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// Go MySQL Driver - A MySQL-Driver for Go's database/sql package
//
// Copyright 2013 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/.
package mysql
import (
"fmt"
"io"
"os"
"strings"
"sync"
)
var (
fileRegister map[string]bool
fileRegisterLock sync.RWMutex
readerRegister map[string]func() io.Reader
readerRegisterLock sync.RWMutex
)
// RegisterLocalFile adds the given file to the file whitelist,
// so that it can be used by "LOAD DATA LOCAL INFILE <filepath>".
// Alternatively you can allow the use of all local files with
// the DSN parameter 'allowAllFiles=true'
//
// filePath := "/home/gopher/data.csv"
// mysql.RegisterLocalFile(filePath)
// err := db.Exec("LOAD DATA LOCAL INFILE '" + filePath + "' INTO TABLE foo")
// if err != nil {
// ...
//
func RegisterLocalFile(filePath string) {
fileRegisterLock.Lock()
// lazy map init
if fileRegister == nil {
fileRegister = make(map[string]bool)
}
fileRegister[strings.Trim(filePath, `"`)] = true
fileRegisterLock.Unlock()
}
// DeregisterLocalFile removes the given filepath from the whitelist.
func DeregisterLocalFile(filePath string) {
fileRegisterLock.Lock()
delete(fileRegister, strings.Trim(filePath, `"`))
fileRegisterLock.Unlock()
}
// RegisterReaderHandler registers a handler function which is used
// to receive a io.Reader.
// The Reader can be used by "LOAD DATA LOCAL INFILE Reader::<name>".
// If the handler returns a io.ReadCloser Close() is called when the
// request is finished.
//
// mysql.RegisterReaderHandler("data", func() io.Reader {
// var csvReader io.Reader // Some Reader that returns CSV data
// ... // Open Reader here
// return csvReader
// })
// err := db.Exec("LOAD DATA LOCAL INFILE 'Reader::data' INTO TABLE foo")
// if err != nil {
// ...
//
func RegisterReaderHandler(name string, handler func() io.Reader) {
readerRegisterLock.Lock()
// lazy map init
if readerRegister == nil {
readerRegister = make(map[string]func() io.Reader)
}
readerRegister[name] = handler
readerRegisterLock.Unlock()
}
// DeregisterReaderHandler removes the ReaderHandler function with
// the given name from the registry.
func DeregisterReaderHandler(name string) {
readerRegisterLock.Lock()
delete(readerRegister, name)
readerRegisterLock.Unlock()
}
func deferredClose(err *error, closer io.Closer) {
closeErr := closer.Close()
if *err == nil {
*err = closeErr
}
}
func (mc *mysqlConn) handleInFileRequest(name string) (err error) {
var rdr io.Reader
var data []byte
packetSize := 16 * 1024 // 16KB is small enough for disk readahead and large enough for TCP
if mc.maxWriteSize < packetSize {
packetSize = mc.maxWriteSize
}
if idx := strings.Index(name, "Reader::"); idx == 0 || (idx > 0 && name[idx-1] == '/') { // io.Reader
// The server might return an an absolute path. See issue #355.
name = name[idx+8:]
readerRegisterLock.RLock()
handler, inMap := readerRegister[name]
readerRegisterLock.RUnlock()
if inMap {
rdr = handler()
if rdr != nil {
if cl, ok := rdr.(io.Closer); ok {
defer deferredClose(&err, cl)
}
} else {
err = fmt.Errorf("Reader '%s' is <nil>", name)
}
} else {
err = fmt.Errorf("Reader '%s' is not registered", name)
}
} else { // File
name = strings.Trim(name, `"`)
fileRegisterLock.RLock()
fr := fileRegister[name]
fileRegisterLock.RUnlock()
if mc.cfg.AllowAllFiles || fr {
var file *os.File
var fi os.FileInfo
if file, err = os.Open(name); err == nil {
defer deferredClose(&err, file)
// get file size
if fi, err = file.Stat(); err == nil {
rdr = file
if fileSize := int(fi.Size()); fileSize < packetSize {
packetSize = fileSize
}
}
}
} else {
err = fmt.Errorf("local file '%s' is not registered", name)
}
}
// send content packets
// if packetSize == 0, the Reader contains no data
if err == nil && packetSize > 0 {
data := make([]byte, 4+packetSize)
var n int
for err == nil {
n, err = rdr.Read(data[4:])
if n > 0 {
if ioErr := mc.writePacket(data[:4+n]); ioErr != nil {
return ioErr
}
}
}
if err == io.EOF {
err = nil
}
}
// send empty packet (termination)
if data == nil {
data = make([]byte, 4)
}
if ioErr := mc.writePacket(data[:4]); ioErr != nil {
return ioErr
}
// read OK packet
if err == nil {
return mc.readResultOK()
}
mc.readPacket()
return err
}