GoToSocial/vendor/github.com/dsoprea/go-photoshop-info-format/info.go

120 lines
2.5 KiB
Go

package photoshopinfo
import (
"fmt"
"io"
"encoding/binary"
"github.com/dsoprea/go-logging"
)
var (
defaultByteOrder = binary.BigEndian
)
// Photoshop30InfoRecord is the data for one parsed Photoshop-info record.
type Photoshop30InfoRecord struct {
// RecordType is the record-type.
RecordType string
// ImageResourceId is the image resource-ID.
ImageResourceId uint16
// Name is the name of the record. It is optional and will be an empty-
// string if not present.
Name string
// Data is the raw record data.
Data []byte
}
// String returns a descriptive string.
func (pir Photoshop30InfoRecord) String() string {
return fmt.Sprintf("RECORD-TYPE=[%s] IMAGE-RESOURCE-ID=[0x%04x] NAME=[%s] DATA-SIZE=(%d)", pir.RecordType, pir.ImageResourceId, pir.Name, len(pir.Data))
}
// ReadPhotoshop30InfoRecord parses a single photoshop-info record.
func ReadPhotoshop30InfoRecord(r io.Reader) (pir Photoshop30InfoRecord, err error) {
defer func() {
if state := recover(); state != nil {
err = log.Wrap(state.(error))
}
}()
recordType := make([]byte, 4)
_, err = io.ReadFull(r, recordType)
if err != nil {
if err == io.EOF {
return pir, err
}
log.Panic(err)
}
// TODO(dustin): Move BigEndian to constant/config.
irId := uint16(0)
err = binary.Read(r, defaultByteOrder, &irId)
log.PanicIf(err)
nameSize := uint8(0)
err = binary.Read(r, defaultByteOrder, &nameSize)
log.PanicIf(err)
// Add an extra byte if the two length+data size is odd to make the total
// bytes read even.
doAddPadding := (1+nameSize)%2 == 1
if doAddPadding == true {
nameSize++
}
name := make([]byte, nameSize)
_, err = io.ReadFull(r, name)
log.PanicIf(err)
// If the last byte is padding, truncate it.
if doAddPadding == true {
name = name[:nameSize-1]
}
dataSize := uint32(0)
err = binary.Read(r, defaultByteOrder, &dataSize)
log.PanicIf(err)
data := make([]byte, dataSize+dataSize%2)
_, err = io.ReadFull(r, data)
log.PanicIf(err)
data = data[:dataSize]
pir = Photoshop30InfoRecord{
RecordType: string(recordType),
ImageResourceId: irId,
Name: string(name),
Data: data,
}
return pir, nil
}
// ReadPhotoshop30Info parses a sequence of photoship-info records from the stream.
func ReadPhotoshop30Info(r io.Reader) (pirIndex map[uint16]Photoshop30InfoRecord, err error) {
pirIndex = make(map[uint16]Photoshop30InfoRecord)
for {
pir, err := ReadPhotoshop30InfoRecord(r)
if err != nil {
if err == io.EOF {
break
}
log.Panic(err)
}
pirIndex[pir.ImageResourceId] = pir
}
return pirIndex, nil
}