queue

README

queue

This is a FIFO queue for Go based on container/list.

Features

• first in first out -- of course ;)
• goroutine safe
• both: blocking and non-blocking reading
• Close to release blocking
• all data is still read on Close

Benchmarks

BenchmarkQueue_Push-12                	10000000	       122 ns/op	      48 B/op	       1 allocs/op
BenchmarkQueue_Pop-12                 	30000000	      42.3 ns/op	       0 B/op	       0 allocs/op
BenchmarkQueue_PopBlocking-12         	30000000	      42.8 ns/op	       0 B/op	       0 allocs/op
BenchmarkQueue_Push_PopBlocking-12    	10000000	       129 ns/op	      48 B/op	       1 allocs/op

Documentation

Index

• type Queue
  • func NewQueue() *Queue
  • func (s *Queue) Clear()
  • func (s *Queue) Close() error
  • func (s *Queue) Has(check func(elem interface{}) bool) bool
  • func (s *Queue) Len() int
  • func (s *Queue) Next() bool
  • func (s *Queue) Pop() (interface{}, bool)
  • func (s *Queue) PopBlocking() (interface{}, bool)
  • func (s *Queue) Push(n interface{}) error
  • func (s *Queue) PushUnique(n interface{}, existFunc func(elem interface{}) bool) (bool, error)
  • func (s *Queue) Wait()

Types

type Queue

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

Queue is a basic FIFO queue.

func NewQueue

func NewQueue() *Queue

NewQueue returns a new FIFO queue.

func (*Queue) Clear

func (s *Queue) Clear()

Clear empties the buffer

func (*Queue) Close

func (s *Queue) Close() error

Close closes the queue. Use this to release all PopBlocking calls. The queue will be emptied before PopBlocking returns false.

func (*Queue) Has

func (s *Queue) Has(check func(elem interface{}) bool) bool

Has checks if an item in the list exists according to the given check function. This is not blocking. When it is done the element you are looking for could have been added.

func (*Queue) Len

func (s *Queue) Len() int

Len reports the current length of the queue.

func (*Queue) Next

func (s *Queue) Next() bool

Next blocks until an element is available or the queue is closed. Reports false if the queue has been emptied and is closed. Beware that if multiple goroutines read from the queue, Pop can return false after Next was true.

func (*Queue) Pop

func (s *Queue) Pop() (interface{}, bool)

Pop removes and returns a node from the queue. The bool value is false if the queue was empty.

func (*Queue) PopBlocking

func (s *Queue) PopBlocking() (interface{}, bool)

PopBlocking removes and returns a node from the queue. It blocks until an element is available or the queue is closed. The bool value is false if the queue has been emptied and was closed.

func (*Queue) Push

func (s *Queue) Push(n interface{}) error

Push adds a node to the queue. Will fail if the queue has been closed.

func (*Queue) PushUnique

func (s *Queue) PushUnique(n interface{}, existFunc func(elem interface{}) bool) (bool, error)

PushUnique adds a node to the queue if it does not exist already. The existence is checked with existFunc. Will fail if the queue has been closed.

func (*Queue) Wait

func (s *Queue) Wait()

Wait blocks if the queue is empty until an item is added or the queue is closed.