client/signal: Revert "add signal 'snapshot', rename existing signal 'wakeup' to 'replication'"

This was merged to master prematurely as the job components are not decoupled well enough
for these signals to be useful yet.

This reverts commit 2c8c2cfa14.

closes #452

daemon/daemon.go

@@ -20,9 +20,8 @@ import (
 
 	"github.com/zrepl/zrepl/config"
 	"github.com/zrepl/zrepl/daemon/job"
-	"github.com/zrepl/zrepl/daemon/job/doreplication"
-	"github.com/zrepl/zrepl/daemon/job/dosnapshot"
 	"github.com/zrepl/zrepl/daemon/job/reset"
+	"github.com/zrepl/zrepl/daemon/job/wakeup"
 	"github.com/zrepl/zrepl/daemon/logging"
 	"github.com/zrepl/zrepl/logger"
 	"github.com/zrepl/zrepl/version"
@@ -132,19 +131,17 @@ type jobs struct {
 	wg sync.WaitGroup
 
 	// m protects all fields below it
-	m              sync.RWMutex
-	doreplications map[string]doreplication.Func // by Job.Name
-	resets         map[string]reset.Func         // by Job.Name
-	dosnapshots    map[string]dosnapshot.Func    // by Job.Name
-	jobs           map[string]job.Job
+	m       sync.RWMutex
+	wakeups map[string]wakeup.Func // by Job.Name
+	resets  map[string]reset.Func  // by Job.Name
+	jobs    map[string]job.Job
 }
 
 func newJobs() *jobs {
 	return &jobs{
-		doreplications: make(map[string]doreplication.Func),
-		resets:         make(map[string]reset.Func),
-		dosnapshots:    make(map[string]dosnapshot.Func),
-		jobs:           make(map[string]job.Job),
+		wakeups: make(map[string]wakeup.Func),
+		resets:  make(map[string]reset.Func),
+		jobs:    make(map[string]job.Job),
 	}
 }
 
@@ -193,11 +190,11 @@ func (s *jobs) status() map[string]*job.Status {
 	return ret
 }
 
-func (s *jobs) doreplication(job string) error {
+func (s *jobs) wakeup(job string) error {
 	s.m.RLock()
 	defer s.m.RUnlock()
 
-	wu, ok := s.doreplications[job]
+	wu, ok := s.wakeups[job]
 	if !ok {
 		return errors.Errorf("Job %s does not exist", job)
 	}
@@ -215,17 +212,6 @@ func (s *jobs) reset(job string) error {
 	return wu()
 }
 
-func (s *jobs) dosnapshot(job string) error {
-	s.m.RLock()
-	defer s.m.RUnlock()
-
-	wu, ok := s.dosnapshots[job]
-	if !ok {
-		return errors.Errorf("Job %s does not exist", job)
-	}
-	return wu()
-}
-
 const (
 	jobNamePrometheus = "_prometheus"
 	jobNameControl    = "_control"
@@ -256,12 +242,10 @@ func (s *jobs) start(ctx context.Context, j job.Job, internal bool) {
 
 	s.jobs[jobName] = j
 	ctx = zfscmd.WithJobID(ctx, j.Name())
-	ctx, doreplication := doreplication.Context(ctx)
+	ctx, wakeup := wakeup.Context(ctx)
 	ctx, resetFunc := reset.Context(ctx)
-	ctx, dosnapshotFunc := dosnapshot.Context(ctx)
-	s.doreplications[jobName] = doreplication
+	s.wakeups[jobName] = wakeup
 	s.resets[jobName] = resetFunc
-	s.dosnapshots[jobName] = dosnapshotFunc
 
 	s.wg.Add(1)
 	go func() {