61 lines
1.5 KiB
Go
61 lines
1.5 KiB
Go
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package raft
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// LogType describes various types of log entries.
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type LogType uint8
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const (
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// LogCommand is applied to a user FSM.
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LogCommand LogType = iota
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// LogNoop is used to assert leadership.
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LogNoop
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// LogAddPeer is used to add a new peer.
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LogAddPeer
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// LogRemovePeer is used to remove an existing peer.
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LogRemovePeer
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// LogBarrier is used to ensure all preceding operations have been
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// applied to the FSM. It is similar to LogNoop, but instead of returning
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// once committed, it only returns once the FSM manager acks it. Otherwise
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// it is possible there are operations committed but not yet applied to
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// the FSM.
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LogBarrier
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)
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// Log entries are replicated to all members of the Raft cluster
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// and form the heart of the replicated state machine.
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type Log struct {
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Index uint64
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Term uint64
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Type LogType
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Data []byte
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// peer is not exported since it is not transmitted, only used
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// internally to construct the Data field.
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peer string
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}
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// LogStore is used to provide an interface for storing
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// and retrieving logs in a durable fashion.
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type LogStore interface {
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// Returns the first index written. 0 for no entries.
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FirstIndex() (uint64, error)
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// Returns the last index written. 0 for no entries.
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LastIndex() (uint64, error)
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// Gets a log entry at a given index.
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GetLog(index uint64, log *Log) error
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// Stores a log entry.
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StoreLog(log *Log) error
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// Stores multiple log entries.
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StoreLogs(logs []*Log) error
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// Deletes a range of log entries. The range is inclusive.
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DeleteRange(min, max uint64) error
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}
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