From 7da7f570015d6fbf391942502d8325fda964f64c Mon Sep 17 00:00:00 2001 From: Alex Yatskov Date: Sun, 10 Feb 2019 08:55:14 -0800 Subject: [PATCH] cleanup --- formats/dcc/dcc.go | 193 ++++++++---------------------------- streaming/bitreader.go | 94 ++++++++++-------- streaming/streaming_test.go | 11 +- 3 files changed, 100 insertions(+), 198 deletions(-) diff --git a/formats/dcc/dcc.go b/formats/dcc/dcc.go index 8abfe06..80ae192 100644 --- a/formats/dcc/dcc.go +++ b/formats/dcc/dcc.go @@ -2,7 +2,6 @@ package dcc import ( "encoding/binary" - "errors" "fmt" "io" @@ -29,26 +28,26 @@ type fileHeader struct { } type directionHeader struct { - CodedSize uint32 + CodedSize uint HasRawPixelEncoding bool CompressEqualCells bool - Variable0Bits uint32 - WidthBits uint32 - HeightBits uint32 - OffsetXBits int32 - OffsetYBits int32 - OptionalBytesBits uint32 - CodedBytesBits uint32 + Variable0Bits uint + WidthBits uint + HeightBits uint + OffsetXBits uint + OffsetYBits uint + OptionalBytesBits uint + CodedBytesBits uint } type frameHeader struct { - Variable0 uint32 - Width uint32 - Height uint32 - OffsetX int32 - OffsetY int32 - OptionalBytes uint32 - CodedBytes uint32 + Variable0 uint + Width uint + Height uint + OffsetX int + OffsetY int + OptionalBytes uint + CodedBytes uint FrameBottomUp bool Extents extents } @@ -86,156 +85,46 @@ func NewFromReader(reader io.ReadSeeker) (*Sprite, error) { return nil, nil } -func readDirectionHeader(bitReader *streaming.BitReader) (*directionHeader, error) { - var ( - dirHead directionHeader - err error - ) +func readDirectionHeader(bitReader *streaming.BitReader) *directionHeader { + var dirHead directionHeader - dirHead.CodedSize, err = bitReader.ReadUint32(32) - if err != nil { - return nil, err - } + dirHead.CodedSize = uint(bitReader.ReadUint(32)) + dirHead.HasRawPixelEncoding = bitReader.ReadBool() + dirHead.CompressEqualCells = bitReader.ReadBool() + dirHead.Variable0Bits = uint(bitReader.ReadUint(4)) + dirHead.WidthBits = uint(bitReader.ReadUint(4)) + dirHead.HeightBits = uint(bitReader.ReadUint(4)) + dirHead.OffsetXBits = uint(bitReader.ReadInt(4)) + dirHead.OffsetYBits = uint(bitReader.ReadInt(4)) + dirHead.OptionalBytesBits = uint(bitReader.ReadUint(4)) + dirHead.CodedBytesBits = uint(bitReader.ReadUint(4)) - dirHead.HasRawPixelEncoding, err = bitReader.ReadBool() - if err != nil { - return nil, err - } - - dirHead.CompressEqualCells, err = bitReader.ReadBool() - if err != nil { - return nil, err - } - - dirHead.Variable0Bits, err = bitReader.ReadUint32(4) - if err != nil { - return nil, err - } - - dirHead.WidthBits, err = bitReader.ReadUint32(4) - if err != nil { - return nil, err - } - - dirHead.HeightBits, err = bitReader.ReadUint32(4) - if err != nil { - return nil, err - } - - dirHead.OffsetXBits, err = bitReader.ReadInt32(4) - if err != nil { - return nil, err - } - - dirHead.OffsetYBits, err = bitReader.ReadInt32(4) - if err != nil { - return nil, err - } - - dirHead.OptionalBytesBits, err = bitReader.ReadUint32(4) - if err != nil { - return nil, err - } - - dirHead.CodedBytesBits, err = bitReader.ReadUint32(4) - if err != nil { - return nil, err - } - - return &dirHead, nil + return &dirHead } -func readFrameHeader(bitReader *streaming.BitReader, dirHead directionHeader) (*frameHeader, error) { - var ( - frameHead frameHeader - err error - ) +func readFrameHeader(bitReader *streaming.BitReader, dirHead directionHeader) *frameHeader { + var frameHead frameHeader - frameHead.Variable0, err = readPackedUint32(bitReader, int(dirHead.Variable0Bits)) - if err != nil { - return nil, err - } + frameHead.Variable0 = uint(bitReader.ReadUintPacked(int(dirHead.Variable0Bits))) + frameHead.Width = uint(bitReader.ReadUintPacked(int(dirHead.WidthBits))) + frameHead.Height = uint(bitReader.ReadUintPacked(int(dirHead.HeightBits))) + frameHead.OffsetX = int(bitReader.ReadIntPacked(int(dirHead.OffsetXBits))) + frameHead.OffsetY = int(bitReader.ReadIntPacked(int(dirHead.OffsetYBits))) + frameHead.OptionalBytes = uint(bitReader.ReadUintPacked(int(dirHead.OptionalBytesBits))) + frameHead.CodedBytes = uint(bitReader.ReadUintPacked(int(dirHead.CodedBytesBits))) + frameHead.FrameBottomUp = bitReader.ReadBool() - frameHead.Width, err = readPackedUint32(bitReader, int(dirHead.WidthBits)) - if err != nil { - return nil, err - } - - frameHead.Height, err = readPackedUint32(bitReader, int(dirHead.HeightBits)) - if err != nil { - return nil, err - } - - frameHead.OffsetX, err = readPackedInt32(bitReader, int(dirHead.OffsetXBits)) - if err != nil { - return nil, err - } - - frameHead.OffsetY, err = readPackedInt32(bitReader, int(dirHead.OffsetYBits)) - if err != nil { - return nil, err - } - - frameHead.OptionalBytes, err = readPackedUint32(bitReader, int(dirHead.OptionalBytesBits)) - if err != nil { - return nil, err - } - - frameHead.CodedBytes, err = readPackedUint32(bitReader, int(dirHead.CodedBytesBits)) - if err != nil { - return nil, err - } - - frameHead.FrameBottomUp, err = bitReader.ReadBool() - if err != nil { - return nil, err - } - - return &frameHead, nil + return &frameHead } func readDirection(reader io.ReadSeeker, fileHead fileHeader) error { bitReader := streaming.NewBitReader(reader) - dirHead, err := readDirectionHeader(bitReader) - if err != nil { - return err - } - - frameHead, err := readFrameHeader(bitReader, *dirHead) - if err != nil { - return err - } + dirHead := readDirectionHeader(bitReader) + frameHead := readFrameHeader(bitReader, *dirHead) fmt.Printf("%+v\n", dirHead) fmt.Printf("%+v\n", frameHead) return nil } - -func readPackedInt32(reader *streaming.BitReader, packedSize int) (int32, error) { - width, err := unpackSize(packedSize) - if err != nil { - return 0, err - } - - return reader.ReadInt32(width) -} - -func readPackedUint32(reader *streaming.BitReader, packedSize int) (uint32, error) { - width, err := unpackSize(packedSize) - if err != nil { - return 0, err - } - - return reader.ReadUint32(width) -} - -func unpackSize(packedSize int) (int, error) { - sizes := []int{0, 1, 2, 4, 6, 8, 10, 12, 14, 16, 20, 24, 26, 28, 30, 32} - if packedSize >= len(sizes) { - return 0, errors.New("invalid packed size") - } - - return sizes[packedSize], nil -} diff --git a/streaming/bitreader.go b/streaming/bitreader.go index 945b6f1..3f18688 100644 --- a/streaming/bitreader.go +++ b/streaming/bitreader.go @@ -1,6 +1,7 @@ package streaming import ( + "errors" "io" ) @@ -8,63 +9,65 @@ type BitReader struct { reader io.Reader bitOffset int tailByte byte + err error } func NewBitReader(reader io.Reader) *BitReader { return &BitReader{reader: reader} } -func (r *BitReader) ReadBool() (bool, error) { - value, err := r.ReadUint64(1) - return value == 1, err +func (r *BitReader) ReadBool() bool { + return r.ReadUint(1) != 0 } -func (r *BitReader) ReadInt8(count int) (int8, error) { - value, err := r.ReadInt64(count) - return int8(value), err -} - -func (r *BitReader) ReadUint8(count int) (uint8, error) { - value, err := r.ReadUint64(count) - return uint8(value), err -} - -func (r *BitReader) ReadInt16(count int) (int16, error) { - value, err := r.ReadInt64(count) - return int16(value), err -} - -func (r *BitReader) ReadUint16(count int) (uint16, error) { - value, err := r.ReadUint64(count) - return uint16(value), err -} - -func (r *BitReader) ReadInt32(count int) (int32, error) { - value, err := r.ReadInt64(count) - return int32(value), err -} - -func (r *BitReader) ReadUint32(count int) (uint32, error) { - value, err := r.ReadUint64(count) - return uint32(value), err -} - -func (r *BitReader) ReadInt64(count int) (int64, error) { - value, err := r.ReadUint64(count) - if err != nil { - return 0, err +func (r *BitReader) ReadIntPacked(countPacked int) int64 { + if r.err != nil { + return 0 } - return twosComplement(value, count), nil + count, err := unpackSize(countPacked) + if err != nil { + r.err = err + return 0 + } + + return r.ReadInt(count) } -func (r *BitReader) ReadUint64(count int) (uint64, error) { +func (r *BitReader) ReadInt(count int) int64 { + return twosComplement(r.ReadUint(count), count) +} + +func (r *BitReader) ReadUintPacked(countPacked int) uint64 { + if r.err != nil { + return 0 + } + + count, err := unpackSize(countPacked) + if err != nil { + r.err = err + return 0 + } + + return r.ReadUint(count) +} + +func (r *BitReader) ReadUint(count int) uint64 { + if r.err != nil { + return 0 + } + buffer, bitOffset, err := r.readBytes(count) if err != nil { - return 0, err + r.err = err + return 0 } - return readBits(buffer, bitOffset, count), nil + return readBits(buffer, bitOffset, count) +} + +func (r *BitReader) Error() error { + return r.err } func (r *BitReader) readBytes(count int) ([]byte, int, error) { @@ -135,3 +138,12 @@ func twosComplement(value uint64, bits int) int64 { return -int64(valueMask & (^value + 1)) } } + +func unpackSize(sizePacked int) (int, error) { + sizes := []int{0, 1, 2, 4, 6, 8, 10, 12, 14, 16, 20, 24, 26, 28, 30, 32} + if sizePacked >= len(sizes) { + return 0, errors.New("invalid packed size") + } + + return sizes[sizePacked], nil +} diff --git a/streaming/streaming_test.go b/streaming/streaming_test.go index df8f35e..2ed3c61 100644 --- a/streaming/streaming_test.go +++ b/streaming/streaming_test.go @@ -21,14 +21,15 @@ func TestBitReader(t *testing.T) { r := NewBitReader(bytes.NewReader(data)) test := func(count int, expected uint64) { - value, err := r.ReadUint64(count) - if err != nil { - log.Printf("error: %s\n", err.Error()) - t.Fail() - } else if value != expected { + if value := r.ReadUint(count); value != expected { log.Printf("value: %.16x, expected: %.16x\n", value, expected) t.Fail() } + + if err := r.Error(); err != nil { + log.Printf("error: %s\n", err.Error()) + t.Fail() + } } test(0, 0x00)