diff options
| author | Russ Cox <rsc@golang.org> | 2009-10-20 13:00:16 -0700 | 
|---|---|---|
| committer | Russ Cox <rsc@golang.org> | 2009-10-20 13:00:16 -0700 | 
| commit | 3b898983005c16f5b182d1b433e622f8a6de99eb (patch) | |
| tree | 4c7e239969079349aa840a7444732ca7cad27deb /src/pkg/encoding/binary/binary.go | |
| parent | 0f60a452df747c97b012636454382f70cddcac31 (diff) | |
| download | golang-3b898983005c16f5b182d1b433e622f8a6de99eb.tar.gz | |
base64 -> encoding/base64
base85 -> encoding/ascii85, encoding/git85
debug/binary -> encoding/binary
R=r
DELTA=3190  (1884 added, 1297 deleted, 9 changed)
OCL=35923
CL=35929
Diffstat (limited to 'src/pkg/encoding/binary/binary.go')
| -rw-r--r-- | src/pkg/encoding/binary/binary.go | 222 | 
1 files changed, 222 insertions, 0 deletions
| diff --git a/src/pkg/encoding/binary/binary.go b/src/pkg/encoding/binary/binary.go new file mode 100644 index 000000000..836a43df0 --- /dev/null +++ b/src/pkg/encoding/binary/binary.go @@ -0,0 +1,222 @@ +// Copyright 2009 The Go Authors.  All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This package implements translation between +// unsigned integer values and byte sequences. +package binary + +import ( +	"math"; +	"io"; +	"os"; +	"reflect"; +) + +// A ByteOrder specifies how to convert byte sequences into +// 16-, 32-, or 64-bit unsigned integers. +type ByteOrder interface { +	Uint16(b []byte) uint16; +	Uint32(b []byte) uint32; +	Uint64(b []byte) uint64; +	String() string; +} + +// This is byte instead of struct{} so that it can be compared, +// allowing, e.g., order == binary.LittleEndian. +type unused byte + +var LittleEndian ByteOrder = littleEndian(0) +var BigEndian ByteOrder = bigEndian(0) + +type littleEndian unused + +func (littleEndian) Uint16(b []byte) uint16 { +	return uint16(b[0]) | uint16(b[1])<<8; +} + +func (littleEndian) Uint32(b []byte) uint32 { +	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24; +} + +func (littleEndian) Uint64(b []byte) uint64 { +	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | +		uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56; +} + +func (littleEndian) String() string { +	return "LittleEndian"; +} + +func (littleEndian) GoString() string { +	return "binary.LittleEndian"; +} + +type bigEndian unused + +func (bigEndian) Uint16(b []byte) uint16 { +	return uint16(b[1]) | uint16(b[0])<<8; +} + +func (bigEndian) Uint32(b []byte) uint32 { +	return uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24; +} + +func (bigEndian) Uint64(b []byte) uint64 { +	return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 | +		uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56; +} + +func (bigEndian) String() string { +	return "BigEndian"; +} + +func (bigEndian) GoString() string { +	return "binary.BigEndian"; +} + +// Read reads structured binary data from r into data. +// Data must be a pointer to a fixed-size value. +// A fixed-size value is either a fixed-size integer +// (int8, uint8, int16, uint16, ...) or an array or struct +// containing only fixed-size values.  Bytes read from +// r are decoded using order and written to successive +// fields of the data. +func Read(r io.Reader, order ByteOrder, data interface{}) os.Error { +	v := reflect.NewValue(data).(*reflect.PtrValue).Elem(); +	size := sizeof(v.Type()); +	if size < 0 { +		return os.NewError("binary.Read: invalid type " + v.Type().String()); +	} +	d := &decoder{order: order, buf: make([]byte, size)}; +	if _, err := io.ReadFull(r, d.buf); err != nil { +		return err; +	} +	d.value(v); +	return nil; +} + +func sizeof(t reflect.Type) int { +	switch t := t.(type) { +	case *reflect.ArrayType: +		n := sizeof(t.Elem()); +		if n < 0 { +			return -1; +		} +		return t.Len() * n; + +	case *reflect.StructType: +		sum := 0; +		for i, n := 0, t.NumField(); i < n; i++ { +			s := sizeof(t.Field(i).Type); +			if s < 0 { +				return -1; +			} +			sum += s; +		} +		return sum; + +	case *reflect.Uint8Type: +		return 1; +	case *reflect.Uint16Type: +		return 2; +	case *reflect.Uint32Type: +		return 4; +	case *reflect.Uint64Type: +		return 8; +	case *reflect.Int8Type: +		return 1; +	case *reflect.Int16Type: +		return 2; +	case *reflect.Int32Type: +		return 4; +	case *reflect.Int64Type: +		return 8; +	case *reflect.Float32Type: +		return 4; +	case *reflect.Float64Type: +		return 8; +	} +	return -1; +} + +type decoder struct { +	order	ByteOrder; +	buf	[]byte; +} + +func (d *decoder) uint8() uint8 { +	x := d.buf[0]; +	d.buf = d.buf[1:len(d.buf)]; +	return x; +} + +func (d *decoder) uint16() uint16 { +	x := d.order.Uint16(d.buf[0:2]); +	d.buf = d.buf[2:len(d.buf)]; +	return x; +} + +func (d *decoder) uint32() uint32 { +	x := d.order.Uint32(d.buf[0:4]); +	d.buf = d.buf[4:len(d.buf)]; +	return x; +} + +func (d *decoder) uint64() uint64 { +	x := d.order.Uint64(d.buf[0:8]); +	d.buf = d.buf[8:len(d.buf)]; +	return x; +} + +func (d *decoder) int8() int8 { +	return int8(d.uint8()); +} + +func (d *decoder) int16() int16 { +	return int16(d.uint16()); +} + +func (d *decoder) int32() int32 { +	return int32(d.uint32()); +} + +func (d *decoder) int64() int64 { +	return int64(d.uint64()); +} + +func (d *decoder) value(v reflect.Value) { +	switch v := v.(type) { +	case *reflect.ArrayValue: +		l := v.Len(); +		for i := 0; i < l; i++ { +			d.value(v.Elem(i)); +		} +	case *reflect.StructValue: +		l := v.NumField(); +		for i := 0; i < l; i++ { +			d.value(v.Field(i)); +		} + +	case *reflect.Uint8Value: +		v.Set(d.uint8()); +	case *reflect.Uint16Value: +		v.Set(d.uint16()); +	case *reflect.Uint32Value: +		v.Set(d.uint32()); +	case *reflect.Uint64Value: +		v.Set(d.uint64()); +	case *reflect.Int8Value: +		v.Set(d.int8()); +	case *reflect.Int16Value: +		v.Set(d.int16()); +	case *reflect.Int32Value: +		v.Set(d.int32()); +	case *reflect.Int64Value: +		v.Set(d.int64()); +	case *reflect.Float32Value: +		v.Set(math.Float32frombits(d.uint32())); +	case *reflect.Float64Value: +		v.Set(math.Float64frombits(d.uint64())); +	} +} | 
