Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/dan-da/crdt-php
Some experimental crdt implemented in PHP.
https://github.com/dan-da/crdt-php
Last synced: about 1 month ago
JSON representation
Some experimental crdt implemented in PHP.
- Host: GitHub
- URL: https://github.com/dan-da/crdt-php
- Owner: dan-da
- License: mit
- Created: 2020-07-21T23:04:25.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2020-09-04T23:16:37.000Z (over 4 years ago)
- Last Synced: 2024-04-17T14:24:59.179Z (9 months ago)
- Language: PHP
- Size: 197 KB
- Stars: 3
- Watchers: 4
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# CRDT-PHP: CRDT experiments
This code was initially written to implement a prototype of the
[bounded counter]() CRDT.
### bounded counter
Some articles about bounded counter:
* [State based CRDTs: bounded counter](https://bartoszsypytkowski.com/state-based-crdts-bounded-counter/)
* [Bounded Counters: maintaining numeric invariants with high availability
](https://pages.lip6.fr/syncfree/attachments/article/59/boundedCounter-white-paper.pdf)
The bounded counter requires pn_counter crdt, which requires g_counter crdt,
so those types are implemented as well.
### tree
Next, a prototype of a crdt tree algo has been added.
References:
* [A highly-available move operation for replicated trees and distributed filesystems](https://martin.kleppmann.com/papers/move-op.pdf)
* [CRDT: The Hard Parts](https://martin.kleppmann.com/2020/07/06/crdt-hard-parts-hydra.html)
* [Youtube Video: CRDT: The Hard Parts]()
## Installation
You will need PHP 7.0+ and [composer](https://getcomposer.org/).
On Ubuntu:
```
apt-get install php composer
```
To install as a standalone repo and run tests:
```
$ git clone https://github.com/dan-da/crdt-php && cd crdt-php
$ composer install
```
To use as a library in your own project:
```
$ mkdir -p && cd
$ composer require dan-da/crdt-php:dev-master
```
## Testing
For b_counter, go into the `tests` directory and run `./tester.php`, like so:
```
$ ./tester.php
Running tests in b_counter...
Running tests in g_counter...
Running tests in pn_counter...
Running tests in v_clock...
[pass] 1 == 1 | b_counter: replica_1->value() == 1
[pass] 7 != 1 | b_counter: replica_0->value() != replica_1->value() [before merge]
[pass] 7 != 2 | b_counter: replica_0->value() != replica_2->value() [before merge]
[pass] 1 != 2 | b_counter: replica_1->value() != replica_2->value() [before merge]
[pass] 10 == 10 | b_counter: replicas 0 and 1 equal [after merge]
[pass] 10 == 10 | b_counter: replicas 0 and 2 equal [after merge]
[pass] 10 == 10 | b_counter: replica_0->value() == 10 [after merge]
[pass] 10 == 10 | g_counter: replicas 0 and 1 equal
[pass] 10 == 10 | g_counter: replicas 0 and 2 equal
[pass] 10 == 10 | g_counter: replica_0->value() == 10
[pass] 6 == 6 | pn_counter: replicas 0 and 1 equal
[pass] 6 == 6 | pn_counter: replicas 0 and 2 equal
[pass] 6 == 6 | pn_counter: replica_0->value() == 6
[pass] object == object | vclock: merge
[pass] 5 == 5 | vclock: merge_less_left(5)
[pass] 6 == 6 | vclock: merge_less_left(6)
[pass] 7 == 7 | vclock: merge_less_left(7)
[pass] 5 == 5 | vclock: merge_less_right(5)
[pass] 6 == 6 | vclock: merge_less_right(6)
[pass] 7 == 7 | vclock: merge_less_right(7)
[pass] 1 == 1 | vclock: merge_same_id(1)
[pass] 1 == 1 | vclock: merge_same_id(2)
[pass] 1 == 1 | vclock: merge_same_id(3)
[pass] 1 == 1 | vclock: ordering. a dominates
[pass] 1 == 1 | vclock: ordering. a dominates
[pass] 1 == 1 | vclock: ordering. a dominates
[pass] 1 == 1 | vclock: ordering. b dominates
[pass] 1 == 1 | vclock: ordering. b dominates
[pass] 1 == 1 | vclock: ordering. b dominates
[pass] 1 == 1 | vclock: ordering. concurrent
[pass] 1 == 1 | vclock: ordering. concurrent
[pass] 1 == 1 | vclock: ordering. concurrent
[pass] 1 == 1 | vclock: ordering. a dominates
[pass] 1 == 1 | vclock: ordering. a dominates
[pass] 1 == 1 | vclock: ordering. a dominates
[pass] 1 == 1 | vclock: ordering. b dominates
[pass] 1 == 1 | vclock: ordering. b dominates
[pass] 1 == 1 | vclock: ordering. b dominates
[pass] 1 == 1 | vclock: ordering. equal
[pass] 1 == 1 | vclock: ordering. equal
[pass] 1 == 1 | vclock: ordering. equal
41 tests passed.
0 tests failed.
```
For `tree`, go into src and run `php tree.php`, like so:
```
$ php tree.php Usage: tree.php
can be any of:
test_concurrent_moves
test_concurrent_moves_cycle
test_apply_ops_random_order
```
```
$ php tree.php test_concurrent_moves
Initial tree state on both replicas
- /
- root
- a
- b
- c
replica_1 tree after move
- /
- root
- b
- a
- c
replica_2 tree after move
- /
- root
- b
- c
- a
replica_1 state matches replica_2 state after each merges other's change. conflict resolved!
--replica_1 --
- /
- root
- b
- c
- a
--replica_2 --
- /
- root
- b
- c
- a
```