Pool first attempt

client/rpc_pool.go

@@ -0,0 +1,71 @@
+package client
+
+import (
+	"sync"
+
+	"github.com/micro/go-micro/transport"
+)
+
+type pool struct {
+	tr transport.Transport
+
+	sync.Mutex
+	conns map[string][]*poolConn
+}
+
+type poolConn struct {
+	transport.Client
+}
+
+var (
+	maxIdleConn = 2
+)
+
+func newPool() *pool {
+	return &pool{
+		conns: make(map[string][]*poolConn),
+	}
+}
+
+// NoOp the Close since we manage it
+func (p *poolConn) Close() error {
+	return nil
+}
+
+func (p *pool) getConn(addr string, tr transport.Transport, opts ...transport.DialOption) (*poolConn, error) {
+	p.Lock()
+	conns, ok := p.conns[addr]
+	// no free conn
+	if !ok || len(conns) == 0 {
+		p.Unlock()
+		// create new conn
+		c, err := tr.Dial(addr, opts...)
+		if err != nil {
+			return nil, err
+		}
+		return &poolConn{c}, nil
+	}
+
+	conn := conns[len(conns)-1]
+	p.conns[addr] = conns[:len(conns)-1]
+	p.Unlock()
+	return conn, nil
+}
+
+func (p *pool) release(addr string, conn *poolConn, err error) {
+	// don't store the conn
+	if err != nil {
+		conn.Client.Close()
+		return
+	}
+
+	// otherwise put it back
+	p.Lock()
+	conns := p.conns[addr]
+	if len(conns) >= maxIdleConn {
+		conn.Client.Close()
+		return
+	}
+	p.conns[addr] = append(conns, conn)
+	p.Unlock()
+}