From 900373fccaa6f010115d17fc9db876e7d94e2c05 Mon Sep 17 00:00:00 2001
From: Stanislav Seletskiy <s.seletskiy@gmail.com>
Date: Fri, 10 Jun 2016 12:56:33 +0600
Subject: [PATCH] refactor acquireDistributedLock

---
 distributed_lock.go |  4 +--
 lock.go             | 67 ++++++++++++++++++++++-----------------------
 2 files changed, 34 insertions(+), 37 deletions(-)

diff --git a/distributed_lock.go b/distributed_lock.go
index e3ca322..841f65c 100644
--- a/distributed_lock.go
+++ b/distributed_lock.go
@@ -18,13 +18,11 @@ type distributedLock struct {
 func (lock *distributedLock) addNodeRunner(
 	runner runcmd.Runner,
 	address address,
-) error {
+) {
 	lock.nodes = append(lock.nodes, &distributedLockNode{
 		address: address,
 		runner:  runner,
 	})
-
-	return nil
 }
 
 func (lock *distributedLock) acquire(filename string) error {
diff --git a/lock.go b/lock.go
index 016b013..b00e920 100644
--- a/lock.go
+++ b/lock.go
@@ -19,7 +19,7 @@ func acquireDistributedLock(
 	noLockFail bool,
 ) (*distributedLock, error) {
 	var (
-		lock = &distributedLock{
+		cluster = &distributedLock{
 			noFail: noLockFail,
 		}
 
@@ -31,43 +31,17 @@ func acquireDistributedLock(
 
 	for _, nodeAddress := range addresses {
 		go func(nodeAddress address) {
-			tracef(`connecting to address: '%s'`,
-				nodeAddress,
-			)
+			err := connectToNode(cluster, runnerFactory, nodeAddress, mutex)
 
-			runner, err := runnerFactory(nodeAddress)
 			if err != nil {
-				errors <- hierr.Errorf(
-					err,
-					`can't create runner for address: %s`,
+				debugf(`%4d/%d connection established: %s`,
+					atomic.AddInt64(&nodeIndex, 1),
+					len(addresses),
 					nodeAddress,
 				)
-
-				return
-			}
-
-			debugf(`%4d/%d connection established: %s`,
-				atomic.AddInt64(&nodeIndex, 1),
-				len(addresses),
-				nodeAddress,
-			)
-
-			mutex.Lock()
-			{
-				err = lock.addNodeRunner(runner, nodeAddress)
-			}
-			mutex.Unlock()
-			if err != nil {
-				errors <- hierr.Errorf(
-					err,
-					`can't add host to the global cluster lock: %s`,
-					nodeAddress,
-				)
-
-				return
 			}
 
-			errors <- nil
+			errors <- err
 		}(nodeAddress)
 	}
 
@@ -81,7 +55,7 @@ func acquireDistributedLock(
 		}
 	}
 
-	err := lock.acquire(lockFile)
+	err := cluster.acquire(lockFile)
 	if err != nil {
 		return nil, hierr.Errorf(
 			err,
@@ -90,5 +64,30 @@ func acquireDistributedLock(
 		)
 	}
 
-	return lock, nil
+	return cluster, nil
+}
+
+func connectToNode(
+	cluster *distributedLock,
+	runnerFactory runnerFactory,
+	address address,
+	nodeAddMutex sync.Locker,
+) error {
+	tracef(`connecting to address: '%s'`, address)
+
+	runner, err := runnerFactory(address)
+	if err != nil {
+		return hierr.Errorf(
+			err,
+			`can't create runner for address: %s`,
+			address,
+		)
+	}
+
+	nodeAddMutex.Lock()
+	defer nodeAddMutex.Unlock()
+
+	cluster.addNodeRunner(runner, address)
+
+	return nil
 }