task

Documentation

Overview

Package task contains a default implementation of the interfaces in the task package.

Index

• type CancelFlag
• type ChanneledCancelFlag
  • func NewChanneledCancelFlag() *ChanneledCancelFlag
  • func (t *ChanneledCancelFlag) Canceled() bool
  • func (t *ChanneledCancelFlag) Set(state State)
  • func (t *ChanneledCancelFlag) ShutDown() bool
  • func (t *ChanneledCancelFlag) State() State
  • func (t *ChanneledCancelFlag) Wait() (state State)
• type Job
• type JobStore
  • func NewJobStore() *JobStore
  • func (t *JobStore) AddJob(jobID string, token *JobToken) error
  • func (t *JobStore) DeleteAllJobs() map[string]*JobToken
  • func (t *JobStore) DeleteJob(jobID string)
  • func (t *JobStore) GetJob(jobID string) (token *JobToken, found bool)
• type JobToken
• type MockCancelFlag
  • func NewMockDefault() *MockCancelFlag
  • func (flag *MockCancelFlag) Canceled() bool
  • func (flag *MockCancelFlag) Set(state State)
  • func (flag *MockCancelFlag) ShutDown() bool
  • func (flag *MockCancelFlag) State() State
  • func (flag *MockCancelFlag) Wait() (state State)
• type MockedPool
  • func (mockPool *MockedPool) Cancel(jobID string) bool
  • func (mockPool *MockedPool) HasJob(jobID string) bool
  • func (mockPool *MockedPool) Shutdown()
  • func (mockPool *MockedPool) ShutdownAndWait(timeout time.Duration) (finished bool)
  • func (mockPool *MockedPool) Submit(log log.T, jobID string, job Job) error
• type Pool
  • func NewPool(log log.T, maxParallel int, cancelWaitDuration time.Duration, ...) Pool
• type State

Types

type CancelFlag

type CancelFlag interface {
	// Canceled returns true if a cancel or Shutdown has been requested, false otherwise.
	// This method should be called periodically in the job.
	Canceled() bool

	// Set sets the state of this flag and wakes up waiting callers.
	Set(state State)

	// ShutDown returns true if a ShutDown has been requested, false otherwise.
	// This method should be called periodically in the job.
	ShutDown() bool

	// State returns the current flag state
	State() State

	// Wait blocks the caller until either a cancel has been requested or the
	// task has completed normally. Returns Canceled if cancel has been requested,
	// or Completed if the task completed normally.
	// This is intended to be used to wake up a job that may be waiting on some resources, as follows:
	// The main job starts a go routine that calls Wait. The main job then does its processing.
	// During processing the job may be waiting on certain events/conditions.
	// In the go routine, once Wait returns, if the return value indicates that a cancel
	// request has been received, the go routine wakes up the running job.
	Wait() (state State)
}

CancelFlag is an object that is passed to any job submitted to a task in order to communicated job cancellation. Job cancellation has to be cooperative.

type ChanneledCancelFlag

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

ChanneledCancelFlag is a default implementation of the task.CancelFlag interface.

func NewChanneledCancelFlag

func NewChanneledCancelFlag() *ChanneledCancelFlag

NewChanneledCancelFlag creates a new instance of ChanneledCancelFlag.

func (*ChanneledCancelFlag) Canceled

func (t *ChanneledCancelFlag) Canceled() bool

Canceled returns true if this flag has been set to Cancel state, false otherwise.

func (*ChanneledCancelFlag) Set

func (t *ChanneledCancelFlag) Set(state State)

Set sets the state of this flag and wakes up waiting callers.

func (*ChanneledCancelFlag) ShutDown

func (t *ChanneledCancelFlag) ShutDown() bool

ShutDown returns true if this flag has been set to ShutDown state, false otherwise.

func (*ChanneledCancelFlag) State

func (t *ChanneledCancelFlag) State() State

State returns the current flag state.

func (*ChanneledCancelFlag) Wait

func (t *ChanneledCancelFlag) Wait() (state State)

Wait blocks until the flag is set to either Cancel or Completed state. Returns the state.

type Job

type Job func(CancelFlag)

Job is a function that receives a cancel flag through which it can be canceled.

type JobStore

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

JobStore is a collection of jobs.

func NewJobStore

func NewJobStore() *JobStore

NewJobStore creates a new task with no jobs.

func (*JobStore) AddJob

func (t *JobStore) AddJob(jobID string, token *JobToken) error

AddJob adds a job to this task. Returns error if the job already exists.

func (*JobStore) DeleteAllJobs

func (t *JobStore) DeleteAllJobs() map[string]*JobToken

DeleteAllJobs deletes all the jobs of this task. Returns the deleted jobs.

func (*JobStore) DeleteJob

func (t *JobStore) DeleteJob(jobID string)

DeleteJob deletes the job with the given jobID.

func (*JobStore) GetJob

func (t *JobStore) GetJob(jobID string) (token *JobToken, found bool)

GetJob retrieves a job from a task.

type JobToken

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

JobToken embeds a job and its associated info

type MockCancelFlag

type MockCancelFlag struct {
	mock.Mock
}

MockCancelFlag mocks a cancel flag.

func NewMockDefault

func NewMockDefault() *MockCancelFlag

NewMockDefault returns a mocked cancel flag.

func (*MockCancelFlag) Canceled

func (flag *MockCancelFlag) Canceled() bool

Canceled mocks the method with the same name.

func (*MockCancelFlag) Set

func (flag *MockCancelFlag) Set(state State)

func (*MockCancelFlag) ShutDown

func (flag *MockCancelFlag) ShutDown() bool

ShutDown mocks the method with the same name.

func (*MockCancelFlag) State

func (flag *MockCancelFlag) State() State

func (*MockCancelFlag) Wait

func (flag *MockCancelFlag) Wait() (state State)

Wait mocks the method with the same name.

type MockedPool

type MockedPool struct {
	mock.Mock
}

MockedPool stands for a mock pool.

func (*MockedPool) Cancel

func (mockPool *MockedPool) Cancel(jobID string) bool

Cancel mocks the method with the same name.

func (*MockedPool) HasJob

func (mockPool *MockedPool) HasJob(jobID string) bool

ShutdownAndWait mocks the method with the same name.

func (*MockedPool) Shutdown

func (mockPool *MockedPool) Shutdown()

Shutdown mocks the method with the same name.

func (*MockedPool) ShutdownAndWait

func (mockPool *MockedPool) ShutdownAndWait(timeout time.Duration) (finished bool)

ShutdownAndWait mocks the method with the same name.

func (*MockedPool) Submit

func (mockPool *MockedPool) Submit(log log.T, jobID string, job Job) error

Submit mocks the method with the same name.

type Pool

type Pool interface {
	// Submit schedules a job to be executed in the associated worker pool.
	// Returns an error if a job with the same name already exists.
	Submit(log log.T, jobID string, job Job) error

	// Cancel cancels the given job. Jobs that have not started yet will never be started.
	// Jobs that are running will have their CancelFlag set to the Canceled state.
	// It is the responsibility of the job to terminate within a reasonable time.
	// If the job fails to terminate after a Cancel, the job may be abandoned.
	// Returns true if the job has been found and canceled, false if the job was not found.
	Cancel(jobID string) bool

	// Shutdown cancels all the jobs and shuts down the workers.
	Shutdown()

	// ShutdownAndWait calls Shutdown then waits until all the workers have exited
	// or until the timeout has elapsed, whichever comes first. Returns true if all
	// workers terminated before the timeout or false if the timeout expired.
	ShutdownAndWait(timeout time.Duration) (finished bool)

	// HasJob returns if jobStore has specified job
	HasJob(jobID string) bool
}

Pool is a pool of jobs.

func NewPool

func NewPool(log log.T, maxParallel int, cancelWaitDuration time.Duration, clock times.Clock) Pool

NewPool creates a new task pool and launches maxParallel workers. The cancelWaitDuration parameter defines how long to wait for a job to complete a cancellation request.

type State

type State int

State represents the state of a job.

const (
	// Canceled indicates a job for which cancellation has been requested.
	Canceled State = 1

	// Completed indicates a completed job.
	Completed State = 2

	// ShutDown indicates a job for which ShutDown has been requested.
	ShutDown State = 3
)