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package queue

import ""

Package queue provides Vault plugins with a Priority Queue. It can be used as an in-memory list of queue.Item sorted by their priority, and offers methods to find or remove items by their key. Internally it uses container/heap; see Example Priority Queue:


Package Files



var ErrDuplicateItem = errors.New("duplicate item")

ErrDuplicateItem is returned when the queue attmepts to push an item to a key that already exists. The queue does not attempt to update, instead returns this error. If an Item needs to be updated or replaced, pop the item first.

var ErrEmpty = errors.New("queue is empty")

ErrEmpty is returned for queues with no items

type Item Uses

type Item struct {
    // Key is a unique string used to identify items in the internal data map
    Key string
    // Value is an unspecified type that implementations can use to store
    // information
    Value interface{}

    // Priority determines ordering in the queue, with the lowest value being the
    // highest priority
    Priority int64
    // contains filtered or unexported fields

Item is something managed in the priority queue

type PriorityQueue Uses

type PriorityQueue struct {
    // contains filtered or unexported fields

PriorityQueue facilitates queue of Items, providing Push, Pop, and PopByKey convenience methods. The ordering (priority) is an int64 value with the smallest value is the highest priority. PriorityQueue maintains both an internal slice for the queue as well as a map of the same items with their keys as the index. This enables users to find specific items by key. The map must be kept in sync with the data slice. See

func New Uses

func New() *PriorityQueue

New initializes the internal data structures and returns a new PriorityQueue

func (*PriorityQueue) Len Uses

func (pq *PriorityQueue) Len() int

Len returns the count of items in the Priority Queue

func (*PriorityQueue) Pop Uses

func (pq *PriorityQueue) Pop() (*Item, error)

Pop pops the highest priority item from the queue. This is a wrapper/convenience method that calls heap.Pop, so consumers do not need to invoke heap functions directly

func (*PriorityQueue) PopByKey Uses

func (pq *PriorityQueue) PopByKey(key string) (*Item, error)

PopByKey searches the queue for an item with the given key and removes it from the queue if found. Returns nil if not found. This method must fix the queue after removing any key.

func (*PriorityQueue) Push Uses

func (pq *PriorityQueue) Push(i *Item) error

Push pushes an item on to the queue. This is a wrapper/convenience method that calls heap.Push, so consumers do not need to invoke heap functions directly. Items must have unique Keys, and Items in the queue cannot be updated. To modify an Item, users must first remove it and re-push it after modifications

Package queue imports 4 packages (graph) and is imported by 4 packages. Updated 2019-07-26. Refresh now. Tools for package owners.