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// Go MySQL Driver - A MySQL-Driver for Go's database/sql package
//
// Copyright 2012 The Go-MySQL-Driver Authors. All rights reserved.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at http://mozilla.org/MPL/2.0/.
// +build go1.8
package mysql
import (
"context"
"database/sql"
"database/sql/driver"
)
// Ping implements driver.Pinger interface
func (mc *mysqlConn) Ping(ctx context.Context) error {
if mc.closed.IsSet() {
errLog.Print(ErrInvalidConn)
return driver.ErrBadConn
}
if err := mc.watchCancel(ctx); err != nil {
return err
}
defer mc.finish()
if err := mc.writeCommandPacket(comPing); err != nil {
return err
}
if _, err := mc.readResultOK(); err != nil {
return err
}
return nil
}
// BeginTx implements driver.ConnBeginTx interface
func (mc *mysqlConn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, error) {
if err := mc.watchCancel(ctx); err != nil {
return nil, err
}
defer mc.finish()
if sql.IsolationLevel(opts.Isolation) != sql.LevelDefault {
level, err := mapIsolationLevel(opts.Isolation)
if err != nil {
return nil, err
}
err = mc.exec("SET TRANSACTION ISOLATION LEVEL " + level)
if err != nil {
return nil, err
}
}
return mc.begin(opts.ReadOnly)
}
func (mc *mysqlConn) QueryContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Rows, error) {
dargs, err := namedValueToValue(args)
if err != nil {
return nil, err
}
if err := mc.watchCancel(ctx); err != nil {
return nil, err
}
rows, err := mc.query(query, dargs)
if err != nil {
mc.finish()
return nil, err
}
rows.finish = mc.finish
return rows, err
}
func (mc *mysqlConn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
dargs, err := namedValueToValue(args)
if err != nil {
return nil, err
}
if err := mc.watchCancel(ctx); err != nil {
return nil, err
}
defer mc.finish()
return mc.Exec(query, dargs)
}
func (mc *mysqlConn) PrepareContext(ctx context.Context, query string) (driver.Stmt, error) {
if err := mc.watchCancel(ctx); err != nil {
return nil, err
}
stmt, err := mc.Prepare(query)
mc.finish()
if err != nil {
return nil, err
}
select {
default:
case <-ctx.Done():
stmt.Close()
return nil, ctx.Err()
}
return stmt, nil
}
func (stmt *mysqlStmt) QueryContext(ctx context.Context, args []driver.NamedValue) (driver.Rows, error) {
dargs, err := namedValueToValue(args)
if err != nil {
return nil, err
}
if err := stmt.mc.watchCancel(ctx); err != nil {
return nil, err
}
rows, err := stmt.query(dargs)
if err != nil {
stmt.mc.finish()
return nil, err
}
rows.finish = stmt.mc.finish
return rows, err
}
func (stmt *mysqlStmt) ExecContext(ctx context.Context, args []driver.NamedValue) (driver.Result, error) {
dargs, err := namedValueToValue(args)
if err != nil {
return nil, err
}
if err := stmt.mc.watchCancel(ctx); err != nil {
return nil, err
}
defer stmt.mc.finish()
return stmt.Exec(dargs)
}
func (mc *mysqlConn) watchCancel(ctx context.Context) error {
if mc.watching {
// Reach here if canceled,
// so the connection is already invalid
mc.cleanup()
return nil
}
if ctx.Done() == nil {
return nil
}
mc.watching = true
select {
default:
case <-ctx.Done():
return ctx.Err()
}
if mc.watcher == nil {
return nil
}
mc.watcher <- ctx
return nil
}
func (mc *mysqlConn) startWatcher() {
watcher := make(chan mysqlContext, 1)
mc.watcher = watcher
finished := make(chan struct{})
mc.finished = finished
go func() {
for {
var ctx mysqlContext
select {
case ctx = <-watcher:
case <-mc.closech:
return
}
select {
case <-ctx.Done():
mc.cancel(ctx.Err())
case <-finished:
case <-mc.closech:
return
}
}
}()
}
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