tail

README

definitions: tracker - the tracker keeps track of files being tailed via a single fsnotify watcher. Primary Workflow:

1. initialize tracker
2. add path(s)
3. watch for fsnotify events
4. exit when context is cancelled.

Directory Path Workflow:

1. add path to watcher

file path workflow:

1. add path to watcher
2. initialize tailer struct
3. start tailer

event workflow:

• if event is create, add new file path.
• if event is write, stop waiting
• if event is delete, stop associated tailer (if it was file)

tail workflow:

• read all lines from saved position
• if eof, wait for changes

Documentation

Index

• Variables
• type LineProcessor
• type PathInfo
  • func NewInfo(path, dataDir string, processor LineProcessor) (*PathInfo, error)
  • func (p *PathInfo) Done()
  • func (p *PathInfo) ReadLines() ([]string, error)
  • func (p *PathInfo) ReadUntilEOF()
  • func (p *PathInfo) Run()
• type TailTracker
  • func NewTracker(dataDir string) (*TailTracker, error)
  • func (t *TailTracker) AddFromParent(parent, name string) (*PathInfo, error)
  • func (t *TailTracker) AddPath(path string, processor LineProcessor) (*PathInfo, error)
  • func (t *TailTracker) Run(ctx context.Context) error

Variables

var (
	ErrChanClosedEmpty = errors.New("channel is closed or empty")
)

Types

type LineProcessor

type LineProcessor = func(string, string) error

type Config struct{}

type PathInfo

type PathInfo struct {
	Events chan fsnotify.Event
	// contains filtered or unexported fields
}

func NewInfo

func NewInfo(path, dataDir string, processor LineProcessor) (*PathInfo, error)

func (*PathInfo) Done

func (p *PathInfo) Done()

func (*PathInfo) ReadLines

func (p *PathInfo) ReadLines() ([]string, error)

TODO - batch reads

func (*PathInfo) ReadUntilEOF

func (p *PathInfo) ReadUntilEOF()

func (*PathInfo) Run

func (p *PathInfo) Run()

type TailTracker

type TailTracker struct {
	// contains filtered or unexported fields
}

func NewTracker

func NewTracker(dataDir string) (*TailTracker, error)

func (*TailTracker) AddFromParent

func (t *TailTracker) AddFromParent(parent, name string) (*PathInfo, error)

func (*TailTracker) AddPath

func (t *TailTracker) AddPath(path string, processor LineProcessor) (*PathInfo, error)

AddPath adds the given path to the set of watched paths. If the path is a directory, files included in that directory will be added to the watcher as they are updated/created.

func (*TailTracker) Run

func (t *TailTracker) Run(ctx context.Context) error