Add possibility to scale middleproxy buffers

cli/proxy.go

 
 	zap.S().Debugw("Configuration", "config", config.Printable())
 
-	if len(config.C.AdTag) > 0 {
+	if config.C.MiddleProxyMode() {
 		zap.S().Infow("Use middle proxy connection to Telegram")
 
 		diff, err := ntp.Fetch()

config/config.go

 	"encoding/json"
 	"errors"
 	"fmt"
+	"math"
 	"net"
 
 	"github.com/alecthomas/units"
 	AdTag  []byte `json:"adtag"`
 }
 
+func (c *Config) ClientReadBuffer() int {
+	return c.ReadBuffer
+}
+
+func (c *Config) ClientWriteBuffer() int {
+	return c.WriteBuffer
+}
+
+func (c *Config) MiddleProxyMode() bool {
+	return len(c.AdTag) > 0
+}
+
+func (c *Config) ProxyReadBuffer() int {
+	value := c.ReadBuffer
+
+	if c.MiddleProxyMode() {
+		value = c.adjustProxyValue(value)
+	}
+
+	return value
+}
+
+func (c *Config) ProxyWriteBuffer() int {
+	value := c.WriteBuffer
+
+	if c.MiddleProxyMode() {
+		value = c.adjustProxyValue(value)
+	}
+
+	return value
+}
+
+func (c *Config) adjustProxyValue(value int) int {
+	if c.MultiplexPerConnection == 0 {
+		return value
+	}
+
+	fvalue := float64(value)
+	newValue := fvalue * 1.5 * math.Log2(float64(c.MultiplexPerConnection))
+	newValue = math.Max(fvalue, math.Ceil(newValue))
+
+	return int(newValue)
+}
+
 type Opt struct {
 	Option OptionType
 	Value  interface{}

proxy/proxy.go

 	connID := conntypes.NewConnID()
 	logger := p.Logger.With("connection_id", connID)
 
-	if err := utils.InitTCP(conn); err != nil {
+	if err := utils.InitTCP(conn, config.C.ClientReadBuffer(), config.C.ClientWriteBuffer()); err != nil {
 		logger.Errorw("Cannot initialize client TCP connection", "error", err)
 		return
 	}
 
 	err = nil
 
-	if len(config.C.AdTag) > 0 {
+	if config.C.MiddleProxyMode() {
 		middleConnection(req)
 	} else {
 		err = directConnection(req)

telegram/base.go

 			continue
 		}
 
-		if err := utils.InitTCP(conn); err != nil {
+		if err := utils.InitTCP(conn, config.C.ProxyReadBuffer(), config.C.ProxyWriteBuffer()); err != nil {
 			b.logger.Infow("Cannot initialize TCP socket", "address", addr, "error", err)
 			continue
 		}

utils/init_tcp.go

 	"fmt"
 	"net"
 	"time"
-
-	"github.com/9seconds/mtg/config"
 )
 
 const tcpKeepAlivePingPeriod = 2 * time.Second
 
-func InitTCP(conn net.Conn) error {
+func InitTCP(conn net.Conn, readBufferSize int, writeBufferSize int) error {
 	tcpConn := conn.(*net.TCPConn)
 
 	if err := tcpConn.SetNoDelay(true); err != nil {
 		return fmt.Errorf("cannot set TCP_NO_DELAY: %w", err)
 	}
 
-	if err := tcpConn.SetReadBuffer(config.C.ReadBuffer); err != nil {
+	if err := tcpConn.SetReadBuffer(readBufferSize); err != nil {
 		return fmt.Errorf("cannot set read buffer size: %w", err)
 	}
 
-	if err := tcpConn.SetWriteBuffer(config.C.WriteBuffer); err != nil {
+	if err := tcpConn.SetWriteBuffer(writeBufferSize); err != nil {
 		return fmt.Errorf("cannot set write buffer size: %w", err)
 	}