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type context struct {
table [1 << 16]byte
buffer [1 << 3]byte
input []byte
hash uint16
}
// Returns a closure over the provided writer that compresses data when called.
func Compressor(writer io.Writer) func([]byte) error {
var ctx context
ctx.input = ctx.buffer[:0]
// Forward declaration as it is required for recursion
var write func(data []byte) error
write = func(data []byte) error {
var (
blockSize int = 8
bufferLength int = len(ctx.input)
)
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type context struct {
table [1 << 16]byte
buffer [1 << 3]byte
input []byte
hash uint16
}
type compressor func([]byte) error
func (w compressor) Write(data []byte) (int, error) {
return len(data), w(data)
}
// Returns an io.Writer implementation that wraps the provided io.Writer
// and compresses data according to the predictor algorithm
//
// It can buffer data as the predictor mandates 8-byte blocks with a header.
// A call with no data will force a flush.
func Compressor(writer io.Writer) io.Writer {
var ctx context
ctx.input = ctx.buffer[:0]
// Forward declaration as it is required for recursion
var write compressor
write = func(data []byte) error {
var (
blockSize int = 8
bufferLength int = len(ctx.input)
)
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return nil
}
return write
}
type reader func([]byte) (int, error)
func (r reader) Read(output []byte) (int, error) {
return r(output)
}
// TODO - document
func Decompressor(wrapped io.Reader) io.Reader {
var ctx context
ctx.input = ctx.buffer[:0]
return reader(func(output []byte) (int, error) {
var (
err error
flags byte
readCount int
)
// Sanity check for space to read into
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return nil
}
return write
}
// A function type alias so that it can have methods attached to it
type decompressor func([]byte) (int, error)
// Required to implement io.Reader
func (r decompressor) Read(output []byte) (int, error) {
return r(output)
}
// Returns an io.Reader implementation that wraps the provided io.Reader
// and decompresses data according to the predictor algorithm
func Decompressor(wrapped io.Reader) io.Reader {
var ctx context
ctx.input = ctx.buffer[:0]
return decompressor(func(output []byte) (int, error) {
var (
err error
flags byte
readCount int
)
// Sanity check for space to read into
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