From 32391adf4f3be6b902b9e70a5c0cea24990b097e Mon Sep 17 00:00:00 2001
From: Anton Schirg <anton.schirg@posteo.de>
Date: Thu, 30 Aug 2018 17:40:45 +0200
Subject: [PATCH] build pruner in factory and check prune rules

---
 daemon/job/push.go      | 22 ++++---------
 daemon/pruner/pruner.go | 71 ++++++++++++++++++++++++++++++++++++++---
 2 files changed, 74 insertions(+), 19 deletions(-)

diff --git a/daemon/job/push.go b/daemon/job/push.go
index 97746f7..62fbb24 100644
--- a/daemon/job/push.go
+++ b/daemon/job/push.go
@@ -10,10 +10,8 @@ import (
 	"github.com/zrepl/zrepl/daemon/logging"
 	"github.com/zrepl/zrepl/daemon/pruner"
 	"github.com/zrepl/zrepl/endpoint"
-	"github.com/zrepl/zrepl/pruning"
 	"github.com/zrepl/zrepl/replication"
 	"sync"
-	"time"
 )
 
 type Push struct {
@@ -21,8 +19,7 @@ type Push struct {
 	connecter streamrpc.Connecter
 	fsfilter  endpoint.FSFilter
 
-	keepRulesSender   []pruning.KeepRule
-	keepRulesReceiver []pruning.KeepRule
+	prunerFactory *pruner.PrunerFactory
 
 	mtx         sync.Mutex
 	replication *replication.Replication
@@ -39,14 +36,9 @@ func PushFromConfig(g config.Global, in *config.PushJob) (j *Push, err error) {
 		return nil, errors.Wrap(err, "cannnot build filesystem filter")
 	}
 
-	j.keepRulesReceiver, err = pruning.RulesFromConfig(in.Pruning.KeepReceiver)
+	j.prunerFactory, err = pruner.NewPrunerFactory(in.Pruning)
 	if err != nil {
-		return nil, errors.Wrap(err, "cannot build receiver pruning rules")
-	}
-
-	j.keepRulesSender, err = pruning.RulesFromConfig(in.Pruning.KeepSender)
-	if err != nil {
-		return nil, errors.Wrap(err, "cannot build sender pruning rules")
+		return nil, err
 	}
 
 	return j, nil
@@ -112,11 +104,11 @@ func (j *Push) do(ctx context.Context) {
 	j.replication.Drive(ctx, sender, receiver)
 
 	// Prune sender
-	senderPruner := pruner.NewPruner(10*time.Second, sender, sender, j.keepRulesSender) // FIXME constant
-	senderPruner.Prune(pruner.WithLogger(ctx, pruner.GetLogger(ctx).WithField("prune_side", "sender")))
+	senderPruner := j.prunerFactory.BuildSenderPruner(ctx, sender, sender)
+	senderPruner.Prune()
 
 	// Prune receiver
-	receiverPruner := pruner.NewPruner(10*time.Second, receiver, sender, j.keepRulesReceiver) // FIXME constant
-	receiverPruner.Prune(pruner.WithLogger(ctx, pruner.GetLogger(ctx).WithField("prune_side", "receiver")))
+	receiverPruner := j.prunerFactory.BuildReceiverPruner(ctx, receiver, sender)
+	receiverPruner.Prune()
 
 }
diff --git a/daemon/pruner/pruner.go b/daemon/pruner/pruner.go
index 8041cc0..f912a90 100644
--- a/daemon/pruner/pruner.go
+++ b/daemon/pruner/pruner.go
@@ -3,6 +3,8 @@ package pruner
 import (
 	"context"
 	"fmt"
+	"github.com/pkg/errors"
+	"github.com/zrepl/zrepl/config"
 	"github.com/zrepl/zrepl/logger"
 	"github.com/zrepl/zrepl/pruning"
 	"github.com/zrepl/zrepl/replication/pdu"
@@ -63,9 +65,71 @@ type Pruner struct {
 	pruneCompleted []fs
 }
 
-func NewPruner(retryWait time.Duration, target Target, receiver History, rules []pruning.KeepRule) *Pruner {
+type PrunerFactory struct {
+	senderRules   []pruning.KeepRule
+	receiverRules []pruning.KeepRule
+	retryWait     time.Duration
+}
+
+func checkContainsKeep1(rules []pruning.KeepRule) error {
+	if len(rules) == 0 {
+		return nil //No keep rules means keep all - ok
+	}
+	for _, e := range rules {
+		switch e.(type) {
+		case *pruning.KeepLastN:
+			return nil
+		}
+	}
+	return errors.New("sender keep rules must contain last_n or be empty so that the last snapshot is definitely kept")
+}
+
+func NewPrunerFactory(in config.PruningSenderReceiver) (*PrunerFactory, error) {
+	keepRulesReceiver, err := pruning.RulesFromConfig(in.KeepReceiver)
+	if err != nil {
+		return nil, errors.Wrap(err, "cannot build receiver pruning rules")
+	}
+
+	keepRulesSender, err := pruning.RulesFromConfig(in.KeepSender)
+	if err != nil {
+		return nil, errors.Wrap(err, "cannot build sender pruning rules")
+	}
+
+	if err := checkContainsKeep1(keepRulesSender); err != nil {
+		return nil, err
+	}
+
+	f := &PrunerFactory{
+		keepRulesSender,
+		keepRulesReceiver,
+		10 * time.Second, //FIXME constant
+	}
+	return f, nil
+}
+
+func (f *PrunerFactory) BuildSenderPruner(ctx context.Context, target Target, receiver History) *Pruner {
 	p := &Pruner{
-		args:  args{nil, target, receiver, rules, retryWait}, // ctx is filled in Prune()
+		args: args{
+			WithLogger(ctx, GetLogger(ctx).WithField("prune_side", "sender")),
+			target,
+			receiver,
+			f.senderRules,
+			f.retryWait,
+		},
+		state: Plan,
+	}
+	return p
+}
+
+func (f *PrunerFactory) BuildReceiverPruner(ctx context.Context, target Target, receiver History) *Pruner {
+	p := &Pruner{
+		args: args{
+			WithLogger(ctx, GetLogger(ctx).WithField("prune_side", "receiver")),
+			target,
+			receiver,
+			f.receiverRules,
+			f.retryWait,
+		},
 		state: Plan,
 	}
 	return p
@@ -98,8 +162,7 @@ func (s State) statefunc() state {
 type updater func(func(*Pruner)) State
 type state func(args *args, u updater) state
 
-func (p *Pruner) Prune(ctx context.Context) {
-	p.args.ctx = ctx
+func (p *Pruner) Prune() {
 	p.prune(p.args)
 }