forked from TrueCloudLab/frostfs-node
8cf71b7f1c
In this commit we implement algorithm for CRDT trees from https://martin.klepmann.com/papers/move-op.pdf Each tree is identified by the ID of a container it belongs to and the tree name itself. Essentially, it is a sequence of operations which should be applied in chronological order to get a usual tree representation. There are 2 backends for now: bbolt database and in-memory. In-memory backend is here for debugging and will eventually act as a memory-cache for the on-disk database. Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
52 lines
1.1 KiB
Go
52 lines
1.1 KiB
Go
package pilorama
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import (
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"errors"
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"math"
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)
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// Timestamp is an alias for integer timestamp type.
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// TODO: remove after the debugging.
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type Timestamp = uint64
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// Node is used to represent nodes.
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// TODO: remove after the debugging.
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type Node = uint64
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// Meta represents arbitrary meta information.
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// TODO: remove after the debugging or create a proper interface.
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type Meta struct {
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Time Timestamp
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Items []KeyValue
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}
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// KeyValue represents a key-value pair.
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type KeyValue struct {
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Key string
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Value []byte
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}
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// Move represents a single move operation.
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type Move struct {
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Parent Node
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Meta
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// Child represents the ID of a node being moved. If zero, new ID is generated.
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Child Node
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}
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// LogMove represents log record for a single move operation.
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type LogMove struct {
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Move
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HasOld bool
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Old nodeInfo
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}
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const (
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// RootID represents the ID of a root node.
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RootID = 0
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// TrashID is a parent for all removed nodes.
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TrashID = math.MaxUint64
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)
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// ErrTreeNotFound is returned when the requested tree is not found.
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var ErrTreeNotFound = errors.New("tree not found")
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