syncthing/lib/model/rofolder.go
2015-08-09 09:35:26 +02:00

165 lines
3.5 KiB
Go

// Copyright (C) 2014 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at http://mozilla.org/MPL/2.0/.
package model
import (
"fmt"
"math/rand"
"time"
"github.com/syncthing/syncthing/lib/sync"
)
type roFolder struct {
stateTracker
folder string
intv time.Duration
timer *time.Timer
model *Model
stop chan struct{}
scanNow chan rescanRequest
delayScan chan time.Duration
}
type rescanRequest struct {
subs []string
err chan error
}
func newROFolder(model *Model, folder string, interval time.Duration) *roFolder {
return &roFolder{
stateTracker: stateTracker{
folder: folder,
mut: sync.NewMutex(),
},
folder: folder,
intv: interval,
timer: time.NewTimer(time.Millisecond),
model: model,
stop: make(chan struct{}),
scanNow: make(chan rescanRequest),
delayScan: make(chan time.Duration),
}
}
func (s *roFolder) Serve() {
if debug {
l.Debugln(s, "starting")
defer l.Debugln(s, "exiting")
}
defer func() {
s.timer.Stop()
}()
reschedule := func() {
if s.intv == 0 {
return
}
// Sleep a random time between 3/4 and 5/4 of the configured interval.
sleepNanos := (s.intv.Nanoseconds()*3 + rand.Int63n(2*s.intv.Nanoseconds())) / 4
s.timer.Reset(time.Duration(sleepNanos) * time.Nanosecond)
}
initialScanCompleted := false
for {
select {
case <-s.stop:
return
case <-s.timer.C:
if err := s.model.CheckFolderHealth(s.folder); err != nil {
l.Infoln("Skipping folder", s.folder, "scan due to folder error:", err)
reschedule()
continue
}
if debug {
l.Debugln(s, "rescan")
}
if err := s.model.internalScanFolderSubs(s.folder, nil); err != nil {
// Potentially sets the error twice, once in the scanner just
// by doing a check, and once here, if the error returned is
// the same one as returned by CheckFolderHealth, though
// duplicate set is handled by setError.
s.setError(err)
reschedule()
continue
}
if !initialScanCompleted {
l.Infoln("Completed initial scan (ro) of folder", s.folder)
initialScanCompleted = true
}
if s.intv == 0 {
continue
}
reschedule()
case req := <-s.scanNow:
if err := s.model.CheckFolderHealth(s.folder); err != nil {
l.Infoln("Skipping folder", s.folder, "scan due to folder error:", err)
req.err <- err
continue
}
if debug {
l.Debugln(s, "forced rescan")
}
if err := s.model.internalScanFolderSubs(s.folder, req.subs); err != nil {
// Potentially sets the error twice, once in the scanner just
// by doing a check, and once here, if the error returned is
// the same one as returned by CheckFolderHealth, though
// duplicate set is handled by setError.
s.setError(err)
req.err <- err
continue
}
req.err <- nil
case next := <-s.delayScan:
s.timer.Reset(next)
}
}
}
func (s *roFolder) Stop() {
close(s.stop)
}
func (s *roFolder) IndexUpdated() {
}
func (s *roFolder) Scan(subs []string) error {
req := rescanRequest{
subs: subs,
err: make(chan error),
}
s.scanNow <- req
return <-req.err
}
func (s *roFolder) String() string {
return fmt.Sprintf("roFolder/%s@%p", s.folder, s)
}
func (s *roFolder) BringToFront(string) {}
func (s *roFolder) Jobs() ([]string, []string) {
return nil, nil
}
func (s *roFolder) DelayScan(next time.Duration) {
s.delayScan <- next
}