mirror of https://github.com/perkeep/perkeep.git
131 lines
3.9 KiB
Go
131 lines
3.9 KiB
Go
/*
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Copyright 2011 The Camlistore Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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// Package mysql provides an implementation of sorted.KeyValue
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// on top of MySQL.
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package mysql
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import (
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"database/sql"
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"fmt"
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"os"
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"camlistore.org/pkg/jsonconfig"
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"camlistore.org/pkg/sorted"
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"camlistore.org/pkg/sorted/sqlkv"
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_ "camlistore.org/third_party/github.com/ziutek/mymysql/godrv"
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)
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func init() {
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sorted.RegisterKeyValue("mysql", newKeyValueFromJSONConfig)
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}
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// Config holds the parameters used to connect to the MySQL db.
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type Config struct {
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Host string // Optional. Defaults to "localhost" in ConfigFromJSON.
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Database string // Required.
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User string // Required.
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Password string // Optional.
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}
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// ConfigFromJSON populates Config from config, and validates
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// config. It returns an error if config fails to validate.
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func ConfigFromJSON(config jsonconfig.Obj) (Config, error) {
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conf := Config{
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Host: config.OptionalString("host", "localhost"),
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User: config.RequiredString("user"),
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Password: config.OptionalString("password", ""),
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Database: config.RequiredString("database"),
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}
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if err := config.Validate(); err != nil {
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return Config{}, err
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}
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return conf, nil
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}
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func newKeyValueFromJSONConfig(cfg jsonconfig.Obj) (sorted.KeyValue, error) {
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conf, err := ConfigFromJSON(cfg)
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if err != nil {
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return nil, err
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}
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return NewKeyValue(conf)
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}
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// NewKeyValue returns a sorted.KeyValue implementation of the described MySQL database.
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func NewKeyValue(cfg Config) (sorted.KeyValue, error) {
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// TODO(bradfitz,mpl): host is ignored for now. I think we can connect to host with:
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// tcp:ADDR*DBNAME/USER/PASSWD (http://godoc.org/github.com/ziutek/mymysql/godrv#Driver.Open)
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// I suppose we'll have to do a lookup first.
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dsn := cfg.Database + "/" + cfg.User + "/" + cfg.Password
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db, err := sql.Open("mymysql", dsn)
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if err != nil {
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return nil, err
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}
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kv := &keyValue{
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db: db,
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KeyValue: &sqlkv.KeyValue{
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DB: db,
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},
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conf: cfg,
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}
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if err := kv.ping(); err != nil {
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return nil, fmt.Errorf("MySQL db unreachable: %v", err)
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}
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version, err := kv.SchemaVersion()
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if err != nil {
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return nil, fmt.Errorf("error getting schema version (need to init database?): %v", err)
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}
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if version != requiredSchemaVersion {
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if version == 20 && requiredSchemaVersion == 21 {
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fmt.Fprintf(os.Stderr, fixSchema20to21)
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}
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if os.Getenv("CAMLI_DEV_CAMLI_ROOT") != "" {
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// Good signal that we're using the devcam server, so help out
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// the user with a more useful tip:
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return nil, fmt.Errorf("database schema version is %d; expect %d (run \"devcam server --wipe\" to wipe both your blobs and re-populate the database schema)", version, requiredSchemaVersion)
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}
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return nil, fmt.Errorf("database schema version is %d; expect %d (need to re-init/upgrade database?)",
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version, requiredSchemaVersion)
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}
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return kv, nil
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}
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type keyValue struct {
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*sqlkv.KeyValue
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conf Config
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db *sql.DB
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}
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func (kv *keyValue) ping() error {
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// TODO(bradfitz): something more efficient here?
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_, err := kv.SchemaVersion()
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return err
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}
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func (kv *keyValue) SchemaVersion() (version int, err error) {
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err = kv.db.QueryRow("SELECT value FROM meta WHERE metakey='version'").Scan(&version)
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return
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}
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const fixSchema20to21 = `Character set in tables changed to binary, you can fix your tables with:
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ALTER TABLE rows CONVERT TO CHARACTER SET binary;
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ALTER TABLE meta CONVERT TO CHARACTER SET binary;
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UPDATE meta SET value=21 WHERE metakey='version' AND value=20;
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`
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