Initial commit

vendor/github.com/hyperhq/hypercli/pkg/ioutils/bytespipe.go

@@ -0,0 +1,152 @@
+package ioutils
+
+import (
+	"errors"
+	"io"
+	"sync"
+)
+
+// maxCap is the highest capacity to use in byte slices that buffer data.
+const maxCap = 1e6
+
+// blockThreshold is the minimum number of bytes in the buffer which will cause
+// a write to BytesPipe to block when allocating a new slice.
+const blockThreshold = 1e6
+
+// ErrClosed is returned when Write is called on a closed BytesPipe.
+var ErrClosed = errors.New("write to closed BytesPipe")
+
+// BytesPipe is io.ReadWriteCloser which works similarly to pipe(queue).
+// All written data may be read at most once. Also, BytesPipe allocates
+// and releases new byte slices to adjust to current needs, so the buffer
+// won't be overgrown after peak loads.
+type BytesPipe struct {
+	mu       sync.Mutex
+	wait     *sync.Cond
+	buf      [][]byte // slice of byte-slices of buffered data
+	lastRead int      // index in the first slice to a read point
+	bufLen   int      // length of data buffered over the slices
+	closeErr error    // error to return from next Read. set to nil if not closed.
+}
+
+// NewBytesPipe creates new BytesPipe, initialized by specified slice.
+// If buf is nil, then it will be initialized with slice which cap is 64.
+// buf will be adjusted in a way that len(buf) == 0, cap(buf) == cap(buf).
+func NewBytesPipe(buf []byte) *BytesPipe {
+	if cap(buf) == 0 {
+		buf = make([]byte, 0, 64)
+	}
+	bp := &BytesPipe{
+		buf: [][]byte{buf[:0]},
+	}
+	bp.wait = sync.NewCond(&bp.mu)
+	return bp
+}
+
+// Write writes p to BytesPipe.
+// It can allocate new []byte slices in a process of writing.
+func (bp *BytesPipe) Write(p []byte) (int, error) {
+	bp.mu.Lock()
+	defer bp.mu.Unlock()
+	written := 0
+	for {
+		if bp.closeErr != nil {
+			return written, ErrClosed
+		}
+		// write data to the last buffer
+		b := bp.buf[len(bp.buf)-1]
+		// copy data to the current empty allocated area
+		n := copy(b[len(b):cap(b)], p)
+		// increment buffered data length
+		bp.bufLen += n
+		// include written data in last buffer
+		bp.buf[len(bp.buf)-1] = b[:len(b)+n]
+
+		written += n
+
+		// if there was enough room to write all then break
+		if len(p) == n {
+			break
+		}
+
+		// more data: write to the next slice
+		p = p[n:]
+
+		// block if too much data is still in the buffer
+		for bp.bufLen >= blockThreshold {
+			bp.wait.Wait()
+		}
+
+		// allocate slice that has twice the size of the last unless maximum reached
+		nextCap := 2 * cap(bp.buf[len(bp.buf)-1])
+		if nextCap > maxCap {
+			nextCap = maxCap
+		}
+		// add new byte slice to the buffers slice and continue writing
+		bp.buf = append(bp.buf, make([]byte, 0, nextCap))
+	}
+	bp.wait.Broadcast()
+	return written, nil
+}
+
+// CloseWithError causes further reads from a BytesPipe to return immediately.
+func (bp *BytesPipe) CloseWithError(err error) error {
+	bp.mu.Lock()
+	if err != nil {
+		bp.closeErr = err
+	} else {
+		bp.closeErr = io.EOF
+	}
+	bp.wait.Broadcast()
+	bp.mu.Unlock()
+	return nil
+}
+
+// Close causes further reads from a BytesPipe to return immediately.
+func (bp *BytesPipe) Close() error {
+	return bp.CloseWithError(nil)
+}
+
+func (bp *BytesPipe) len() int {
+	return bp.bufLen - bp.lastRead
+}
+
+// Read reads bytes from BytesPipe.
+// Data could be read only once.
+func (bp *BytesPipe) Read(p []byte) (n int, err error) {
+	bp.mu.Lock()
+	defer bp.mu.Unlock()
+	if bp.len() == 0 {
+		if bp.closeErr != nil {
+			return 0, bp.closeErr
+		}
+		bp.wait.Wait()
+		if bp.len() == 0 && bp.closeErr != nil {
+			return 0, bp.closeErr
+		}
+	}
+	for {
+		read := copy(p, bp.buf[0][bp.lastRead:])
+		n += read
+		bp.lastRead += read
+		if bp.len() == 0 {
+			// we have read everything. reset to the beginning.
+			bp.lastRead = 0
+			bp.bufLen -= len(bp.buf[0])
+			bp.buf[0] = bp.buf[0][:0]
+			break
+		}
+		// break if everything was read
+		if len(p) == read {
+			break
+		}
+		// more buffered data and more asked. read from next slice.
+		p = p[read:]
+		bp.lastRead = 0
+		bp.bufLen -= len(bp.buf[0])
+		bp.buf[0] = nil     // throw away old slice
+		bp.buf = bp.buf[1:] // switch to next
+	}
+	bp.wait.Broadcast()
+	return
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/bytespipe_test.go

@@ -0,0 +1,158 @@
+package ioutils
+
+import (
+	"crypto/sha1"
+	"encoding/hex"
+	"math/rand"
+	"testing"
+	"time"
+)
+
+func TestBytesPipeRead(t *testing.T) {
+	buf := NewBytesPipe(nil)
+	buf.Write([]byte("12"))
+	buf.Write([]byte("34"))
+	buf.Write([]byte("56"))
+	buf.Write([]byte("78"))
+	buf.Write([]byte("90"))
+	rd := make([]byte, 4)
+	n, err := buf.Read(rd)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != 4 {
+		t.Fatalf("Wrong number of bytes read: %d, should be %d", n, 4)
+	}
+	if string(rd) != "1234" {
+		t.Fatalf("Read %s, but must be %s", rd, "1234")
+	}
+	n, err = buf.Read(rd)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != 4 {
+		t.Fatalf("Wrong number of bytes read: %d, should be %d", n, 4)
+	}
+	if string(rd) != "5678" {
+		t.Fatalf("Read %s, but must be %s", rd, "5679")
+	}
+	n, err = buf.Read(rd)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != 2 {
+		t.Fatalf("Wrong number of bytes read: %d, should be %d", n, 2)
+	}
+	if string(rd[:n]) != "90" {
+		t.Fatalf("Read %s, but must be %s", rd, "90")
+	}
+}
+
+func TestBytesPipeWrite(t *testing.T) {
+	buf := NewBytesPipe(nil)
+	buf.Write([]byte("12"))
+	buf.Write([]byte("34"))
+	buf.Write([]byte("56"))
+	buf.Write([]byte("78"))
+	buf.Write([]byte("90"))
+	if string(buf.buf[0]) != "1234567890" {
+		t.Fatalf("Buffer %s, must be %s", buf.buf, "1234567890")
+	}
+}
+
+// Write and read in different speeds/chunk sizes and check valid data is read.
+func TestBytesPipeWriteRandomChunks(t *testing.T) {
+	cases := []struct{ iterations, writesPerLoop, readsPerLoop int }{
+		{100, 10, 1},
+		{1000, 10, 5},
+		{1000, 100, 0},
+		{1000, 5, 6},
+		{10000, 50, 25},
+	}
+
+	testMessage := []byte("this is a random string for testing")
+	// random slice sizes to read and write
+	writeChunks := []int{25, 35, 15, 20}
+	readChunks := []int{5, 45, 20, 25}
+
+	for _, c := range cases {
+		// first pass: write directly to hash
+		hash := sha1.New()
+		for i := 0; i < c.iterations*c.writesPerLoop; i++ {
+			if _, err := hash.Write(testMessage[:writeChunks[i%len(writeChunks)]]); err != nil {
+				t.Fatal(err)
+			}
+		}
+		expected := hex.EncodeToString(hash.Sum(nil))
+
+		// write/read through buffer
+		buf := NewBytesPipe(nil)
+		hash.Reset()
+
+		done := make(chan struct{})
+
+		go func() {
+			// random delay before read starts
+			<-time.After(time.Duration(rand.Intn(10)) * time.Millisecond)
+			for i := 0; ; i++ {
+				p := make([]byte, readChunks[(c.iterations*c.readsPerLoop+i)%len(readChunks)])
+				n, _ := buf.Read(p)
+				if n == 0 {
+					break
+				}
+				hash.Write(p[:n])
+			}
+
+			close(done)
+		}()
+
+		for i := 0; i < c.iterations; i++ {
+			for w := 0; w < c.writesPerLoop; w++ {
+				buf.Write(testMessage[:writeChunks[(i*c.writesPerLoop+w)%len(writeChunks)]])
+			}
+		}
+		buf.Close()
+		<-done
+
+		actual := hex.EncodeToString(hash.Sum(nil))
+
+		if expected != actual {
+			t.Fatalf("BytesPipe returned invalid data. Expected checksum %v, got %v", expected, actual)
+		}
+
+	}
+}
+
+func BenchmarkBytesPipeWrite(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		readBuf := make([]byte, 1024)
+		buf := NewBytesPipe(nil)
+		go func() {
+			var err error
+			for err == nil {
+				_, err = buf.Read(readBuf)
+			}
+		}()
+		for j := 0; j < 1000; j++ {
+			buf.Write([]byte("pretty short line, because why not?"))
+		}
+		buf.Close()
+	}
+}
+
+func BenchmarkBytesPipeRead(b *testing.B) {
+	rd := make([]byte, 512)
+	for i := 0; i < b.N; i++ {
+		b.StopTimer()
+		buf := NewBytesPipe(nil)
+		for j := 0; j < 500; j++ {
+			buf.Write(make([]byte, 1024))
+		}
+		b.StartTimer()
+		for j := 0; j < 1000; j++ {
+			if n, _ := buf.Read(rd); n != 512 {
+				b.Fatalf("Wrong number of bytes: %d", n)
+			}
+		}
+	}
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/fmt.go

@@ -0,0 +1,22 @@
+package ioutils
+
+import (
+	"fmt"
+	"io"
+)
+
+// FprintfIfNotEmpty prints the string value if it's not empty
+func FprintfIfNotEmpty(w io.Writer, format, value string) (int, error) {
+	if value != "" {
+		return fmt.Fprintf(w, format, value)
+	}
+	return 0, nil
+}
+
+// FprintfIfTrue prints the boolean value if it's true
+func FprintfIfTrue(w io.Writer, format string, ok bool) (int, error) {
+	if ok {
+		return fmt.Fprintf(w, format, ok)
+	}
+	return 0, nil
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/fmt_test.go

@@ -0,0 +1,17 @@
+package ioutils
+
+import "testing"
+
+func TestFprintfIfNotEmpty(t *testing.T) {
+	wc := NewWriteCounter(&NopWriter{})
+	n, _ := FprintfIfNotEmpty(wc, "foo%s", "")
+
+	if wc.Count != 0 || n != 0 {
+		t.Errorf("Wrong count: %v vs. %v vs. 0", wc.Count, n)
+	}
+
+	n, _ = FprintfIfNotEmpty(wc, "foo%s", "bar")
+	if wc.Count != 6 || n != 6 {
+		t.Errorf("Wrong count: %v vs. %v vs. 6", wc.Count, n)
+	}
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/multireader.go

@@ -0,0 +1,226 @@
+package ioutils
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+)
+
+type pos struct {
+	idx    int
+	offset int64
+}
+
+type multiReadSeeker struct {
+	readers []io.ReadSeeker
+	pos     *pos
+	posIdx  map[io.ReadSeeker]int
+}
+
+func (r *multiReadSeeker) Seek(offset int64, whence int) (int64, error) {
+	var tmpOffset int64
+	switch whence {
+	case os.SEEK_SET:
+		for i, rdr := range r.readers {
+			// get size of the current reader
+			s, err := rdr.Seek(0, os.SEEK_END)
+			if err != nil {
+				return -1, err
+			}
+
+			if offset > tmpOffset+s {
+				if i == len(r.readers)-1 {
+					rdrOffset := s + (offset - tmpOffset)
+					if _, err := rdr.Seek(rdrOffset, os.SEEK_SET); err != nil {
+						return -1, err
+					}
+					r.pos = &pos{i, rdrOffset}
+					return offset, nil
+				}
+
+				tmpOffset += s
+				continue
+			}
+
+			rdrOffset := offset - tmpOffset
+			idx := i
+
+			rdr.Seek(rdrOffset, os.SEEK_SET)
+			// make sure all following readers are at 0
+			for _, rdr := range r.readers[i+1:] {
+				rdr.Seek(0, os.SEEK_SET)
+			}
+
+			if rdrOffset == s && i != len(r.readers)-1 {
+				idx++
+				rdrOffset = 0
+			}
+			r.pos = &pos{idx, rdrOffset}
+			return offset, nil
+		}
+	case os.SEEK_END:
+		for _, rdr := range r.readers {
+			s, err := rdr.Seek(0, os.SEEK_END)
+			if err != nil {
+				return -1, err
+			}
+			tmpOffset += s
+		}
+		r.Seek(tmpOffset+offset, os.SEEK_SET)
+		return tmpOffset + offset, nil
+	case os.SEEK_CUR:
+		if r.pos == nil {
+			return r.Seek(offset, os.SEEK_SET)
+		}
+		// Just return the current offset
+		if offset == 0 {
+			return r.getCurOffset()
+		}
+
+		curOffset, err := r.getCurOffset()
+		if err != nil {
+			return -1, err
+		}
+		rdr, rdrOffset, err := r.getReaderForOffset(curOffset + offset)
+		if err != nil {
+			return -1, err
+		}
+
+		r.pos = &pos{r.posIdx[rdr], rdrOffset}
+		return curOffset + offset, nil
+	default:
+		return -1, fmt.Errorf("Invalid whence: %d", whence)
+	}
+
+	return -1, fmt.Errorf("Error seeking for whence: %d, offset: %d", whence, offset)
+}
+
+func (r *multiReadSeeker) getReaderForOffset(offset int64) (io.ReadSeeker, int64, error) {
+	var rdr io.ReadSeeker
+	var rdrOffset int64
+
+	for i, rdr := range r.readers {
+		offsetTo, err := r.getOffsetToReader(rdr)
+		if err != nil {
+			return nil, -1, err
+		}
+		if offsetTo > offset {
+			rdr = r.readers[i-1]
+			rdrOffset = offsetTo - offset
+			break
+		}
+
+		if rdr == r.readers[len(r.readers)-1] {
+			rdrOffset = offsetTo + offset
+			break
+		}
+	}
+
+	return rdr, rdrOffset, nil
+}
+
+func (r *multiReadSeeker) getCurOffset() (int64, error) {
+	var totalSize int64
+	for _, rdr := range r.readers[:r.pos.idx+1] {
+		if r.posIdx[rdr] == r.pos.idx {
+			totalSize += r.pos.offset
+			break
+		}
+
+		size, err := getReadSeekerSize(rdr)
+		if err != nil {
+			return -1, fmt.Errorf("error getting seeker size: %v", err)
+		}
+		totalSize += size
+	}
+	return totalSize, nil
+}
+
+func (r *multiReadSeeker) getOffsetToReader(rdr io.ReadSeeker) (int64, error) {
+	var offset int64
+	for _, r := range r.readers {
+		if r == rdr {
+			break
+		}
+
+		size, err := getReadSeekerSize(rdr)
+		if err != nil {
+			return -1, err
+		}
+		offset += size
+	}
+	return offset, nil
+}
+
+func (r *multiReadSeeker) Read(b []byte) (int, error) {
+	if r.pos == nil {
+		r.pos = &pos{0, 0}
+	}
+
+	bCap := int64(cap(b))
+	buf := bytes.NewBuffer(nil)
+	var rdr io.ReadSeeker
+
+	for _, rdr = range r.readers[r.pos.idx:] {
+		readBytes, err := io.CopyN(buf, rdr, bCap)
+		if err != nil && err != io.EOF {
+			return -1, err
+		}
+		bCap -= readBytes
+
+		if bCap == 0 {
+			break
+		}
+	}
+
+	rdrPos, err := rdr.Seek(0, os.SEEK_CUR)
+	if err != nil {
+		return -1, err
+	}
+	r.pos = &pos{r.posIdx[rdr], rdrPos}
+	return buf.Read(b)
+}
+
+func getReadSeekerSize(rdr io.ReadSeeker) (int64, error) {
+	// save the current position
+	pos, err := rdr.Seek(0, os.SEEK_CUR)
+	if err != nil {
+		return -1, err
+	}
+
+	// get the size
+	size, err := rdr.Seek(0, os.SEEK_END)
+	if err != nil {
+		return -1, err
+	}
+
+	// reset the position
+	if _, err := rdr.Seek(pos, os.SEEK_SET); err != nil {
+		return -1, err
+	}
+	return size, nil
+}
+
+// MultiReadSeeker returns a ReadSeeker that's the logical concatenation of the provided
+// input readseekers. After calling this method the initial position is set to the
+// beginning of the first ReadSeeker. At the end of a ReadSeeker, Read always advances
+// to the beginning of the next ReadSeeker and returns EOF at the end of the last ReadSeeker.
+// Seek can be used over the sum of lengths of all readseekers.
+//
+// When a MultiReadSeeker is used, no Read and Seek operations should be made on
+// its ReadSeeker components. Also, users should make no assumption on the state
+// of individual readseekers while the MultiReadSeeker is used.
+func MultiReadSeeker(readers ...io.ReadSeeker) io.ReadSeeker {
+	if len(readers) == 1 {
+		return readers[0]
+	}
+	idx := make(map[io.ReadSeeker]int)
+	for i, rdr := range readers {
+		idx[rdr] = i
+	}
+	return &multiReadSeeker{
+		readers: readers,
+		posIdx:  idx,
+	}
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/multireader_test.go

@@ -0,0 +1,149 @@
+package ioutils
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"strings"
+	"testing"
+)
+
+func TestMultiReadSeekerReadAll(t *testing.T) {
+	str := "hello world"
+	s1 := strings.NewReader(str + " 1")
+	s2 := strings.NewReader(str + " 2")
+	s3 := strings.NewReader(str + " 3")
+	mr := MultiReadSeeker(s1, s2, s3)
+
+	expectedSize := int64(s1.Len() + s2.Len() + s3.Len())
+
+	b, err := ioutil.ReadAll(mr)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expected := "hello world 1hello world 2hello world 3"
+	if string(b) != expected {
+		t.Fatalf("ReadAll failed, got: %q, expected %q", string(b), expected)
+	}
+
+	size, err := mr.Seek(0, os.SEEK_END)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if size != expectedSize {
+		t.Fatalf("reader size does not match, got %d, expected %d", size, expectedSize)
+	}
+
+	// Reset the position and read again
+	pos, err := mr.Seek(0, os.SEEK_SET)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if pos != 0 {
+		t.Fatalf("expected position to be set to 0, got %d", pos)
+	}
+
+	b, err = ioutil.ReadAll(mr)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if string(b) != expected {
+		t.Fatalf("ReadAll failed, got: %q, expected %q", string(b), expected)
+	}
+}
+
+func TestMultiReadSeekerReadEach(t *testing.T) {
+	str := "hello world"
+	s1 := strings.NewReader(str + " 1")
+	s2 := strings.NewReader(str + " 2")
+	s3 := strings.NewReader(str + " 3")
+	mr := MultiReadSeeker(s1, s2, s3)
+
+	var totalBytes int64
+	for i, s := range []*strings.Reader{s1, s2, s3} {
+		sLen := int64(s.Len())
+		buf := make([]byte, s.Len())
+		expected := []byte(fmt.Sprintf("%s %d", str, i+1))
+
+		if _, err := mr.Read(buf); err != nil && err != io.EOF {
+			t.Fatal(err)
+		}
+
+		if !bytes.Equal(buf, expected) {
+			t.Fatalf("expected %q to be %q", string(buf), string(expected))
+		}
+
+		pos, err := mr.Seek(0, os.SEEK_CUR)
+		if err != nil {
+			t.Fatalf("iteration: %d, error: %v", i+1, err)
+		}
+
+		// check that the total bytes read is the current position of the seeker
+		totalBytes += sLen
+		if pos != totalBytes {
+			t.Fatalf("expected current position to be: %d, got: %d, iteration: %d", totalBytes, pos, i+1)
+		}
+
+		// This tests not only that SEEK_SET and SEEK_CUR give the same values, but that the next iteration is in the expected position as well
+		newPos, err := mr.Seek(pos, os.SEEK_SET)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if newPos != pos {
+			t.Fatalf("expected to get same position when calling SEEK_SET with value from SEEK_CUR, cur: %d, set: %d", pos, newPos)
+		}
+	}
+}
+
+func TestMultiReadSeekerReadSpanningChunks(t *testing.T) {
+	str := "hello world"
+	s1 := strings.NewReader(str + " 1")
+	s2 := strings.NewReader(str + " 2")
+	s3 := strings.NewReader(str + " 3")
+	mr := MultiReadSeeker(s1, s2, s3)
+
+	buf := make([]byte, s1.Len()+3)
+	_, err := mr.Read(buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// expected is the contents of s1 + 3 bytes from s2, ie, the `hel` at the end of this string
+	expected := "hello world 1hel"
+	if string(buf) != expected {
+		t.Fatalf("expected %s to be %s", string(buf), expected)
+	}
+}
+
+func TestMultiReadSeekerNegativeSeek(t *testing.T) {
+	str := "hello world"
+	s1 := strings.NewReader(str + " 1")
+	s2 := strings.NewReader(str + " 2")
+	s3 := strings.NewReader(str + " 3")
+	mr := MultiReadSeeker(s1, s2, s3)
+
+	s1Len := s1.Len()
+	s2Len := s2.Len()
+	s3Len := s3.Len()
+
+	s, err := mr.Seek(int64(-1*s3.Len()), os.SEEK_END)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if s != int64(s1Len+s2Len) {
+		t.Fatalf("expected %d to be %d", s, s1.Len()+s2.Len())
+	}
+
+	buf := make([]byte, s3Len)
+	if _, err := mr.Read(buf); err != nil && err != io.EOF {
+		t.Fatal(err)
+	}
+	expected := fmt.Sprintf("%s %d", str, 3)
+	if string(buf) != fmt.Sprintf("%s %d", str, 3) {
+		t.Fatalf("expected %q to be %q", string(buf), expected)
+	}
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/readers.go

@@ -0,0 +1,154 @@
+package ioutils
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"io"
+
+	"golang.org/x/net/context"
+)
+
+type readCloserWrapper struct {
+	io.Reader
+	closer func() error
+}
+
+func (r *readCloserWrapper) Close() error {
+	return r.closer()
+}
+
+// NewReadCloserWrapper returns a new io.ReadCloser.
+func NewReadCloserWrapper(r io.Reader, closer func() error) io.ReadCloser {
+	return &readCloserWrapper{
+		Reader: r,
+		closer: closer,
+	}
+}
+
+type readerErrWrapper struct {
+	reader io.Reader
+	closer func()
+}
+
+func (r *readerErrWrapper) Read(p []byte) (int, error) {
+	n, err := r.reader.Read(p)
+	if err != nil {
+		r.closer()
+	}
+	return n, err
+}
+
+// NewReaderErrWrapper returns a new io.Reader.
+func NewReaderErrWrapper(r io.Reader, closer func()) io.Reader {
+	return &readerErrWrapper{
+		reader: r,
+		closer: closer,
+	}
+}
+
+// HashData returns the sha256 sum of src.
+func HashData(src io.Reader) (string, error) {
+	h := sha256.New()
+	if _, err := io.Copy(h, src); err != nil {
+		return "", err
+	}
+	return "sha256:" + hex.EncodeToString(h.Sum(nil)), nil
+}
+
+// OnEOFReader wraps a io.ReadCloser and a function
+// the function will run at the end of file or close the file.
+type OnEOFReader struct {
+	Rc io.ReadCloser
+	Fn func()
+}
+
+func (r *OnEOFReader) Read(p []byte) (n int, err error) {
+	n, err = r.Rc.Read(p)
+	if err == io.EOF {
+		r.runFunc()
+	}
+	return
+}
+
+// Close closes the file and run the function.
+func (r *OnEOFReader) Close() error {
+	err := r.Rc.Close()
+	r.runFunc()
+	return err
+}
+
+func (r *OnEOFReader) runFunc() {
+	if fn := r.Fn; fn != nil {
+		fn()
+		r.Fn = nil
+	}
+}
+
+// cancelReadCloser wraps an io.ReadCloser with a context for cancelling read
+// operations.
+type cancelReadCloser struct {
+	cancel func()
+	pR     *io.PipeReader // Stream to read from
+	pW     *io.PipeWriter
+}
+
+// NewCancelReadCloser creates a wrapper that closes the ReadCloser when the
+// context is cancelled. The returned io.ReadCloser must be closed when it is
+// no longer needed.
+func NewCancelReadCloser(ctx context.Context, in io.ReadCloser) io.ReadCloser {
+	pR, pW := io.Pipe()
+
+	// Create a context used to signal when the pipe is closed
+	doneCtx, cancel := context.WithCancel(context.Background())
+
+	p := &cancelReadCloser{
+		cancel: cancel,
+		pR:     pR,
+		pW:     pW,
+	}
+
+	go func() {
+		_, err := io.Copy(pW, in)
+		select {
+		case <-ctx.Done():
+			// If the context was closed, p.closeWithError
+			// was already called. Calling it again would
+			// change the error that Read returns.
+		default:
+			p.closeWithError(err)
+		}
+		in.Close()
+	}()
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				p.closeWithError(ctx.Err())
+			case <-doneCtx.Done():
+				return
+			}
+		}
+	}()
+
+	return p
+}
+
+// Read wraps the Read method of the pipe that provides data from the wrapped
+// ReadCloser.
+func (p *cancelReadCloser) Read(buf []byte) (n int, err error) {
+	return p.pR.Read(buf)
+}
+
+// closeWithError closes the wrapper and its underlying reader. It will
+// cause future calls to Read to return err.
+func (p *cancelReadCloser) closeWithError(err error) {
+	p.pW.CloseWithError(err)
+	p.cancel()
+}
+
+// Close closes the wrapper its underlying reader. It will cause
+// future calls to Read to return io.EOF.
+func (p *cancelReadCloser) Close() error {
+	p.closeWithError(io.EOF)
+	return nil
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/readers_test.go

@@ -0,0 +1,94 @@
+package ioutils
+
+import (
+	"fmt"
+	"io/ioutil"
+	"strings"
+	"testing"
+	"time"
+
+	"golang.org/x/net/context"
+)
+
+// Implement io.Reader
+type errorReader struct{}
+
+func (r *errorReader) Read(p []byte) (int, error) {
+	return 0, fmt.Errorf("Error reader always fail.")
+}
+
+func TestReadCloserWrapperClose(t *testing.T) {
+	reader := strings.NewReader("A string reader")
+	wrapper := NewReadCloserWrapper(reader, func() error {
+		return fmt.Errorf("This will be called when closing")
+	})
+	err := wrapper.Close()
+	if err == nil || !strings.Contains(err.Error(), "This will be called when closing") {
+		t.Fatalf("readCloserWrapper should have call the anonymous func and thus, fail.")
+	}
+}
+
+func TestReaderErrWrapperReadOnError(t *testing.T) {
+	called := false
+	reader := &errorReader{}
+	wrapper := NewReaderErrWrapper(reader, func() {
+		called = true
+	})
+	_, err := wrapper.Read([]byte{})
+	if err == nil || !strings.Contains(err.Error(), "Error reader always fail.") {
+		t.Fatalf("readErrWrapper should returned an error")
+	}
+	if !called {
+		t.Fatalf("readErrWrapper should have call the anonymous function on failure")
+	}
+}
+
+func TestReaderErrWrapperRead(t *testing.T) {
+	reader := strings.NewReader("a string reader.")
+	wrapper := NewReaderErrWrapper(reader, func() {
+		t.Fatalf("readErrWrapper should not have called the anonymous function")
+	})
+	// Read 20 byte (should be ok with the string above)
+	num, err := wrapper.Read(make([]byte, 20))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if num != 16 {
+		t.Fatalf("readerErrWrapper should have read 16 byte, but read %d", num)
+	}
+}
+
+func TestHashData(t *testing.T) {
+	reader := strings.NewReader("hash-me")
+	actual, err := HashData(reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected := "sha256:4d11186aed035cc624d553e10db358492c84a7cd6b9670d92123c144930450aa"
+	if actual != expected {
+		t.Fatalf("Expecting %s, got %s", expected, actual)
+	}
+}
+
+type perpetualReader struct{}
+
+func (p *perpetualReader) Read(buf []byte) (n int, err error) {
+	for i := 0; i != len(buf); i++ {
+		buf[i] = 'a'
+	}
+	return len(buf), nil
+}
+
+func TestCancelReadCloser(t *testing.T) {
+	ctx, _ := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	cancelReadCloser := NewCancelReadCloser(ctx, ioutil.NopCloser(&perpetualReader{}))
+	for {
+		var buf [128]byte
+		_, err := cancelReadCloser.Read(buf[:])
+		if err == context.DeadlineExceeded {
+			break
+		} else if err != nil {
+			t.Fatalf("got unexpected error: %v", err)
+		}
+	}
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/scheduler.go

@@ -0,0 +1,6 @@
+// +build !gccgo
+
+package ioutils
+
+func callSchedulerIfNecessary() {
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/scheduler_gccgo.go

@@ -0,0 +1,13 @@
+// +build gccgo
+
+package ioutils
+
+import (
+	"runtime"
+)
+
+func callSchedulerIfNecessary() {
+	//allow or force Go scheduler to switch context, without explicitly
+	//forcing this will make it hang when using gccgo implementation
+	runtime.Gosched()
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/temp_unix.go

@@ -0,0 +1,10 @@
+// +build !windows
+
+package ioutils
+
+import "io/ioutil"
+
+// TempDir on Unix systems is equivalent to ioutil.TempDir.
+func TempDir(dir, prefix string) (string, error) {
+	return ioutil.TempDir(dir, prefix)
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/temp_windows.go

@@ -0,0 +1,18 @@
+// +build windows
+
+package ioutils
+
+import (
+	"io/ioutil"
+
+	"github.com/hyperhq/hypercli/pkg/longpath"
+)
+
+// TempDir is the equivalent of ioutil.TempDir, except that the result is in Windows longpath format.
+func TempDir(dir, prefix string) (string, error) {
+	tempDir, err := ioutil.TempDir(dir, prefix)
+	if err != nil {
+		return "", err
+	}
+	return longpath.AddPrefix(tempDir), nil
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/writeflusher.go

@@ -0,0 +1,92 @@
+package ioutils
+
+import (
+	"errors"
+	"io"
+	"net/http"
+	"sync"
+)
+
+// WriteFlusher wraps the Write and Flush operation ensuring that every write
+// is a flush. In addition, the Close method can be called to intercept
+// Read/Write calls if the targets lifecycle has already ended.
+type WriteFlusher struct {
+	mu      sync.Mutex
+	w       io.Writer
+	flusher http.Flusher
+	flushed bool
+	closed  error
+
+	// TODO(stevvooe): Use channel for closed instead, remove mutex. Using a
+	// channel will allow one to properly order the operations.
+}
+
+var errWriteFlusherClosed = errors.New("writeflusher: closed")
+
+func (wf *WriteFlusher) Write(b []byte) (n int, err error) {
+	wf.mu.Lock()
+	defer wf.mu.Unlock()
+	if wf.closed != nil {
+		return 0, wf.closed
+	}
+
+	n, err = wf.w.Write(b)
+	wf.flush() // every write is a flush.
+	return n, err
+}
+
+// Flush the stream immediately.
+func (wf *WriteFlusher) Flush() {
+	wf.mu.Lock()
+	defer wf.mu.Unlock()
+
+	wf.flush()
+}
+
+// flush the stream immediately without taking a lock. Used internally.
+func (wf *WriteFlusher) flush() {
+	if wf.closed != nil {
+		return
+	}
+
+	wf.flushed = true
+	wf.flusher.Flush()
+}
+
+// Flushed returns the state of flushed.
+// If it's flushed, return true, or else it return false.
+func (wf *WriteFlusher) Flushed() bool {
+	// BUG(stevvooe): Remove this method. Its use is inherently racy. Seems to
+	// be used to detect whether or a response code has been issued or not.
+	// Another hook should be used instead.
+	wf.mu.Lock()
+	defer wf.mu.Unlock()
+
+	return wf.flushed
+}
+
+// Close closes the write flusher, disallowing any further writes to the
+// target. After the flusher is closed, all calls to write or flush will
+// result in an error.
+func (wf *WriteFlusher) Close() error {
+	wf.mu.Lock()
+	defer wf.mu.Unlock()
+
+	if wf.closed != nil {
+		return wf.closed
+	}
+
+	wf.closed = errWriteFlusherClosed
+	return nil
+}
+
+// NewWriteFlusher returns a new WriteFlusher.
+func NewWriteFlusher(w io.Writer) *WriteFlusher {
+	var flusher http.Flusher
+	if f, ok := w.(http.Flusher); ok {
+		flusher = f
+	} else {
+		flusher = &NopFlusher{}
+	}
+	return &WriteFlusher{w: w, flusher: flusher}
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/writers.go

@@ -0,0 +1,66 @@
+package ioutils
+
+import "io"
+
+// NopWriter represents a type which write operation is nop.
+type NopWriter struct{}
+
+func (*NopWriter) Write(buf []byte) (int, error) {
+	return len(buf), nil
+}
+
+type nopWriteCloser struct {
+	io.Writer
+}
+
+func (w *nopWriteCloser) Close() error { return nil }
+
+// NopWriteCloser returns a nopWriteCloser.
+func NopWriteCloser(w io.Writer) io.WriteCloser {
+	return &nopWriteCloser{w}
+}
+
+// NopFlusher represents a type which flush operation is nop.
+type NopFlusher struct{}
+
+// Flush is a nop operation.
+func (f *NopFlusher) Flush() {}
+
+type writeCloserWrapper struct {
+	io.Writer
+	closer func() error
+}
+
+func (r *writeCloserWrapper) Close() error {
+	return r.closer()
+}
+
+// NewWriteCloserWrapper returns a new io.WriteCloser.
+func NewWriteCloserWrapper(r io.Writer, closer func() error) io.WriteCloser {
+	return &writeCloserWrapper{
+		Writer: r,
+		closer: closer,
+	}
+}
+
+// WriteCounter wraps a concrete io.Writer and hold a count of the number
+// of bytes written to the writer during a "session".
+// This can be convenient when write return is masked
+// (e.g., json.Encoder.Encode())
+type WriteCounter struct {
+	Count  int64
+	Writer io.Writer
+}
+
+// NewWriteCounter returns a new WriteCounter.
+func NewWriteCounter(w io.Writer) *WriteCounter {
+	return &WriteCounter{
+		Writer: w,
+	}
+}
+
+func (wc *WriteCounter) Write(p []byte) (count int, err error) {
+	count, err = wc.Writer.Write(p)
+	wc.Count += int64(count)
+	return
+}

vendor/github.com/hyperhq/hypercli/pkg/ioutils/writers_test.go

@@ -0,0 +1,65 @@
+package ioutils
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+func TestWriteCloserWrapperClose(t *testing.T) {
+	called := false
+	writer := bytes.NewBuffer([]byte{})
+	wrapper := NewWriteCloserWrapper(writer, func() error {
+		called = true
+		return nil
+	})
+	if err := wrapper.Close(); err != nil {
+		t.Fatal(err)
+	}
+	if !called {
+		t.Fatalf("writeCloserWrapper should have call the anonymous function.")
+	}
+}
+
+func TestNopWriteCloser(t *testing.T) {
+	writer := bytes.NewBuffer([]byte{})
+	wrapper := NopWriteCloser(writer)
+	if err := wrapper.Close(); err != nil {
+		t.Fatal("NopWriteCloser always return nil on Close.")
+	}
+
+}
+
+func TestNopWriter(t *testing.T) {
+	nw := &NopWriter{}
+	l, err := nw.Write([]byte{'c'})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if l != 1 {
+		t.Fatalf("Expected 1 got %d", l)
+	}
+}
+
+func TestWriteCounter(t *testing.T) {
+	dummy1 := "This is a dummy string."
+	dummy2 := "This is another dummy string."
+	totalLength := int64(len(dummy1) + len(dummy2))
+
+	reader1 := strings.NewReader(dummy1)
+	reader2 := strings.NewReader(dummy2)
+
+	var buffer bytes.Buffer
+	wc := NewWriteCounter(&buffer)
+
+	reader1.WriteTo(wc)
+	reader2.WriteTo(wc)
+
+	if wc.Count != totalLength {
+		t.Errorf("Wrong count: %d vs. %d", wc.Count, totalLength)
+	}
+
+	if buffer.String() != dummy1+dummy2 {
+		t.Error("Wrong message written")
+	}
+}