130 lines
3.2 KiB
Go
130 lines
3.2 KiB
Go
// Copyright 2014 Google Inc. 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 container
|
|
|
|
import (
|
|
"fmt"
|
|
"log"
|
|
"strings"
|
|
"sync"
|
|
)
|
|
|
|
type ContainerHandlerFactory interface {
|
|
NewContainerHandler(name string) (ContainerHandler, error)
|
|
|
|
// for testability
|
|
String() string
|
|
}
|
|
|
|
type factoryTreeNode struct {
|
|
defaultFactory ContainerHandlerFactory
|
|
children map[string]*factoryTreeNode
|
|
}
|
|
|
|
func (self *factoryTreeNode) find(elems ...string) ContainerHandlerFactory {
|
|
node := self
|
|
for _, elem := range elems {
|
|
if len(node.children) == 0 {
|
|
break
|
|
}
|
|
if child, ok := node.children[elem]; ok {
|
|
node = child
|
|
} else {
|
|
return node.defaultFactory
|
|
}
|
|
}
|
|
|
|
return node.defaultFactory
|
|
}
|
|
|
|
func (self *factoryTreeNode) add(factory ContainerHandlerFactory, elems ...string) {
|
|
node := self
|
|
for _, elem := range elems {
|
|
if node.children == nil {
|
|
node.children = make(map[string]*factoryTreeNode, 16)
|
|
}
|
|
child, ok := self.children[elem]
|
|
if !ok {
|
|
child = &factoryTreeNode{
|
|
defaultFactory: node.defaultFactory,
|
|
children: make(map[string]*factoryTreeNode, 16),
|
|
}
|
|
node.children[elem] = child
|
|
}
|
|
node = child
|
|
}
|
|
node.defaultFactory = factory
|
|
}
|
|
|
|
type factoryManager struct {
|
|
root *factoryTreeNode
|
|
lock sync.RWMutex
|
|
}
|
|
|
|
func dropEmptyString(elems ...string) []string {
|
|
ret := make([]string, 0, len(elems))
|
|
for _, e := range elems {
|
|
if len(e) > 0 {
|
|
ret = append(ret, e)
|
|
}
|
|
}
|
|
return ret
|
|
}
|
|
|
|
// Must register factory for root container!
|
|
func (self *factoryManager) Register(path string, factory ContainerHandlerFactory) {
|
|
self.lock.Lock()
|
|
defer self.lock.Unlock()
|
|
|
|
if self.root == nil {
|
|
self.root = &factoryTreeNode{
|
|
defaultFactory: nil,
|
|
children: make(map[string]*factoryTreeNode, 10),
|
|
}
|
|
}
|
|
|
|
elems := dropEmptyString(strings.Split(path, "/")...)
|
|
self.root.add(factory, elems...)
|
|
}
|
|
|
|
func (self *factoryManager) NewContainerHandler(path string) (ContainerHandler, error) {
|
|
self.lock.RLock()
|
|
defer self.lock.RUnlock()
|
|
|
|
if self.root == nil {
|
|
err := fmt.Errorf("nil factory for container %v: no factory registered", path)
|
|
return nil, err
|
|
}
|
|
|
|
elems := dropEmptyString(strings.Split(path, "/")...)
|
|
factory := self.root.find(elems...)
|
|
if factory == nil {
|
|
err := fmt.Errorf("nil factory for container %v", path)
|
|
return nil, err
|
|
}
|
|
log.Printf("Container handler factory for %v is %v\n", path, factory)
|
|
return factory.NewContainerHandler(path)
|
|
}
|
|
|
|
var globalFactoryManager factoryManager
|
|
|
|
func RegisterContainerHandlerFactory(path string, factory ContainerHandlerFactory) {
|
|
globalFactoryManager.Register(path, factory)
|
|
}
|
|
|
|
func NewContainerHandler(path string) (ContainerHandler, error) {
|
|
return globalFactoryManager.NewContainerHandler(path)
|
|
}
|