Code review comment for lp:~themue/juju-core/026-transaction-resumer

Reviewers: mp+169234_code.launchpad.net,

Message:
Please take a look.

Description:
resumer: periodically resume transaction

The resumer is a periodically worker which is
resuming pending transactions in state each
minute.

https://code.launchpad.net/~themue/juju-core/026-transaction-resumer/+merge/169234

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/10266043/

Affected files:
   A [revision details]
   M state/state.go
   A worker/resumer/resumer.go
   A worker/resumer/resumer_test.go

Index: [revision details]
=== added file '[revision details]'
--- [revision details] 2012-01-01 00:00:00 +0000
+++ [revision details] 2012-01-01 00:00:00 +0000
@@ -0,0 +1,2 @@
+Old revision: tarmac-20130613115315-e58eqa122kc07o1a
+New revision: <email address hidden>

Index: state/state.go
=== modified file 'state/state.go'
--- state/state.go 2013-06-12 02:45:22 +0000
+++ state/state.go 2013-06-13 15:29:49 +0000
@@ -1123,6 +1123,11 @@
   return nil
  }

+// ResumeTransactions resumes all pending transactions.
+func (st *State) ResumeTransactions() error {
+ return st.runner.ResumeAll()
+}
+
  var tagPrefix = map[byte]string{
   'm': "machine-",
   's': "service-",

Index: worker/resumer/resumer.go
=== added file 'worker/resumer/resumer.go'
--- worker/resumer/resumer.go 1970-01-01 00:00:00 +0000
+++ worker/resumer/resumer.go 2013-06-13 15:29:49 +0000
@@ -0,0 +1,62 @@
+// Copyright 2012, 2013 Canonical Ltd.
+// Licensed under the AGPLv3, see LICENCE file for details.
+
+package resumer
+
+import (
+ "fmt"
+ "launchpad.net/juju-core/log"
+ "launchpad.net/juju-core/state"
+ "launchpad.net/tomb"
+ "time"
+)
+
+// interval sets how often the resuming is called.
+const interval = time.Minute
+
+// Resumer is responsible for a periodical resuming of pending
transactions.
+type Resumer struct {
+ tomb tomb.Tomb
+ st *state.State
+}
+
+// NewResumer ...
+func NewResumer(st *state.State) *Resumer {
+ rr := &Resumer{st: st}
+ go func() {
+ defer rr.tomb.Done()
+ rr.tomb.Kill(rr.loop())
+ }()
+ return rr
+}
+
+func (rr *Resumer) String() string {
+ return fmt.Sprintf("resumer")
+}
+
+func (rr *Resumer) Kill() {
+ rr.tomb.Kill(nil)
+}
+
+func (rr *Resumer) Stop() error {
+ rr.tomb.Kill(nil)
+ return rr.tomb.Wait()
+}
+
+func (rr *Resumer) Wait() error {
+ return rr.tomb.Wait()
+}
+
+func (rr *Resumer) loop() error {
+ for {
+ select {
+ case <-rr.tomb.Dying():
+ return tomb.ErrDying
+ case <-time.After(interval):
+ if err := rr.st.ResumeTransactions(); err != nil {
+ log.Errorf("worker/resumer: cannot resume transactions: %v", err)
+ }
+ }
+ }
+ panic("unreachable")
+}

Index: worker/resumer/resumer_test.go
=== added file 'worker/resumer/resumer_test.go'
--- worker/resumer/resumer_test.go 1970-01-01 00:00:00 +0000
+++ worker/resumer/resumer_test.go 2013-06-13 15:29:49 +0000
@@ -0,0 +1,28 @@
+// Copyright 2013 Canonical Ltd.
+// Licensed under the AGPLv3, see LICENCE file for details.
+
+package resumer_test
+
+import (
+ . "launchpad.net/gocheck"
+ "launchpad.net/juju-core/juju/testing"
+ coretesting "launchpad.net/juju-core/testing"
+ "launchpad.net/juju-core/worker/resumer"
+ stdtesting "testing"
+)
+
+func TestPackage(t *stdtesting.T) {
+ coretesting.MgoTestPackage(t)
+}
+
+type ResumerSuite struct {
+ testing.JujuConnSuite
+}
+
+var _ = Suite(&ResumerSuite{})
+
+func (s *ResumerSuite) TestRunStop(c *C) {
+ rr := resumer.NewResumer(s.State)
+
+ c.Assert(rr.Stop(), IsNil)
+}