harness-drone/vendor/github.com/cncd/queue/queue.go
2017-03-05 18:56:08 +11:00

110 lines
2.9 KiB
Go

package queue
import (
"context"
"errors"
)
var (
// ErrCancel indicates the task was cancelled.
ErrCancel = errors.New("queue: task cancelled")
// ErrNotFound indicates the task was not found in the queue.
ErrNotFound = errors.New("queue: task not found")
)
// Task defines a unit of work in the queue.
type Task struct {
// ID identifies this task.
ID string `json:"id,omitempty"`
// Data is the actual data in the entry.
Data []byte `json:"data"`
// Labels represents the key-value pairs the entry is lebeled with.
Labels map[string]string `json:"labels,omitempty"`
}
// InfoT provides runtime information.
type InfoT struct {
Pending []*Task `json:"pending"`
Running []*Task `json:"running"`
Stats struct {
Workers int `json:"worker_count"`
Pending int `json:"pending_count"`
Running int `json:"running_count"`
Complete int `json:"completed_count"`
} `json:"stats"`
}
// Filter filters tasks in the queue. If the Filter returns false,
// the Task is skipped and not returned to the subscriber.
type Filter func(*Task) bool
// Queue defines a task queue for scheduling tasks among
// a pool of workers.
type Queue interface {
// Push pushes an task to the tail of this queue.
Push(c context.Context, task *Task) error
// Poll retrieves and removes a task head of this queue.
Poll(c context.Context, f Filter) (*Task, error)
// Extend extends the deadline for a task.
Extend(c context.Context, id string) error
// Done signals the task is complete.
Done(c context.Context, id string) error
// Error signals the task is complete with errors.
Error(c context.Context, id string, err error) error
// Wait waits until the task is complete.
Wait(c context.Context, id string) error
// Info returns internal queue information.
Info(c context.Context) InfoT
}
// // global instance of the queue.
// var global = New()
//
// // Set sets the global queue.
// func Set(queue Queue) {
// global = queue
// }
//
// // Push pushes an task to the tail of the global queue.
// func Push(c context.Context, task *Task) error {
// return global.Push(c, task)
// }
//
// // Poll retrieves and removes a task head of the global queue.
// func Poll(c context.Context, f Filter) (*Task, error) {
// return global.Poll(c, f)
// }
//
// // Extend extends the deadline for a task.
// func Extend(c context.Context, id string) error {
// return global.Extend(c, id)
// }
//
// // Done signals the task is complete.
// func Done(c context.Context, id string) error {
// return global.Done(c, id)
// }
//
// // Error signals the task is complete with errors.
// func Error(c context.Context, id string, err error) {
// global.Error(c, id, err)
// }
//
// // Wait waits until the task is complete.
// func Wait(c context.Context, id string) error {
// return global.Wait(c, id)
// }
//
// // Info returns internal queue information.
// func Info(c context.Context) InfoT {
// return global.Info(c)
// }