mirror of https://github.com/k3s-io/k3s
95 lines
2.6 KiB
Go
95 lines
2.6 KiB
Go
/*
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Copyright 2018 The Kubernetes 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 v1alpha1
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import (
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"errors"
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"sync"
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)
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const (
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// NotFound is the not found error message.
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NotFound = "not found"
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)
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// ContextData is a generic type for arbitrary data stored in PluginContext.
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type ContextData interface{}
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// ContextKey is the type of keys stored in PluginContext.
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type ContextKey string
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// PluginContext provides a mechanism for plugins to store and retrieve arbitrary data.
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// ContextData stored by one plugin can be read, altered, or deleted by another plugin.
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// PluginContext does not provide any data protection, as all plugins are assumed to be
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// trusted.
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type PluginContext struct {
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Mx sync.RWMutex
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storage map[ContextKey]ContextData
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}
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// NewPluginContext initializes a new PluginContext and returns its pointer.
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func NewPluginContext() *PluginContext {
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return &PluginContext{
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storage: make(map[ContextKey]ContextData),
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}
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}
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// Read retrieves data with the given "key" from PluginContext. If the key is not
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// present an error is returned.
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func (c *PluginContext) Read(key ContextKey) (ContextData, error) {
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if v, ok := c.storage[key]; ok {
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return v, nil
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}
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return nil, errors.New(NotFound)
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}
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// SyncRead is the thread safe version of Read(...).
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func (c *PluginContext) SyncRead(key ContextKey) (ContextData, error) {
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c.Mx.RLock()
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defer c.Mx.RUnlock()
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return c.Read(key)
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}
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// Write stores the given "val" in PluginContext with the given "key".
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func (c *PluginContext) Write(key ContextKey, val ContextData) {
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c.storage[key] = val
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}
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// SyncWrite is the thread safe version of Write(...).
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func (c *PluginContext) SyncWrite(key ContextKey, val ContextData) {
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c.Mx.Lock()
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defer c.Mx.Unlock()
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c.Write(key, val)
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}
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// Delete deletes data with the given key from PluginContext.
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func (c *PluginContext) Delete(key ContextKey) {
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delete(c.storage, key)
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}
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// SyncDelete is the thread safe version of Write(...).
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func (c *PluginContext) SyncDelete(key ContextKey) {
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c.Mx.Lock()
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defer c.Mx.Unlock()
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c.Delete(key)
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}
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// Reset removes all the information in the PluginContext.
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func (c *PluginContext) Reset() {
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c.storage = make(map[ContextKey]ContextData)
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}
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