58 lines
1.2 KiB
Go
58 lines
1.2 KiB
Go
// +build linux darwin dragonfly freebsd netbsd openbsd solaris illumos
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package clickhouse
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import (
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"errors"
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"fmt"
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"io"
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"syscall"
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"time"
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)
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var errUnexpectedRead = errors.New("unexpected read from socket")
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func (conn *connect) connCheck() error {
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var sysErr error
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sysConn, ok := conn.Conn.(syscall.Conn)
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if !ok {
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return nil
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}
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rawConn, err := sysConn.SyscallConn()
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if err != nil {
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return err
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}
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// If this connection has a ReadTimeout which we've been setting on
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// reads, reset it to zero value before we attempt a non-blocking
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// read, otherwise we may get os.ErrDeadlineExceeded for the cached
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// connection from the pool with an expired timeout.
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if conn.readTimeout != 0 {
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err = conn.SetReadDeadline(time.Time{})
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if err != nil {
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return fmt.Errorf("set read deadline: %w", err)
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}
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conn.lastReadDeadlineTime = time.Time{}
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}
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err = rawConn.Read(func(fd uintptr) bool {
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var buf [1]byte
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n, err := syscall.Read(int(fd), buf[:])
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switch {
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case n == 0 && err == nil:
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sysErr = io.EOF
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case n > 0:
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sysErr = errUnexpectedRead
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case err == syscall.EAGAIN || err == syscall.EWOULDBLOCK:
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sysErr = nil
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default:
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sysErr = err
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}
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return true
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})
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if err != nil {
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return err
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}
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return sysErr
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}
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