Added all required dependencies

5 files changed, 1174 insertions, 0 deletions

diff --git a/vendor/gopkg.in/bufio.v1/LICENSE b/vendor/gopkg.in/bufio.v1/LICENSE
new file mode 100644
index 0000000000..07a316cbf4
--- /dev/null
+++ b/vendor/gopkg.in/bufio.v1/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2013 The bufio Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/gopkg.in/bufio.v1/Makefile b/vendor/gopkg.in/bufio.v1/Makefile
new file mode 100644
index 0000000000..038ed47e94
--- /dev/null
+++ b/vendor/gopkg.in/bufio.v1/Makefile
@@ -0,0 +1,2 @@
+all:
+	go test gopkg.in/bufio.v1
diff --git a/vendor/gopkg.in/bufio.v1/README.md b/vendor/gopkg.in/bufio.v1/README.md
new file mode 100644
index 0000000000..bfb85ee544
--- /dev/null
+++ b/vendor/gopkg.in/bufio.v1/README.md
@@ -0,0 +1,4 @@
+bufio
+=====
+
+This is a fork of the http://golang.org/pkg/bufio/ package. It adds `ReadN` method that allows reading next `n` bytes from the internal buffer without allocating intermediate buffer. This method works just like the [Buffer.Next](http://golang.org/pkg/bytes/#Buffer.Next) method, but has slightly different signature.
diff --git a/vendor/gopkg.in/bufio.v1/buffer.go b/vendor/gopkg.in/bufio.v1/buffer.go
new file mode 100644
index 0000000000..8b915605b6
--- /dev/null
+++ b/vendor/gopkg.in/bufio.v1/buffer.go
@@ -0,0 +1,413 @@
+// 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 bufio
+
+// Simple byte buffer for marshaling data.
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"unicode/utf8"
+)
+
+// A Buffer is a variable-sized buffer of bytes with Read and Write methods.
+// The zero value for Buffer is an empty buffer ready to use.
+type Buffer struct {
+	buf       []byte            // contents are the bytes buf[off : len(buf)]
+	off       int               // read at &buf[off], write at &buf[len(buf)]
+	runeBytes [utf8.UTFMax]byte // avoid allocation of slice on each WriteByte or Rune
+	bootstrap [64]byte          // memory to hold first slice; helps small buffers (Printf) avoid allocation.
+	lastRead  readOp            // last read operation, so that Unread* can work correctly.
+}
+
+// The readOp constants describe the last action performed on
+// the buffer, so that UnreadRune and UnreadByte can
+// check for invalid usage.
+type readOp int
+
+const (
+	opInvalid  readOp = iota // Non-read operation.
+	opReadRune               // Read rune.
+	opRead                   // Any other read operation.
+)
+
+// ErrTooLarge is passed to panic if memory cannot be allocated to store data in a buffer.
+var ErrTooLarge = errors.New("bytes.Buffer: too large")
+
+// Bytes returns a slice of the contents of the unread portion of the buffer;
+// len(b.Bytes()) == b.Len().  If the caller changes the contents of the
+// returned slice, the contents of the buffer will change provided there
+// are no intervening method calls on the Buffer.
+func (b *Buffer) Bytes() []byte { return b.buf[b.off:] }
+
+// String returns the contents of the unread portion of the buffer
+// as a string.  If the Buffer is a nil pointer, it returns "<nil>".
+func (b *Buffer) String() string {
+	if b == nil {
+		// Special case, useful in debugging.
+		return "<nil>"
+	}
+	return string(b.buf[b.off:])
+}
+
+// Len returns the number of bytes of the unread portion of the buffer;
+// b.Len() == len(b.Bytes()).
+func (b *Buffer) Len() int { return len(b.buf) - b.off }
+
+// Truncate discards all but the first n unread bytes from the buffer.
+// It panics if n is negative or greater than the length of the buffer.
+func (b *Buffer) Truncate(n int) {
+	b.lastRead = opInvalid
+	switch {
+	case n < 0 || n > b.Len():
+		panic("bytes.Buffer: truncation out of range")
+	case n == 0:
+		// Reuse buffer space.
+		b.off = 0
+	}
+	b.buf = b.buf[0 : b.off+n]
+}
+
+// Reset resets the buffer so it has no content.
+// b.Reset() is the same as b.Truncate(0).
+func (b *Buffer) Reset() { b.Truncate(0) }
+
+// grow grows the buffer to guarantee space for n more bytes.
+// It returns the index where bytes should be written.
+// If the buffer can't grow it will panic with ErrTooLarge.
+func (b *Buffer) grow(n int) int {
+	m := b.Len()
+	// If buffer is empty, reset to recover space.
+	if m == 0 && b.off != 0 {
+		b.Truncate(0)
+	}
+	if len(b.buf)+n > cap(b.buf) {
+		var buf []byte
+		if b.buf == nil && n <= len(b.bootstrap) {
+			buf = b.bootstrap[0:]
+		} else if m+n <= cap(b.buf)/2 {
+			// We can slide things down instead of allocating a new
+			// slice. We only need m+n <= cap(b.buf) to slide, but
+			// we instead let capacity get twice as large so we
+			// don't spend all our time copying.
+			copy(b.buf[:], b.buf[b.off:])
+			buf = b.buf[:m]
+		} else {
+			// not enough space anywhere
+			buf = makeSlice(2*cap(b.buf) + n)
+			copy(buf, b.buf[b.off:])
+		}
+		b.buf = buf
+		b.off = 0
+	}
+	b.buf = b.buf[0 : b.off+m+n]
+	return b.off + m
+}
+
+// Grow grows the buffer's capacity, if necessary, to guarantee space for
+// another n bytes. After Grow(n), at least n bytes can be written to the
+// buffer without another allocation.
+// If n is negative, Grow will panic.
+// If the buffer can't grow it will panic with ErrTooLarge.
+func (b *Buffer) Grow(n int) {
+	if n < 0 {
+		panic("bytes.Buffer.Grow: negative count")
+	}
+	m := b.grow(n)
+	b.buf = b.buf[0:m]
+}
+
+// Write appends the contents of p to the buffer, growing the buffer as
+// needed. The return value n is the length of p; err is always nil. If the
+// buffer becomes too large, Write will panic with ErrTooLarge.
+func (b *Buffer) Write(p []byte) (n int, err error) {
+	b.lastRead = opInvalid
+	m := b.grow(len(p))
+	return copy(b.buf[m:], p), nil
+}
+
+// WriteString appends the contents of s to the buffer, growing the buffer as
+// needed. The return value n is the length of s; err is always nil. If the
+// buffer becomes too large, WriteString will panic with ErrTooLarge.
+func (b *Buffer) WriteString(s string) (n int, err error) {
+	b.lastRead = opInvalid
+	m := b.grow(len(s))
+	return copy(b.buf[m:], s), nil
+}
+
+// MinRead is the minimum slice size passed to a Read call by
+// Buffer.ReadFrom.  As long as the Buffer has at least MinRead bytes beyond
+// what is required to hold the contents of r, ReadFrom will not grow the
+// underlying buffer.
+const MinRead = 512
+
+// ReadFrom reads data from r until EOF and appends it to the buffer, growing
+// the buffer as needed. The return value n is the number of bytes read. Any
+// error except io.EOF encountered during the read is also returned. If the
+// buffer becomes too large, ReadFrom will panic with ErrTooLarge.
+func (b *Buffer) ReadFrom(r io.Reader) (n int64, err error) {
+	b.lastRead = opInvalid
+	// If buffer is empty, reset to recover space.
+	if b.off >= len(b.buf) {
+		b.Truncate(0)
+	}
+	for {
+		if free := cap(b.buf) - len(b.buf); free < MinRead {
+			// not enough space at end
+			newBuf := b.buf
+			if b.off+free < MinRead {
+				// not enough space using beginning of buffer;
+				// double buffer capacity
+				newBuf = makeSlice(2*cap(b.buf) + MinRead)
+			}
+			copy(newBuf, b.buf[b.off:])
+			b.buf = newBuf[:len(b.buf)-b.off]
+			b.off = 0
+		}
+		m, e := r.Read(b.buf[len(b.buf):cap(b.buf)])
+		b.buf = b.buf[0 : len(b.buf)+m]
+		n += int64(m)
+		if e == io.EOF {
+			break
+		}
+		if e != nil {
+			return n, e
+		}
+	}
+	return n, nil // err is EOF, so return nil explicitly
+}
+
+// makeSlice allocates a slice of size n. If the allocation fails, it panics
+// with ErrTooLarge.
+func makeSlice(n int) []byte {
+	// If the make fails, give a known error.
+	defer func() {
+		if recover() != nil {
+			panic(ErrTooLarge)
+		}
+	}()
+	return make([]byte, n)
+}
+
+// WriteTo writes data to w until the buffer is drained or an error occurs.
+// The return value n is the number of bytes written; it always fits into an
+// int, but it is int64 to match the io.WriterTo interface. Any error
+// encountered during the write is also returned.
+func (b *Buffer) WriteTo(w io.Writer) (n int64, err error) {
+	b.lastRead = opInvalid
+	if b.off < len(b.buf) {
+		nBytes := b.Len()
+		m, e := w.Write(b.buf[b.off:])
+		if m > nBytes {
+			panic("bytes.Buffer.WriteTo: invalid Write count")
+		}
+		b.off += m
+		n = int64(m)
+		if e != nil {
+			return n, e
+		}
+		// all bytes should have been written, by definition of
+		// Write method in io.Writer
+		if m != nBytes {
+			return n, io.ErrShortWrite
+		}
+	}
+	// Buffer is now empty; reset.
+	b.Truncate(0)
+	return
+}
+
+// WriteByte appends the byte c to the buffer, growing the buffer as needed.
+// The returned error is always nil, but is included to match bufio.Writer's
+// WriteByte. If the buffer becomes too large, WriteByte will panic with
+// ErrTooLarge.
+func (b *Buffer) WriteByte(c byte) error {
+	b.lastRead = opInvalid
+	m := b.grow(1)
+	b.buf[m] = c
+	return nil
+}
+
+// WriteRune appends the UTF-8 encoding of Unicode code point r to the
+// buffer, returning its length and an error, which is always nil but is
+// included to match bufio.Writer's WriteRune. The buffer is grown as needed;
+// if it becomes too large, WriteRune will panic with ErrTooLarge.
+func (b *Buffer) WriteRune(r rune) (n int, err error) {
+	if r < utf8.RuneSelf {
+		b.WriteByte(byte(r))
+		return 1, nil
+	}
+	n = utf8.EncodeRune(b.runeBytes[0:], r)
+	b.Write(b.runeBytes[0:n])
+	return n, nil
+}
+
+// Read reads the next len(p) bytes from the buffer or until the buffer
+// is drained.  The return value n is the number of bytes read.  If the
+// buffer has no data to return, err is io.EOF (unless len(p) is zero);
+// otherwise it is nil.
+func (b *Buffer) Read(p []byte) (n int, err error) {
+	b.lastRead = opInvalid
+	if b.off >= len(b.buf) {
+		// Buffer is empty, reset to recover space.
+		b.Truncate(0)
+		if len(p) == 0 {
+			return
+		}
+		return 0, io.EOF
+	}
+	n = copy(p, b.buf[b.off:])
+	b.off += n
+	if n > 0 {
+		b.lastRead = opRead
+	}
+	return
+}
+
+// Next returns a slice containing the next n bytes from the buffer,
+// advancing the buffer as if the bytes had been returned by Read.
+// If there are fewer than n bytes in the buffer, Next returns the entire buffer.
+// The slice is only valid until the next call to a read or write method.
+func (b *Buffer) Next(n int) []byte {
+	b.lastRead = opInvalid
+	m := b.Len()
+	if n > m {
+		n = m
+	}
+	data := b.buf[b.off : b.off+n]
+	b.off += n
+	if n > 0 {
+		b.lastRead = opRead
+	}
+	return data
+}
+
+// ReadByte reads and returns the next byte from the buffer.
+// If no byte is available, it returns error io.EOF.
+func (b *Buffer) ReadByte() (c byte, err error) {
+	b.lastRead = opInvalid
+	if b.off >= len(b.buf) {
+		// Buffer is empty, reset to recover space.
+		b.Truncate(0)
+		return 0, io.EOF
+	}
+	c = b.buf[b.off]
+	b.off++
+	b.lastRead = opRead
+	return c, nil
+}
+
+// ReadRune reads and returns the next UTF-8-encoded
+// Unicode code point from the buffer.
+// If no bytes are available, the error returned is io.EOF.
+// If the bytes are an erroneous UTF-8 encoding, it
+// consumes one byte and returns U+FFFD, 1.
+func (b *Buffer) ReadRune() (r rune, size int, err error) {
+	b.lastRead = opInvalid
+	if b.off >= len(b.buf) {
+		// Buffer is empty, reset to recover space.
+		b.Truncate(0)
+		return 0, 0, io.EOF
+	}
+	b.lastRead = opReadRune
+	c := b.buf[b.off]
+	if c < utf8.RuneSelf {
+		b.off++
+		return rune(c), 1, nil
+	}
+	r, n := utf8.DecodeRune(b.buf[b.off:])
+	b.off += n
+	return r, n, nil
+}
+
+// UnreadRune unreads the last rune returned by ReadRune.
+// If the most recent read or write operation on the buffer was
+// not a ReadRune, UnreadRune returns an error.  (In this regard
+// it is stricter than UnreadByte, which will unread the last byte
+// from any read operation.)
+func (b *Buffer) UnreadRune() error {
+	if b.lastRead != opReadRune {
+		return errors.New("bytes.Buffer: UnreadRune: previous operation was not ReadRune")
+	}
+	b.lastRead = opInvalid
+	if b.off > 0 {
+		_, n := utf8.DecodeLastRune(b.buf[0:b.off])
+		b.off -= n
+	}
+	return nil
+}
+
+// UnreadByte unreads the last byte returned by the most recent
+// read operation.  If write has happened since the last read, UnreadByte
+// returns an error.
+func (b *Buffer) UnreadByte() error {
+	if b.lastRead != opReadRune && b.lastRead != opRead {
+		return errors.New("bytes.Buffer: UnreadByte: previous operation was not a read")
+	}
+	b.lastRead = opInvalid
+	if b.off > 0 {
+		b.off--
+	}
+	return nil
+}
+
+// ReadBytes reads until the first occurrence of delim in the input,
+// returning a slice containing the data up to and including the delimiter.
+// If ReadBytes encounters an error before finding a delimiter,
+// it returns the data read before the error and the error itself (often io.EOF).
+// ReadBytes returns err != nil if and only if the returned data does not end in
+// delim.
+func (b *Buffer) ReadBytes(delim byte) (line []byte, err error) {
+	slice, err := b.readSlice(delim)
+	// return a copy of slice. The buffer's backing array may
+	// be overwritten by later calls.
+	line = append(line, slice...)
+	return
+}
+
+// readSlice is like ReadBytes but returns a reference to internal buffer data.
+func (b *Buffer) readSlice(delim byte) (line []byte, err error) {
+	i := bytes.IndexByte(b.buf[b.off:], delim)
+	end := b.off + i + 1
+	if i < 0 {
+		end = len(b.buf)
+		err = io.EOF
+	}
+	line = b.buf[b.off:end]
+	b.off = end
+	b.lastRead = opRead
+	return line, err
+}
+
+// ReadString reads until the first occurrence of delim in the input,
+// returning a string containing the data up to and including the delimiter.
+// If ReadString encounters an error before finding a delimiter,
+// it returns the data read before the error and the error itself (often io.EOF).
+// ReadString returns err != nil if and only if the returned data does not end
+// in delim.
+func (b *Buffer) ReadString(delim byte) (line string, err error) {
+	slice, err := b.readSlice(delim)
+	return string(slice), err
+}
+
+// NewBuffer creates and initializes a new Buffer using buf as its initial
+// contents.  It is intended to prepare a Buffer to read existing data.  It
+// can also be used to size the internal buffer for writing. To do that,
+// buf should have the desired capacity but a length of zero.
+//
+// In most cases, new(Buffer) (or just declaring a Buffer variable) is
+// sufficient to initialize a Buffer.
+func NewBuffer(buf []byte) *Buffer { return &Buffer{buf: buf} }
+
+// NewBufferString creates and initializes a new Buffer using string s as its
+// initial contents. It is intended to prepare a buffer to read an existing
+// string.
+//
+// In most cases, new(Buffer) (or just declaring a Buffer variable) is
+// sufficient to initialize a Buffer.
+func NewBufferString(s string) *Buffer {
+	return &Buffer{buf: []byte(s)}
+}
diff --git a/vendor/gopkg.in/bufio.v1/bufio.go b/vendor/gopkg.in/bufio.v1/bufio.go
new file mode 100644
index 0000000000..8f5cdc084d
--- /dev/null
+++ b/vendor/gopkg.in/bufio.v1/bufio.go
@@ -0,0 +1,728 @@
+// 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 bufio implements buffered I/O.  It wraps an io.Reader or io.Writer
+// object, creating another object (Reader or Writer) that also implements
+// the interface but provides buffering and some help for textual I/O.
+package bufio
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"unicode/utf8"
+)
+
+const (
+	defaultBufSize = 4096
+)
+
+var (
+	ErrInvalidUnreadByte = errors.New("bufio: invalid use of UnreadByte")
+	ErrInvalidUnreadRune = errors.New("bufio: invalid use of UnreadRune")
+	ErrBufferFull        = errors.New("bufio: buffer full")
+	ErrNegativeCount     = errors.New("bufio: negative count")
+)
+
+// Buffered input.
+
+// Reader implements buffering for an io.Reader object.
+type Reader struct {
+	buf          []byte
+	rd           io.Reader
+	r, w         int
+	err          error
+	lastByte     int
+	lastRuneSize int
+}
+
+const minReadBufferSize = 16
+const maxConsecutiveEmptyReads = 100
+
+// NewReaderSize returns a new Reader whose buffer has at least the specified
+// size. If the argument io.Reader is already a Reader with large enough
+// size, it returns the underlying Reader.
+func NewReaderSize(rd io.Reader, size int) *Reader {
+	// Is it already a Reader?
+	b, ok := rd.(*Reader)
+	if ok && len(b.buf) >= size {
+		return b
+	}
+	if size < minReadBufferSize {
+		size = minReadBufferSize
+	}
+	r := new(Reader)
+	r.reset(make([]byte, size), rd)
+	return r
+}
+
+// NewReader returns a new Reader whose buffer has the default size.
+func NewReader(rd io.Reader) *Reader {
+	return NewReaderSize(rd, defaultBufSize)
+}
+
+// Reset discards any buffered data, resets all state, and switches
+// the buffered reader to read from r.
+func (b *Reader) Reset(r io.Reader) {
+	b.reset(b.buf, r)
+}
+
+func (b *Reader) reset(buf []byte, r io.Reader) {
+	*b = Reader{
+		buf:          buf,
+		rd:           r,
+		lastByte:     -1,
+		lastRuneSize: -1,
+	}
+}
+
+var errNegativeRead = errors.New("bufio: reader returned negative count from Read")
+
+// fill reads a new chunk into the buffer.
+func (b *Reader) fill() {
+	// Slide existing data to beginning.
+	if b.r > 0 {
+		copy(b.buf, b.buf[b.r:b.w])
+		b.w -= b.r
+		b.r = 0
+	}
+
+	if b.w >= len(b.buf) {
+		panic("bufio: tried to fill full buffer")
+	}
+
+	// Read new data: try a limited number of times.
+	for i := maxConsecutiveEmptyReads; i > 0; i-- {
+		n, err := b.rd.Read(b.buf[b.w:])
+		if n < 0 {
+			panic(errNegativeRead)
+		}
+		b.w += n
+		if err != nil {
+			b.err = err
+			return
+		}
+		if n > 0 {
+			return
+		}
+	}
+	b.err = io.ErrNoProgress
+}
+
+func (b *Reader) readErr() error {
+	err := b.err
+	b.err = nil
+	return err
+}
+
+// Peek returns the next n bytes without advancing the reader. The bytes stop
+// being valid at the next read call. If Peek returns fewer than n bytes, it
+// also returns an error explaining why the read is short. The error is
+// ErrBufferFull if n is larger than b's buffer size.
+func (b *Reader) Peek(n int) ([]byte, error) {
+	if n < 0 {
+		return nil, ErrNegativeCount
+	}
+	if n > len(b.buf) {
+		return nil, ErrBufferFull
+	}
+	// 0 <= n <= len(b.buf)
+	for b.w-b.r < n && b.err == nil {
+		b.fill() // b.w-b.r < len(b.buf) => buffer is not full
+	}
+	m := b.w - b.r
+	if m > n {
+		m = n
+	}
+	var err error
+	if m < n {
+		err = b.readErr()
+		if err == nil {
+			err = ErrBufferFull
+		}
+	}
+	return b.buf[b.r : b.r+m], err
+}
+
+// Read reads data into p.
+// It returns the number of bytes read into p.
+// It calls Read at most once on the underlying Reader,
+// hence n may be less than len(p).
+// At EOF, the count will be zero and err will be io.EOF.
+func (b *Reader) Read(p []byte) (n int, err error) {
+	n = len(p)
+	if n == 0 {
+		return 0, b.readErr()
+	}
+	if b.r == b.w {
+		if b.err != nil {
+			return 0, b.readErr()
+		}
+		if len(p) >= len(b.buf) {
+			// Large read, empty buffer.
+			// Read directly into p to avoid copy.
+			n, b.err = b.rd.Read(p)
+			if n < 0 {
+				panic(errNegativeRead)
+			}
+			if n > 0 {
+				b.lastByte = int(p[n-1])
+				b.lastRuneSize = -1
+			}
+			return n, b.readErr()
+		}
+		b.fill() // buffer is empty
+		if b.w == b.r {
+			return 0, b.readErr()
+		}
+	}
+
+	if n > b.w-b.r {
+		n = b.w - b.r
+	}
+	copy(p[0:n], b.buf[b.r:])
+	b.r += n
+	b.lastByte = int(b.buf[b.r-1])
+	b.lastRuneSize = -1
+	return n, nil
+}
+
+// ReadByte reads and returns a single byte.
+// If no byte is available, returns an error.
+func (b *Reader) ReadByte() (c byte, err error) {
+	b.lastRuneSize = -1
+	for b.r == b.w {
+		if b.err != nil {
+			return 0, b.readErr()
+		}
+		b.fill() // buffer is empty
+	}
+	c = b.buf[b.r]
+	b.r++
+	b.lastByte = int(c)
+	return c, nil
+}
+
+// UnreadByte unreads the last byte.  Only the most recently read byte can be unread.
+func (b *Reader) UnreadByte() error {
+	if b.lastByte < 0 || b.r == 0 && b.w > 0 {
+		return ErrInvalidUnreadByte
+	}
+	// b.r > 0 || b.w == 0
+	if b.r > 0 {
+		b.r--
+	} else {
+		// b.r == 0 && b.w == 0
+		b.w = 1
+	}
+	b.buf[b.r] = byte(b.lastByte)
+	b.lastByte = -1
+	b.lastRuneSize = -1
+	return nil
+}
+
+// ReadRune reads a single UTF-8 encoded Unicode character and returns the
+// rune and its size in bytes. If the encoded rune is invalid, it consumes one byte
+// and returns unicode.ReplacementChar (U+FFFD) with a size of 1.
+func (b *Reader) ReadRune() (r rune, size int, err error) {
+	for b.r+utf8.UTFMax > b.w && !utf8.FullRune(b.buf[b.r:b.w]) && b.err == nil && b.w-b.r < len(b.buf) {
+		b.fill() // b.w-b.r < len(buf) => buffer is not full
+	}
+	b.lastRuneSize = -1
+	if b.r == b.w {
+		return 0, 0, b.readErr()
+	}
+	r, size = rune(b.buf[b.r]), 1
+	if r >= 0x80 {
+		r, size = utf8.DecodeRune(b.buf[b.r:b.w])
+	}
+	b.r += size
+	b.lastByte = int(b.buf[b.r-1])
+	b.lastRuneSize = size
+	return r, size, nil
+}
+
+// UnreadRune unreads the last rune.  If the most recent read operation on
+// the buffer was not a ReadRune, UnreadRune returns an error.  (In this
+// regard it is stricter than UnreadByte, which will unread the last byte
+// from any read operation.)
+func (b *Reader) UnreadRune() error {
+	if b.lastRuneSize < 0 || b.r < b.lastRuneSize {
+		return ErrInvalidUnreadRune
+	}
+	b.r -= b.lastRuneSize
+	b.lastByte = -1
+	b.lastRuneSize = -1
+	return nil
+}
+
+// Buffered returns the number of bytes that can be read from the current buffer.
+func (b *Reader) Buffered() int { return b.w - b.r }
+
+// ReadSlice reads until the first occurrence of delim in the input,
+// returning a slice pointing at the bytes in the buffer.
+// The bytes stop being valid at the next read.
+// If ReadSlice encounters an error before finding a delimiter,
+// it returns all the data in the buffer and the error itself (often io.EOF).
+// ReadSlice fails with error ErrBufferFull if the buffer fills without a delim.
+// Because the data returned from ReadSlice will be overwritten
+// by the next I/O operation, most clients should use
+// ReadBytes or ReadString instead.
+// ReadSlice returns err != nil if and only if line does not end in delim.
+func (b *Reader) ReadSlice(delim byte) (line []byte, err error) {
+	for {
+		// Search buffer.
+		if i := bytes.IndexByte(b.buf[b.r:b.w], delim); i >= 0 {
+			line = b.buf[b.r : b.r+i+1]
+			b.r += i + 1
+			break
+		}
+
+		// Pending error?
+		if b.err != nil {
+			line = b.buf[b.r:b.w]
+			b.r = b.w
+			err = b.readErr()
+			break
+		}
+
+		// Buffer full?
+		if n := b.Buffered(); n >= len(b.buf) {
+			b.r = b.w
+			line = b.buf
+			err = ErrBufferFull
+			break
+		}
+
+		b.fill() // buffer is not full
+	}
+
+	// Handle last byte, if any.
+	if i := len(line) - 1; i >= 0 {
+		b.lastByte = int(line[i])
+	}
+
+	return
+}
+
+// ReadN tries to read exactly n bytes.
+// The bytes stop being valid at the next read call.
+// If ReadN encounters an error before reading n bytes,
+// it returns all the data in the buffer and the error itself (often io.EOF).
+// ReadN fails with error ErrBufferFull if the buffer fills
+// without reading N bytes.
+// Because the data returned from ReadN will be overwritten
+// by the next I/O operation, most clients should use
+// ReadBytes or ReadString instead.
+func (b *Reader) ReadN(n int) ([]byte, error) {
+	for b.Buffered() < n {
+		if b.err != nil {
+			buf := b.buf[b.r:b.w]
+			b.r = b.w
+			return buf, b.readErr()
+		}
+
+		// Buffer is full?
+		if b.Buffered() >= len(b.buf) {
+			b.r = b.w
+			return b.buf, ErrBufferFull
+		}
+
+		b.fill()
+	}
+	buf := b.buf[b.r : b.r+n]
+	b.r += n
+	return buf, nil
+}
+
+// ReadLine is a low-level line-reading primitive. Most callers should use
+// ReadBytes('\n') or ReadString('\n') instead or use a Scanner.
+//
+// ReadLine tries to return a single line, not including the end-of-line bytes.
+// If the line was too long for the buffer then isPrefix is set and the
+// beginning of the line is returned. The rest of the line will be returned
+// from future calls. isPrefix will be false when returning the last fragment
+// of the line. The returned buffer is only valid until the next call to
+// ReadLine. ReadLine either returns a non-nil line or it returns an error,
+// never both.
+//
+// The text returned from ReadLine does not include the line end ("\r\n" or "\n").
+// No indication or error is given if the input ends without a final line end.
+// Calling UnreadByte after ReadLine will always unread the last byte read
+// (possibly a character belonging to the line end) even if that byte is not
+// part of the line returned by ReadLine.
+func (b *Reader) ReadLine() (line []byte, isPrefix bool, err error) {
+	line, err = b.ReadSlice('\n')
+	if err == ErrBufferFull {
+		// Handle the case where "\r\n" straddles the buffer.
+		if len(line) > 0 && line[len(line)-1] == '\r' {
+			// Put the '\r' back on buf and drop it from line.
+			// Let the next call to ReadLine check for "\r\n".
+			if b.r == 0 {
+				// should be unreachable
+				panic("bufio: tried to rewind past start of buffer")
+			}
+			b.r--
+			line = line[:len(line)-1]
+		}
+		return line, true, nil
+	}
+
+	if len(line) == 0 {
+		if err != nil {
+			line = nil
+		}
+		return
+	}
+	err = nil
+
+	if line[len(line)-1] == '\n' {
+		drop := 1
+		if len(line) > 1 && line[len(line)-2] == '\r' {
+			drop = 2
+		}
+		line = line[:len(line)-drop]
+	}
+	return
+}
+
+// ReadBytes reads until the first occurrence of delim in the input,
+// returning a slice containing the data up to and including the delimiter.
+// If ReadBytes encounters an error before finding a delimiter,
+// it returns the data read before the error and the error itself (often io.EOF).
+// ReadBytes returns err != nil if and only if the returned data does not end in
+// delim.
+// For simple uses, a Scanner may be more convenient.
+func (b *Reader) ReadBytes(delim byte) (line []byte, err error) {
+	// Use ReadSlice to look for array,
+	// accumulating full buffers.
+	var frag []byte
+	var full [][]byte
+	err = nil
+
+	for {
+		var e error
+		frag, e = b.ReadSlice(delim)
+		if e == nil { // got final fragment
+			break
+		}
+		if e != ErrBufferFull { // unexpected error
+			err = e
+			break
+		}
+
+		// Make a copy of the buffer.
+		buf := make([]byte, len(frag))
+		copy(buf, frag)
+		full = append(full, buf)
+	}
+
+	// Allocate new buffer to hold the full pieces and the fragment.
+	n := 0
+	for i := range full {
+		n += len(full[i])
+	}
+	n += len(frag)
+
+	// Copy full pieces and fragment in.
+	buf := make([]byte, n)
+	n = 0
+	for i := range full {
+		n += copy(buf[n:], full[i])
+	}
+	copy(buf[n:], frag)
+	return buf, err
+}
+
+// ReadString reads until the first occurrence of delim in the input,
+// returning a string containing the data up to and including the delimiter.
+// If ReadString encounters an error before finding a delimiter,
+// it returns the data read before the error and the error itself (often io.EOF).
+// ReadString returns err != nil if and only if the returned data does not end in
+// delim.
+// For simple uses, a Scanner may be more convenient.
+func (b *Reader) ReadString(delim byte) (line string, err error) {
+	bytes, err := b.ReadBytes(delim)
+	line = string(bytes)
+	return line, err
+}
+
+// WriteTo implements io.WriterTo.
+func (b *Reader) WriteTo(w io.Writer) (n int64, err error) {
+	n, err = b.writeBuf(w)
+	if err != nil {
+		return
+	}
+
+	if r, ok := b.rd.(io.WriterTo); ok {
+		m, err := r.WriteTo(w)
+		n += m
+		return n, err
+	}
+
+	if w, ok := w.(io.ReaderFrom); ok {
+		m, err := w.ReadFrom(b.rd)
+		n += m
+		return n, err
+	}
+
+	if b.w-b.r < len(b.buf) {
+		b.fill() // buffer not full
+	}
+
+	for b.r < b.w {
+		// b.r < b.w => buffer is not empty
+		m, err := b.writeBuf(w)
+		n += m
+		if err != nil {
+			return n, err
+		}
+		b.fill() // buffer is empty
+	}
+
+	if b.err == io.EOF {
+		b.err = nil
+	}
+
+	return n, b.readErr()
+}
+
+// writeBuf writes the Reader's buffer to the writer.
+func (b *Reader) writeBuf(w io.Writer) (int64, error) {
+	n, err := w.Write(b.buf[b.r:b.w])
+	if n < b.r-b.w {
+		panic(errors.New("bufio: writer did not write all data"))
+	}
+	b.r += n
+	return int64(n), err
+}
+
+// buffered output
+
+// Writer implements buffering for an io.Writer object.
+// If an error occurs writing to a Writer, no more data will be
+// accepted and all subsequent writes will return the error.
+// After all data has been written, the client should call the
+// Flush method to guarantee all data has been forwarded to
+// the underlying io.Writer.
+type Writer struct {
+	err error
+	buf []byte
+	n   int
+	wr  io.Writer
+}
+
+// NewWriterSize returns a new Writer whose buffer has at least the specified
+// size. If the argument io.Writer is already a Writer with large enough
+// size, it returns the underlying Writer.
+func NewWriterSize(w io.Writer, size int) *Writer {
+	// Is it already a Writer?
+	b, ok := w.(*Writer)
+	if ok && len(b.buf) >= size {
+		return b
+	}
+	if size <= 0 {
+		size = defaultBufSize
+	}
+	return &Writer{
+		buf: make([]byte, size),
+		wr:  w,
+	}
+}
+
+// NewWriter returns a new Writer whose buffer has the default size.
+func NewWriter(w io.Writer) *Writer {
+	return NewWriterSize(w, defaultBufSize)
+}
+
+// Reset discards any unflushed buffered data, clears any error, and
+// resets b to write its output to w.
+func (b *Writer) Reset(w io.Writer) {
+	b.err = nil
+	b.n = 0
+	b.wr = w
+}
+
+// Flush writes any buffered data to the underlying io.Writer.
+func (b *Writer) Flush() error {
+	err := b.flush()
+	return err
+}
+
+func (b *Writer) flush() error {
+	if b.err != nil {
+		return b.err
+	}
+	if b.n == 0 {
+		return nil
+	}
+	n, err := b.wr.Write(b.buf[0:b.n])
+	if n < b.n && err == nil {
+		err = io.ErrShortWrite
+	}
+	if err != nil {
+		if n > 0 && n < b.n {
+			copy(b.buf[0:b.n-n], b.buf[n:b.n])
+		}
+		b.n -= n
+		b.err = err
+		return err
+	}
+	b.n = 0
+	return nil
+}
+
+// Available returns how many bytes are unused in the buffer.
+func (b *Writer) Available() int { return len(b.buf) - b.n }
+
+// Buffered returns the number of bytes that have been written into the current buffer.
+func (b *Writer) Buffered() int { return b.n }
+
+// Write writes the contents of p into the buffer.
+// It returns the number of bytes written.
+// If nn < len(p), it also returns an error explaining
+// why the write is short.
+func (b *Writer) Write(p []byte) (nn int, err error) {
+	for len(p) > b.Available() && b.err == nil {
+		var n int
+		if b.Buffered() == 0 {
+			// Large write, empty buffer.
+			// Write directly from p to avoid copy.
+			n, b.err = b.wr.Write(p)
+		} else {
+			n = copy(b.buf[b.n:], p)
+			b.n += n
+			b.flush()
+		}
+		nn += n
+		p = p[n:]
+	}
+	if b.err != nil {
+		return nn, b.err
+	}
+	n := copy(b.buf[b.n:], p)
+	b.n += n
+	nn += n
+	return nn, nil
+}
+
+// WriteByte writes a single byte.
+func (b *Writer) WriteByte(c byte) error {
+	if b.err != nil {
+		return b.err
+	}
+	if b.Available() <= 0 && b.flush() != nil {
+		return b.err
+	}
+	b.buf[b.n] = c
+	b.n++
+	return nil
+}
+
+// WriteRune writes a single Unicode code point, returning
+// the number of bytes written and any error.
+func (b *Writer) WriteRune(r rune) (size int, err error) {
+	if r < utf8.RuneSelf {
+		err = b.WriteByte(byte(r))
+		if err != nil {
+			return 0, err
+		}
+		return 1, nil
+	}
+	if b.err != nil {
+		return 0, b.err
+	}
+	n := b.Available()
+	if n < utf8.UTFMax {
+		if b.flush(); b.err != nil {
+			return 0, b.err
+		}
+		n = b.Available()
+		if n < utf8.UTFMax {
+			// Can only happen if buffer is silly small.
+			return b.WriteString(string(r))
+		}
+	}
+	size = utf8.EncodeRune(b.buf[b.n:], r)
+	b.n += size
+	return size, nil
+}
+
+// WriteString writes a string.
+// It returns the number of bytes written.
+// If the count is less than len(s), it also returns an error explaining
+// why the write is short.
+func (b *Writer) WriteString(s string) (int, error) {
+	nn := 0
+	for len(s) > b.Available() && b.err == nil {
+		n := copy(b.buf[b.n:], s)
+		b.n += n
+		nn += n
+		s = s[n:]
+		b.flush()
+	}
+	if b.err != nil {
+		return nn, b.err
+	}
+	n := copy(b.buf[b.n:], s)
+	b.n += n
+	nn += n
+	return nn, nil
+}
+
+// ReadFrom implements io.ReaderFrom.
+func (b *Writer) ReadFrom(r io.Reader) (n int64, err error) {
+	if b.Buffered() == 0 {
+		if w, ok := b.wr.(io.ReaderFrom); ok {
+			return w.ReadFrom(r)
+		}
+	}
+	var m int
+	for {
+		if b.Available() == 0 {
+			if err1 := b.flush(); err1 != nil {
+				return n, err1
+			}
+		}
+		nr := 0
+		for nr < maxConsecutiveEmptyReads {
+			m, err = r.Read(b.buf[b.n:])
+			if m != 0 || err != nil {
+				break
+			}
+			nr++
+		}
+		if nr == maxConsecutiveEmptyReads {
+			return n, io.ErrNoProgress
+		}
+		b.n += m
+		n += int64(m)
+		if err != nil {
+			break
+		}
+	}
+	if err == io.EOF {
+		// If we filled the buffer exactly, flush pre-emptively.
+		if b.Available() == 0 {
+			err = b.flush()
+		} else {
+			err = nil
+		}
+	}
+	return n, err
+}
+
+// buffered input and output
+
+// ReadWriter stores pointers to a Reader and a Writer.
+// It implements io.ReadWriter.
+type ReadWriter struct {
+	*Reader
+	*Writer
+}
+
+// NewReadWriter allocates a new ReadWriter that dispatches to r and w.
+func NewReadWriter(r *Reader, w *Writer) *ReadWriter {
+	return &ReadWriter{r, w}
+}