7ddc75c41b
commit6bf9fe89f6Author: Satnam Singh <satnam@google.com> Date: Fri Sep 26 10:23:16 2014 -0700 Change error to warning during handling check. commitc580907183Author: Satnam Singh <satnam@google.com> Date: Fri Sep 26 10:21:41 2014 -0700 Decapatalise fmt.Errorf error messages. commit3ecc5745d6Author: Satnam Singh <satnam@google.com> Date: Fri Sep 26 10:19:15 2014 -0700 Fix misunderstanding about when CanHandle fails. commitadce0c5433Author: Satnam Singh <satnam@google.com> Date: Fri Sep 26 10:13:32 2014 -0700 Change the interface of CanHandle to return error information.
78 lines
2.3 KiB
Go
78 lines
2.3 KiB
Go
// Copyright 2014 Google Inc. All Rights Reserved.
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//
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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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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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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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package container
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import (
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"fmt"
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"sync"
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"github.com/golang/glog"
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)
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type ContainerHandlerFactory interface {
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// Create a new ContainerHandler using this factory. CanHandle() must have returned true.
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NewContainerHandler(name string) (ContainerHandler, error)
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// Returns whether this factory can handle the specified container.
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CanHandle(name string) (bool, error)
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// Name of the factory.
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String() string
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}
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// TODO(vmarmol): Consider not making this global.
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// Global list of factories.
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var (
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factories []ContainerHandlerFactory
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factoriesLock sync.RWMutex
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)
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// Register a ContainerHandlerFactory. These should be registered from least general to most general
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// as they will be asked in order whether they can handle a particular container.
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func RegisterContainerHandlerFactory(factory ContainerHandlerFactory) {
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factoriesLock.Lock()
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defer factoriesLock.Unlock()
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factories = append(factories, factory)
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}
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// Create a new ContainerHandler for the specified container.
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func NewContainerHandler(name string) (ContainerHandler, error) {
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factoriesLock.RLock()
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defer factoriesLock.RUnlock()
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// Create the ContainerHandler with the first factory that supports it.
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for _, factory := range factories {
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canHandle, err := factory.CanHandle(name)
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if err != nil {
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glog.V(1).Infof("Error trying to work out if we can hande %s: %v", name, err)
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}
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if canHandle {
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glog.V(1).Infof("Using factory %q for container %q", factory.String(), name)
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return factory.NewContainerHandler(name)
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}
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}
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return nil, fmt.Errorf("no known factory can handle creation of container")
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}
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// Clear the known factories.
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func ClearContainerHandlerFactories() {
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factoriesLock.Lock()
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defer factoriesLock.Unlock()
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factories = make([]ContainerHandlerFactory, 0, 4)
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}
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