job.go

package core

import (
	"fmt"
	"github.com/pkg/errors"
	"io"
	"log"
	"sync"
)

type Job struct {
	// Function to call on Collect. This is the function
	// that will (1) update the state of this job, (2)
	// do the actual importing, (3) write to the Job-internal
	// log and eventually (4) finish either with success
	// or in failure.
	collectfunc func(self *Job, c *Collector) error

	// Waiting room for people to wait on completion of this
	// job.
	wr waitingroom

	// Global lock for all following members.
	mu sync.Mutex

	// Unique identifier of this job.
	id JobId

	// The state the job is currently in.
	state JobState

	// When state is set to Failed, contains the reason
	// for this failure.
	failure error

	// Recorded logs for this job.
	logged concurrentbuffer
}

// Return the unique identifier of this job.
func (bj *Job) Id() JobId {
	bj.mu.Lock()
	defer bj.mu.Unlock()

	return bj.id
}

// Return the current state of this job.
func (bj *Job) State() JobState {
	bj.mu.Lock()
	defer bj.mu.Unlock()

	return bj.state
}

// When State is Failed, return the error that caused
// the failure. When State is not failed, this method
// always returns nil.
func (bj *Job) Error() error {
	bj.mu.Lock()
	defer bj.mu.Unlock()

	return bj.failure
}

// This is a synchronous operation that might take a long
// time. Instead of invoking Collect directly, you should
// create a Collector and Submit this job to it.
func (bj *Job) Collect(c *Collector) error {
	if bj.collectfunc == nil {
		return errors.New("collectfunc not set on Job")
	}

	bj.collectfunc(bj, c)
	return nil
}

// Write to the log associated with this Job. The log message
// will be output with the standard logger as well as recorded
// to the buffer accessible with Job.Logs().
func (bj *Job) Log(v ...interface{}) {
	log.Output(2, fmt.Sprint(v...))
}

// Write a formatted string to the log associated with this
// Job. The log message will be output with the standard
// logger as well as recorded to the buffer accessible with
// Job.Logs().
func (bj *Job) Logf(format string, v ...interface{}) {
	log.Output(2, fmt.Sprintf(format, v...))
}

// Return the log stream of this job.
func (bj *Job) Logs() io.Reader {
	panic("not yet implemented")
}

// Wait for this job to complete. If this job was never submitted
// before a call to Wait, this call to Wait will never return.
func (bj *Job) Wait() {
	bj.wr.Wait()
}