54 lines
1.0 KiB
Go
54 lines
1.0 KiB
Go
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// Go MySQL Driver - A MySQL-Driver for Go's database/sql package
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//
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// Copyright 2019 The Go-MySQL-Driver Authors. All rights reserved.
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this file,
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// You can obtain one at http://mozilla.org/MPL/2.0/.
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// +build !windows,!appengine
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package mysql
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import (
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"errors"
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"io"
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"net"
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"syscall"
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)
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var errUnexpectedRead = errors.New("unexpected read from socket")
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func connCheck(c net.Conn) error {
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var (
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n int
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err error
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buff [1]byte
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)
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sconn, ok := c.(syscall.Conn)
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if !ok {
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return nil
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}
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rc, err := sconn.SyscallConn()
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if err != nil {
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return err
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}
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rerr := rc.Read(func(fd uintptr) bool {
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n, err = syscall.Read(int(fd), buff[:])
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return true
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})
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switch {
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case rerr != nil:
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return rerr
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case n == 0 && err == nil:
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return io.EOF
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case n > 0:
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return errUnexpectedRead
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case err == syscall.EAGAIN || err == syscall.EWOULDBLOCK:
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return nil
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default:
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return err
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}
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}
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