
tableSize = ibe.TableSize(len(ib.tags))
|
||||
|
||||
b := new(bytes.Buffer)
|
||||
bw := NewByteWriter(b, ib.byteOrder)
|
||||
b := new(bytes.Buffer)
|
||||
bw := NewByteWriter(b, ib.byteOrder)
|
||||
|
||||
// Write tag count.
|
||||
err = bw.WriteUint16(uint16(len(ib.tags)))
|
||||
log.PanicIf(err)
|
||||
// Write tag count.
|
||||
err = bw.WriteUint16(uint16(len(ib.tags)))
|
||||
log.PanicIf(err)
|
||||
|
||||
ida := newIfdDataAllocator(ifdAddressableOffset)
|
||||
ida := newIfdDataAllocator(ifdAddressableOffset)
|
||||
|
||||
childIfdBlocks := make([][]byte, 0)
|
||||
childIfdBlocks := make([][]byte, 0)
|
||||
|
||||
// Write raw bytes for each tag entry. Allocate larger data to be referred
|
||||
// to in the follow-up data-block as required. Any "unknown"-byte tags that
|
||||
// we can't parse will not be present here (using AddTagsFromExisting(), at
|
||||
// least).
|
||||
for _, bt := range ib.tags {
|
||||
childIfdBlock, err := ibe.encodeTagToBytes(ib, bt, bw, ida, nextIfdOffsetToWrite)
|
||||
log.PanicIf(err)
|
||||
// Write raw bytes for each tag entry. Allocate larger data to be referred
|
||||
// to in the follow-up data-block as required. Any "unknown"-byte tags that
|
||||
// we can't parse will not be present here (using AddTagsFromExisting(), at
|
||||
// least).
|
||||
for _, bt := range ib.tags {
|
||||
childIfdBlock, err := ibe.encodeTagToBytes(ib, bt, bw, ida, nextIfdOffsetToWrite)
|
||||
log.PanicIf(err)
|
||||
|
||||
if childIfdBlock != nil {
|
||||
// We aren't allowed to have non-nil child IFDs if we're just
|
||||
// sizing things up.
|
||||
if nextIfdOffsetToWrite == 0 {
|
||||
log.Panicf("no IFD offset provided for child-IFDs; no new child-IFDs permitted")
|
||||
}
|
||||
if childIfdBlock != nil {
|
||||
// We aren't allowed to have non-nil child IFDs if we're just
|
||||
// sizing things up.
|
||||
if nextIfdOffsetToWrite == 0 {
|
||||
log.Panicf("no IFD offset provided for child-IFDs; no new child-IFDs permitted")
|
||||
}
|
||||
|
||||
nextIfdOffsetToWrite += uint32(len(childIfdBlock))
|
||||
childIfdBlocks = append(childIfdBlocks, childIfdBlock)
|
||||
}
|
||||
}
|
||||
nextIfdOffsetToWrite += uint32(len(childIfdBlock))
|
||||
childIfdBlocks = append(childIfdBlocks, childIfdBlock)
|
||||
}
|
||||
}
|
||||
|
||||
dataBytes := ida.Bytes()
|
||||
dataSize = uint32(len(dataBytes))
|
||||
dataBytes := ida.Bytes()
|
||||
dataSize = uint32(len(dataBytes))
|
||||
|
||||
childIfdSizes = make([]uint32, len(childIfdBlocks))
|
||||
childIfdsTotalSize := uint32(0)
|
||||
for i, childIfdBlock := range childIfdBlocks {
|
||||
len_ := uint32(len(childIfdBlock))
|
||||
childIfdSizes[i] = len_
|
||||
childIfdsTotalSize += len_
|
||||
}
|
||||
childIfdSizes = make([]uint32, len(childIfdBlocks))
|
||||
childIfdsTotalSize := uint32(0)
|
||||
for i, childIfdBlock := range childIfdBlocks {
|
||||
len_ := uint32(len(childIfdBlock))
|
||||
childIfdSizes[i] = len_
|
||||
childIfdsTotalSize += len_
|
||||
}
|
||||
|
||||
// N the link from this IFD to the next IFD that will be written in the
|
||||
// next cycle.
|
||||
if setNextIb == true {
|
||||
// Write address of next IFD in chain. This will be the original
|
||||
// allocation offset plus the size of everything we have allocated for
|
||||
// this IFD and its child-IFDs.
|
||||
//
|
||||
// It is critical that this number is stepped properly. We experienced
|
||||
// an issue whereby it first looked like we were duplicating the IFD and
|
||||
// then that we were duplicating the tags in the wrong IFD, and then
|
||||
// finally we determined that the next-IFD offset for the first IFD was
|
||||
// accidentally pointing back to the EXIF IFD, so we were visiting it
|
||||
// twice when visiting through the tags after decoding. It was an
|
||||
// expensive bug to find.
|
||||
// N the link from this IFD to the next IFD that will be written in the
|
||||
// next cycle.
|
||||
if setNextIb == true {
|
||||
// Write address of next IFD in chain. This will be the original
|
||||
// allocation offset plus the size of everything we have allocated for
|
||||
// this IFD and its child-IFDs.
|
||||
//
|
||||
// It is critical that this number is stepped properly. We experienced
|
||||
// an issue whereby it first looked like we were duplicating the IFD and
|
||||
// then that we were duplicating the tags in the wrong IFD, and then
|
||||
// finally we determined that the next-IFD offset for the first IFD was
|
||||
// accidentally pointing back to the EXIF IFD, so we were visiting it
|
||||
// twice when visiting through the tags after decoding. It was an
|
||||
// expensive bug to find.
|
||||
|
||||
ibe.pushToJournal("encodeIfdToBytes", "-", "Setting 'next' IFD to (0x%08x).", nextIfdOffsetToWrite)
|
||||
ibe.pushToJournal("encodeIfdToBytes", "-", "Setting 'next' IFD to (0x%08x).", nextIfdOffsetToWrite)
|
||||
|
||||
err := bw.WriteUint32(nextIfdOffsetToWrite)
|
||||
log.PanicIf(err)
|
||||
} else {
|
||||
err := bw.WriteUint32(0)
|
||||
log.PanicIf(err)
|
||||
}
|
||||
err := bw.WriteUint32(nextIfdOffsetToWrite)
|
||||
log.PanicIf(err)
|
||||
} else {
|
||||
err := bw.WriteUint32(0)
|
||||
log.PanicIf(err)
|
||||
}
|
||||
|
||||
_, err = b.Write(dataBytes)
|
||||
log.PanicIf(err)
|
||||
_, err = b.Write(dataBytes)
|
||||
log.PanicIf(err)
|
||||
|
||||
// TODO(dustin): !! Debugging.
|
||||
// if thumbnailOffset != uint32(0) {
|
||||
// currentRelativeOffset := thumbnailOffset - ifdAddressableOffset
|
||||
// currentBuffer := b.Bytes()
|
||||
// TODO(dustin): !! Debugging.
|
||||
// if thumbnailOffset != uint32(0) {
|
||||
// currentRelativeOffset := thumbnailOffset - ifdAddressableOffset
|
||||
// currentBuffer := b.Bytes()
|
||||
|
||||
// len_ := len(thumbnailData)
|
||||
// extractedThumbnailData := currentBuffer[int(currentRelativeOffset):int(currentRelativeOffset) + len_]
|
||||
// len_ := len(thumbnailData)
|
||||
// extractedThumbnailData := currentBuffer[int(currentRelativeOffset):int(currentRelativeOffset) + len_]
|
||||
|
||||
// // We didn't have enough data available, which would be queer.
|
||||
// if len(extractedThumbnailData) != len_ {
|
||||
// log.Panicf("extracted thumbnail data was truncated; not enough data")
|
||||
// }
|
||||
// // We didn't have enough data available, which would be queer.
|
||||
// if len(extractedThumbnailData) != len_ {
|
||||
// log.Panicf("extracted thumbnail data was truncated; not enough data")
|
||||
// }
|
||||
|
||||
// // fmt.Printf("Re-extracted (%d) bytes of thumbnail data.\n", len(extractedThumbnailData))
|
||||
// // DumpBytes(extractedThumbnailData[:50])
|
||||
// }
|
||||
// // fmt.Printf("Re-extracted (%d) bytes of thumbnail data.\n", len(extractedThumbnailData))
|
||||
// // DumpBytes(extractedThumbnailData[:50])
|
||||
// }
|
||||
|
||||
// Append any child IFD blocks after our table and data blocks. These IFDs
|
||||
// were equipped with the appropriate offset information so it's expected
|
||||
// that all offsets referred to by these will be correct.
|
||||
//
|
||||
// Note that child-IFDs are append after the current IFD and before the
|
||||
// next IFD, as opposed to the root IFDs, which are chained together but
|
||||
// will be interrupted by these child-IFDs (which is expected, per the
|
||||
// standard).
|
||||
// Append any child IFD blocks after our table and data blocks. These IFDs
|
||||
// were equipped with the appropriate offset information so it's expected
|
||||
// that all offsets referred to by these will be correct.
|
||||
//
|
||||
// Note that child-IFDs are append after the current IFD and before the
|
||||
// next IFD, as opposed to the root IFDs, which are chained together but
|
||||
// will be interrupted by these child-IFDs (which is expected, per the
|
||||
// standard).
|
||||
|
||||
for _, childIfdBlock := range childIfdBlocks {
|
||||
_, err = b.Write(childIfdBlock)
|
||||
log.PanicIf(err)
|
||||
}
|
||||
for _, childIfdBlock := range childIfdBlocks {
|
||||
_, err = b.Write(childIfdBlock)
|
||||
log.PanicIf(err)
|
||||
}
|
||||
|
||||
ibe.pushToJournal("encodeIfdToBytes", "<", "%s", ib)
|
||||
ibe.pushToJournal("encodeIfdToBytes", "<", "%s", ib)
|
||||
|
||||
// if nextIfdOffsetToWrite > uint32(0) {
|
||||
// fmt.Printf("Encoded IB: %s ADDRESSABLE-OFFSET=(0x%08x; %d):\n", ib.ii, ifdAddressableOffset, ifdAddressableOffset)
|
||||
// fmt.Printf("\n")
|
||||
// DumpBytes(b.Bytes())
|
||||
// fmt.Printf("\n")
|
||||
// }
|
||||
// if nextIfdOffsetToWrite > uint32(0) {
|
||||
// fmt.Printf("Encoded IB: %s ADDRESSABLE-OFFSET=(0x%08x; %d):\n", ib.ii, ifdAddressableOffset, ifdAddressableOffset)
|
||||
// fmt.Printf("\n")
|
||||
// DumpBytes(b.Bytes())
|
||||
// fmt.Printf("\n")
|
||||
// }
|
||||
|
||||
return b.Bytes(), tableSize, dataSize, childIfdSizes, nil
|
||||
return b.Bytes(), tableSize, dataSize, childIfdSizes, nil
|
||||
}
|
||||
|
||||
// encodeAndAttachIfd is a reentrant function that processes the IFD chain.
|
||||
func (ibe *IfdByteEncoder) encodeAndAttachIfd(ib *IfdBuilder, ifdAddressableOffset uint32) (data []byte, err error) {
|
||||
defer func() {
|
||||
if state := recover(); state != nil {
|
||||
err = log.Wrap(state.(error))
|
||||
}
|
||||
}()
|
||||
defer func() {
|
||||
if state := recover(); state != nil {
|
||||
err = log.Wrap(state.(error))
|
||||
}
|
||||
}()
|
||||
|
||||
ibe.pushToJournal("encodeAndAttachIfd", ">", "%s", ib)
|
||||
ibe.pushToJournal("encodeAndAttachIfd", ">", "%s", ib)
|
||||
|
||||
if len(ib.tags) == 0 {
|
||||
log.Panicf("trying to encode an IfdBuilder that doesn't have any tags")
|
||||
}
|
||||
if len(ib.tags) == 0 {
|
||||
log.Panicf("trying to encode an IfdBuilder that doesn't have any tags")
|
||||
}
|
||||
|
||||
b := new(bytes.Buffer)
|
||||
b := new(bytes.Buffer)
|
||||
|
||||
i := 0
|
||||
i := 0
|
||||
|
||||
// TODO(dustin): !! We suspect there's an issue with encoding sibling IFDs, here.
|
||||
// TODO(dustin): !! We suspect there's an issue with encoding sibling IFDs, here.
|
||||
|
||||
for thisIb := ib; thisIb != nil; thisIb = thisIb.nextIb {
|
||||
for thisIb := ib; thisIb != nil; thisIb = thisIb.nextIb {
|
||||
|
||||
// Do a dry-run in order to pre-determine its size requirement.
|
||||
|
||||
// Do a dry-run in order to pre-determine its size requirement.
|
||||
ibe.pushToJournal("encodeAndAttachIfd", ">", "Beginning encoding process: (%d) [%s]", i, thisIb.ii.IfdName)
|
||||
|
||||
ibe.pushToJournal("encodeAndAttachIfd", ">", "Beginning encoding process: (%d) [%s]", i, thisIb.ii.IfdName)
|
||||
ibe.pushToJournal("encodeAndAttachIfd", ">", "Calculating size: (%d) [%s]", i, thisIb.ii.IfdName)
|
||||
|
||||
ibe.pushToJournal("encodeAndAttachIfd", ">", "Calculating size: (%d) [%s]", i, thisIb.ii.IfdName)
|
||||
_, tableSize, allocatedDataSize, _, err := ibe.encodeIfdToBytes(thisIb, ifdAddressableOffset, 0, false)
|
||||
log.PanicIf(err)
|
||||
|
||||
_, tableSize, allocatedDataSize, _, err := ibe.encodeIfdToBytes(thisIb, ifdAddressableOffset, 0, false)
|
||||
log.PanicIf(err)
|
||||
ibe.pushToJournal("encodeAndAttachIfd", "<", "Finished calculating size: (%d) [%s]", i, thisIb.ii.IfdName)
|
||||
|
||||
ibe.pushToJournal("encodeAndAttachIfd", "<", "Finished calculating size: (%d) [%s]", i, thisIb.ii.IfdName)
|
||||
ifdAddressableOffset += tableSize
|
||||
nextIfdOffsetToWrite := ifdAddressableOffset + allocatedDataSize
|
||||
|
||||
ifdAddressableOffset += tableSize
|
||||
nextIfdOffsetToWrite := ifdAddressableOffset + allocatedDataSize
|
||||
ibe.pushToJournal("encodeAndAttachIfd", ">", "Next IFD will be written at offset (0x%08x)", nextIfdOffsetToWrite)
|
||||
|
||||
ibe.pushToJournal("encodeAndAttachIfd", ">", "Next IFD will be written at offset (0x%08x)", nextIfdOffsetToWrite)
|
||||
// Write our IFD as well as any child-IFDs (now that we know the offset
|
||||
// where new IFDs and their data will be allocated).
|
||||
|
||||
// Write our IFD as well as any child-IFDs (now that we know the offset
|
||||
// where new IFDs and their data will be allocated).
|
||||
setNextIb := thisIb.nextIb != nil
|
||||
|
||||
setNextIb := thisIb.nextIb != nil
|
||||
ibe.pushToJournal("encodeAndAttachIfd", ">", "Encoding starting: (%d) [%s] NEXT-IFD-OFFSET-TO-WRITE=(0x%08x)", i, thisIb.ii.IfdName, nextIfdOffsetToWrite)
|
||||
|
||||
ibe.pushToJournal("encodeAndAttachIfd", ">", "Encoding starting: (%d) [%s] NEXT-IFD-OFFSET-TO-WRITE=(0x%08x)", i, thisIb.ii.IfdName, nextIfdOffsetToWrite)
|
||||
tableAndAllocated, effectiveTableSize, effectiveAllocatedDataSize, childIfdSizes, err :=
|
||||
ibe.encodeIfdToBytes(thisIb, ifdAddressableOffset, nextIfdOffsetToWrite, setNextIb)
|
||||
|
||||
tableAndAllocated, effectiveTableSize, effectiveAllocatedDataSize, childIfdSizes, err :=
|
||||
ibe.encodeIfdToBytes(thisIb, ifdAddressableOffset, nextIfdOffsetToWrite, setNextIb)
|
||||
log.PanicIf(err)
|
||||
|
||||
log.PanicIf(err)
|
||||
if effectiveTableSize != tableSize {
|
||||
log.Panicf("written table size does not match the pre-calculated table size: (%d) != (%d) %s", effectiveTableSize, tableSize, ib)
|
||||
} else if effectiveAllocatedDataSize != allocatedDataSize {
|
||||
log.Panicf("written allocated-data size does not match the pre-calculated allocated-data size: (%d) != (%d) %s", effectiveAllocatedDataSize, allocatedDataSize, ib)
|
||||
}
|
||||
|
||||
if effectiveTableSize != tableSize {
|
||||
log.Panicf("written table size does not match the pre-calculated table size: (%d) != (%d) %s", effectiveTableSize, tableSize, ib)
|
||||
} else if effectiveAllocatedDataSize != allocatedDataSize {
|
||||
log.Panicf("written allocated-data size does not match the pre-calculated allocated-data size: (%d) != (%d) %s", effectiveAllocatedDataSize, allocatedDataSize, ib)
|
||||
}
|
||||
ibe.pushToJournal("encodeAndAttachIfd", "<", "Encoding done: (%d) [%s]", i, thisIb.ii.IfdName)
|
||||
|
||||
ibe.pushToJournal("encodeAndAttachIfd", "<", "Encoding done: (%d) [%s]", i, thisIb.ii.IfdName)
|
||||
totalChildIfdSize := uint32(0)
|
||||
for _, childIfdSize := range childIfdSizes {
|
||||
totalChildIfdSize += childIfdSize
|
||||
}
|
||||
|
||||
totalChildIfdSize := uint32(0)
|
||||
for _, childIfdSize := range childIfdSizes {
|
||||
totalChildIfdSize += childIfdSize
|
||||
}
|
||||
if len(tableAndAllocated) != int(tableSize+allocatedDataSize+totalChildIfdSize) {
|
||||
log.Panicf("IFD table and data is not a consistent size: (%d) != (%d)", len(tableAndAllocated), tableSize+allocatedDataSize+totalChildIfdSize)
|
||||
}
|
||||
|
||||
if len(tableAndAllocated) != int(tableSize + allocatedDataSize + totalChildIfdSize) {
|
||||
log.Panicf("IFD table and data is not a consistent size: (%d) != (%d)", len(tableAndAllocated), tableSize + allocatedDataSize + totalChildIfdSize)
|
||||
}
|
||||
// TODO(dustin): !! We might want to verify the original tableAndAllocated length, too.
|
||||
|
||||
// TODO(dustin): !! We might want to verify the original tableAndAllocated length, too.
|
||||
_, err = b.Write(tableAndAllocated)
|
||||
log.PanicIf(err)
|
||||
|
||||
_, err = b.Write(tableAndAllocated)
|
||||
log.PanicIf(err)
|
||||
// Advance past what we've allocated, thus far.
|
||||
|
||||
// Advance past what we've allocated, thus far.
|
||||
// TODO(dustin): !! If this doesn't work (or doesn't work easily), we may need to send a complex type for the addressable-offset instead of a simple integer.
|
||||
ifdAddressableOffset += allocatedDataSize + totalChildIfdSize
|
||||
|
||||
// TODO(dustin): !! If this doesn't work (or doesn't work easily), we may need to send a complex type for the addressable-offset instead of a simple integer.
|
||||
ifdAddressableOffset += allocatedDataSize + totalChildIfdSize
|
||||
ibe.pushToJournal("encodeAndAttachIfd", "<", "Finishing encoding process: (%d) [%s] [FINAL:] NEXT-IFD-OFFSET-TO-WRITE=(0x%08x)", i, ib.ii.IfdName, nextIfdOffsetToWrite)
|
||||
|
||||
ibe.pushToJournal("encodeAndAttachIfd", "<", "Finishing encoding process: (%d) [%s] [FINAL:] NEXT-IFD-OFFSET-TO-WRITE=(0x%08x)", i, ib.ii.IfdName, nextIfdOffsetToWrite)
|
||||
i++
|
||||
}
|
||||
|
||||
i++
|
||||
}
|
||||
ibe.pushToJournal("encodeAndAttachIfd", "<", "%s", ib)
|
||||
|
||||
ibe.pushToJournal("encodeAndAttachIfd", "<", "%s", ib)
|
||||
|
||||
return b.Bytes(), nil
|
||||
return b.Bytes(), nil
|
||||
}
|
||||
|
||||
// EncodeToExifPayload is the base encoding step that transcribes the entire IB
|
||||
// structure to its on-disk layout.
|
||||
func (ibe *IfdByteEncoder) EncodeToExifPayload(ib *IfdBuilder) (data []byte, err error) {
|
||||
defer func() {
|
||||
if state := recover(); state != nil {
|
||||
err = log.Wrap(state.(error))
|
||||
}
|
||||
}()
|
||||
defer func() {
|
||||
if state := recover(); state != nil {
|
||||
err = log.Wrap(state.(error))
|
||||
}
|
||||
}()
|
||||
|
||||
data, err = ibe.encodeAndAttachIfd(ib, ExifDefaultFirstIfdOffset)
|
||||
log.PanicIf(err)
|
||||
data, err = ibe.encodeAndAttachIfd(ib, ExifDefaultFirstIfdOffset)
|
||||
log.PanicIf(err)
|
||||
|
||||
return data, nil
|
||||
return data, nil
|
||||
}
|
||||
|
||||
// EncodeToExif calls EncodeToExifPayload and then packages the result into a
|
||||
// complete EXIF block.
|
||||
func (ibe *IfdByteEncoder) EncodeToExif(ib *IfdBuilder) (data []byte, err error) {
|
||||
defer func() {
|
||||
if state := recover(); state != nil {
|
||||
err = log.Wrap(state.(error))
|
||||
}
|
||||
}()
|
||||
defer func() {
|
||||
if state := recover(); state != nil {
|
||||
err = log.Wrap(state.(error))
|
||||
}
|
||||
}()
|
||||
|
||||
encodedIfds, err := ibe.EncodeToExifPayload(ib)
|
||||
log.PanicIf(err)
|
||||
encodedIfds, err := ibe.EncodeToExifPayload(ib)
|
||||
log.PanicIf(err)
|
||||
|
||||
// Wrap the IFD in a formal EXIF block.
|
||||
// Wrap the IFD in a formal EXIF block.
|
||||
|
||||
b := new(bytes.Buffer)
|
||||
b := new(bytes.Buffer)
|
||||
|
||||
headerBytes, err := BuildExifHeader(ib.byteOrder, ExifDefaultFirstIfdOffset)
|
||||
log.PanicIf(err)
|
||||
headerBytes, err := BuildExifHeader(ib.byteOrder, ExifDefaultFirstIfdOffset)
|
||||
log.PanicIf(err)
|
||||
|
||||
_, err = b.Write(headerBytes)
|
||||
log.PanicIf(err)
|
||||
_, err = b.Write(headerBytes)
|
||||
log.PanicIf(err)
|
||||
|
||||
_, err = b.Write(encodedIfds)
|
||||
log.PanicIf(err)
|
||||
_, err = b.Write(encodedIfds)
|
||||
log.PanicIf(err)
|
||||
|
||||
return b.Bytes(), nil
|
||||
return b.Bytes(), nil
|
||||
}
|
||||
|
|
|
|||
2562
ifd_builder_test.go
2562
ifd_builder_test.go
File diff suppressed because it is too large
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Reference in New Issue