perkeep/lib/go/camli/mysqlindexer/mysqlindexer.go

133 lines
3.6 KiB
Go

/*
Copyright 2011 Google Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package mysqlindexer
import (
"fmt"
"io"
"os"
"sync"
"camli/blobref"
"camli/blobserver"
"camli/jsonconfig"
mysql "camli/third_party/github.com/Philio/GoMySQL"
)
type Indexer struct {
*blobserver.SimpleBlobHubPartitionMap
Host, User, Password, Database string
Port int
// TODO: does this belong at this layer?
KeyFetcher blobref.StreamingFetcher // for verifying claims
OwnerBlobRef *blobref.BlobRef
clientLock sync.Mutex
cachedClients []*mysql.Client
}
func newFromConfig(_ blobserver.Loader, config jsonconfig.Obj) (blobserver.Storage, os.Error) {
indexer := &Indexer{
SimpleBlobHubPartitionMap: &blobserver.SimpleBlobHubPartitionMap{},
Host: config.OptionalString("host", "localhost"),
User: config.RequiredString("user"),
Password: config.OptionalString("password", ""),
Database: config.RequiredString("database"),
}
if err := config.Validate(); err != nil {
return nil, err
}
//ownerBlobRef = client.SignerPublicKeyBlobref()
//if ownerBlobRef == nil {
// log.Fatalf("Public key not configured.")
//}
//KeyFetcher: blobref.NewSerialStreamingFetcher(
// blobref.NewConfigDirFetcher(),
// storage),
//}
ok, err := indexer.IsAlive()
if !ok {
return nil, fmt.Errorf("Failed to connect to MySQL: %v", err)
}
return indexer, nil
}
func init() {
blobserver.RegisterStorageConstructor("mysqlindexer", blobserver.StorageConstructor(newFromConfig))
}
func (mi *Indexer) IsAlive() (ok bool, err os.Error) {
var client *mysql.Client
client, err = mi.getConnection()
if err != nil {
return
}
defer mi.releaseConnection(client)
err = client.Query("SELECT 1 + 1")
if err != nil {
return
}
_, err = client.UseResult()
if err != nil {
return
}
client.FreeResult()
return true, nil
}
// Get a free cached connection or allocate a new one.
func (mi *Indexer) getConnection() (client *mysql.Client, err os.Error) {
mi.clientLock.Lock()
if len(mi.cachedClients) > 0 {
defer mi.clientLock.Unlock()
client = mi.cachedClients[len(mi.cachedClients)-1]
mi.cachedClients = mi.cachedClients[:len(mi.cachedClients)-1]
// TODO: Outside the mutex, double check that the client is still good.
return
}
mi.clientLock.Unlock()
client, err = mysql.DialTCP(mi.Host, mi.User, mi.Password, mi.Database)
return
}
// Release a client to the cached client pool.
func (mi *Indexer) releaseConnection(client *mysql.Client) {
mi.clientLock.Lock()
defer mi.clientLock.Unlock()
mi.cachedClients = append(mi.cachedClients, client)
}
func (mi *Indexer) Fetch(blob *blobref.BlobRef) (blobref.ReadSeekCloser, int64, os.Error) {
return nil, 0, os.NewError("Fetch isn't supported by the MySQL indexer")
}
func (mi *Indexer) FetchStreaming(blob *blobref.BlobRef) (io.ReadCloser, int64, os.Error) {
return nil, 0, os.NewError("Fetch isn't supported by the MySQL indexer")
}
func (mi *Indexer) Remove(blobs []*blobref.BlobRef) os.Error {
return os.NewError("Remove isn't supported by the MySQL indexer")
}