/
tcp4Connection.go
168 lines (135 loc) · 4.17 KB
/
tcp4Connection.go
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package connection
import (
"net"
"sync"
"time"
)
type TCP4Connection struct {
dialer net.Dialer
underlyingConn net.Conn
keepAlive time.Duration
mu sync.RWMutex
Closed bool
}
func NewTCPConnection(keepAlive time.Duration) *TCP4Connection {
c := new(TCP4Connection)
c.dialer = net.Dialer{}
c.dialer.KeepAlive = keepAlive
return c
}
// Read reads data from the connection.
// Read can be made to time out and return an error after a fixed
// time limit; see SetDeadline and SetReadDeadline.
func (tc *TCP4Connection) Read(b []byte) (n int, err error) {
tc.mu.RLock()
defer tc.mu.RUnlock()
if tc.underlyingConn == nil {
return 0, ErrNotConnected
}
return tc.underlyingConn.Read(b)
}
// Write writes data to the connection.
// Write can be made to time out and return an error after a fixed
// time limit; see SetDeadline and SetWriteDeadline.
func (tc *TCP4Connection) Write(b []byte) (n int, err error) {
tc.mu.RLock()
defer tc.mu.RUnlock()
if tc.underlyingConn == nil {
return 0, ErrNotConnected
}
return tc.underlyingConn.Write(b)
}
// Close closes the connection.
// Any blocked Read or Write operations will be unblocked and return errors.
func (tc *TCP4Connection) Close() error {
tc.mu.RLock()
defer tc.mu.RUnlock()
if tc.underlyingConn == nil {
return ErrNotConnected
}
tc.Closed = true
return tc.underlyingConn.Close()
}
// LocalAddr returns the local network address, if known.
func (tc *TCP4Connection) LocalAddr() net.Addr {
tc.mu.RLock()
defer tc.mu.RUnlock()
if tc.underlyingConn == nil {
return nil
}
return tc.underlyingConn.LocalAddr()
}
// RemoteAddr returns the remote network address, if known.
func (tc *TCP4Connection) RemoteAddr() net.Addr {
tc.mu.RLock()
defer tc.mu.RUnlock()
if tc.underlyingConn == nil {
return nil
}
return tc.underlyingConn.RemoteAddr()
}
// SetDeadline sets the read and write deadlines associated
// with the connection. It is equivalent to calling both
// SetReadDeadline and SetWriteDeadline.
//
// A deadline is an absolute time after which I/O operations
// fail instead of blocking. The deadline applies to all future
// and pending I/O, not just the immediately following call to
// Read or Write. After a deadline has been exceeded, the
// connection can be refreshed by setting a deadline in the future.
//
// If the deadline is exceeded a call to Read or Write or to other
// I/O methods will return an error that wraps os.ErrDeadlineExceeded.
// This can be tested using errors.Is(err, os.ErrDeadlineExceeded).
// The error's Timeout method will return true, but note that there
// are other possible errors for which the Timeout method will
// return true even if the deadline has not been exceeded.
//
// An idle timeout can be implemented by repeatedly extending
// the deadline after successful Read or Write calls.
//
// A zero value for t means I/O operations will not time out.
func (tc *TCP4Connection) SetDeadline(t time.Time) error {
tc.mu.RLock()
defer tc.mu.RUnlock()
if tc.underlyingConn == nil {
return ErrNotConnected
}
return tc.underlyingConn.SetDeadline(t)
}
// SetReadDeadline sets the deadline for future Read calls
// and any currently-blocked Read call.
// A zero value for t means Read will not time out.
func (tc *TCP4Connection) SetReadDeadline(t time.Time) error {
tc.mu.RLock()
defer tc.mu.RUnlock()
if tc.underlyingConn == nil {
return ErrNotConnected
}
return tc.underlyingConn.SetReadDeadline(t)
}
// SetWriteDeadline sets the deadline for future Write calls
// and any currently-blocked Write call.
// Even if write times out, it may return n > 0, indicating that
// some of the data was successfully written.
// A zero value for t means Write will not time out.
func (tc *TCP4Connection) SetWriteDeadline(t time.Time) error {
tc.mu.RLock()
defer tc.mu.RUnlock()
if tc.underlyingConn == nil {
return ErrNotConnected
}
return tc.underlyingConn.SetWriteDeadline(t)
}
// Establish connection with remote side.
// LocalAddr get local addr.
func (tc *TCP4Connection) Connect(addr net.Addr) error {
tc.mu.Lock()
defer tc.mu.Unlock()
conn, err := tc.dialer.Dial("tcp4", addr.String())
if err != nil {
return err
}
tc.underlyingConn = conn
return nil
}