Adding upstream version 1.17.13.upstream/1.17.13upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 2025 insertions, 0 deletions

diff --git a/src/encoding/binary/binary.go b/src/encoding/binary/binary.go
new file mode 100644
index 0000000..a311499
--- /dev/null
+++ b/src/encoding/binary/binary.go
@@ -0,0 +1,737 @@
+// 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.
+
+// Package binary implements simple translation between numbers and byte
+// sequences and encoding and decoding of varints.
+//
+// Numbers are translated by reading and writing fixed-size values.
+// A fixed-size value is either a fixed-size arithmetic
+// type (bool, int8, uint8, int16, float32, complex64, ...)
+// or an array or struct containing only fixed-size values.
+//
+// The varint functions encode and decode single integer values using
+// a variable-length encoding; smaller values require fewer bytes.
+// For a specification, see
+// https://developers.google.com/protocol-buffers/docs/encoding.
+//
+// This package favors simplicity over efficiency. Clients that require
+// high-performance serialization, especially for large data structures,
+// should look at more advanced solutions such as the encoding/gob
+// package or protocol buffers.
+package binary
+
+import (
+	"errors"
+	"io"
+	"math"
+	"reflect"
+	"sync"
+)
+
+// A ByteOrder specifies how to convert byte sequences into
+// 16-, 32-, or 64-bit unsigned integers.
+type ByteOrder interface {
+	Uint16([]byte) uint16
+	Uint32([]byte) uint32
+	Uint64([]byte) uint64
+	PutUint16([]byte, uint16)
+	PutUint32([]byte, uint32)
+	PutUint64([]byte, uint64)
+	String() string
+}
+
+// LittleEndian is the little-endian implementation of ByteOrder.
+var LittleEndian littleEndian
+
+// BigEndian is the big-endian implementation of ByteOrder.
+var BigEndian bigEndian
+
+type littleEndian struct{}
+
+func (littleEndian) Uint16(b []byte) uint16 {
+	_ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint16(b[0]) | uint16(b[1])<<8
+}
+
+func (littleEndian) PutUint16(b []byte, v uint16) {
+	_ = b[1] // early bounds check to guarantee safety of writes below
+	b[0] = byte(v)
+	b[1] = byte(v >> 8)
+}
+
+func (littleEndian) Uint32(b []byte) uint32 {
+	_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+}
+
+func (littleEndian) PutUint32(b []byte, v uint32) {
+	_ = b[3] // early bounds check to guarantee safety of writes below
+	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 {
+	_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
+	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[7] // early bounds check to guarantee safety of writes below
+	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 struct{}
+
+func (bigEndian) Uint16(b []byte) uint16 {
+	_ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint16(b[1]) | uint16(b[0])<<8
+}
+
+func (bigEndian) PutUint16(b []byte, v uint16) {
+	_ = b[1] // early bounds check to guarantee safety of writes below
+	b[0] = byte(v >> 8)
+	b[1] = byte(v)
+}
+
+func (bigEndian) Uint32(b []byte) uint32 {
+	_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24
+}
+
+func (bigEndian) PutUint32(b []byte, v uint32) {
+	_ = b[3] // early bounds check to guarantee safety of writes below
+	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 {
+	_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
+	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[7] // early bounds check to guarantee safety of writes below
+	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.
+// Bytes read from r are decoded using the specified byte order
+// and written to successive fields of the data.
+// When decoding boolean values, a zero byte is decoded as false, and
+// any other non-zero byte is decoded as true.
+// When reading into structs, the field data for fields with
+// blank (_) field names is skipped; i.e., blank field names
+// may be used for padding.
+// When reading into a struct, all non-blank fields must be exported
+// or Read may panic.
+//
+// The error is EOF only if no bytes were read.
+// If an EOF happens after reading some but not all the bytes,
+// Read returns ErrUnexpectedEOF.
+func Read(r io.Reader, order ByteOrder, data interface{}) error {
+	// Fast path for basic types and slices.
+	if n := intDataSize(data); n != 0 {
+		bs := make([]byte, n)
+		if _, err := io.ReadFull(r, bs); err != nil {
+			return err
+		}
+		switch data := data.(type) {
+		case *bool:
+			*data = bs[0] != 0
+		case *int8:
+			*data = int8(bs[0])
+		case *uint8:
+			*data = bs[0]
+		case *int16:
+			*data = int16(order.Uint16(bs))
+		case *uint16:
+			*data = order.Uint16(bs)
+		case *int32:
+			*data = int32(order.Uint32(bs))
+		case *uint32:
+			*data = order.Uint32(bs)
+		case *int64:
+			*data = int64(order.Uint64(bs))
+		case *uint64:
+			*data = order.Uint64(bs)
+		case *float32:
+			*data = math.Float32frombits(order.Uint32(bs))
+		case *float64:
+			*data = math.Float64frombits(order.Uint64(bs))
+		case []bool:
+			for i, x := range bs { // Easier to loop over the input for 8-bit values.
+				data[i] = x != 0
+			}
+		case []int8:
+			for i, x := range bs {
+				data[i] = int8(x)
+			}
+		case []uint8:
+			copy(data, bs)
+		case []int16:
+			for i := range data {
+				data[i] = int16(order.Uint16(bs[2*i:]))
+			}
+		case []uint16:
+			for i := range data {
+				data[i] = order.Uint16(bs[2*i:])
+			}
+		case []int32:
+			for i := range data {
+				data[i] = int32(order.Uint32(bs[4*i:]))
+			}
+		case []uint32:
+			for i := range data {
+				data[i] = order.Uint32(bs[4*i:])
+			}
+		case []int64:
+			for i := range data {
+				data[i] = int64(order.Uint64(bs[8*i:]))
+			}
+		case []uint64:
+			for i := range data {
+				data[i] = order.Uint64(bs[8*i:])
+			}
+		case []float32:
+			for i := range data {
+				data[i] = math.Float32frombits(order.Uint32(bs[4*i:]))
+			}
+		case []float64:
+			for i := range data {
+				data[i] = math.Float64frombits(order.Uint64(bs[8*i:]))
+			}
+		default:
+			n = 0 // fast path doesn't apply
+		}
+		if n != 0 {
+			return nil
+		}
+	}
+
+	// Fallback to reflect-based decoding.
+	v := reflect.ValueOf(data)
+	size := -1
+	switch v.Kind() {
+	case reflect.Ptr:
+		v = v.Elem()
+		size = dataSize(v)
+	case reflect.Slice:
+		size = dataSize(v)
+	}
+	if size < 0 {
+		return errors.New("binary.Read: invalid type " + reflect.TypeOf(data).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 slice of fixed-size
+// values, or a pointer to such data.
+// Boolean values encode as one byte: 1 for true, and 0 for false.
+// Bytes written to w are encoded using the specified byte order
+// and read from successive fields of the data.
+// When writing structs, zero values are written for fields
+// with blank (_) field names.
+func Write(w io.Writer, order ByteOrder, data interface{}) error {
+	// Fast path for basic types and slices.
+	if n := intDataSize(data); n != 0 {
+		bs := make([]byte, n)
+		switch v := data.(type) {
+		case *bool:
+			if *v {
+				bs[0] = 1
+			} else {
+				bs[0] = 0
+			}
+		case bool:
+			if v {
+				bs[0] = 1
+			} else {
+				bs[0] = 0
+			}
+		case []bool:
+			for i, x := range v {
+				if x {
+					bs[i] = 1
+				} else {
+					bs[i] = 0
+				}
+			}
+		case *int8:
+			bs[0] = byte(*v)
+		case int8:
+			bs[0] = byte(v)
+		case []int8:
+			for i, x := range v {
+				bs[i] = byte(x)
+			}
+		case *uint8:
+			bs[0] = *v
+		case uint8:
+			bs[0] = v
+		case []uint8:
+			bs = v
+		case *int16:
+			order.PutUint16(bs, uint16(*v))
+		case int16:
+			order.PutUint16(bs, uint16(v))
+		case []int16:
+			for i, x := range v {
+				order.PutUint16(bs[2*i:], uint16(x))
+			}
+		case *uint16:
+			order.PutUint16(bs, *v)
+		case uint16:
+			order.PutUint16(bs, v)
+		case []uint16:
+			for i, x := range v {
+				order.PutUint16(bs[2*i:], x)
+			}
+		case *int32:
+			order.PutUint32(bs, uint32(*v))
+		case int32:
+			order.PutUint32(bs, uint32(v))
+		case []int32:
+			for i, x := range v {
+				order.PutUint32(bs[4*i:], uint32(x))
+			}
+		case *uint32:
+			order.PutUint32(bs, *v)
+		case uint32:
+			order.PutUint32(bs, v)
+		case []uint32:
+			for i, x := range v {
+				order.PutUint32(bs[4*i:], x)
+			}
+		case *int64:
+			order.PutUint64(bs, uint64(*v))
+		case int64:
+			order.PutUint64(bs, uint64(v))
+		case []int64:
+			for i, x := range v {
+				order.PutUint64(bs[8*i:], uint64(x))
+			}
+		case *uint64:
+			order.PutUint64(bs, *v)
+		case uint64:
+			order.PutUint64(bs, v)
+		case []uint64:
+			for i, x := range v {
+				order.PutUint64(bs[8*i:], x)
+			}
+		case *float32:
+			order.PutUint32(bs, math.Float32bits(*v))
+		case float32:
+			order.PutUint32(bs, math.Float32bits(v))
+		case []float32:
+			for i, x := range v {
+				order.PutUint32(bs[4*i:], math.Float32bits(x))
+			}
+		case *float64:
+			order.PutUint64(bs, math.Float64bits(*v))
+		case float64:
+			order.PutUint64(bs, math.Float64bits(v))
+		case []float64:
+			for i, x := range v {
+				order.PutUint64(bs[8*i:], math.Float64bits(x))
+			}
+		}
+		_, err := w.Write(bs)
+		return err
+	}
+
+	// Fallback to reflect-based encoding.
+	v := reflect.Indirect(reflect.ValueOf(data))
+	size := dataSize(v)
+	if size < 0 {
+		return errors.New("binary.Write: invalid type " + reflect.TypeOf(data).String())
+	}
+	buf := make([]byte, size)
+	e := &encoder{order: order, buf: buf}
+	e.value(v)
+	_, err := w.Write(buf)
+	return err
+}
+
+// Size returns how many bytes Write would generate to encode the value v, which
+// must be a fixed-size value or a slice of fixed-size values, or a pointer to such data.
+// If v is neither of these, Size returns -1.
+func Size(v interface{}) int {
+	return dataSize(reflect.Indirect(reflect.ValueOf(v)))
+}
+
+var structSize sync.Map // map[reflect.Type]int
+
+// dataSize returns the number of bytes the actual data represented by v occupies in memory.
+// For compound structures, it sums the sizes of the elements. Thus, for instance, for a slice
+// it returns the length of the slice times the element size and does not count the memory
+// occupied by the header. If the type of v is not acceptable, dataSize returns -1.
+func dataSize(v reflect.Value) int {
+	switch v.Kind() {
+	case reflect.Slice:
+		if s := sizeof(v.Type().Elem()); s >= 0 {
+			return s * v.Len()
+		}
+		return -1
+
+	case reflect.Struct:
+		t := v.Type()
+		if size, ok := structSize.Load(t); ok {
+			return size.(int)
+		}
+		size := sizeof(t)
+		structSize.Store(t, size)
+		return size
+
+	default:
+		return sizeof(v.Type())
+	}
+}
+
+// sizeof returns the size >= 0 of variables for the given type or -1 if the type is not acceptable.
+func sizeof(t reflect.Type) int {
+	switch t.Kind() {
+	case reflect.Array:
+		if s := sizeof(t.Elem()); s >= 0 {
+			return s * t.Len()
+		}
+
+	case reflect.Struct:
+		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.Bool,
+		reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
+		reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Float32, reflect.Float64, reflect.Complex64, reflect.Complex128:
+		return int(t.Size())
+	}
+
+	return -1
+}
+
+type coder struct {
+	order  ByteOrder
+	buf    []byte
+	offset int
+}
+
+type decoder coder
+type encoder coder
+
+func (d *decoder) bool() bool {
+	x := d.buf[d.offset]
+	d.offset++
+	return x != 0
+}
+
+func (e *encoder) bool(x bool) {
+	if x {
+		e.buf[e.offset] = 1
+	} else {
+		e.buf[e.offset] = 0
+	}
+	e.offset++
+}
+
+func (d *decoder) uint8() uint8 {
+	x := d.buf[d.offset]
+	d.offset++
+	return x
+}
+
+func (e *encoder) uint8(x uint8) {
+	e.buf[e.offset] = x
+	e.offset++
+}
+
+func (d *decoder) uint16() uint16 {
+	x := d.order.Uint16(d.buf[d.offset : d.offset+2])
+	d.offset += 2
+	return x
+}
+
+func (e *encoder) uint16(x uint16) {
+	e.order.PutUint16(e.buf[e.offset:e.offset+2], x)
+	e.offset += 2
+}
+
+func (d *decoder) uint32() uint32 {
+	x := d.order.Uint32(d.buf[d.offset : d.offset+4])
+	d.offset += 4
+	return x
+}
+
+func (e *encoder) uint32(x uint32) {
+	e.order.PutUint32(e.buf[e.offset:e.offset+4], x)
+	e.offset += 4
+}
+
+func (d *decoder) uint64() uint64 {
+	x := d.order.Uint64(d.buf[d.offset : d.offset+8])
+	d.offset += 8
+	return x
+}
+
+func (e *encoder) uint64(x uint64) {
+	e.order.PutUint64(e.buf[e.offset:e.offset+8], x)
+	e.offset += 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.Kind() {
+	case reflect.Array:
+		l := v.Len()
+		for i := 0; i < l; i++ {
+			d.value(v.Index(i))
+		}
+
+	case reflect.Struct:
+		t := v.Type()
+		l := v.NumField()
+		for i := 0; i < l; i++ {
+			// Note: Calling v.CanSet() below is an optimization.
+			// It would be sufficient to check the field name,
+			// but creating the StructField info for each field is
+			// costly (run "go test -bench=ReadStruct" and compare
+			// results when making changes to this code).
+			if v := v.Field(i); v.CanSet() || t.Field(i).Name != "_" {
+				d.value(v)
+			} else {
+				d.skip(v)
+			}
+		}
+
+	case reflect.Slice:
+		l := v.Len()
+		for i := 0; i < l; i++ {
+			d.value(v.Index(i))
+		}
+
+	case reflect.Bool:
+		v.SetBool(d.bool())
+
+	case reflect.Int8:
+		v.SetInt(int64(d.int8()))
+	case reflect.Int16:
+		v.SetInt(int64(d.int16()))
+	case reflect.Int32:
+		v.SetInt(int64(d.int32()))
+	case reflect.Int64:
+		v.SetInt(d.int64())
+
+	case reflect.Uint8:
+		v.SetUint(uint64(d.uint8()))
+	case reflect.Uint16:
+		v.SetUint(uint64(d.uint16()))
+	case reflect.Uint32:
+		v.SetUint(uint64(d.uint32()))
+	case reflect.Uint64:
+		v.SetUint(d.uint64())
+
+	case reflect.Float32:
+		v.SetFloat(float64(math.Float32frombits(d.uint32())))
+	case reflect.Float64:
+		v.SetFloat(math.Float64frombits(d.uint64()))
+
+	case reflect.Complex64:
+		v.SetComplex(complex(
+			float64(math.Float32frombits(d.uint32())),
+			float64(math.Float32frombits(d.uint32())),
+		))
+	case reflect.Complex128:
+		v.SetComplex(complex(
+			math.Float64frombits(d.uint64()),
+			math.Float64frombits(d.uint64()),
+		))
+	}
+}
+
+func (e *encoder) value(v reflect.Value) {
+	switch v.Kind() {
+	case reflect.Array:
+		l := v.Len()
+		for i := 0; i < l; i++ {
+			e.value(v.Index(i))
+		}
+
+	case reflect.Struct:
+		t := v.Type()
+		l := v.NumField()
+		for i := 0; i < l; i++ {
+			// see comment for corresponding code in decoder.value()
+			if v := v.Field(i); v.CanSet() || t.Field(i).Name != "_" {
+				e.value(v)
+			} else {
+				e.skip(v)
+			}
+		}
+
+	case reflect.Slice:
+		l := v.Len()
+		for i := 0; i < l; i++ {
+			e.value(v.Index(i))
+		}
+
+	case reflect.Bool:
+		e.bool(v.Bool())
+
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		switch v.Type().Kind() {
+		case reflect.Int8:
+			e.int8(int8(v.Int()))
+		case reflect.Int16:
+			e.int16(int16(v.Int()))
+		case reflect.Int32:
+			e.int32(int32(v.Int()))
+		case reflect.Int64:
+			e.int64(v.Int())
+		}
+
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		switch v.Type().Kind() {
+		case reflect.Uint8:
+			e.uint8(uint8(v.Uint()))
+		case reflect.Uint16:
+			e.uint16(uint16(v.Uint()))
+		case reflect.Uint32:
+			e.uint32(uint32(v.Uint()))
+		case reflect.Uint64:
+			e.uint64(v.Uint())
+		}
+
+	case reflect.Float32, reflect.Float64:
+		switch v.Type().Kind() {
+		case reflect.Float32:
+			e.uint32(math.Float32bits(float32(v.Float())))
+		case reflect.Float64:
+			e.uint64(math.Float64bits(v.Float()))
+		}
+
+	case reflect.Complex64, reflect.Complex128:
+		switch v.Type().Kind() {
+		case reflect.Complex64:
+			x := v.Complex()
+			e.uint32(math.Float32bits(float32(real(x))))
+			e.uint32(math.Float32bits(float32(imag(x))))
+		case reflect.Complex128:
+			x := v.Complex()
+			e.uint64(math.Float64bits(real(x)))
+			e.uint64(math.Float64bits(imag(x)))
+		}
+	}
+}
+
+func (d *decoder) skip(v reflect.Value) {
+	d.offset += dataSize(v)
+}
+
+func (e *encoder) skip(v reflect.Value) {
+	n := dataSize(v)
+	zero := e.buf[e.offset : e.offset+n]
+	for i := range zero {
+		zero[i] = 0
+	}
+	e.offset += n
+}
+
+// intDataSize returns the size of the data required to represent the data when encoded.
+// It returns zero if the type cannot be implemented by the fast path in Read or Write.
+func intDataSize(data interface{}) int {
+	switch data := data.(type) {
+	case bool, int8, uint8, *bool, *int8, *uint8:
+		return 1
+	case []bool:
+		return len(data)
+	case []int8:
+		return len(data)
+	case []uint8:
+		return len(data)
+	case int16, uint16, *int16, *uint16:
+		return 2
+	case []int16:
+		return 2 * len(data)
+	case []uint16:
+		return 2 * len(data)
+	case int32, uint32, *int32, *uint32:
+		return 4
+	case []int32:
+		return 4 * len(data)
+	case []uint32:
+		return 4 * len(data)
+	case int64, uint64, *int64, *uint64:
+		return 8
+	case []int64:
+		return 8 * len(data)
+	case []uint64:
+		return 8 * len(data)
+	case float32, *float32:
+		return 4
+	case float64, *float64:
+		return 8
+	case []float32:
+		return 4 * len(data)
+	case []float64:
+		return 8 * len(data)
+	}
+	return 0
+}
diff --git a/src/encoding/binary/binary_test.go b/src/encoding/binary/binary_test.go
new file mode 100644
index 0000000..83af89e
--- /dev/null
+++ b/src/encoding/binary/binary_test.go
@@ -0,0 +1,731 @@
+// 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.
+
+package binary
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"math"
+	"reflect"
+	"strings"
+	"sync"
+	"testing"
+)
+
+type Struct struct {
+	Int8       int8
+	Int16      int16
+	Int32      int32
+	Int64      int64
+	Uint8      uint8
+	Uint16     uint16
+	Uint32     uint32
+	Uint64     uint64
+	Float32    float32
+	Float64    float64
+	Complex64  complex64
+	Complex128 complex128
+	Array      [4]uint8
+	Bool       bool
+	BoolArray  [4]bool
+}
+
+type T struct {
+	Int     int
+	Uint    uint
+	Uintptr uintptr
+	Array   [4]int
+}
+
+var s = Struct{
+	0x01,
+	0x0203,
+	0x04050607,
+	0x08090a0b0c0d0e0f,
+	0x10,
+	0x1112,
+	0x13141516,
+	0x1718191a1b1c1d1e,
+
+	math.Float32frombits(0x1f202122),
+	math.Float64frombits(0x232425262728292a),
+	complex(
+		math.Float32frombits(0x2b2c2d2e),
+		math.Float32frombits(0x2f303132),
+	),
+	complex(
+		math.Float64frombits(0x333435363738393a),
+		math.Float64frombits(0x3b3c3d3e3f404142),
+	),
+
+	[4]uint8{0x43, 0x44, 0x45, 0x46},
+
+	true,
+	[4]bool{true, false, true, false},
+}
+
+var big = []byte{
+	1,
+	2, 3,
+	4, 5, 6, 7,
+	8, 9, 10, 11, 12, 13, 14, 15,
+	16,
+	17, 18,
+	19, 20, 21, 22,
+	23, 24, 25, 26, 27, 28, 29, 30,
+
+	31, 32, 33, 34,
+	35, 36, 37, 38, 39, 40, 41, 42,
+	43, 44, 45, 46, 47, 48, 49, 50,
+	51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66,
+
+	67, 68, 69, 70,
+
+	1,
+	1, 0, 1, 0,
+}
+
+var little = []byte{
+	1,
+	3, 2,
+	7, 6, 5, 4,
+	15, 14, 13, 12, 11, 10, 9, 8,
+	16,
+	18, 17,
+	22, 21, 20, 19,
+	30, 29, 28, 27, 26, 25, 24, 23,
+
+	34, 33, 32, 31,
+	42, 41, 40, 39, 38, 37, 36, 35,
+	46, 45, 44, 43, 50, 49, 48, 47,
+	58, 57, 56, 55, 54, 53, 52, 51, 66, 65, 64, 63, 62, 61, 60, 59,
+
+	67, 68, 69, 70,
+
+	1,
+	1, 0, 1, 0,
+}
+
+var src = []byte{1, 2, 3, 4, 5, 6, 7, 8}
+var res = []int32{0x01020304, 0x05060708}
+var putbuf = []byte{0, 0, 0, 0, 0, 0, 0, 0}
+
+func checkResult(t *testing.T, dir string, order ByteOrder, err error, have, want interface{}) {
+	if err != nil {
+		t.Errorf("%v %v: %v", dir, order, err)
+		return
+	}
+	if !reflect.DeepEqual(have, want) {
+		t.Errorf("%v %v:\n\thave %+v\n\twant %+v", dir, order, have, want)
+	}
+}
+
+func testRead(t *testing.T, order ByteOrder, b []byte, s1 interface{}) {
+	var s2 Struct
+	err := Read(bytes.NewReader(b), order, &s2)
+	checkResult(t, "Read", order, err, s2, s1)
+}
+
+func testWrite(t *testing.T, order ByteOrder, b []byte, s1 interface{}) {
+	buf := new(bytes.Buffer)
+	err := Write(buf, order, s1)
+	checkResult(t, "Write", order, err, buf.Bytes(), b)
+}
+
+func TestLittleEndianRead(t *testing.T)     { testRead(t, LittleEndian, little, s) }
+func TestLittleEndianWrite(t *testing.T)    { testWrite(t, LittleEndian, little, s) }
+func TestLittleEndianPtrWrite(t *testing.T) { testWrite(t, LittleEndian, little, &s) }
+
+func TestBigEndianRead(t *testing.T)     { testRead(t, BigEndian, big, s) }
+func TestBigEndianWrite(t *testing.T)    { testWrite(t, BigEndian, big, s) }
+func TestBigEndianPtrWrite(t *testing.T) { testWrite(t, BigEndian, big, &s) }
+
+func TestReadSlice(t *testing.T) {
+	slice := make([]int32, 2)
+	err := Read(bytes.NewReader(src), BigEndian, slice)
+	checkResult(t, "ReadSlice", BigEndian, err, slice, res)
+}
+
+func TestWriteSlice(t *testing.T) {
+	buf := new(bytes.Buffer)
+	err := Write(buf, BigEndian, res)
+	checkResult(t, "WriteSlice", BigEndian, err, buf.Bytes(), src)
+}
+
+func TestReadBool(t *testing.T) {
+	var res bool
+	var err error
+	err = Read(bytes.NewReader([]byte{0}), BigEndian, &res)
+	checkResult(t, "ReadBool", BigEndian, err, res, false)
+	res = false
+	err = Read(bytes.NewReader([]byte{1}), BigEndian, &res)
+	checkResult(t, "ReadBool", BigEndian, err, res, true)
+	res = false
+	err = Read(bytes.NewReader([]byte{2}), BigEndian, &res)
+	checkResult(t, "ReadBool", BigEndian, err, res, true)
+}
+
+func TestReadBoolSlice(t *testing.T) {
+	slice := make([]bool, 4)
+	err := Read(bytes.NewReader([]byte{0, 1, 2, 255}), BigEndian, slice)
+	checkResult(t, "ReadBoolSlice", BigEndian, err, slice, []bool{false, true, true, true})
+}
+
+// Addresses of arrays are easier to manipulate with reflection than are slices.
+var intArrays = []interface{}{
+	&[100]int8{},
+	&[100]int16{},
+	&[100]int32{},
+	&[100]int64{},
+	&[100]uint8{},
+	&[100]uint16{},
+	&[100]uint32{},
+	&[100]uint64{},
+}
+
+func TestSliceRoundTrip(t *testing.T) {
+	buf := new(bytes.Buffer)
+	for _, array := range intArrays {
+		src := reflect.ValueOf(array).Elem()
+		unsigned := false
+		switch src.Index(0).Kind() {
+		case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+			unsigned = true
+		}
+		for i := 0; i < src.Len(); i++ {
+			if unsigned {
+				src.Index(i).SetUint(uint64(i * 0x07654321))
+			} else {
+				src.Index(i).SetInt(int64(i * 0x07654321))
+			}
+		}
+		buf.Reset()
+		srcSlice := src.Slice(0, src.Len())
+		err := Write(buf, BigEndian, srcSlice.Interface())
+		if err != nil {
+			t.Fatal(err)
+		}
+		dst := reflect.New(src.Type()).Elem()
+		dstSlice := dst.Slice(0, dst.Len())
+		err = Read(buf, BigEndian, dstSlice.Interface())
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !reflect.DeepEqual(src.Interface(), dst.Interface()) {
+			t.Fatal(src)
+		}
+	}
+}
+
+func TestWriteT(t *testing.T) {
+	buf := new(bytes.Buffer)
+	ts := T{}
+	if err := Write(buf, BigEndian, ts); err == nil {
+		t.Errorf("WriteT: have err == nil, want non-nil")
+	}
+
+	tv := reflect.Indirect(reflect.ValueOf(ts))
+	for i, n := 0, tv.NumField(); i < n; i++ {
+		typ := tv.Field(i).Type().String()
+		if typ == "[4]int" {
+			typ = "int" // the problem is int, not the [4]
+		}
+		if err := Write(buf, BigEndian, tv.Field(i).Interface()); err == nil {
+			t.Errorf("WriteT.%v: have err == nil, want non-nil", tv.Field(i).Type())
+		} else if !strings.Contains(err.Error(), typ) {
+			t.Errorf("WriteT: have err == %q, want it to mention %s", err, typ)
+		}
+	}
+}
+
+type BlankFields struct {
+	A uint32
+	_ int32
+	B float64
+	_ [4]int16
+	C byte
+	_ [7]byte
+	_ struct {
+		f [8]float32
+	}
+}
+
+type BlankFieldsProbe struct {
+	A  uint32
+	P0 int32
+	B  float64
+	P1 [4]int16
+	C  byte
+	P2 [7]byte
+	P3 struct {
+		F [8]float32
+	}
+}
+
+func TestBlankFields(t *testing.T) {
+	buf := new(bytes.Buffer)
+	b1 := BlankFields{A: 1234567890, B: 2.718281828, C: 42}
+	if err := Write(buf, LittleEndian, &b1); err != nil {
+		t.Error(err)
+	}
+
+	// zero values must have been written for blank fields
+	var p BlankFieldsProbe
+	if err := Read(buf, LittleEndian, &p); err != nil {
+		t.Error(err)
+	}
+
+	// quick test: only check first value of slices
+	if p.P0 != 0 || p.P1[0] != 0 || p.P2[0] != 0 || p.P3.F[0] != 0 {
+		t.Errorf("non-zero values for originally blank fields: %#v", p)
+	}
+
+	// write p and see if we can probe only some fields
+	if err := Write(buf, LittleEndian, &p); err != nil {
+		t.Error(err)
+	}
+
+	// read should ignore blank fields in b2
+	var b2 BlankFields
+	if err := Read(buf, LittleEndian, &b2); err != nil {
+		t.Error(err)
+	}
+	if b1.A != b2.A || b1.B != b2.B || b1.C != b2.C {
+		t.Errorf("%#v != %#v", b1, b2)
+	}
+}
+
+func TestSizeStructCache(t *testing.T) {
+	// Reset the cache, otherwise multiple test runs fail.
+	structSize = sync.Map{}
+
+	count := func() int {
+		var i int
+		structSize.Range(func(_, _ interface{}) bool {
+			i++
+			return true
+		})
+		return i
+	}
+
+	var total int
+	added := func() int {
+		delta := count() - total
+		total += delta
+		return delta
+	}
+
+	type foo struct {
+		A uint32
+	}
+
+	type bar struct {
+		A Struct
+		B foo
+		C Struct
+	}
+
+	testcases := []struct {
+		val  interface{}
+		want int
+	}{
+		{new(foo), 1},
+		{new(bar), 1},
+		{new(bar), 0},
+		{new(struct{ A Struct }), 1},
+		{new(struct{ A Struct }), 0},
+	}
+
+	for _, tc := range testcases {
+		if Size(tc.val) == -1 {
+			t.Fatalf("Can't get the size of %T", tc.val)
+		}
+
+		if n := added(); n != tc.want {
+			t.Errorf("Sizing %T added %d entries to the cache, want %d", tc.val, n, tc.want)
+		}
+	}
+}
+
+// An attempt to read into a struct with an unexported field will
+// panic. This is probably not the best choice, but at this point
+// anything else would be an API change.
+
+type Unexported struct {
+	a int32
+}
+
+func TestUnexportedRead(t *testing.T) {
+	var buf bytes.Buffer
+	u1 := Unexported{a: 1}
+	if err := Write(&buf, LittleEndian, &u1); err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() {
+		if recover() == nil {
+			t.Fatal("did not panic")
+		}
+	}()
+	var u2 Unexported
+	Read(&buf, LittleEndian, &u2)
+}
+
+func TestReadErrorMsg(t *testing.T) {
+	var buf bytes.Buffer
+	read := func(data interface{}) {
+		err := Read(&buf, LittleEndian, data)
+		want := "binary.Read: invalid type " + reflect.TypeOf(data).String()
+		if err == nil {
+			t.Errorf("%T: got no error; want %q", data, want)
+			return
+		}
+		if got := err.Error(); got != want {
+			t.Errorf("%T: got %q; want %q", data, got, want)
+		}
+	}
+	read(0)
+	s := new(struct{})
+	read(&s)
+	p := &s
+	read(&p)
+}
+
+func TestReadTruncated(t *testing.T) {
+	const data = "0123456789abcdef"
+
+	var b1 = make([]int32, 4)
+	var b2 struct {
+		A, B, C, D byte
+		E          int32
+		F          float64
+	}
+
+	for i := 0; i <= len(data); i++ {
+		var errWant error
+		switch i {
+		case 0:
+			errWant = io.EOF
+		case len(data):
+			errWant = nil
+		default:
+			errWant = io.ErrUnexpectedEOF
+		}
+
+		if err := Read(strings.NewReader(data[:i]), LittleEndian, &b1); err != errWant {
+			t.Errorf("Read(%d) with slice: got %v, want %v", i, err, errWant)
+		}
+		if err := Read(strings.NewReader(data[:i]), LittleEndian, &b2); err != errWant {
+			t.Errorf("Read(%d) with struct: got %v, want %v", i, err, errWant)
+		}
+	}
+}
+
+func testUint64SmallSliceLengthPanics() (panicked bool) {
+	defer func() {
+		panicked = recover() != nil
+	}()
+	b := [8]byte{1, 2, 3, 4, 5, 6, 7, 8}
+	LittleEndian.Uint64(b[:4])
+	return false
+}
+
+func testPutUint64SmallSliceLengthPanics() (panicked bool) {
+	defer func() {
+		panicked = recover() != nil
+	}()
+	b := [8]byte{}
+	LittleEndian.PutUint64(b[:4], 0x0102030405060708)
+	return false
+}
+
+func TestEarlyBoundsChecks(t *testing.T) {
+	if testUint64SmallSliceLengthPanics() != true {
+		t.Errorf("binary.LittleEndian.Uint64 expected to panic for small slices, but didn't")
+	}
+	if testPutUint64SmallSliceLengthPanics() != true {
+		t.Errorf("binary.LittleEndian.PutUint64 expected to panic for small slices, but didn't")
+	}
+}
+
+func TestReadInvalidDestination(t *testing.T) {
+	testReadInvalidDestination(t, BigEndian)
+	testReadInvalidDestination(t, LittleEndian)
+}
+
+func testReadInvalidDestination(t *testing.T, order ByteOrder) {
+	destinations := []interface{}{
+		int8(0),
+		int16(0),
+		int32(0),
+		int64(0),
+
+		uint8(0),
+		uint16(0),
+		uint32(0),
+		uint64(0),
+
+		bool(false),
+	}
+
+	for _, dst := range destinations {
+		err := Read(bytes.NewReader([]byte{1, 2, 3, 4, 5, 6, 7, 8}), order, dst)
+		want := fmt.Sprintf("binary.Read: invalid type %T", dst)
+		if err == nil || err.Error() != want {
+			t.Fatalf("for type %T: got %q; want %q", dst, err, want)
+		}
+	}
+}
+
+type byteSliceReader struct {
+	remain []byte
+}
+
+func (br *byteSliceReader) Read(p []byte) (int, error) {
+	n := copy(p, br.remain)
+	br.remain = br.remain[n:]
+	return n, nil
+}
+
+func BenchmarkReadSlice1000Int32s(b *testing.B) {
+	bsr := &byteSliceReader{}
+	slice := make([]int32, 1000)
+	buf := make([]byte, len(slice)*4)
+	b.SetBytes(int64(len(buf)))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		bsr.remain = buf
+		Read(bsr, BigEndian, slice)
+	}
+}
+
+func BenchmarkReadStruct(b *testing.B) {
+	bsr := &byteSliceReader{}
+	var buf bytes.Buffer
+	Write(&buf, BigEndian, &s)
+	b.SetBytes(int64(dataSize(reflect.ValueOf(s))))
+	t := s
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		bsr.remain = buf.Bytes()
+		Read(bsr, BigEndian, &t)
+	}
+	b.StopTimer()
+	if b.N > 0 && !reflect.DeepEqual(s, t) {
+		b.Fatalf("struct doesn't match:\ngot  %v;\nwant %v", t, s)
+	}
+}
+
+func BenchmarkWriteStruct(b *testing.B) {
+	b.SetBytes(int64(Size(&s)))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Write(io.Discard, BigEndian, &s)
+	}
+}
+
+func BenchmarkReadInts(b *testing.B) {
+	var ls Struct
+	bsr := &byteSliceReader{}
+	var r io.Reader = bsr
+	b.SetBytes(2 * (1 + 2 + 4 + 8))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		bsr.remain = big
+		Read(r, BigEndian, &ls.Int8)
+		Read(r, BigEndian, &ls.Int16)
+		Read(r, BigEndian, &ls.Int32)
+		Read(r, BigEndian, &ls.Int64)
+		Read(r, BigEndian, &ls.Uint8)
+		Read(r, BigEndian, &ls.Uint16)
+		Read(r, BigEndian, &ls.Uint32)
+		Read(r, BigEndian, &ls.Uint64)
+	}
+	b.StopTimer()
+	want := s
+	want.Float32 = 0
+	want.Float64 = 0
+	want.Complex64 = 0
+	want.Complex128 = 0
+	want.Array = [4]uint8{0, 0, 0, 0}
+	want.Bool = false
+	want.BoolArray = [4]bool{false, false, false, false}
+	if b.N > 0 && !reflect.DeepEqual(ls, want) {
+		b.Fatalf("struct doesn't match:\ngot  %v;\nwant %v", ls, want)
+	}
+}
+
+func BenchmarkWriteInts(b *testing.B) {
+	buf := new(bytes.Buffer)
+	var w io.Writer = buf
+	b.SetBytes(2 * (1 + 2 + 4 + 8))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		buf.Reset()
+		Write(w, BigEndian, s.Int8)
+		Write(w, BigEndian, s.Int16)
+		Write(w, BigEndian, s.Int32)
+		Write(w, BigEndian, s.Int64)
+		Write(w, BigEndian, s.Uint8)
+		Write(w, BigEndian, s.Uint16)
+		Write(w, BigEndian, s.Uint32)
+		Write(w, BigEndian, s.Uint64)
+	}
+	b.StopTimer()
+	if b.N > 0 && !bytes.Equal(buf.Bytes(), big[:30]) {
+		b.Fatalf("first half doesn't match: %x %x", buf.Bytes(), big[:30])
+	}
+}
+
+func BenchmarkWriteSlice1000Int32s(b *testing.B) {
+	slice := make([]int32, 1000)
+	buf := new(bytes.Buffer)
+	var w io.Writer = buf
+	b.SetBytes(4 * 1000)
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		buf.Reset()
+		Write(w, BigEndian, slice)
+	}
+	b.StopTimer()
+}
+
+func BenchmarkPutUint16(b *testing.B) {
+	b.SetBytes(2)
+	for i := 0; i < b.N; i++ {
+		BigEndian.PutUint16(putbuf[:], uint16(i))
+	}
+}
+
+func BenchmarkPutUint32(b *testing.B) {
+	b.SetBytes(4)
+	for i := 0; i < b.N; i++ {
+		BigEndian.PutUint32(putbuf[:], uint32(i))
+	}
+}
+
+func BenchmarkPutUint64(b *testing.B) {
+	b.SetBytes(8)
+	for i := 0; i < b.N; i++ {
+		BigEndian.PutUint64(putbuf[:], uint64(i))
+	}
+}
+func BenchmarkLittleEndianPutUint16(b *testing.B) {
+	b.SetBytes(2)
+	for i := 0; i < b.N; i++ {
+		LittleEndian.PutUint16(putbuf[:], uint16(i))
+	}
+}
+
+func BenchmarkLittleEndianPutUint32(b *testing.B) {
+	b.SetBytes(4)
+	for i := 0; i < b.N; i++ {
+		LittleEndian.PutUint32(putbuf[:], uint32(i))
+	}
+}
+
+func BenchmarkLittleEndianPutUint64(b *testing.B) {
+	b.SetBytes(8)
+	for i := 0; i < b.N; i++ {
+		LittleEndian.PutUint64(putbuf[:], uint64(i))
+	}
+}
+
+func BenchmarkReadFloats(b *testing.B) {
+	var ls Struct
+	bsr := &byteSliceReader{}
+	var r io.Reader = bsr
+	b.SetBytes(4 + 8)
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		bsr.remain = big[30:]
+		Read(r, BigEndian, &ls.Float32)
+		Read(r, BigEndian, &ls.Float64)
+	}
+	b.StopTimer()
+	want := s
+	want.Int8 = 0
+	want.Int16 = 0
+	want.Int32 = 0
+	want.Int64 = 0
+	want.Uint8 = 0
+	want.Uint16 = 0
+	want.Uint32 = 0
+	want.Uint64 = 0
+	want.Complex64 = 0
+	want.Complex128 = 0
+	want.Array = [4]uint8{0, 0, 0, 0}
+	want.Bool = false
+	want.BoolArray = [4]bool{false, false, false, false}
+	if b.N > 0 && !reflect.DeepEqual(ls, want) {
+		b.Fatalf("struct doesn't match:\ngot  %v;\nwant %v", ls, want)
+	}
+}
+
+func BenchmarkWriteFloats(b *testing.B) {
+	buf := new(bytes.Buffer)
+	var w io.Writer = buf
+	b.SetBytes(4 + 8)
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		buf.Reset()
+		Write(w, BigEndian, s.Float32)
+		Write(w, BigEndian, s.Float64)
+	}
+	b.StopTimer()
+	if b.N > 0 && !bytes.Equal(buf.Bytes(), big[30:30+4+8]) {
+		b.Fatalf("first half doesn't match: %x %x", buf.Bytes(), big[30:30+4+8])
+	}
+}
+
+func BenchmarkReadSlice1000Float32s(b *testing.B) {
+	bsr := &byteSliceReader{}
+	slice := make([]float32, 1000)
+	buf := make([]byte, len(slice)*4)
+	b.SetBytes(int64(len(buf)))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		bsr.remain = buf
+		Read(bsr, BigEndian, slice)
+	}
+}
+
+func BenchmarkWriteSlice1000Float32s(b *testing.B) {
+	slice := make([]float32, 1000)
+	buf := new(bytes.Buffer)
+	var w io.Writer = buf
+	b.SetBytes(4 * 1000)
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		buf.Reset()
+		Write(w, BigEndian, slice)
+	}
+	b.StopTimer()
+}
+
+func BenchmarkReadSlice1000Uint8s(b *testing.B) {
+	bsr := &byteSliceReader{}
+	slice := make([]uint8, 1000)
+	buf := make([]byte, len(slice))
+	b.SetBytes(int64(len(buf)))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		bsr.remain = buf
+		Read(bsr, BigEndian, slice)
+	}
+}
+
+func BenchmarkWriteSlice1000Uint8s(b *testing.B) {
+	slice := make([]uint8, 1000)
+	buf := new(bytes.Buffer)
+	var w io.Writer = buf
+	b.SetBytes(1000)
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		buf.Reset()
+		Write(w, BigEndian, slice)
+	}
+}
diff --git a/src/encoding/binary/example_test.go b/src/encoding/binary/example_test.go
new file mode 100644
index 0000000..b994b89
--- /dev/null
+++ b/src/encoding/binary/example_test.go
@@ -0,0 +1,187 @@
+// Copyright 2011 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.
+
+package binary_test
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"math"
+)
+
+func ExampleWrite() {
+	buf := new(bytes.Buffer)
+	var pi float64 = math.Pi
+	err := binary.Write(buf, binary.LittleEndian, pi)
+	if err != nil {
+		fmt.Println("binary.Write failed:", err)
+	}
+	fmt.Printf("% x", buf.Bytes())
+	// Output: 18 2d 44 54 fb 21 09 40
+}
+
+func ExampleWrite_multi() {
+	buf := new(bytes.Buffer)
+	var data = []interface{}{
+		uint16(61374),
+		int8(-54),
+		uint8(254),
+	}
+	for _, v := range data {
+		err := binary.Write(buf, binary.LittleEndian, v)
+		if err != nil {
+			fmt.Println("binary.Write failed:", err)
+		}
+	}
+	fmt.Printf("%x", buf.Bytes())
+	// Output: beefcafe
+}
+
+func ExampleRead() {
+	var pi float64
+	b := []byte{0x18, 0x2d, 0x44, 0x54, 0xfb, 0x21, 0x09, 0x40}
+	buf := bytes.NewReader(b)
+	err := binary.Read(buf, binary.LittleEndian, &pi)
+	if err != nil {
+		fmt.Println("binary.Read failed:", err)
+	}
+	fmt.Print(pi)
+	// Output: 3.141592653589793
+}
+
+func ExampleRead_multi() {
+	b := []byte{0x18, 0x2d, 0x44, 0x54, 0xfb, 0x21, 0x09, 0x40, 0xff, 0x01, 0x02, 0x03, 0xbe, 0xef}
+	r := bytes.NewReader(b)
+
+	var data struct {
+		PI   float64
+		Uate uint8
+		Mine [3]byte
+		Too  uint16
+	}
+
+	if err := binary.Read(r, binary.LittleEndian, &data); err != nil {
+		fmt.Println("binary.Read failed:", err)
+	}
+
+	fmt.Println(data.PI)
+	fmt.Println(data.Uate)
+	fmt.Printf("% x\n", data.Mine)
+	fmt.Println(data.Too)
+	// Output:
+	// 3.141592653589793
+	// 255
+	// 01 02 03
+	// 61374
+}
+
+func ExampleByteOrder_put() {
+	b := make([]byte, 4)
+	binary.LittleEndian.PutUint16(b[0:], 0x03e8)
+	binary.LittleEndian.PutUint16(b[2:], 0x07d0)
+	fmt.Printf("% x\n", b)
+	// Output:
+	// e8 03 d0 07
+}
+
+func ExampleByteOrder_get() {
+	b := []byte{0xe8, 0x03, 0xd0, 0x07}
+	x1 := binary.LittleEndian.Uint16(b[0:])
+	x2 := binary.LittleEndian.Uint16(b[2:])
+	fmt.Printf("%#04x %#04x\n", x1, x2)
+	// Output:
+	// 0x03e8 0x07d0
+}
+
+func ExamplePutUvarint() {
+	buf := make([]byte, binary.MaxVarintLen64)
+
+	for _, x := range []uint64{1, 2, 127, 128, 255, 256} {
+		n := binary.PutUvarint(buf, x)
+		fmt.Printf("%x\n", buf[:n])
+	}
+	// Output:
+	// 01
+	// 02
+	// 7f
+	// 8001
+	// ff01
+	// 8002
+}
+
+func ExamplePutVarint() {
+	buf := make([]byte, binary.MaxVarintLen64)
+
+	for _, x := range []int64{-65, -64, -2, -1, 0, 1, 2, 63, 64} {
+		n := binary.PutVarint(buf, x)
+		fmt.Printf("%x\n", buf[:n])
+	}
+	// Output:
+	// 8101
+	// 7f
+	// 03
+	// 01
+	// 00
+	// 02
+	// 04
+	// 7e
+	// 8001
+}
+
+func ExampleUvarint() {
+	inputs := [][]byte{
+		{0x01},
+		{0x02},
+		{0x7f},
+		{0x80, 0x01},
+		{0xff, 0x01},
+		{0x80, 0x02},
+	}
+	for _, b := range inputs {
+		x, n := binary.Uvarint(b)
+		if n != len(b) {
+			fmt.Println("Uvarint did not consume all of in")
+		}
+		fmt.Println(x)
+	}
+	// Output:
+	// 1
+	// 2
+	// 127
+	// 128
+	// 255
+	// 256
+}
+
+func ExampleVarint() {
+	inputs := [][]byte{
+		{0x81, 0x01},
+		{0x7f},
+		{0x03},
+		{0x01},
+		{0x00},
+		{0x02},
+		{0x04},
+		{0x7e},
+		{0x80, 0x01},
+	}
+	for _, b := range inputs {
+		x, n := binary.Varint(b)
+		if n != len(b) {
+			fmt.Println("Varint did not consume all of in")
+		}
+		fmt.Println(x)
+	}
+	// Output:
+	// -65
+	// -64
+	// -2
+	// -1
+	// 0
+	// 1
+	// 2
+	// 63
+	// 64
+}
diff --git a/src/encoding/binary/varint.go b/src/encoding/binary/varint.go
new file mode 100644
index 0000000..8fe20b5
--- /dev/null
+++ b/src/encoding/binary/varint.go
@@ -0,0 +1,139 @@
+// Copyright 2011 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.
+
+package binary
+
+// This file implements "varint" encoding of 64-bit integers.
+// The encoding is:
+// - unsigned integers are serialized 7 bits at a time, starting with the
+//   least significant bits
+// - the most significant bit (msb) in each output byte indicates if there
+//   is a continuation byte (msb = 1)
+// - signed integers are mapped to unsigned integers using "zig-zag"
+//   encoding: Positive values x are written as 2*x + 0, negative values
+//   are written as 2*(^x) + 1; that is, negative numbers are complemented
+//   and whether to complement is encoded in bit 0.
+//
+// Design note:
+// At most 10 bytes are needed for 64-bit values. The encoding could
+// be more dense: a full 64-bit value needs an extra byte just to hold bit 63.
+// Instead, the msb of the previous byte could be used to hold bit 63 since we
+// know there can't be more than 64 bits. This is a trivial improvement and
+// would reduce the maximum encoding length to 9 bytes. However, it breaks the
+// invariant that the msb is always the "continuation bit" and thus makes the
+// format incompatible with a varint encoding for larger numbers (say 128-bit).
+
+import (
+	"errors"
+	"io"
+)
+
+// MaxVarintLenN is the maximum length of a varint-encoded N-bit integer.
+const (
+	MaxVarintLen16 = 3
+	MaxVarintLen32 = 5
+	MaxVarintLen64 = 10
+)
+
+// PutUvarint encodes a uint64 into buf and returns the number of bytes written.
+// If the buffer is too small, PutUvarint will panic.
+func PutUvarint(buf []byte, x uint64) int {
+	i := 0
+	for x >= 0x80 {
+		buf[i] = byte(x) | 0x80
+		x >>= 7
+		i++
+	}
+	buf[i] = byte(x)
+	return i + 1
+}
+
+// Uvarint decodes a uint64 from buf and returns that value and the
+// number of bytes read (> 0). If an error occurred, the value is 0
+// and the number of bytes n is <= 0 meaning:
+//
+// 	n == 0: buf too small
+// 	n  < 0: value larger than 64 bits (overflow)
+// 	        and -n is the number of bytes read
+//
+func Uvarint(buf []byte) (uint64, int) {
+	var x uint64
+	var s uint
+	for i, b := range buf {
+		if i == MaxVarintLen64 {
+			// Catch byte reads past MaxVarintLen64.
+			// See issue https://golang.org/issues/41185
+			return 0, -(i + 1) // overflow
+		}
+		if b < 0x80 {
+			if i == MaxVarintLen64-1 && b > 1 {
+				return 0, -(i + 1) // overflow
+			}
+			return x | uint64(b)<<s, i + 1
+		}
+		x |= uint64(b&0x7f) << s
+		s += 7
+	}
+	return 0, 0
+}
+
+// PutVarint encodes an int64 into buf and returns the number of bytes written.
+// If the buffer is too small, PutVarint will panic.
+func PutVarint(buf []byte, x int64) int {
+	ux := uint64(x) << 1
+	if x < 0 {
+		ux = ^ux
+	}
+	return PutUvarint(buf, ux)
+}
+
+// Varint decodes an int64 from buf and returns that value and the
+// number of bytes read (> 0). If an error occurred, the value is 0
+// and the number of bytes n is <= 0 with the following meaning:
+//
+// 	n == 0: buf too small
+// 	n  < 0: value larger than 64 bits (overflow)
+// 	        and -n is the number of bytes read
+//
+func Varint(buf []byte) (int64, int) {
+	ux, n := Uvarint(buf) // ok to continue in presence of error
+	x := int64(ux >> 1)
+	if ux&1 != 0 {
+		x = ^x
+	}
+	return x, n
+}
+
+var overflow = errors.New("binary: varint overflows a 64-bit integer")
+
+// ReadUvarint reads an encoded unsigned integer from r and returns it as a uint64.
+func ReadUvarint(r io.ByteReader) (uint64, error) {
+	var x uint64
+	var s uint
+	for i := 0; i < MaxVarintLen64; i++ {
+		b, err := r.ReadByte()
+		if err != nil {
+			return x, err
+		}
+		if b < 0x80 {
+			if i == MaxVarintLen64-1 && b > 1 {
+				return x, overflow
+			}
+			return x | uint64(b)<<s, nil
+		}
+		x |= uint64(b&0x7f) << s
+		s += 7
+	}
+	return x, overflow
+}
+
+// ReadVarint reads an encoded signed integer from r and returns it as an int64.
+func ReadVarint(r io.ByteReader) (int64, error) {
+	ux, err := ReadUvarint(r) // ok to continue in presence of error
+	x := int64(ux >> 1)
+	if ux&1 != 0 {
+		x = ^x
+	}
+	return x, err
+}
diff --git a/src/encoding/binary/varint_test.go b/src/encoding/binary/varint_test.go
new file mode 100644
index 0000000..d025a67
--- /dev/null
+++ b/src/encoding/binary/varint_test.go
@@ -0,0 +1,231 @@
+// Copyright 2011 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.
+
+package binary
+
+import (
+	"bytes"
+	"io"
+	"math"
+	"testing"
+)
+
+func testConstant(t *testing.T, w uint, max int) {
+	buf := make([]byte, MaxVarintLen64)
+	n := PutUvarint(buf, 1<<w-1)
+	if n != max {
+		t.Errorf("MaxVarintLen%d = %d; want %d", w, max, n)
+	}
+}
+
+func TestConstants(t *testing.T) {
+	testConstant(t, 16, MaxVarintLen16)
+	testConstant(t, 32, MaxVarintLen32)
+	testConstant(t, 64, MaxVarintLen64)
+}
+
+func testVarint(t *testing.T, x int64) {
+	buf := make([]byte, MaxVarintLen64)
+	n := PutVarint(buf, x)
+	y, m := Varint(buf[0:n])
+	if x != y {
+		t.Errorf("Varint(%d): got %d", x, y)
+	}
+	if n != m {
+		t.Errorf("Varint(%d): got n = %d; want %d", x, m, n)
+	}
+
+	y, err := ReadVarint(bytes.NewReader(buf))
+	if err != nil {
+		t.Errorf("ReadVarint(%d): %s", x, err)
+	}
+	if x != y {
+		t.Errorf("ReadVarint(%d): got %d", x, y)
+	}
+}
+
+func testUvarint(t *testing.T, x uint64) {
+	buf := make([]byte, MaxVarintLen64)
+	n := PutUvarint(buf, x)
+	y, m := Uvarint(buf[0:n])
+	if x != y {
+		t.Errorf("Uvarint(%d): got %d", x, y)
+	}
+	if n != m {
+		t.Errorf("Uvarint(%d): got n = %d; want %d", x, m, n)
+	}
+
+	y, err := ReadUvarint(bytes.NewReader(buf))
+	if err != nil {
+		t.Errorf("ReadUvarint(%d): %s", x, err)
+	}
+	if x != y {
+		t.Errorf("ReadUvarint(%d): got %d", x, y)
+	}
+}
+
+var tests = []int64{
+	-1 << 63,
+	-1<<63 + 1,
+	-1,
+	0,
+	1,
+	2,
+	10,
+	20,
+	63,
+	64,
+	65,
+	127,
+	128,
+	129,
+	255,
+	256,
+	257,
+	1<<63 - 1,
+}
+
+func TestVarint(t *testing.T) {
+	for _, x := range tests {
+		testVarint(t, x)
+		testVarint(t, -x)
+	}
+	for x := int64(0x7); x != 0; x <<= 1 {
+		testVarint(t, x)
+		testVarint(t, -x)
+	}
+}
+
+func TestUvarint(t *testing.T) {
+	for _, x := range tests {
+		testUvarint(t, uint64(x))
+	}
+	for x := uint64(0x7); x != 0; x <<= 1 {
+		testUvarint(t, x)
+	}
+}
+
+func TestBufferTooSmall(t *testing.T) {
+	buf := []byte{0x80, 0x80, 0x80, 0x80}
+	for i := 0; i <= len(buf); i++ {
+		buf := buf[0:i]
+		x, n := Uvarint(buf)
+		if x != 0 || n != 0 {
+			t.Errorf("Uvarint(%v): got x = %d, n = %d", buf, x, n)
+		}
+
+		x, err := ReadUvarint(bytes.NewReader(buf))
+		if x != 0 || err != io.EOF {
+			t.Errorf("ReadUvarint(%v): got x = %d, err = %s", buf, x, err)
+		}
+	}
+}
+
+// Ensure that we catch overflows of bytes going past MaxVarintLen64.
+// See issue https://golang.org/issues/41185
+func TestBufferTooBigWithOverflow(t *testing.T) {
+	tests := []struct {
+		in        []byte
+		name      string
+		wantN     int
+		wantValue uint64
+	}{
+		{
+			name: "invalid: 1000 bytes",
+			in: func() []byte {
+				b := make([]byte, 1000)
+				for i := range b {
+					b[i] = 0xff
+				}
+				b[999] = 0
+				return b
+			}(),
+			wantN:     -11,
+			wantValue: 0,
+		},
+		{
+			name:      "valid: math.MaxUint64-40",
+			in:        []byte{0xd7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01},
+			wantValue: math.MaxUint64 - 40,
+			wantN:     10,
+		},
+		{
+			name:      "invalid: with more than MaxVarintLen64 bytes",
+			in:        []byte{0xd7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01},
+			wantN:     -11,
+			wantValue: 0,
+		},
+		{
+			name:      "invalid: 10th byte",
+			in:        []byte{0xd7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f},
+			wantN:     -10,
+			wantValue: 0,
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			value, n := Uvarint(tt.in)
+			if g, w := n, tt.wantN; g != w {
+				t.Errorf("bytes returned=%d, want=%d", g, w)
+			}
+			if g, w := value, tt.wantValue; g != w {
+				t.Errorf("value=%d, want=%d", g, w)
+			}
+		})
+	}
+}
+
+func testOverflow(t *testing.T, buf []byte, x0 uint64, n0 int, err0 error) {
+	x, n := Uvarint(buf)
+	if x != 0 || n != n0 {
+		t.Errorf("Uvarint(% X): got x = %d, n = %d; want 0, %d", buf, x, n, n0)
+	}
+
+	r := bytes.NewReader(buf)
+	len := r.Len()
+	x, err := ReadUvarint(r)
+	if x != x0 || err != err0 {
+		t.Errorf("ReadUvarint(%v): got x = %d, err = %s; want %d, %s", buf, x, err, x0, err0)
+	}
+	if read := len - r.Len(); read > MaxVarintLen64 {
+		t.Errorf("ReadUvarint(%v): read more than MaxVarintLen64 bytes, got %d", buf, read)
+	}
+}
+
+func TestOverflow(t *testing.T) {
+	testOverflow(t, []byte{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x2}, 0, -10, overflow)
+	testOverflow(t, []byte{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x1, 0, 0}, 0, -11, overflow)
+	testOverflow(t, []byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}, 1<<64-1, -11, overflow) // 11 bytes, should overflow
+}
+
+func TestNonCanonicalZero(t *testing.T) {
+	buf := []byte{0x80, 0x80, 0x80, 0}
+	x, n := Uvarint(buf)
+	if x != 0 || n != 4 {
+		t.Errorf("Uvarint(%v): got x = %d, n = %d; want 0, 4", buf, x, n)
+
+	}
+}
+
+func BenchmarkPutUvarint32(b *testing.B) {
+	buf := make([]byte, MaxVarintLen32)
+	b.SetBytes(4)
+	for i := 0; i < b.N; i++ {
+		for j := uint(0); j < MaxVarintLen32; j++ {
+			PutUvarint(buf, 1<<(j*7))
+		}
+	}
+}
+
+func BenchmarkPutUvarint64(b *testing.B) {
+	buf := make([]byte, MaxVarintLen64)
+	b.SetBytes(8)
+	for i := 0; i < b.N; i++ {
+		for j := uint(0); j < MaxVarintLen64; j++ {
+			PutUvarint(buf, 1<<(j*7))
+		}
+	}
+}