5 files changed, 557 insertions, 0 deletions
diff --git a/vendor/github.com/nxadm/tail/watch/filechanges.go b/vendor/github.com/nxadm/tail/watch/filechanges.go
new file mode 100644
index 000000000..f80aead9a
--- /dev/null
+++ b/vendor/github.com/nxadm/tail/watch/filechanges.go
@@ -0,0 +1,36 @@
+package watch
+
+type FileChanges struct {
+	Modified  chan bool // Channel to get notified of modifications
+	Truncated chan bool // Channel to get notified of truncations
+	Deleted   chan bool // Channel to get notified of deletions/renames
+}
+
+func NewFileChanges() *FileChanges {
+	return &FileChanges{
+		make(chan bool, 1), make(chan bool, 1), make(chan bool, 1)}
+}
+
+func (fc *FileChanges) NotifyModified() {
+	sendOnlyIfEmpty(fc.Modified)
+}
+
+func (fc *FileChanges) NotifyTruncated() {
+	sendOnlyIfEmpty(fc.Truncated)
+}
+
+func (fc *FileChanges) NotifyDeleted() {
+	sendOnlyIfEmpty(fc.Deleted)
+}
+
+// sendOnlyIfEmpty sends on a bool channel only if the channel has no
+// backlog to be read by other goroutines. This concurrency pattern
+// can be used to notify other goroutines if and only if they are
+// looking for it (i.e., subsequent notifications can be compressed
+// into one).
+func sendOnlyIfEmpty(ch chan bool) {
+	select {
+	case ch <- true:
+	default:
+	}
+}
diff --git a/vendor/github.com/nxadm/tail/watch/inotify.go b/vendor/github.com/nxadm/tail/watch/inotify.go
new file mode 100644
index 000000000..439921810
--- /dev/null
+++ b/vendor/github.com/nxadm/tail/watch/inotify.go
@@ -0,0 +1,135 @@
+// Copyright (c) 2015 HPE Software Inc. All rights reserved.
+// Copyright (c) 2013 ActiveState Software Inc. All rights reserved.
+
+package watch
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/nxadm/tail/util"
+
+    "github.com/fsnotify/fsnotify"
+	"gopkg.in/tomb.v1"
+)
+
+// InotifyFileWatcher uses inotify to monitor file changes.
+type InotifyFileWatcher struct {
+	Filename string
+	Size     int64
+}
+
+func NewInotifyFileWatcher(filename string) *InotifyFileWatcher {
+	fw := &InotifyFileWatcher{filepath.Clean(filename), 0}
+	return fw
+}
+
+func (fw *InotifyFileWatcher) BlockUntilExists(t *tomb.Tomb) error {
+	err := WatchCreate(fw.Filename)
+	if err != nil {
+		return err
+	}
+	defer RemoveWatchCreate(fw.Filename)
+
+	// Do a real check now as the file might have been created before
+	// calling `WatchFlags` above.
+	if _, err = os.Stat(fw.Filename); !os.IsNotExist(err) {
+		// file exists, or stat returned an error.
+		return err
+	}
+
+	events := Events(fw.Filename)
+
+	for {
+		select {
+		case evt, ok := <-events:
+			if !ok {
+				return fmt.Errorf("inotify watcher has been closed")
+			}
+			evtName, err := filepath.Abs(evt.Name)
+			if err != nil {
+				return err
+			}
+			fwFilename, err := filepath.Abs(fw.Filename)
+			if err != nil {
+				return err
+			}
+			if evtName == fwFilename {
+				return nil
+			}
+		case <-t.Dying():
+			return tomb.ErrDying
+		}
+	}
+	panic("unreachable")
+}
+
+func (fw *InotifyFileWatcher) ChangeEvents(t *tomb.Tomb, pos int64) (*FileChanges, error) {
+	err := Watch(fw.Filename)
+	if err != nil {
+		return nil, err
+	}
+
+	changes := NewFileChanges()
+	fw.Size = pos
+
+	go func() {
+
+		events := Events(fw.Filename)
+
+		for {
+			prevSize := fw.Size
+
+			var evt fsnotify.Event
+			var ok bool
+
+			select {
+			case evt, ok = <-events:
+				if !ok {
+					RemoveWatch(fw.Filename)
+					return
+				}
+			case <-t.Dying():
+				RemoveWatch(fw.Filename)
+				return
+			}
+
+			switch {
+			case evt.Op&fsnotify.Remove == fsnotify.Remove:
+				fallthrough
+
+			case evt.Op&fsnotify.Rename == fsnotify.Rename:
+				RemoveWatch(fw.Filename)
+				changes.NotifyDeleted()
+				return
+
+			//With an open fd, unlink(fd) - inotify returns IN_ATTRIB (==fsnotify.Chmod)
+			case evt.Op&fsnotify.Chmod == fsnotify.Chmod:
+				fallthrough
+
+			case evt.Op&fsnotify.Write == fsnotify.Write:
+				fi, err := os.Stat(fw.Filename)
+				if err != nil {
+					if os.IsNotExist(err) {
+						RemoveWatch(fw.Filename)
+						changes.NotifyDeleted()
+						return
+					}
+					// XXX: report this error back to the user
+					util.Fatal("Failed to stat file %v: %v", fw.Filename, err)
+				}
+				fw.Size = fi.Size()
+
+				if prevSize > 0 && prevSize > fw.Size {
+					changes.NotifyTruncated()
+				} else {
+					changes.NotifyModified()
+				}
+				prevSize = fw.Size
+			}
+		}
+	}()
+
+	return changes, nil
+}
diff --git a/vendor/github.com/nxadm/tail/watch/inotify_tracker.go b/vendor/github.com/nxadm/tail/watch/inotify_tracker.go
new file mode 100644
index 000000000..a94bcd4cb
--- /dev/null
+++ b/vendor/github.com/nxadm/tail/watch/inotify_tracker.go
@@ -0,0 +1,248 @@
+// Copyright (c) 2015 HPE Software Inc. All rights reserved.
+// Copyright (c) 2013 ActiveState Software Inc. All rights reserved.
+
+package watch
+
+import (
+	"log"
+	"os"
+	"path/filepath"
+	"sync"
+	"syscall"
+
+	"github.com/nxadm/tail/util"
+
+    "github.com/fsnotify/fsnotify"
+)
+
+type InotifyTracker struct {
+	mux       sync.Mutex
+	watcher   *fsnotify.Watcher
+	chans     map[string]chan fsnotify.Event
+	done      map[string]chan bool
+	watchNums map[string]int
+	watch     chan *watchInfo
+	remove    chan *watchInfo
+	error     chan error
+}
+
+type watchInfo struct {
+	op    fsnotify.Op
+	fname string
+}
+
+func (this *watchInfo) isCreate() bool {
+	return this.op == fsnotify.Create
+}
+
+var (
+	// globally shared InotifyTracker; ensures only one fsnotify.Watcher is used
+	shared *InotifyTracker
+
+	// these are used to ensure the shared InotifyTracker is run exactly once
+	once  = sync.Once{}
+	goRun = func() {
+		shared = &InotifyTracker{
+			mux:       sync.Mutex{},
+			chans:     make(map[string]chan fsnotify.Event),
+			done:      make(map[string]chan bool),
+			watchNums: make(map[string]int),
+			watch:     make(chan *watchInfo),
+			remove:    make(chan *watchInfo),
+			error:     make(chan error),
+		}
+		go shared.run()
+	}
+
+	logger = log.New(os.Stderr, "", log.LstdFlags)
+)
+
+// Watch signals the run goroutine to begin watching the input filename
+func Watch(fname string) error {
+	return watch(&watchInfo{
+		fname: fname,
+	})
+}
+
+// Watch create signals the run goroutine to begin watching the input filename
+// if call the WatchCreate function, don't call the Cleanup, call the RemoveWatchCreate
+func WatchCreate(fname string) error {
+	return watch(&watchInfo{
+		op:    fsnotify.Create,
+		fname: fname,
+	})
+}
+
+func watch(winfo *watchInfo) error {
+	// start running the shared InotifyTracker if not already running
+	once.Do(goRun)
+
+	winfo.fname = filepath.Clean(winfo.fname)
+	shared.watch <- winfo
+	return <-shared.error
+}
+
+// RemoveWatch signals the run goroutine to remove the watch for the input filename
+func RemoveWatch(fname string) error {
+	return remove(&watchInfo{
+		fname: fname,
+	})
+}
+
+// RemoveWatch create signals the run goroutine to remove the watch for the input filename
+func RemoveWatchCreate(fname string) error {
+	return remove(&watchInfo{
+		op:    fsnotify.Create,
+		fname: fname,
+	})
+}
+
+func remove(winfo *watchInfo) error {
+	// start running the shared InotifyTracker if not already running
+	once.Do(goRun)
+
+	winfo.fname = filepath.Clean(winfo.fname)
+	shared.mux.Lock()
+	done := shared.done[winfo.fname]
+	if done != nil {
+		delete(shared.done, winfo.fname)
+		close(done)
+	}
+	shared.mux.Unlock()
+
+	shared.remove <- winfo
+	return <-shared.error
+}
+
+// Events returns a channel to which FileEvents corresponding to the input filename
+// will be sent. This channel will be closed when removeWatch is called on this
+// filename.
+func Events(fname string) <-chan fsnotify.Event {
+	shared.mux.Lock()
+	defer shared.mux.Unlock()
+
+	return shared.chans[fname]
+}
+
+// Cleanup removes the watch for the input filename if necessary.
+func Cleanup(fname string) error {
+	return RemoveWatch(fname)
+}
+
+// watchFlags calls fsnotify.WatchFlags for the input filename and flags, creating
+// a new Watcher if the previous Watcher was closed.
+func (shared *InotifyTracker) addWatch(winfo *watchInfo) error {
+	shared.mux.Lock()
+	defer shared.mux.Unlock()
+
+	if shared.chans[winfo.fname] == nil {
+		shared.chans[winfo.fname] = make(chan fsnotify.Event)
+	}
+	if shared.done[winfo.fname] == nil {
+		shared.done[winfo.fname] = make(chan bool)
+	}
+
+	fname := winfo.fname
+	if winfo.isCreate() {
+		// Watch for new files to be created in the parent directory.
+		fname = filepath.Dir(fname)
+	}
+
+	var err error
+	// already in inotify watch
+	if shared.watchNums[fname] == 0 {
+		err = shared.watcher.Add(fname)
+	}
+	if err == nil {
+		shared.watchNums[fname]++
+	}
+	return err
+}
+
+// removeWatch calls fsnotify.RemoveWatch for the input filename and closes the
+// corresponding events channel.
+func (shared *InotifyTracker) removeWatch(winfo *watchInfo) error {
+	shared.mux.Lock()
+
+	ch := shared.chans[winfo.fname]
+	if ch != nil {
+		delete(shared.chans, winfo.fname)
+		close(ch)
+	}
+
+	fname := winfo.fname
+	if winfo.isCreate() {
+		// Watch for new files to be created in the parent directory.
+		fname = filepath.Dir(fname)
+	}
+	shared.watchNums[fname]--
+	watchNum := shared.watchNums[fname]
+	if watchNum == 0 {
+		delete(shared.watchNums, fname)
+	}
+	shared.mux.Unlock()
+
+	var err error
+	// If we were the last ones to watch this file, unsubscribe from inotify.
+	// This needs to happen after releasing the lock because fsnotify waits
+	// synchronously for the kernel to acknowledge the removal of the watch
+	// for this file, which causes us to deadlock if we still held the lock.
+	if watchNum == 0 {
+		err = shared.watcher.Remove(fname)
+	}
+
+	return err
+}
+
+// sendEvent sends the input event to the appropriate Tail.
+func (shared *InotifyTracker) sendEvent(event fsnotify.Event) {
+	name := filepath.Clean(event.Name)
+
+	shared.mux.Lock()
+	ch := shared.chans[name]
+	done := shared.done[name]
+	shared.mux.Unlock()
+
+	if ch != nil && done != nil {
+		select {
+		case ch <- event:
+		case <-done:
+		}
+	}
+}
+
+// run starts the goroutine in which the shared struct reads events from its
+// Watcher's Event channel and sends the events to the appropriate Tail.
+func (shared *InotifyTracker) run() {
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		util.Fatal("failed to create Watcher")
+	}
+	shared.watcher = watcher
+
+	for {
+		select {
+		case winfo := <-shared.watch:
+			shared.error <- shared.addWatch(winfo)
+
+		case winfo := <-shared.remove:
+			shared.error <- shared.removeWatch(winfo)
+
+		case event, open := <-shared.watcher.Events:
+			if !open {
+				return
+			}
+			shared.sendEvent(event)
+
+		case err, open := <-shared.watcher.Errors:
+			if !open {
+				return
+			} else if err != nil {
+				sysErr, ok := err.(*os.SyscallError)
+				if !ok || sysErr.Err != syscall.EINTR {
+					logger.Printf("Error in Watcher Error channel: %s", err)
+				}
+			}
+		}
+	}
+}
diff --git a/vendor/github.com/nxadm/tail/watch/polling.go b/vendor/github.com/nxadm/tail/watch/polling.go
new file mode 100644
index 000000000..fb1706908
--- /dev/null
+++ b/vendor/github.com/nxadm/tail/watch/polling.go
@@ -0,0 +1,118 @@
+// Copyright (c) 2015 HPE Software Inc. All rights reserved.
+// Copyright (c) 2013 ActiveState Software Inc. All rights reserved.
+
+package watch
+
+import (
+	"os"
+	"runtime"
+	"time"
+
+	"github.com/nxadm/tail/util"
+	"gopkg.in/tomb.v1"
+)
+
+// PollingFileWatcher polls the file for changes.
+type PollingFileWatcher struct {
+	Filename string
+	Size     int64
+}
+
+func NewPollingFileWatcher(filename string) *PollingFileWatcher {
+	fw := &PollingFileWatcher{filename, 0}
+	return fw
+}
+
+var POLL_DURATION time.Duration
+
+func (fw *PollingFileWatcher) BlockUntilExists(t *tomb.Tomb) error {
+	for {
+		if _, err := os.Stat(fw.Filename); err == nil {
+			return nil
+		} else if !os.IsNotExist(err) {
+			return err
+		}
+		select {
+		case <-time.After(POLL_DURATION):
+			continue
+		case <-t.Dying():
+			return tomb.ErrDying
+		}
+	}
+	panic("unreachable")
+}
+
+func (fw *PollingFileWatcher) ChangeEvents(t *tomb.Tomb, pos int64) (*FileChanges, error) {
+	origFi, err := os.Stat(fw.Filename)
+	if err != nil {
+		return nil, err
+	}
+
+	changes := NewFileChanges()
+	var prevModTime time.Time
+
+	// XXX: use tomb.Tomb to cleanly manage these goroutines. replace
+	// the fatal (below) with tomb's Kill.
+
+	fw.Size = pos
+
+	go func() {
+		prevSize := fw.Size
+		for {
+			select {
+			case <-t.Dying():
+				return
+			default:
+			}
+
+			time.Sleep(POLL_DURATION)
+			fi, err := os.Stat(fw.Filename)
+			if err != nil {
+				// Windows cannot delete a file if a handle is still open (tail keeps one open)
+				// so it gives access denied to anything trying to read it until all handles are released.
+				if os.IsNotExist(err) || (runtime.GOOS == "windows" && os.IsPermission(err)) {
+					// File does not exist (has been deleted).
+					changes.NotifyDeleted()
+					return
+				}
+
+				// XXX: report this error back to the user
+				util.Fatal("Failed to stat file %v: %v", fw.Filename, err)
+			}
+
+			// File got moved/renamed?
+			if !os.SameFile(origFi, fi) {
+				changes.NotifyDeleted()
+				return
+			}
+
+			// File got truncated?
+			fw.Size = fi.Size()
+			if prevSize > 0 && prevSize > fw.Size {
+				changes.NotifyTruncated()
+				prevSize = fw.Size
+				continue
+			}
+			// File got bigger?
+			if prevSize > 0 && prevSize < fw.Size {
+				changes.NotifyModified()
+				prevSize = fw.Size
+				continue
+			}
+			prevSize = fw.Size
+
+			// File was appended to (changed)?
+			modTime := fi.ModTime()
+			if modTime != prevModTime {
+				prevModTime = modTime
+				changes.NotifyModified()
+			}
+		}
+	}()
+
+	return changes, nil
+}
+
+func init() {
+	POLL_DURATION = 250 * time.Millisecond
+}
diff --git a/vendor/github.com/nxadm/tail/watch/watch.go b/vendor/github.com/nxadm/tail/watch/watch.go
new file mode 100644
index 000000000..2e1783ef0
--- /dev/null
+++ b/vendor/github.com/nxadm/tail/watch/watch.go
@@ -0,0 +1,20 @@
+// Copyright (c) 2015 HPE Software Inc. All rights reserved.
+// Copyright (c) 2013 ActiveState Software Inc. All rights reserved.
+
+package watch
+
+import "gopkg.in/tomb.v1"
+
+// FileWatcher monitors file-level events.
+type FileWatcher interface {
+	// BlockUntilExists blocks until the file comes into existence.
+	BlockUntilExists(*tomb.Tomb) error
+
+	// ChangeEvents reports on changes to a file, be it modification,
+	// deletion, renames or truncations. Returned FileChanges group of
+	// channels will be closed, thus become unusable, after a deletion
+	// or truncation event.
+	// In order to properly report truncations, ChangeEvents requires
+	// the caller to pass their current offset in the file.
+	ChangeEvents(*tomb.Tomb, int64) (*FileChanges, error)
+}