Riak Dart client

Riak database client, written in Dart.

Features

Available Riak functionality:

• fetch, store and delete objects (with vclock, vtag and last modified preconditions)
• store and query secondary index
• get and set bucket properties
• resolve conflicts if parallel writes produce siblings
• counters (fetch, increment/decrement)

Dart client design goals:

• Meaningful wrapper objects
• Immutable structures (exception: JSON content, but changes won't be pushed)

Usage Examples

Create an HTTP client and target a bucket:

Client client = new Client.http('127.0.0.1', 10017);
Bucket exampleBucket = client.getBucket('example');

Fetch a text object:

String exampleKey = 'text_example_key';

exampleBucket.fetch(exampleKey).then((Response value) {
  String text = value.result.content.asText;
  ... do something with text ...
});

Fetch a JSON object:

String exampleKey = 'json_example_key';

exampleBucket.fetch(exampleKey).then((Response value) {
  Map json = value.result.content.asJson;
  ... do something with JSON ...
});

Store a text object:

String key = 'text_message';
String message = 'hello from the Dart server';
Content content = new Content.text(message);

exampleBucket.store(key, content).then((Response response) {
  ... do something with response ...
});

Store a JSON object:

String key = 'json_message';
Map json = { 'foo': 'bar' };
Content content = new Content.json(json);

exampleBucket.store(key, content).then((Response response) {
  ... do something with response ...
});

List all buckets (not recommended in production environments):

client.listBuckets().toList().then((List<String> buckets) {
  print(buckets);
});

List all keys in a bucket (also not recommended in production environments):

bucket.listKeys().toList().then((List<String> keys) {
  print(keys);
});

Modify an existing object using a vclock:

String key = 'text_message';
String newMessage = 'this is the most up-to-date message';

exampleBucket.fetch(key).then((Response value) {
  if (value.code == 200) {
    String v = value.result.vclock;
    Content content = new Content.text(newMessage);
    exampleBucket.store(key, content, vclock: v).then((Response response) {
      print(response.code);
    });
  } else {
    print('Not found');
  }
});

Roadmap

0.7

• map-reduce support
• link-walking support
• list-resources support

0.8

• protobuf client implementation
• mixed client (protobuf / http, based on the request)
• search support

0.9

• mock backend for testing (in-memory and filesystem)
• configurable retry-on-failure
• robust stream handling (e.g. what to do on backend failure, re-start?)
• non-buffered HTTP response processing
• pooling client (simple round-robin)

1.0

• stable API
• pool monitoring and stats

The order might vary, depending on the contributor's requirements. If you would like to add something, contact us (see AUTHORS or pubspec file).

Migration guide

0.4 -> 0.5

• full API changed

0.5 -> 0.6

• Renamed BucketProps's fields to follow the Dart conventions (n_val -> replicas, allow_mult -> allowSiblings, last_write_wins -> lastWriteWins).
• Renamed Quorum's fields to follow the Dart conventions (basic_quorum -> basicQuorum, not_found_ok -> notFoundIsSuccess).

References

• Riak: http://basho.com/riak/

• Dart: http://dartlang.org/

• Main site: http://code.google.com/p/riak-dart/

• GitHub mirror: https://github.com/agilord/riak_dart_client/