https://github.com/google/cayley
Tip revision: 6fb42084bad95ecdb98a4bf9eb354c82558c7506 authored by 3pCode on 07 January 2019, 16:42:23 UTC
Merge pull request #1 from cayleygraph/master
Merge pull request #1 from cayleygraph/master
Tip revision: 6fb4208
registry.go
// Copyright 2014 The Cayley Authors. All rights reserved.
//
// 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 graph
import (
"fmt"
"sort"
)
var (
ErrQuadStoreNotRegistred = fmt.Errorf("This QuadStore is not registered.")
ErrQuadStoreNotPersistent = fmt.Errorf("cannot specify address for non-persistent backend")
ErrOperationNotSupported = fmt.Errorf("This Operation is not supported.")
)
var storeRegistry = make(map[string]QuadStoreRegistration)
type NewStoreFunc func(string, Options) (QuadStore, error)
type InitStoreFunc func(string, Options) error
type UpgradeStoreFunc func(string, Options) error
type QuadStoreRegistration struct {
NewFunc NewStoreFunc
UpgradeFunc UpgradeStoreFunc
InitFunc InitStoreFunc
IsPersistent bool
}
func RegisterQuadStore(name string, register QuadStoreRegistration) {
if register.NewFunc == nil {
panic("NewFunc must not be nil")
}
// Register QuadStore with friendly name
if _, found := storeRegistry[name]; found {
panic(fmt.Sprintf("Already registered QuadStore %q.", name))
}
storeRegistry[name] = register
}
func NewQuadStore(name string, dbpath string, opts Options) (QuadStore, error) {
r, registered := storeRegistry[name]
if !registered {
return nil, ErrQuadStoreNotRegistred
} else if dbpath != "" && !r.IsPersistent {
return nil, ErrQuadStoreNotPersistent
}
return r.NewFunc(dbpath, opts)
}
func InitQuadStore(name string, dbpath string, opts Options) error {
r, registered := storeRegistry[name]
if !registered {
return ErrQuadStoreNotRegistred
} else if r.InitFunc == nil {
return ErrOperationNotSupported
}
return r.InitFunc(dbpath, opts)
}
func UpgradeQuadStore(name string, dbpath string, opts Options) error {
r, registered := storeRegistry[name]
if !registered {
return ErrQuadStoreNotRegistred
} else if r.UpgradeFunc == nil {
// return ErrOperationNotSupported
return nil
}
return r.UpgradeFunc(dbpath, opts)
}
func IsRegistered(name string) bool {
_, ok := storeRegistry[name]
return ok
}
func IsPersistent(name string) bool {
return storeRegistry[name].IsPersistent
}
func QuadStores() []string {
t := make([]string, 0, len(storeRegistry))
for n := range storeRegistry {
t = append(t, n)
}
sort.Strings(t)
return t
}