137 lines
3.1 KiB
Go
137 lines
3.1 KiB
Go
package main
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import (
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"encoding/json"
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"github.com/coreos/etcd/store"
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"github.com/coreos/go-raft"
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"time"
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)
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// A command represents an action to be taken on the replicated state machine.
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type Command interface {
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CommandName() string
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Apply(server *raft.Server) (interface{}, error)
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}
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// Set command
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type SetCommand struct {
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Key string `json:"key"`
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Value string `json:"value"`
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ExpireTime time.Time `json:"expireTime"`
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}
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// The name of the set command in the log
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func (c *SetCommand) CommandName() string {
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return "set"
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}
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// Set the key-value pair
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func (c *SetCommand) Apply(server *raft.Server) (interface{}, error) {
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return etcdStore.Set(c.Key, c.Value, c.ExpireTime, server.CommitIndex())
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}
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// TestAndSet command
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type TestAndSetCommand struct {
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Key string `json:"key"`
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Value string `json:"value"`
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PrevValue string `json: prevValue`
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ExpireTime time.Time `json:"expireTime"`
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}
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// The name of the testAndSet command in the log
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func (c *TestAndSetCommand) CommandName() string {
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return "testAndSet"
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}
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// Set the key-value pair if the current value of the key equals to the given prevValue
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func (c *TestAndSetCommand) Apply(server *raft.Server) (interface{}, error) {
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return etcdStore.TestAndSet(c.Key, c.PrevValue, c.Value, c.ExpireTime, server.CommitIndex())
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}
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// Get command
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type GetCommand struct {
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Key string `json:"key"`
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}
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// The name of the get command in the log
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func (c *GetCommand) CommandName() string {
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return "get"
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}
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// Get the value of key
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func (c *GetCommand) Apply(server *raft.Server) (interface{}, error) {
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res := etcdStore.Get(c.Key)
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return json.Marshal(res)
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}
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// List command
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type ListCommand struct {
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Prefix string `json:"prefix"`
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}
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// The name of the list command in the log
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func (c *ListCommand) CommandName() string {
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return "list"
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}
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// List all the keys have the given prefix path
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func (c *ListCommand) Apply(server *raft.Server) (interface{}, error) {
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return etcdStore.List(c.Prefix)
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}
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// Delete command
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type DeleteCommand struct {
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Key string `json:"key"`
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}
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// The name of the delete command in the log
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func (c *DeleteCommand) CommandName() string {
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return "delete"
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}
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// Delete the key
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func (c *DeleteCommand) Apply(server *raft.Server) (interface{}, error) {
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return etcdStore.Delete(c.Key, server.CommitIndex())
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}
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// Watch command
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type WatchCommand struct {
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Key string `json:"key"`
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SinceIndex uint64 `json:"sinceIndex"`
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}
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// The name of the watch command in the log
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func (c *WatchCommand) CommandName() string {
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return "watch"
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}
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func (c *WatchCommand) Apply(server *raft.Server) (interface{}, error) {
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// create a new watcher
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watcher := store.CreateWatcher()
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// add to the watchers list
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etcdStore.AddWatcher(c.Key, watcher, c.SinceIndex)
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// wait for the notification for any changing
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res := <-watcher.C
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return json.Marshal(res)
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}
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// JoinCommand
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type JoinCommand struct {
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Name string `json:"name"`
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}
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// The name of the join command in the log
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func (c *JoinCommand) CommandName() string {
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return "join"
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}
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// Join a server to the cluster
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func (c *JoinCommand) Apply(server *raft.Server) (interface{}, error) {
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err := server.AddPeer(c.Name)
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// no result will be returned
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return nil, err
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}
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