client_test.go

@@ -2085,6 +2085,7 @@ func handleTestServerConnection(connection net.Conn, featureSet string, failRese
 
 	data, err := reader.ReadString('\n')
 	if err != nil {
+		fmt.Printf("unable to read from connection: %s\n", err)
 		return
 	}
 	if !strings.HasPrefix(data, "EHLO") && !strings.HasPrefix(data, "HELO") {
@@ -2092,12 +2093,17 @@ func handleTestServerConnection(connection net.Conn, featureSet string, failRese
 		return
 	}
 	if err = writeLine("250-localhost.localdomain\r\n" + featureSet); err != nil {
+		fmt.Printf("unable to write to connection: %s\n", err)
 		return
 	}
 
 	for {
 		data, err = reader.ReadString('\n')
 		if err != nil {
+			if errors.Is(err, io.EOF) {
+				break
+			}
+			fmt.Println("Error reading data:", err)
 			break
 		}
 

connpool.go

@@ -5,23 +5,16 @@
 package mail
 
 import (
-	"context"
 	"errors"
-	"fmt"
 	"net"
 	"sync"
 )
 
-// Parts of the connection pool code is forked/took inspiration from https://github.com/fatih/pool/
+// Parts of the connection pool code is forked from https://github.com/fatih/pool/
-// Thanks to Fatih Arslan and the project contributors for providing this great concurrency template.
+// Thanks to Fatih Arslan and the project contributors for providing this great
+// concurrency template.
 
 var (
-	// ErrClosed is returned when an operation is attempted on a closed connection pool.
-	ErrClosed = errors.New("connection pool is closed")
-	// ErrNilConn is returned when a nil connection is passed back to the connection pool.
-	ErrNilConn = errors.New("connection is nil")
-	// ErrPoolInvalidCap is returned when the connection pool's capacity settings are
-	// invalid (e.g., initial capacity is negative).
 	ErrPoolInvalidCap = errors.New("invalid connection pool capacity settings")
 )
 
@@ -37,56 +30,18 @@ type Pool interface {
 	// no longer usable.
 	Close()
 
-	// Size returns the current number of connections of the pool.
+	// Len returns the current number of connections of the pool.
-	Size() int
+	Len() int
 }
 
 // connPool implements the Pool interface
 type connPool struct {
-	// mutex is used to synchronize access to the connection pool to ensure thread-safe operations.
+	// mutex is used to synchronize access to the connection pool to ensure thread-safe operations
 	mutex sync.RWMutex
-	// conns is a channel used to manage and distribute net.Conn objects within the connection pool.
+	// conns is a channel used to manage and distribute net.Conn objects within the connection pool
 	conns chan net.Conn
-
+	// dialCtx represents the actual net.Conn returned by the DialContextFunc
-	// dialCtxFunc represents the actual net.Conn returned by the DialContextFunc.
+	dialCtx DialContextFunc
-	dialCtxFunc DialContextFunc
-	// dialContext is the context used for dialing new network connections within the connection pool.
-	dialContext context.Context
-	// dialNetwork specifies the network type (e.g., "tcp", "udp") used to establish connections in
-	// the connection pool.
-	dialNetwork string
-	// dialAddress specifies the address used to establish network connections within the connection pool.
-	dialAddress string
-}
-
-// PoolConn is a wrapper around net.Conn to modify the the behavior of net.Conn's Close() method.
-type PoolConn struct {
-	net.Conn
-	mutex    sync.RWMutex
-	pool     *connPool
-	unusable bool
-}
-
-// Close puts a given pool connection back to the pool instead of closing it.
-func (c *PoolConn) Close() error {
-	c.mutex.RLock()
-	defer c.mutex.RUnlock()
-
-	if c.unusable {
-		if c.Conn != nil {
-			return c.Conn.Close()
-		}
-		return nil
-	}
-	return c.pool.put(c.Conn)
-}
-
-// MarkUnusable marks the connection not usable any more, to let the pool close it instead
-// of returning it to pool.
-func (c *PoolConn) MarkUnusable() {
-	c.mutex.Lock()
-	c.unusable = true
-	c.mutex.Unlock()
 }
 
 // NewConnPool returns a new pool based on buffered channels with an initial
@@ -95,126 +50,40 @@ func (c *PoolConn) MarkUnusable() {
 // fill the Pool until a new Get() is called. During a Get(), if there is no
 // new connection available in the pool, a new connection will be created via
 // the corresponding DialContextFunc() method.
-func NewConnPool(ctx context.Context, initialCap, maxCap int, dialCtxFunc DialContextFunc,
+func NewConnPool(initialCap, maxCap int, dialCtxFunc DialContextFunc) (Pool, error) {
-	network, address string) (Pool, error) {
 	if initialCap < 0 || maxCap <= 0 || initialCap > maxCap {
 		return nil, ErrPoolInvalidCap
 	}
 
 	pool := &connPool{
 		conns:   make(chan net.Conn, maxCap),
-		dialCtxFunc: dialCtxFunc,
+		dialCtx: dialCtxFunc,
-		dialContext: ctx,
-		dialAddress: address,
-		dialNetwork: network,
 	}
 
-	// Initial connections for the pool. Pool will be closed on connection error
+	// create initial connections, if something goes wrong,
+	// just close the pool error out.
 	for i := 0; i < initialCap; i++ {
-		conn, err := dialCtxFunc(ctx, network, address)
+		/*
+			conn, err := dialCtxFunc()
 			if err != nil {
 				pool.Close()
-			return nil, fmt.Errorf("dialContextFunc is not able to fill the connection pool: %s", err)
+				return nil, fmt.Errorf("factory is not able to fill the pool: %s", err)
 			}
-		pool.conns <- conn
+			c.conns <- conn
 
+		*/
 	}
 
 	return pool, nil
 }
 
-// Get satisfies the Get() method of the Pool inteface. If there is no new
+func (c *connPool) Get() (net.Conn, error) {
-// connection available in the Pool, a new connection will be created via the
+	return nil, nil
-// DialContextFunc() method.
-func (p *connPool) Get() (net.Conn, error) {
-	ctx, conns, dialCtxFunc := p.getConnsAndDialContext()
-	if conns == nil {
-		return nil, ErrClosed
-	}
-
-	// wrap the connections into the custom net.Conn implementation that puts
-	// connections back to the pool
-	select {
-	case <-ctx.Done():
-		return nil, ctx.Err()
-	case conn := <-conns:
-		if conn == nil {
-			return nil, ErrClosed
-		}
-		return p.wrapConn(conn), nil
-	default:
-		conn, err := dialCtxFunc(ctx, p.dialNetwork, p.dialAddress)
-		if err != nil {
-			return nil, err
-		}
-		return p.wrapConn(conn), nil
-	}
 }
-
+func (c *connPool) Close() {
-// Close terminates all connections in the pool and frees associated resources. Once closed,
-// the pool is no longer usable.
-func (p *connPool) Close() {
-	p.mutex.Lock()
-	conns := p.conns
-	p.conns = nil
-	p.dialCtxFunc = nil
-	p.dialContext = nil
-	p.dialAddress = ""
-	p.dialNetwork = ""
-	p.mutex.Unlock()
-
-	if conns == nil {
 	return
-	}
-
-	close(conns)
-	for conn := range conns {
-		_ = conn.Close()
-	}
 }
 
-// Size returns the current number of connections in the connection pool.
+func (c *connPool) Len() int {
-func (p *connPool) Size() int {
+	return 0
-	_, conns, _ := p.getConnsAndDialContext()
-	return len(conns)
-}
-
-// getConnsAndDialContext returns the connection channel and the DialContext function for the
-// connection pool.
-func (p *connPool) getConnsAndDialContext() (context.Context, chan net.Conn, DialContextFunc) {
-	p.mutex.RLock()
-	conns := p.conns
-	dialCtxFunc := p.dialCtxFunc
-	ctx := p.dialContext
-	p.mutex.RUnlock()
-	return ctx, conns, dialCtxFunc
-}
-
-// put puts a passed connection back into the pool. If the pool is full or closed,
-// conn is simply closed. A nil conn will be rejected with an error.
-func (p *connPool) put(conn net.Conn) error {
-	if conn == nil {
-		return ErrNilConn
-	}
-
-	p.mutex.RLock()
-	defer p.mutex.RUnlock()
-
-	if p.conns == nil {
-		return conn.Close()
-	}
-
-	select {
-	case p.conns <- conn:
-		return nil
-	default:
-		return conn.Close()
-	}
-}
-
-// wrapConn wraps a given net.Conn with a PoolConn, modifying the net.Conn's Close() method.
-func (p *connPool) wrapConn(conn net.Conn) net.Conn {
-	poolconn := &PoolConn{pool: p}
-	poolconn.Conn = conn
-	return poolconn
 }

connpool_test.go

@@ -1,362 +0,0 @@
-// SPDX-FileCopyrightText: 2022-2024 The go-mail Authors
-//
-// SPDX-License-Identifier: MIT
-
-package mail
-
-import (
-	"context"
-	"fmt"
-	"net"
-	"sync"
-	"testing"
-	"time"
-)
-
-func TestNewConnPool(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	serverPort := TestServerPortBase + 10
-	featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
-	go func() {
-		if err := simpleSMTPServer(ctx, featureSet, true, serverPort); err != nil {
-			t.Errorf("failed to start test server: %s", err)
-			return
-		}
-	}()
-	time.Sleep(time.Millisecond * 300)
-
-	pool, err := newConnPool(serverPort)
-	if err != nil {
-		t.Errorf("failed to create connection pool: %s", err)
-	}
-	defer pool.Close()
-	if pool == nil {
-		t.Errorf("connection pool is nil")
-		return
-	}
-	if pool.Size() != 5 {
-		t.Errorf("expected 5 connections, got %d", pool.Size())
-	}
-	conn, err := pool.Get()
-	if err != nil {
-		t.Errorf("failed to get connection: %s", err)
-	}
-	if _, err := conn.Write([]byte("EHLO test.localhost.localdomain\r\nQUIT\r\n")); err != nil {
-		t.Errorf("failed to write quit command to first connection: %s", err)
-	}
-}
-
-func TestConnPool_Get_Type(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	serverPort := TestServerPortBase + 11
-	featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
-	go func() {
-		if err := simpleSMTPServer(ctx, featureSet, true, serverPort); err != nil {
-			t.Errorf("failed to start test server: %s", err)
-			return
-		}
-	}()
-	time.Sleep(time.Millisecond * 300)
-
-	pool, err := newConnPool(serverPort)
-	if err != nil {
-		t.Errorf("failed to create connection pool: %s", err)
-	}
-	defer pool.Close()
-
-	conn, err := pool.Get()
-	if err != nil {
-		t.Errorf("failed to get new connection from pool: %s", err)
-		return
-	}
-
-	_, ok := conn.(*PoolConn)
-	if !ok {
-		t.Error("received connection from pool is not of type PoolConn")
-		return
-	}
-	if _, err := conn.Write([]byte("EHLO test.localhost.localdomain\r\nQUIT\r\n")); err != nil {
-		t.Errorf("failed to write quit command to first connection: %s", err)
-	}
-}
-
-func TestConnPool_Get(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	serverPort := TestServerPortBase + 12
-	featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
-	go func() {
-		if err := simpleSMTPServer(ctx, featureSet, true, serverPort); err != nil {
-			t.Errorf("failed to start test server: %s", err)
-			return
-		}
-	}()
-	time.Sleep(time.Millisecond * 300)
-
-	p, _ := newConnPool(serverPort)
-	defer p.Close()
-
-	conn, err := p.Get()
-	if err != nil {
-		t.Errorf("failed to get new connection from pool: %s", err)
-		return
-	}
-	if _, err = conn.Write([]byte("EHLO test.localhost.localdomain\r\nQUIT\r\n")); err != nil {
-		t.Errorf("failed to write quit command to first connection: %s", err)
-	}
-
-	if p.Size() != 4 {
-		t.Errorf("getting new connection from pool failed. Expected pool size: 4, got %d", p.Size())
-	}
-
-	var wg sync.WaitGroup
-	for i := 0; i < 4; i++ {
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-			wgconn, err := p.Get()
-			if err != nil {
-				t.Errorf("failed to get new connection from pool: %s", err)
-			}
-			if _, err = wgconn.Write([]byte("EHLO test.localhost.localdomain\r\nQUIT\r\n")); err != nil {
-				t.Errorf("failed to write quit command to first connection: %s", err)
-			}
-		}()
-	}
-	wg.Wait()
-
-	if p.Size() != 0 {
-		t.Errorf("Get error. Expecting 0, got %d", p.Size())
-	}
-
-	conn, err = p.Get()
-	if err != nil {
-		t.Errorf("failed to get new connection from pool: %s", err)
-	}
-	if _, err = conn.Write([]byte("EHLO test.localhost.localdomain\r\nQUIT\r\n")); err != nil {
-		t.Errorf("failed to write quit command to first connection: %s", err)
-	}
-	p.Close()
-}
-
-func TestPoolConn_Close(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	serverPort := TestServerPortBase + 13
-	featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
-	go func() {
-		if err := simpleSMTPServer(ctx, featureSet, true, serverPort); err != nil {
-			t.Errorf("failed to start test server: %s", err)
-			return
-		}
-	}()
-	time.Sleep(time.Millisecond * 300)
-
-	netDialer := net.Dialer{}
-	p, err := NewConnPool(context.Background(), 0, 30, netDialer.DialContext, "tcp",
-		fmt.Sprintf("127.0.0.1:%d", serverPort))
-	if err != nil {
-		t.Errorf("failed to create connection pool: %s", err)
-	}
-	defer p.Close()
-
-	conns := make([]net.Conn, 30)
-	for i := 0; i < 30; i++ {
-		conn, _ := p.Get()
-		if _, err = conn.Write([]byte("EHLO test.localhost.localdomain\r\nQUIT\r\n")); err != nil {
-			t.Errorf("failed to write quit command to first connection: %s", err)
-		}
-		conns[i] = conn
-	}
-	for _, conn := range conns {
-		if err = conn.Close(); err != nil {
-			t.Errorf("failed to close connection: %s", err)
-		}
-	}
-
-	if p.Size() != 30 {
-		t.Errorf("failed to return all connections to pool. Expected pool size: 30, got %d", p.Size())
-	}
-
-	conn, err := p.Get()
-	if err != nil {
-		t.Errorf("failed to get new connection from pool: %s", err)
-	}
-	if _, err = conn.Write([]byte("EHLO test.localhost.localdomain\r\nQUIT\r\n")); err != nil {
-		t.Errorf("failed to write quit command to first connection: %s", err)
-	}
-	p.Close()
-
-	if err = conn.Close(); err != nil {
-		t.Errorf("failed to close connection: %s", err)
-	}
-	if p.Size() != 0 {
-		t.Errorf("closed pool shouldn't allow to put connections.")
-	}
-}
-
-func TestPoolConn_MarkUnusable(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	serverPort := TestServerPortBase + 14
-	featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
-	go func() {
-		if err := simpleSMTPServer(ctx, featureSet, true, serverPort); err != nil {
-			t.Errorf("failed to start test server: %s", err)
-			return
-		}
-	}()
-	time.Sleep(time.Millisecond * 300)
-
-	pool, _ := newConnPool(serverPort)
-	defer pool.Close()
-
-	conn, err := pool.Get()
-	if err != nil {
-		t.Errorf("failed to get new connection from pool: %s", err)
-	}
-	if err = conn.Close(); err != nil {
-		t.Errorf("failed to close connection: %s", err)
-	}
-
-	poolSize := pool.Size()
-	conn, err = pool.Get()
-	if err != nil {
-		t.Errorf("failed to get new connection from pool: %s", err)
-	}
-	if err = conn.Close(); err != nil {
-		t.Errorf("failed to close connection: %s", err)
-	}
-	if pool.Size() != poolSize {
-		t.Errorf("pool size is expected to be equal to initial size")
-	}
-
-	conn, err = pool.Get()
-	if err != nil {
-		t.Errorf("failed to get new connection from pool: %s", err)
-	}
-	if pc, ok := conn.(*PoolConn); !ok {
-		t.Errorf("this should never happen")
-	} else {
-		pc.MarkUnusable()
-	}
-	if err = conn.Close(); err != nil {
-		t.Errorf("failed to close connection: %s", err)
-	}
-	if pool.Size() != poolSize-1 {
-		t.Errorf("pool size is expected to be: %d but got: %d", poolSize-1, pool.Size())
-	}
-}
-
-func TestConnPool_Close(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	serverPort := TestServerPortBase + 15
-	featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
-	go func() {
-		if err := simpleSMTPServer(ctx, featureSet, true, serverPort); err != nil {
-			t.Errorf("failed to start test server: %s", err)
-			return
-		}
-	}()
-	time.Sleep(time.Millisecond * 300)
-
-	pool, err := newConnPool(serverPort)
-	if err != nil {
-		t.Errorf("failed to create connection pool: %s", err)
-	}
-	pool.Close()
-
-	castPool := pool.(*connPool)
-
-	if castPool.conns != nil {
-		t.Error("closing pool failed: conns channel should be nil")
-	}
-	if castPool.dialCtxFunc != nil {
-		t.Error("closing pool failed: dialCtxFunc should be nil")
-	}
-	if castPool.dialContext != nil {
-		t.Error("closing pool failed: dialContext should be nil")
-	}
-	if castPool.dialAddress != "" {
-		t.Error("closing pool failed: dialAddress should be empty")
-	}
-	if castPool.dialNetwork != "" {
-		t.Error("closing pool failed: dialNetwork should be empty")
-	}
-
-	conn, err := pool.Get()
-	if err == nil {
-		t.Errorf("closing pool failed: getting new connection should return an error")
-	}
-	if conn != nil {
-		t.Errorf("closing pool failed: getting new connection should return a nil-connection")
-	}
-	if pool.Size() != 0 {
-		t.Errorf("closing pool failed: pool size should be 0, but got: %d", pool.Size())
-	}
-}
-
-func TestConnPool_Concurrency(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	serverPort := TestServerPortBase + 16
-	featureSet := "250-AUTH PLAIN\r\n250-8BITMIME\r\n250-DSN\r\n250 SMTPUTF8"
-	go func() {
-		if err := simpleSMTPServer(ctx, featureSet, true, serverPort); err != nil {
-			t.Errorf("failed to start test server: %s", err)
-			return
-		}
-	}()
-	time.Sleep(time.Millisecond * 300)
-
-	pool, err := newConnPool(serverPort)
-	if err != nil {
-		t.Errorf("failed to create connection pool: %s", err)
-	}
-	defer pool.Close()
-	pipe := make(chan net.Conn)
-
-	getWg := sync.WaitGroup{}
-	closeWg := sync.WaitGroup{}
-	for i := 0; i < 30; i++ {
-		getWg.Add(1)
-		closeWg.Add(1)
-		go func() {
-			conn, err := pool.Get()
-			if err != nil {
-				t.Errorf("failed to get new connection from pool: %s", err)
-			}
-			pipe <- conn
-			getWg.Done()
-		}()
-
-		go func() {
-			conn := <-pipe
-			if conn == nil {
-				return
-			}
-			if err = conn.Close(); err != nil {
-				t.Errorf("failed to close connection: %s", err)
-			}
-			closeWg.Done()
-		}()
-		getWg.Wait()
-		closeWg.Wait()
-	}
-}
-
-func newConnPool(port int) (Pool, error) {
-	netDialer := net.Dialer{}
-	return NewConnPool(context.Background(), 5, 30, netDialer.DialContext, "tcp",
-		fmt.Sprintf("127.0.0.1:%d", port))
-}