Retro68/gcc/libgo/go/database/sql/ctxutil.go
2018-12-28 16:30:48 +01:00

149 lines
3.6 KiB
Go

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package sql
import (
"context"
"database/sql/driver"
"errors"
)
func ctxDriverPrepare(ctx context.Context, ci driver.Conn, query string) (driver.Stmt, error) {
if ciCtx, is := ci.(driver.ConnPrepareContext); is {
return ciCtx.PrepareContext(ctx, query)
}
si, err := ci.Prepare(query)
if err == nil {
select {
default:
case <-ctx.Done():
si.Close()
return nil, ctx.Err()
}
}
return si, err
}
func ctxDriverExec(ctx context.Context, execerCtx driver.ExecerContext, execer driver.Execer, query string, nvdargs []driver.NamedValue) (driver.Result, error) {
if execerCtx != nil {
return execerCtx.ExecContext(ctx, query, nvdargs)
}
dargs, err := namedValueToValue(nvdargs)
if err != nil {
return nil, err
}
select {
default:
case <-ctx.Done():
return nil, ctx.Err()
}
return execer.Exec(query, dargs)
}
func ctxDriverQuery(ctx context.Context, queryerCtx driver.QueryerContext, queryer driver.Queryer, query string, nvdargs []driver.NamedValue) (driver.Rows, error) {
if queryerCtx != nil {
return queryerCtx.QueryContext(ctx, query, nvdargs)
}
dargs, err := namedValueToValue(nvdargs)
if err != nil {
return nil, err
}
select {
default:
case <-ctx.Done():
return nil, ctx.Err()
}
return queryer.Query(query, dargs)
}
func ctxDriverStmtExec(ctx context.Context, si driver.Stmt, nvdargs []driver.NamedValue) (driver.Result, error) {
if siCtx, is := si.(driver.StmtExecContext); is {
return siCtx.ExecContext(ctx, nvdargs)
}
dargs, err := namedValueToValue(nvdargs)
if err != nil {
return nil, err
}
select {
default:
case <-ctx.Done():
return nil, ctx.Err()
}
return si.Exec(dargs)
}
func ctxDriverStmtQuery(ctx context.Context, si driver.Stmt, nvdargs []driver.NamedValue) (driver.Rows, error) {
if siCtx, is := si.(driver.StmtQueryContext); is {
return siCtx.QueryContext(ctx, nvdargs)
}
dargs, err := namedValueToValue(nvdargs)
if err != nil {
return nil, err
}
select {
default:
case <-ctx.Done():
return nil, ctx.Err()
}
return si.Query(dargs)
}
var errLevelNotSupported = errors.New("sql: selected isolation level is not supported")
func ctxDriverBegin(ctx context.Context, opts *TxOptions, ci driver.Conn) (driver.Tx, error) {
if ciCtx, is := ci.(driver.ConnBeginTx); is {
dopts := driver.TxOptions{}
if opts != nil {
dopts.Isolation = driver.IsolationLevel(opts.Isolation)
dopts.ReadOnly = opts.ReadOnly
}
return ciCtx.BeginTx(ctx, dopts)
}
if opts != nil {
// Check the transaction level. If the transaction level is non-default
// then return an error here as the BeginTx driver value is not supported.
if opts.Isolation != LevelDefault {
return nil, errors.New("sql: driver does not support non-default isolation level")
}
// If a read-only transaction is requested return an error as the
// BeginTx driver value is not supported.
if opts.ReadOnly {
return nil, errors.New("sql: driver does not support read-only transactions")
}
}
if ctx.Done() == nil {
return ci.Begin()
}
txi, err := ci.Begin()
if err == nil {
select {
default:
case <-ctx.Done():
txi.Rollback()
return nil, ctx.Err()
}
}
return txi, err
}
func namedValueToValue(named []driver.NamedValue) ([]driver.Value, error) {
dargs := make([]driver.Value, len(named))
for n, param := range named {
if len(param.Name) > 0 {
return nil, errors.New("sql: driver does not support the use of Named Parameters")
}
dargs[n] = param.Value
}
return dargs, nil
}