| Andrea Luzzardi | a27b4b8 | 2013-01-19 00:13:39 | [diff] [blame] | 1 | package docker |
| 2 | |
| 3 | import ( |
| 4 | "bytes" |
| 5 | "container/list" |
| 6 | "io" |
| Andrea Luzzardi | e6adfa2 | 2013-02-13 21:58:28 | [diff] [blame] | 7 | "os" |
| Solomon Hykes | 3703536 | 2013-01-27 08:59:49 | [diff] [blame] | 8 | "os/exec" |
| Andrea Luzzardi | e6adfa2 | 2013-02-13 21:58:28 | [diff] [blame] | 9 | "path/filepath" |
| Andrea Luzzardi | 333abbf | 2013-01-28 22:30:05 | [diff] [blame] | 10 | "sync" |
| Andrea Luzzardi | a27b4b8 | 2013-01-19 00:13:39 | [diff] [blame] | 11 | ) |
| 12 | |
| Solomon Hykes | bcfe2aa | 2013-01-29 11:18:07 | [diff] [blame] | 13 | func Trunc(s string, maxlen int) string { |
| 14 | if len(s) <= maxlen { |
| 15 | return s |
| 16 | } |
| 17 | return s[:maxlen] |
| 18 | } |
| 19 | |
| Andrea Luzzardi | e6adfa2 | 2013-02-13 21:58:28 | [diff] [blame] | 20 | // Figure out the absolute path of our own binary |
| 21 | func SelfPath() string { |
| 22 | path, err := exec.LookPath(os.Args[0]) |
| 23 | if err != nil { |
| 24 | panic(err) |
| 25 | } |
| 26 | path, err = filepath.Abs(path) |
| 27 | if err != nil { |
| 28 | panic(err) |
| 29 | } |
| 30 | return path |
| 31 | } |
| 32 | |
| Solomon Hykes | 5d6dd22 | 2013-01-26 23:56:42 | [diff] [blame] | 33 | type nopWriteCloser struct { |
| 34 | io.Writer |
| 35 | } |
| 36 | |
| 37 | func (w *nopWriteCloser) Close() error { return nil } |
| 38 | |
| 39 | func NopWriteCloser(w io.Writer) io.WriteCloser { |
| 40 | return &nopWriteCloser{w} |
| 41 | } |
| 42 | |
| Andrea Luzzardi | a27b4b8 | 2013-01-19 00:13:39 | [diff] [blame] | 43 | type bufReader struct { |
| 44 | buf *bytes.Buffer |
| 45 | reader io.Reader |
| 46 | err error |
| 47 | l sync.Mutex |
| 48 | wait sync.Cond |
| 49 | } |
| 50 | |
| 51 | func newBufReader(r io.Reader) *bufReader { |
| 52 | reader := &bufReader{ |
| 53 | buf: &bytes.Buffer{}, |
| 54 | reader: r, |
| 55 | } |
| 56 | reader.wait.L = &reader.l |
| 57 | go reader.drain() |
| 58 | return reader |
| 59 | } |
| 60 | |
| 61 | func (r *bufReader) drain() { |
| 62 | buf := make([]byte, 1024) |
| 63 | for { |
| 64 | n, err := r.reader.Read(buf) |
| 65 | if err != nil { |
| 66 | r.err = err |
| 67 | } else { |
| 68 | r.buf.Write(buf[0:n]) |
| 69 | } |
| 70 | r.l.Lock() |
| 71 | r.wait.Signal() |
| 72 | r.l.Unlock() |
| 73 | if err != nil { |
| 74 | break |
| 75 | } |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | func (r *bufReader) Read(p []byte) (n int, err error) { |
| 80 | for { |
| 81 | n, err = r.buf.Read(p) |
| 82 | if n > 0 { |
| 83 | return n, err |
| 84 | } |
| 85 | if r.err != nil { |
| 86 | return 0, r.err |
| 87 | } |
| 88 | r.l.Lock() |
| 89 | r.wait.Wait() |
| 90 | r.l.Unlock() |
| 91 | } |
| 92 | return |
| 93 | } |
| 94 | |
| 95 | func (r *bufReader) Close() error { |
| 96 | closer, ok := r.reader.(io.ReadCloser) |
| 97 | if !ok { |
| 98 | return nil |
| 99 | } |
| 100 | return closer.Close() |
| 101 | } |
| 102 | |
| 103 | type writeBroadcaster struct { |
| 104 | writers *list.List |
| 105 | } |
| 106 | |
| 107 | func (w *writeBroadcaster) AddWriter(writer io.WriteCloser) { |
| 108 | w.writers.PushBack(writer) |
| 109 | } |
| 110 | |
| 111 | func (w *writeBroadcaster) RemoveWriter(writer io.WriteCloser) { |
| 112 | for e := w.writers.Front(); e != nil; e = e.Next() { |
| 113 | v := e.Value.(io.Writer) |
| 114 | if v == writer { |
| 115 | w.writers.Remove(e) |
| 116 | return |
| 117 | } |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | func (w *writeBroadcaster) Write(p []byte) (n int, err error) { |
| 122 | failed := []*list.Element{} |
| 123 | for e := w.writers.Front(); e != nil; e = e.Next() { |
| 124 | writer := e.Value.(io.Writer) |
| 125 | if n, err := writer.Write(p); err != nil || n != len(p) { |
| 126 | // On error, evict the writer |
| 127 | failed = append(failed, e) |
| 128 | } |
| 129 | } |
| 130 | // We cannot remove while iterating, so it has to be done in |
| 131 | // a separate step |
| 132 | for _, e := range failed { |
| 133 | w.writers.Remove(e) |
| 134 | } |
| 135 | return len(p), nil |
| 136 | } |
| 137 | |
| 138 | func (w *writeBroadcaster) Close() error { |
| 139 | for e := w.writers.Front(); e != nil; e = e.Next() { |
| 140 | writer := e.Value.(io.WriteCloser) |
| 141 | writer.Close() |
| 142 | } |
| 143 | return nil |
| 144 | } |
| 145 | |
| 146 | func newWriteBroadcaster() *writeBroadcaster { |
| 147 | return &writeBroadcaster{list.New()} |
| 148 | } |
