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WordReader.go
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/
WordReader.go
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package compression
import "github.com/inkyblackness/hacked/ss1/serial"
// WordReader provides word instances from a serialized stream.
type WordReader struct {
coder serial.Coder
buffer byte
bufferBitsAvailable uint
}
// NewWordReader returns a new instance.
func NewWordReader(coder serial.Coder) *WordReader {
reader := &WordReader{coder: coder, buffer: 0x00, bufferBitsAvailable: 0}
return reader
}
// Read returns the next word from the stream.
func (reader *WordReader) Read() (value Word) {
remaining := bitsPerWord
for remaining > reader.bufferBitsAvailable {
value = Word((uint(value) << reader.bufferBitsAvailable) | uint(reader.buffer))
remaining -= reader.bufferBitsAvailable
reader.bufferByte()
}
value = Word((uint(value) << remaining) | uint(reader.buffer)>>(8-remaining))
reader.buffer &= 1<<(8-remaining) - 1
reader.bufferBitsAvailable -= remaining
return
}
func (reader *WordReader) bufferByte() {
reader.coder.Code(&reader.buffer)
reader.bufferBitsAvailable = 8
}