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author | OpenShift Merge Robot <openshift-merge-robot@users.noreply.github.com> | 2020-05-21 15:32:07 +0200 |
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committer | GitHub <noreply@github.com> | 2020-05-21 15:32:07 +0200 |
commit | a594de2cf457a1a5e5fecd8329853e9ec19c5582 (patch) | |
tree | b0e6f8f6cad5468b930d03491f1516ff1680b581 /vendor/github.com/nxadm/tail/watch/polling.go | |
parent | 72e880351a88ae54b69046ab14a9a4a52c51c78b (diff) | |
parent | cdd1f2bbaf99f5fae8f5c08a25bccdf478cd9ada (diff) | |
download | podman-a594de2cf457a1a5e5fecd8329853e9ec19c5582.tar.gz podman-a594de2cf457a1a5e5fecd8329853e9ec19c5582.tar.bz2 podman-a594de2cf457a1a5e5fecd8329853e9ec19c5582.zip |
Merge pull request #6317 from containers/dependabot/go_modules/github.com/onsi/gomega-1.10.1
Bump github.com/onsi/gomega from 1.10.0 to 1.10.1
Diffstat (limited to 'vendor/github.com/nxadm/tail/watch/polling.go')
-rw-r--r-- | vendor/github.com/nxadm/tail/watch/polling.go | 118 |
1 files changed, 118 insertions, 0 deletions
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 +} |