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author | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
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committer | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
commit | 554fd8c5195424bdbcabf5de30fdc183aba391bd (patch) | |
tree | 976dc5ab7fddf506dadce60ae936f43f58787092 /libgo/go/encoding/binary/binary.go | |
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Diffstat (limited to 'libgo/go/encoding/binary/binary.go')
-rw-r--r-- | libgo/go/encoding/binary/binary.go | 409 |
1 files changed, 409 insertions, 0 deletions
diff --git a/libgo/go/encoding/binary/binary.go b/libgo/go/encoding/binary/binary.go new file mode 100644 index 000000000..77ff3a9f3 --- /dev/null +++ b/libgo/go/encoding/binary/binary.go @@ -0,0 +1,409 @@ +// 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 + PutUint16([]byte, uint16) + PutUint32([]byte, uint32) + PutUint64([]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 + +// LittleEndian is the little-endian implementation of ByteOrder. +var LittleEndian littleEndian + +// BigEndian is the big-endian implementation of ByteOrder. +var BigEndian bigEndian + +type littleEndian unused + +func (littleEndian) Uint16(b []byte) uint16 { return uint16(b[0]) | uint16(b[1])<<8 } + +func (littleEndian) PutUint16(b []byte, v uint16) { + b[0] = byte(v) + b[1] = byte(v >> 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) PutUint32(b []byte, v uint32) { + b[0] = byte(v) + b[1] = byte(v >> 8) + b[2] = byte(v >> 16) + b[3] = byte(v >> 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) PutUint64(b []byte, v uint64) { + b[0] = byte(v) + b[1] = byte(v >> 8) + b[2] = byte(v >> 16) + b[3] = byte(v >> 24) + b[4] = byte(v >> 32) + b[5] = byte(v >> 40) + b[6] = byte(v >> 48) + b[7] = byte(v >> 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) PutUint16(b []byte, v uint16) { + b[0] = byte(v >> 8) + b[1] = byte(v) +} + +func (bigEndian) Uint32(b []byte) uint32 { + return uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24 +} + +func (bigEndian) PutUint32(b []byte, v uint32) { + b[0] = byte(v >> 24) + b[1] = byte(v >> 16) + b[2] = byte(v >> 8) + b[3] = byte(v) +} + +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) PutUint64(b []byte, v uint64) { + b[0] = byte(v >> 56) + b[1] = byte(v >> 48) + b[2] = byte(v >> 40) + b[3] = byte(v >> 32) + b[4] = byte(v >> 24) + b[5] = byte(v >> 16) + b[6] = byte(v >> 8) + b[7] = byte(v) +} + +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 or a slice +// of fixed-size values. +// A fixed-size value is either a fixed-size arithmetic +// type (int8, uint8, int16, float32, complex64, ...) +// or an array or struct containing only fixed-size values. +// Bytes read from r are decoded using the specified byte order +// and written to successive fields of the data. +func Read(r io.Reader, order ByteOrder, data interface{}) os.Error { + var v reflect.Value + switch d := reflect.NewValue(data).(type) { + case *reflect.PtrValue: + v = d.Elem() + case *reflect.SliceValue: + v = d + default: + return os.NewError("binary.Read: invalid type " + d.Type().String()) + } + size := TotalSize(v) + 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 +} + +// Write writes the binary representation of data into w. +// Data must be a fixed-size value or a pointer to +// a fixed-size value. +// A fixed-size value is either a fixed-size arithmetic +// type (int8, uint8, int16, float32, complex64, ...) +// or an array or struct containing only fixed-size values. +// Bytes written to w are encoded using the specified byte order +// and read from successive fields of the data. +func Write(w io.Writer, order ByteOrder, data interface{}) os.Error { + v := reflect.Indirect(reflect.NewValue(data)) + size := TotalSize(v) + if size < 0 { + return os.NewError("binary.Write: invalid type " + v.Type().String()) + } + buf := make([]byte, size) + e := &encoder{order: order, buf: buf} + e.value(v) + _, err := w.Write(buf) + return err +} + +func TotalSize(v reflect.Value) int { + if sv, ok := v.(*reflect.SliceValue); ok { + elem := sizeof(v.Type().(*reflect.SliceType).Elem()) + if elem < 0 { + return -1 + } + return sv.Len() * elem + } + return sizeof(v.Type()) +} + +func sizeof(v reflect.Type) int { + switch t := v.(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.UintType, *reflect.IntType, *reflect.FloatType, *reflect.ComplexType: + switch t := t.Kind(); t { + case reflect.Int, reflect.Uint, reflect.Uintptr: + return -1 + } + return int(v.Size()) + } + return -1 +} + +type decoder struct { + order ByteOrder + buf []byte +} + +type encoder struct { + order ByteOrder + buf []byte +} + +func (d *decoder) uint8() uint8 { + x := d.buf[0] + d.buf = d.buf[1:] + return x +} + +func (e *encoder) uint8(x uint8) { + e.buf[0] = x + e.buf = e.buf[1:] +} + +func (d *decoder) uint16() uint16 { + x := d.order.Uint16(d.buf[0:2]) + d.buf = d.buf[2:] + return x +} + +func (e *encoder) uint16(x uint16) { + e.order.PutUint16(e.buf[0:2], x) + e.buf = e.buf[2:] +} + +func (d *decoder) uint32() uint32 { + x := d.order.Uint32(d.buf[0:4]) + d.buf = d.buf[4:] + return x +} + +func (e *encoder) uint32(x uint32) { + e.order.PutUint32(e.buf[0:4], x) + e.buf = e.buf[4:] +} + +func (d *decoder) uint64() uint64 { + x := d.order.Uint64(d.buf[0:8]) + d.buf = d.buf[8:] + return x +} + +func (e *encoder) uint64(x uint64) { + e.order.PutUint64(e.buf[0:8], x) + e.buf = e.buf[8:] +} + +func (d *decoder) int8() int8 { return int8(d.uint8()) } + +func (e *encoder) int8(x int8) { e.uint8(uint8(x)) } + +func (d *decoder) int16() int16 { return int16(d.uint16()) } + +func (e *encoder) int16(x int16) { e.uint16(uint16(x)) } + +func (d *decoder) int32() int32 { return int32(d.uint32()) } + +func (e *encoder) int32(x int32) { e.uint32(uint32(x)) } + +func (d *decoder) int64() int64 { return int64(d.uint64()) } + +func (e *encoder) int64(x int64) { e.uint64(uint64(x)) } + +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.SliceValue: + l := v.Len() + for i := 0; i < l; i++ { + d.value(v.Elem(i)) + } + + case *reflect.IntValue: + switch v.Type().Kind() { + case reflect.Int8: + v.Set(int64(d.int8())) + case reflect.Int16: + v.Set(int64(d.int16())) + case reflect.Int32: + v.Set(int64(d.int32())) + case reflect.Int64: + v.Set(d.int64()) + } + + case *reflect.UintValue: + switch v.Type().Kind() { + case reflect.Uint8: + v.Set(uint64(d.uint8())) + case reflect.Uint16: + v.Set(uint64(d.uint16())) + case reflect.Uint32: + v.Set(uint64(d.uint32())) + case reflect.Uint64: + v.Set(d.uint64()) + } + + case *reflect.FloatValue: + switch v.Type().Kind() { + case reflect.Float32: + v.Set(float64(math.Float32frombits(d.uint32()))) + case reflect.Float64: + v.Set(math.Float64frombits(d.uint64())) + } + + case *reflect.ComplexValue: + switch v.Type().Kind() { + case reflect.Complex64: + v.Set(complex( + float64(math.Float32frombits(d.uint32())), + float64(math.Float32frombits(d.uint32())), + )) + case reflect.Complex128: + v.Set(complex( + math.Float64frombits(d.uint64()), + math.Float64frombits(d.uint64()), + )) + } + } +} + +func (e *encoder) value(v reflect.Value) { + switch v := v.(type) { + case *reflect.ArrayValue: + l := v.Len() + for i := 0; i < l; i++ { + e.value(v.Elem(i)) + } + case *reflect.StructValue: + l := v.NumField() + for i := 0; i < l; i++ { + e.value(v.Field(i)) + } + case *reflect.SliceValue: + l := v.Len() + for i := 0; i < l; i++ { + e.value(v.Elem(i)) + } + + case *reflect.IntValue: + switch v.Type().Kind() { + case reflect.Int8: + e.int8(int8(v.Get())) + case reflect.Int16: + e.int16(int16(v.Get())) + case reflect.Int32: + e.int32(int32(v.Get())) + case reflect.Int64: + e.int64(v.Get()) + } + + case *reflect.UintValue: + switch v.Type().Kind() { + case reflect.Uint8: + e.uint8(uint8(v.Get())) + case reflect.Uint16: + e.uint16(uint16(v.Get())) + case reflect.Uint32: + e.uint32(uint32(v.Get())) + case reflect.Uint64: + e.uint64(v.Get()) + } + + case *reflect.FloatValue: + switch v.Type().Kind() { + case reflect.Float32: + e.uint32(math.Float32bits(float32(v.Get()))) + case reflect.Float64: + e.uint64(math.Float64bits(v.Get())) + } + + case *reflect.ComplexValue: + switch v.Type().Kind() { + case reflect.Complex64: + x := v.Get() + e.uint32(math.Float32bits(float32(real(x)))) + e.uint32(math.Float32bits(float32(imag(x)))) + case reflect.Complex128: + x := v.Get() + e.uint64(math.Float64bits(real(x))) + e.uint64(math.Float64bits(imag(x))) + } + } +} |