Remove SimpleConnPool, remove custom pools

Remove custom pools so that the driver can be simplified and
make more assumptions about the underlying conneciton pool whilst
still allowing configuration of host select and conn selection policies.

cass1batch_test.go

@@ -10,7 +10,7 @@ import (
 func TestProto1BatchInsert(t *testing.T) {
 	session := createSession(t)
 	if err := createTable(session, "CREATE TABLE large (id int primary key)"); err != nil {
-		t.Fatal("create table:", err)
+		t.Fatal(err)
 	}
 	defer session.Close()
 

cassandra_test.go

@@ -96,7 +96,7 @@ func createKeyspace(tb testing.TB, cluster *ClusterConfig, keyspace string) {
 	}
 
 	// should reuse the same conn apparently
-	conn := session.Pool.Pick(nil)
+	conn := session.pool.Pick(nil)
 	if conn == nil {
 		tb.Fatal("no connections available in the pool")
 	}
@@ -189,7 +189,9 @@ func TestRingDiscovery(t *testing.T) {
 		time.Sleep(*flagAutoWait)
 	}
 
-	size := len(session.Pool.(*SimplePool).connPool)
+	session.pool.mu.RLock()
+	size := len(session.pool.hostConnPools)
+	session.pool.mu.RUnlock()
 
 	if *clusterSize != size {
 		t.Logf("WARN: Expected a cluster size of %d, but actual size was %d", *clusterSize, size)
@@ -1139,7 +1141,7 @@ func injectInvalidPreparedStatement(t *testing.T, session *Session, table string
 		t.Fatal("create:", err)
 	}
 	stmt := "INSERT INTO " + table + " (foo, bar) VALUES (?, 7)"
-	conn := session.Pool.Pick(nil)
+	conn := session.pool.Pick(nil)
 	flight := new(inflightPrepare)
 	stmtsLRU.Lock()
 	stmtsLRU.lru.Add(conn.addr+stmt, flight)
@@ -1165,7 +1167,7 @@ func injectInvalidPreparedStatement(t *testing.T, session *Session, table string
 
 func TestMissingSchemaPrepare(t *testing.T) {
 	s := createSession(t)
-	conn := s.Pool.Pick(nil)
+	conn := s.pool.Pick(nil)
 	defer s.Close()
 
 	insertQry := &Query{stmt: "INSERT INTO invalidschemaprep (val) VALUES (?)", values: []interface{}{5}, cons: s.cons,
@@ -1214,7 +1216,7 @@ func TestQueryInfo(t *testing.T) {
 	session := createSession(t)
 	defer session.Close()
 
-	conn := session.Pool.Pick(nil)
+	conn := session.pool.Pick(nil)
 	info, err := conn.prepareStatement("SELECT release_version, host_id FROM system.local WHERE key = ?", nil)
 
 	if err != nil {
@@ -2016,7 +2018,7 @@ func TestRoutingKey(t *testing.T) {
 // Integration test of the token-aware policy-based connection pool
 func TestTokenAwareConnPool(t *testing.T) {
 	cluster := createCluster()
-	cluster.ConnPoolType = NewTokenAwareConnPool
+	cluster.PoolConfig.HostSelectionPolicy = TokenAwareHostPolicy(RoundRobinHostPolicy())
 	cluster.DiscoverHosts = true
 
 	// Drop and re-create the keyspace once. Different tests should use their own
@@ -2037,8 +2039,8 @@ func TestTokenAwareConnPool(t *testing.T) {
 		time.Sleep(*flagAutoWait)
 	}
 
-	if session.Pool.Size() != cluster.NumConns*len(cluster.Hosts) {
-		t.Errorf("Expected pool size %d but was %d", cluster.NumConns*len(cluster.Hosts), session.Pool.Size())
+	if session.pool.Size() != cluster.NumConns*len(cluster.Hosts) {
+		t.Errorf("Expected pool size %d but was %d", cluster.NumConns*len(cluster.Hosts), session.pool.Size())
 	}
 
 	if err := createTable(session, "CREATE TABLE test_token_aware (id int, data text, PRIMARY KEY (id))"); err != nil {
@@ -2077,7 +2079,7 @@ func TestStream0(t *testing.T) {
 			break
 		}
 
-		conn = session.Pool.Pick(nil)
+		conn = session.pool.Pick(nil)
 	}
 
 	if conn == nil {
@@ -2116,7 +2118,7 @@ func TestNegativeStream(t *testing.T) {
 			break
 		}
 
-		conn = session.Pool.Pick(nil)
+		conn = session.pool.Pick(nil)
 	}
 
 	if conn == nil {
@@ -2222,7 +2224,7 @@ func TestLexicalUUIDType(t *testing.T) {
 // Issue 475
 func TestSessionBindRoutingKey(t *testing.T) {
 	cluster := createCluster()
-	cluster.ConnPoolType = NewTokenAwareConnPool
+	cluster.PoolConfig.HostSelectionPolicy = TokenAwareHostPolicy(RoundRobinHostPolicy())
 
 	session := createSessionFromCluster(cluster, t)
 	defer session.Close()

cluster.go

@@ -50,6 +50,33 @@ type DiscoveryConfig struct {
 	Sleep time.Duration
 }
 
+// PoolConfig configures the connection pool used by the driver, it defaults to
+// using a round robbin host selection policy and a round robbin connection selection
+// policy for each host.
+type PoolConfig struct {
+	// HostSelectionPolicy sets the policy for selecting which host to use for a
+	// given query (default: RoundRobinHostPolicy())
+	HostSelectionPolicy HostSelectionPolicy
+
+	// ConnSelectionPolicy sets the policy factory for selecting a connection to use for
+	// each host for a query (default: RoundRobinConnPolicy())
+	ConnSelectionPolicy func() ConnSelectionPolicy
+}
+
+func (p PoolConfig) buildPool(cfg *ClusterConfig) (*policyConnPool, error) {
+	hostSelection := p.HostSelectionPolicy
+	if hostSelection == nil {
+		hostSelection = RoundRobinHostPolicy()
+	}
+
+	connSelection := p.ConnSelectionPolicy
+	if connSelection == nil {
+		connSelection = RoundRobinConnPolicy()
+	}
+
+	return newPolicyConnPool(cfg, hostSelection, connSelection)
+}
+
 // ClusterConfig is a struct to configure the default cluster implementation
 // of gocoql. It has a varity of attributes that can be used to modify the
 // behavior to fit the most common use cases. Applications that requre a
@@ -68,7 +95,6 @@ type ClusterConfig struct {
 	Authenticator     Authenticator     // authenticator (default: nil)
 	RetryPolicy       RetryPolicy       // Default retry policy to use for queries (default: 0)
 	SocketKeepalive   time.Duration     // The keepalive period to use, enabled if > 0 (default: 0)
-	ConnPoolType      NewPoolFunc       // The function used to create the connection pool for the session (default: NewSimplePool)
 	DiscoverHosts     bool              // If set, gocql will attempt to automatically discover other members of the Cassandra cluster (default: false)
 	MaxPreparedStmts  int               // Sets the maximum cache size for prepared statements globally for gocql (default: 1000)
 	MaxRoutingKeyInfo int               // Sets the maximum cache size for query info about statements for each session (default: 1000)
@@ -77,6 +103,9 @@ type ClusterConfig struct {
 	Discovery         DiscoveryConfig
 	SslOpts           *SslOptions
 	DefaultTimestamp  bool // Sends a client side timestamp for all requests which overrides the timestamp at which it arrives at the server. (default: true, only enabled for protocol 3 and above)
+	// PoolConfig configures the underlying connection pool, allowing the
+	// configuration of host selection and connection selection policies.
+	PoolConfig PoolConfig
 }
 
 // NewCluster generates a new config for the default cluster implementation.
@@ -89,7 +118,6 @@ func NewCluster(hosts ...string) *ClusterConfig {
 		Port:              9042,
 		NumConns:          2,
 		Consistency:       Quorum,
-		ConnPoolType:      NewSimplePool,
 		DiscoverHosts:     false,
 		MaxPreparedStmts:  defaultMaxPreparedStmts,
 		MaxRoutingKeyInfo: 1000,

conn_test.go

@@ -259,8 +259,7 @@ func TestConnClosing(t *testing.T) {
 	wg.Wait()
 
 	time.Sleep(1 * time.Second) //Sleep so the fillPool can complete.
-	pool := db.Pool.(ConnectionPool)
-	conns := pool.Size()
+	conns := db.pool.Size()
 
 	if conns != numConns {
 		t.Errorf("Expected to have %d connections but have %d", numConns, conns)
@@ -390,7 +389,8 @@ func TestRoundRobinConnPoolRoundRobin(t *testing.T) {
 
 	// create a new cluster using the policy-based round robin conn pool
 	cluster := NewCluster(addrs...)
-	cluster.ConnPoolType = NewRoundRobinConnPool
+	cluster.PoolConfig.HostSelectionPolicy = RoundRobinHostPolicy()
+	cluster.PoolConfig.ConnSelectionPolicy = RoundRobinConnPolicy()
 
 	db, err := cluster.CreateSession()
 	if err != nil {
@@ -420,7 +420,7 @@ func TestRoundRobinConnPoolRoundRobin(t *testing.T) {
 
 	// wait for the pool to drain
 	time.Sleep(100 * time.Millisecond)
-	size := db.Pool.Size()
+	size := db.pool.Size()
 	if size != 0 {
 		t.Errorf("connection pool did not drain, still contains %d connections", size)
 	}
@@ -450,7 +450,8 @@ func TestPolicyConnPoolSSL(t *testing.T) {
 	defer srv.Stop()
 
 	cluster := createTestSslCluster(srv.Address, defaultProto, true)
-	cluster.ConnPoolType = NewRoundRobinConnPool
+	cluster.PoolConfig.HostSelectionPolicy = RoundRobinHostPolicy()
+	cluster.PoolConfig.ConnSelectionPolicy = RoundRobinConnPolicy()
 
 	db, err := cluster.CreateSession()
 	if err != nil {
@@ -465,7 +466,7 @@ func TestPolicyConnPoolSSL(t *testing.T) {
 
 	// wait for the pool to drain
 	time.Sleep(100 * time.Millisecond)
-	size := db.Pool.Size()
+	size := db.pool.Size()
 	if size != 0 {
 		t.Errorf("connection pool did not drain, still contains %d connections", size)
 	}