https://github.com/hankjacobs/vvmap
A delta-based CRDT map implementation in Go
https://github.com/hankjacobs/vvmap
crdt delta-crdt distributed distributed-systems go golang map
Last synced: over 1 year ago
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A delta-based CRDT map implementation in Go
- Host: GitHub
- URL: https://github.com/hankjacobs/vvmap
- Owner: hankjacobs
- License: mit
- Created: 2018-10-08T03:21:49.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2018-10-09T16:26:52.000Z (over 7 years ago)
- Last Synced: 2024-06-20T17:35:06.628Z (about 2 years ago)
- Topics: crdt, delta-crdt, distributed, distributed-systems, go, golang, map
- Language: Go
- Homepage:
- Size: 9.77 KB
- Stars: 15
- Watchers: 1
- Forks: 5
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# vvmap [](https://godoc.org/github.com/hankjacobs/vv)
vvmap is a [Go](http://www.golang.org) implementation of a delta-based CRDT map as written about in ["∆-CRDTs: Making δ-CRDTs Delta-Based"](http://nova-lincs.di.fct.unl.pt/system/publication_files/files/000/000/666/original/a12-van_der_linde.pdf?1483708753), ["Dotted Version Vectors: Logical Clocks for Optimistic Replication"](https://arxiv.org/pdf/1011.5808.pdf), and Tyler McMullen's excellent talk ["The Anatomy of a Distributed System"](https://www.infoq.com/presentations/health-distributed-system).
Usage:
```go
package main
import (
"fmt"
"strings"
"github.com/hankjacobs/vvmap"
)
func main() {
lexicographicConflictResolver := func(key string, left, right vvmap.Record) bool {
leftVal := left.Value.(string)
rightVal := right.Value.(string)
return strings.Compare(leftVal, rightVal) > 0 // choose left if lexicographically greater
}
alice := vvmap.New("alice", lexicographicConflictResolver)
bob := vvmap.New("bob", lexicographicConflictResolver)
tim := vvmap.New("tim", lexicographicConflictResolver)
// concurrently update everyone -- causes a conflict, should all resolve to "turkey" since
// lexicographically greatest
alice.Set("lunch", "turkey")
bob.Set("lunch", "ham")
tim.Set("lunch", "chicken")
// get records that Bob has but Alice doesn't
delta := bob.Delta(alice.Version())
alice.Merge(delta)
// get records that Tim has but Alice doesn't
delta = tim.Delta(alice.Version())
alice.Merge(delta)
// sync bob
bob.Merge(alice.Delta(bob.Version())) // alice is most up-to-date so no need to sync with Tim
// sync tim
tim.Merge(alice.Delta(tim.Version()))
fmt.Println("alice:", alice.Get("lunch"))
fmt.Println("bob:", bob.Get("lunch"))
fmt.Println("tim:", tim.Get("lunch"))
}
```