41 lines
1.3 KiB
Go
41 lines
1.3 KiB
Go
package raft
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import (
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"io"
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)
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// SnapshotMeta is for metadata of a snapshot.
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type SnapshotMeta struct {
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ID string // ID is opaque to the store, and is used for opening
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Index uint64
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Term uint64
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Peers []byte
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Size int64
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}
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// SnapshotStore interface is used to allow for flexible implementations
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// of snapshot storage and retrieval. For example, a client could implement
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// a shared state store such as S3, allowing new nodes to restore snapshots
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// without steaming from the leader.
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type SnapshotStore interface {
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// Create is used to begin a snapshot at a given index and term,
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// with the current peer set already encoded.
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Create(index, term uint64, peers []byte) (SnapshotSink, error)
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// List is used to list the available snapshots in the store.
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// It should return then in descending order, with the highest index first.
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List() ([]*SnapshotMeta, error)
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// Open takes a snapshot ID and provides a ReadCloser. Once close is
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// called it is assumed the snapshot is no longer needed.
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Open(id string) (*SnapshotMeta, io.ReadCloser, error)
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}
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// SnapshotSink is returned by StartSnapshot. The FSM will Write state
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// to the sink and call Close on completion. On error, Cancel will be invoked.
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type SnapshotSink interface {
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io.WriteCloser
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ID() string
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Cancel() error
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}
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