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authordependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>2020-05-21 09:08:47 +0000
committerDaniel J Walsh <dwalsh@redhat.com>2020-05-21 07:35:42 -0400
commitcdd1f2bbaf99f5fae8f5c08a25bccdf478cd9ada (patch)
treedb1c0b9dfc258c40779d38875e71240f93544d22 /vendor/github.com/nxadm/tail/tail.go
parent8db7b9ea219ef06c50919dcfabdfdca5676e1456 (diff)
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Bump github.com/onsi/gomega from 1.10.0 to 1.10.1
Bumps [github.com/onsi/gomega](https://github.com/onsi/gomega) from 1.10.0 to 1.10.1. - [Release notes](https://github.com/onsi/gomega/releases) - [Changelog](https://github.com/onsi/gomega/blob/master/CHANGELOG.md) - [Commits](https://github.com/onsi/gomega/compare/v1.10.0...v1.10.1) Signed-off-by: dependabot-preview[bot] <support@dependabot.com> Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Diffstat (limited to 'vendor/github.com/nxadm/tail/tail.go')
-rw-r--r--vendor/github.com/nxadm/tail/tail.go440
1 files changed, 440 insertions, 0 deletions
diff --git a/vendor/github.com/nxadm/tail/tail.go b/vendor/github.com/nxadm/tail/tail.go
new file mode 100644
index 000000000..58d3c4b95
--- /dev/null
+++ b/vendor/github.com/nxadm/tail/tail.go
@@ -0,0 +1,440 @@
+// Copyright (c) 2015 HPE Software Inc. All rights reserved.
+// Copyright (c) 2013 ActiveState Software Inc. All rights reserved.
+
+package tail
+
+import (
+ "bufio"
+ "errors"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "log"
+ "os"
+ "strings"
+ "sync"
+ "time"
+
+ "github.com/nxadm/tail/ratelimiter"
+ "github.com/nxadm/tail/util"
+ "github.com/nxadm/tail/watch"
+ "gopkg.in/tomb.v1"
+)
+
+var (
+ ErrStop = errors.New("tail should now stop")
+)
+
+type Line struct {
+ Text string
+ Num int
+ SeekInfo SeekInfo
+ Time time.Time
+ Err error // Error from tail
+}
+
+// NewLine returns a Line with present time.
+func NewLine(text string, lineNum int) *Line {
+ return &Line{text, lineNum, SeekInfo{}, time.Now(), nil}
+}
+
+// SeekInfo represents arguments to `io.Seek`
+type SeekInfo struct {
+ Offset int64
+ Whence int // io.Seek*
+}
+
+type logger interface {
+ Fatal(v ...interface{})
+ Fatalf(format string, v ...interface{})
+ Fatalln(v ...interface{})
+ Panic(v ...interface{})
+ Panicf(format string, v ...interface{})
+ Panicln(v ...interface{})
+ Print(v ...interface{})
+ Printf(format string, v ...interface{})
+ Println(v ...interface{})
+}
+
+// Config is used to specify how a file must be tailed.
+type Config struct {
+ // File-specifc
+ Location *SeekInfo // Seek to this location before tailing
+ ReOpen bool // Reopen recreated files (tail -F)
+ MustExist bool // Fail early if the file does not exist
+ Poll bool // Poll for file changes instead of using inotify
+ Pipe bool // Is a named pipe (mkfifo)
+ RateLimiter *ratelimiter.LeakyBucket
+
+ // Generic IO
+ Follow bool // Continue looking for new lines (tail -f)
+ MaxLineSize int // If non-zero, split longer lines into multiple lines
+
+ // Logger, when nil, is set to tail.DefaultLogger
+ // To disable logging: set field to tail.DiscardingLogger
+ Logger logger
+}
+
+type Tail struct {
+ Filename string
+ Lines chan *Line
+ Config
+
+ file *os.File
+ reader *bufio.Reader
+ lineNum int
+
+ watcher watch.FileWatcher
+ changes *watch.FileChanges
+
+ tomb.Tomb // provides: Done, Kill, Dying
+
+ lk sync.Mutex
+}
+
+var (
+ // DefaultLogger is used when Config.Logger == nil
+ DefaultLogger = log.New(os.Stderr, "", log.LstdFlags)
+ // DiscardingLogger can be used to disable logging output
+ DiscardingLogger = log.New(ioutil.Discard, "", 0)
+)
+
+// TailFile begins tailing the file. Output stream is made available
+// via the `Tail.Lines` channel. To handle errors during tailing,
+// invoke the `Wait` or `Err` method after finishing reading from the
+// `Lines` channel.
+func TailFile(filename string, config Config) (*Tail, error) {
+ if config.ReOpen && !config.Follow {
+ util.Fatal("cannot set ReOpen without Follow.")
+ }
+
+ t := &Tail{
+ Filename: filename,
+ Lines: make(chan *Line),
+ Config: config,
+ }
+
+ // when Logger was not specified in config, use default logger
+ if t.Logger == nil {
+ t.Logger = DefaultLogger
+ }
+
+ if t.Poll {
+ t.watcher = watch.NewPollingFileWatcher(filename)
+ } else {
+ t.watcher = watch.NewInotifyFileWatcher(filename)
+ }
+
+ if t.MustExist {
+ var err error
+ t.file, err = OpenFile(t.Filename)
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ go t.tailFileSync()
+
+ return t, nil
+}
+
+// Tell returns the file's current position, like stdio's ftell().
+// But this value is not very accurate.
+// One line from the chan(tail.Lines) may have been read,
+// so it may have lost one line.
+func (tail *Tail) Tell() (offset int64, err error) {
+ if tail.file == nil {
+ return
+ }
+ offset, err = tail.file.Seek(0, io.SeekCurrent)
+ if err != nil {
+ return
+ }
+
+ tail.lk.Lock()
+ defer tail.lk.Unlock()
+ if tail.reader == nil {
+ return
+ }
+
+ offset -= int64(tail.reader.Buffered())
+ return
+}
+
+// Stop stops the tailing activity.
+func (tail *Tail) Stop() error {
+ tail.Kill(nil)
+ return tail.Wait()
+}
+
+// StopAtEOF stops tailing as soon as the end of the file is reached.
+func (tail *Tail) StopAtEOF() error {
+ tail.Kill(errStopAtEOF)
+ return tail.Wait()
+}
+
+var errStopAtEOF = errors.New("tail: stop at eof")
+
+func (tail *Tail) close() {
+ close(tail.Lines)
+ tail.closeFile()
+}
+
+func (tail *Tail) closeFile() {
+ if tail.file != nil {
+ tail.file.Close()
+ tail.file = nil
+ }
+}
+
+func (tail *Tail) reopen() error {
+ tail.closeFile()
+ tail.lineNum = 0
+ for {
+ var err error
+ tail.file, err = OpenFile(tail.Filename)
+ if err != nil {
+ if os.IsNotExist(err) {
+ tail.Logger.Printf("Waiting for %s to appear...", tail.Filename)
+ if err := tail.watcher.BlockUntilExists(&tail.Tomb); err != nil {
+ if err == tomb.ErrDying {
+ return err
+ }
+ return fmt.Errorf("Failed to detect creation of %s: %s", tail.Filename, err)
+ }
+ continue
+ }
+ return fmt.Errorf("Unable to open file %s: %s", tail.Filename, err)
+ }
+ break
+ }
+ return nil
+}
+
+func (tail *Tail) readLine() (string, error) {
+ tail.lk.Lock()
+ line, err := tail.reader.ReadString('\n')
+ tail.lk.Unlock()
+ if err != nil {
+ // Note ReadString "returns the data read before the error" in
+ // case of an error, including EOF, so we return it as is. The
+ // caller is expected to process it if err is EOF.
+ return line, err
+ }
+
+ line = strings.TrimRight(line, "\n")
+
+ return line, err
+}
+
+func (tail *Tail) tailFileSync() {
+ defer tail.Done()
+ defer tail.close()
+
+ if !tail.MustExist {
+ // deferred first open.
+ err := tail.reopen()
+ if err != nil {
+ if err != tomb.ErrDying {
+ tail.Kill(err)
+ }
+ return
+ }
+ }
+
+ // Seek to requested location on first open of the file.
+ if tail.Location != nil {
+ _, err := tail.file.Seek(tail.Location.Offset, tail.Location.Whence)
+ if err != nil {
+ tail.Killf("Seek error on %s: %s", tail.Filename, err)
+ return
+ }
+ }
+
+ tail.openReader()
+
+ // Read line by line.
+ for {
+ // do not seek in named pipes
+ if !tail.Pipe {
+ // grab the position in case we need to back up in the event of a half-line
+ if _, err := tail.Tell(); err != nil {
+ tail.Kill(err)
+ return
+ }
+ }
+
+ line, err := tail.readLine()
+
+ // Process `line` even if err is EOF.
+ if err == nil {
+ cooloff := !tail.sendLine(line)
+ if cooloff {
+ // Wait a second before seeking till the end of
+ // file when rate limit is reached.
+ msg := ("Too much log activity; waiting a second before resuming tailing")
+ offset, _ := tail.Tell()
+ tail.Lines <- &Line{msg, tail.lineNum, SeekInfo{Offset: offset}, time.Now(), errors.New(msg)}
+ select {
+ case <-time.After(time.Second):
+ case <-tail.Dying():
+ return
+ }
+ if err := tail.seekEnd(); err != nil {
+ tail.Kill(err)
+ return
+ }
+ }
+ } else if err == io.EOF {
+ if !tail.Follow {
+ if line != "" {
+ tail.sendLine(line)
+ }
+ return
+ }
+
+ if tail.Follow && line != "" {
+ tail.sendLine(line)
+ if err := tail.seekEnd(); err != nil {
+ tail.Kill(err)
+ return
+ }
+ }
+
+ // When EOF is reached, wait for more data to become
+ // available. Wait strategy is based on the `tail.watcher`
+ // implementation (inotify or polling).
+ err := tail.waitForChanges()
+ if err != nil {
+ if err != ErrStop {
+ tail.Kill(err)
+ }
+ return
+ }
+ } else {
+ // non-EOF error
+ tail.Killf("Error reading %s: %s", tail.Filename, err)
+ return
+ }
+
+ select {
+ case <-tail.Dying():
+ if tail.Err() == errStopAtEOF {
+ continue
+ }
+ return
+ default:
+ }
+ }
+}
+
+// waitForChanges waits until the file has been appended, deleted,
+// moved or truncated. When moved or deleted - the file will be
+// reopened if ReOpen is true. Truncated files are always reopened.
+func (tail *Tail) waitForChanges() error {
+ if tail.changes == nil {
+ pos, err := tail.file.Seek(0, io.SeekCurrent)
+ if err != nil {
+ return err
+ }
+ tail.changes, err = tail.watcher.ChangeEvents(&tail.Tomb, pos)
+ if err != nil {
+ return err
+ }
+ }
+
+ select {
+ case <-tail.changes.Modified:
+ return nil
+ case <-tail.changes.Deleted:
+ tail.changes = nil
+ if tail.ReOpen {
+ // XXX: we must not log from a library.
+ tail.Logger.Printf("Re-opening moved/deleted file %s ...", tail.Filename)
+ if err := tail.reopen(); err != nil {
+ return err
+ }
+ tail.Logger.Printf("Successfully reopened %s", tail.Filename)
+ tail.openReader()
+ return nil
+ }
+ tail.Logger.Printf("Stopping tail as file no longer exists: %s", tail.Filename)
+ return ErrStop
+ case <-tail.changes.Truncated:
+ // Always reopen truncated files (Follow is true)
+ tail.Logger.Printf("Re-opening truncated file %s ...", tail.Filename)
+ if err := tail.reopen(); err != nil {
+ return err
+ }
+ tail.Logger.Printf("Successfully reopened truncated %s", tail.Filename)
+ tail.openReader()
+ return nil
+ case <-tail.Dying():
+ return ErrStop
+ }
+}
+
+func (tail *Tail) openReader() {
+ tail.lk.Lock()
+ if tail.MaxLineSize > 0 {
+ // add 2 to account for newline characters
+ tail.reader = bufio.NewReaderSize(tail.file, tail.MaxLineSize+2)
+ } else {
+ tail.reader = bufio.NewReader(tail.file)
+ }
+ tail.lk.Unlock()
+}
+
+func (tail *Tail) seekEnd() error {
+ return tail.seekTo(SeekInfo{Offset: 0, Whence: io.SeekEnd})
+}
+
+func (tail *Tail) seekTo(pos SeekInfo) error {
+ _, err := tail.file.Seek(pos.Offset, pos.Whence)
+ if err != nil {
+ return fmt.Errorf("Seek error on %s: %s", tail.Filename, err)
+ }
+ // Reset the read buffer whenever the file is re-seek'ed
+ tail.reader.Reset(tail.file)
+ return nil
+}
+
+// sendLine sends the line(s) to Lines channel, splitting longer lines
+// if necessary. Return false if rate limit is reached.
+func (tail *Tail) sendLine(line string) bool {
+ now := time.Now()
+ lines := []string{line}
+
+ // Split longer lines
+ if tail.MaxLineSize > 0 && len(line) > tail.MaxLineSize {
+ lines = util.PartitionString(line, tail.MaxLineSize)
+ }
+
+ for _, line := range lines {
+ tail.lineNum++
+ offset, _ := tail.Tell()
+ select {
+ case tail.Lines <- &Line{line, tail.lineNum, SeekInfo{Offset: offset}, now, nil}:
+ case <-tail.Dying():
+ return true
+ }
+ }
+
+ if tail.Config.RateLimiter != nil {
+ ok := tail.Config.RateLimiter.Pour(uint16(len(lines)))
+ if !ok {
+ tail.Logger.Printf("Leaky bucket full (%v); entering 1s cooloff period.",
+ tail.Filename)
+ return false
+ }
+ }
+
+ return true
+}
+
+// Cleanup removes inotify watches added by the tail package. This function is
+// meant to be invoked from a process's exit handler. Linux kernel may not
+// automatically remove inotify watches after the process exits.
+func (tail *Tail) Cleanup() {
+ watch.Cleanup(tail.Filename)
+}