improved error handling, make functions into methods where appropriate

This commit is contained in:
Alex Yatskov 2019-02-10 12:31:51 -08:00
parent ea282171fc
commit 40c09c36a6
2 changed files with 40 additions and 32 deletions

View File

@ -19,13 +19,7 @@ type directionHeader struct {
CodedBytesBits uint8 CodedBytesBits uint8
} }
type direction struct { func readDirectionHeader(bitReader *streaming.BitReader) (*directionHeader, error) {
header directionHeader
frames []frame
bounds bounds
}
func readDirectionHeader(bitReader *streaming.BitReader) directionHeader {
var dirHead directionHeader var dirHead directionHeader
dirHead.CodedSize = uint32(bitReader.ReadUint(32)) dirHead.CodedSize = uint32(bitReader.ReadUint(32))
@ -39,18 +33,22 @@ func readDirectionHeader(bitReader *streaming.BitReader) directionHeader {
dirHead.OptionalBytesBits = uint8(bitReader.ReadUint(4)) dirHead.OptionalBytesBits = uint8(bitReader.ReadUint(4))
dirHead.CodedBytesBits = uint8(bitReader.ReadUint(4)) dirHead.CodedBytesBits = uint8(bitReader.ReadUint(4))
return dirHead if err := bitReader.Error(); err != nil {
return nil, err
}
return &dirHead, nil
} }
func readDirection(reader io.ReadSeeker, fileHead fileHeader) (*direction, error) { func readDirection(reader io.ReadSeeker, fileHead fileHeader) (*direction, error) {
bitReader := streaming.NewBitReader(reader) bitReader := streaming.NewBitReader(reader)
dirHead := readDirectionHeader(bitReader) dirHead, err := readDirectionHeader(bitReader)
if err := bitReader.Error(); err != nil { if err != nil {
return nil, err return nil, err
} }
frameHeads, err := readFrameHeaders(bitReader, fileHead, dirHead) frameHeads, err := readFrameHeaders(bitReader, fileHead, *dirHead)
if err != nil { if err != nil {
return nil, err return nil, err
} }
@ -89,12 +87,12 @@ func readDirection(reader io.ReadSeeker, fileHead fileHeader) (*direction, error
var entries []pixelBufferEntry var entries []pixelBufferEntry
entries, err = decodeDirectionStage1(bitReader, &dirData, entries) entries, err = dirData.decodeStage1(bitReader, entries)
if err != nil { if err != nil {
return nil, err return nil, err
} }
entries, err = decodeDirectionStage2(bitReader, &dirData, entries) entries, err = dirData.decodeStage2(bitReader, entries)
if err != nil { if err != nil {
return nil, err return nil, err
} }
@ -102,10 +100,16 @@ func readDirection(reader io.ReadSeeker, fileHead fileHeader) (*direction, error
return &dirData, nil return &dirData, nil
} }
func decodeDirectionStage1(bitReader *streaming.BitReader, dirData *direction, entries []pixelBufferEntry) ([]pixelBufferEntry, error) { type direction struct {
header directionHeader
frames []frame
bounds bounds
}
func (d *direction) decodeStage1(bitReader *streaming.BitReader, entries []pixelBufferEntry) ([]pixelBufferEntry, error) {
return nil, nil return nil, nil
} }
func decodeDirectionStage2(bitReader *streaming.BitReader, dirData *direction, entries []pixelBufferEntry) ([]pixelBufferEntry, error) { func (d *direction) decodeStage2(bitReader *streaming.BitReader, entries []pixelBufferEntry) ([]pixelBufferEntry, error) {
return nil, nil return nil, nil
} }

View File

@ -22,7 +22,7 @@ type frame struct {
bounds bounds bounds bounds
} }
func readFrameHeader(bitReader *streaming.BitReader, dirHead directionHeader) frameHeader { func readFrameHeader(bitReader *streaming.BitReader, dirHead directionHeader) (*frameHeader, error) {
var frameHead frameHeader var frameHead frameHeader
frameHead.Variable0 = uint32(bitReader.ReadUintPacked(int(dirHead.Variable0Bits))) frameHead.Variable0 = uint32(bitReader.ReadUintPacked(int(dirHead.Variable0Bits)))
@ -34,30 +34,34 @@ func readFrameHeader(bitReader *streaming.BitReader, dirHead directionHeader) fr
frameHead.CodedBytes = uint32(bitReader.ReadUintPacked(int(dirHead.CodedBytesBits))) frameHead.CodedBytes = uint32(bitReader.ReadUintPacked(int(dirHead.CodedBytesBits)))
frameHead.FrameBottomUp = bitReader.ReadBool() frameHead.FrameBottomUp = bitReader.ReadBool()
return frameHead if err := bitReader.Error(); err != nil {
return nil, err
}
if frameHead.OptionalBytes != 0 {
return nil, errors.New("optional frame data not supported")
}
if frameHead.FrameBottomUp {
return nil, errors.New("bottom-up frames are not supported")
}
if frameHead.Width == 0 || frameHead.Height == 0 {
return nil, errors.New("invalid frame dimensions")
}
return &frameHead, nil
} }
func readFrameHeaders(bitReader *streaming.BitReader, fileHead fileHeader, dirHead directionHeader) ([]frameHeader, error) { func readFrameHeaders(bitReader *streaming.BitReader, fileHead fileHeader, dirHead directionHeader) ([]frameHeader, error) {
var frameHeads []frameHeader var frameHeads []frameHeader
for i := 0; i < int(fileHead.FramesPerDir); i++ { for i := 0; i < int(fileHead.FramesPerDir); i++ {
frameHead := readFrameHeader(bitReader, dirHead) frameHead, err := readFrameHeader(bitReader, dirHead)
if err := bitReader.Error(); err != nil { if err != nil {
return nil, err return nil, err
} }
if frameHead.OptionalBytes != 0 { frameHeads = append(frameHeads, *frameHead)
return nil, errors.New("optional frame data not supported")
}
if frameHead.FrameBottomUp {
return nil, errors.New("bottom-up frames are not supported")
}
if frameHead.Width == 0 || frameHead.Height == 0 {
return nil, errors.New("invalid frame dimensions")
}
frameHeads = append(frameHeads, frameHead)
} }
return frameHeads, nil return frameHeads, nil