crdt_socket_sync 0.6.0

Conflict-free replicated data type (CRDT) - Socket sync implementation provided in dart

0.6.0

Date: 2026-07-26

compare to previous release

Breaking changes (Dart names only — not the protocol)

The CRDT-aware sync frames and session-event values now live under Sync* types. These are pure source-level renames: update the identifiers, the on-the-wire messages stay byte-identical (a 0.5.x and a 0.6.0 peer still talk to each other).

Messages:

• Message.change → SyncMessage.change
• Message.changes → SyncMessage.changes
• Message.documentStatus → SyncMessage.documentStatus
• Message.documentStatusRequest → SyncMessage.documentStatusRequest
• Message.fromJson now decodes only the shared frames (ping/pong/error); in a custom codec chain it: SyncMessage.fromJson(json) ?? Message.fromJson(json).

Session events:

• SessionEventType.handshakeCompleted → SyncSessionEventType.handshakeCompleted
• SessionEventType.documentStatusCreated → SyncSessionEventType.documentStatusCreated
• SessionEventType.changeApplied → SyncSessionEventType.changeApplied
• SessionEventType.clientOutOfSync → SyncSessionEventType.clientOutOfSync

Added

• Relay mode — a second sync model where the server stays dumb: it only stores change blobs opaquely and rebroadcasts them per room, never parsing CRDT data, so all merging happens on the clients. This enables a CRDT-agnostic backend (no crdt_lf on the server, easy to port to other runtimes, including serverless). Adds the relay_client, web_socket_relay_client, relay_server and web_socket_relay_server libraries; see the README for the full picture. 100

Fixed

• The client libraries now actually export ClientSyncPlugin and SocketClientProvider (the plugin barrel previously self-exported, forcing src/ imports for custom client plugins).

0.5.0+2

Date: 2026-07-19

Documentation release: refreshes the CHANGELOG and docs published on pub.dev. No functional changes since 0.5.0.

0.5.0+1

Date: 2026-07-18

Documentation release: refreshes the CHANGELOG and docs published on pub.dev. No functional changes since 0.5.0.

0.5.0

Date: 2026-07-08

compare to previous release

This release is a general pass to improve the sync process and clean up the code following the improvements introduced in crdt_lf v3.0.0 (see #87).

Added

• Client-side dead-connection detection: the client tracks pong replies and, if no pong arrives within Protocol.pingTimeout, treats the connection as dead and reconnects. Ping/pong durations are injectable via the WebSocketClient constructors.
• Backpressure: outbound sends are serialized through a bounded per-connection queue. A peer that exceeds Protocol.maxBufferSize of un-flushed data is disconnected (and re-syncs on reconnect) instead of growing memory without bound. The bound is injectable on both WebSocketClient and WebSocketServer.
• Server auto-snapshot: clients report their version vector on pings, and the server takes a snapshot and prunes confirmed history once every connected client has confirmed a common frontier (ServerEventType.snapshotCreated).
• PingMessage gained an optional versionVector field. This is backward-compatible on the wire (older peers ignore the extra field).

Fixed

• WebSocketServer.stop() now actually closes every client session (previously a method tear-off meant sessions were never gracefully closed).
• A broadcast no longer aborts when a single client's send fails: the failing client is dropped and the message still reaches every other subscribed client.
• Incoming client frames are decoded per-frame instead of through a shared buffer, so a single malformed/undecodable frame can no longer poison the decoding of every subsequent message.
• Text frames are decoded with UTF-8 on both client and server (previously the client used codeUnits, corrupting multi-byte payloads).
• InMemoryCRDTServerRegistry: The server's out-of-sync recovery path is no longer dead code: InMemoryCRDTServerRegistry.applyChange now propagates CausallyNotReadyException so the server tells the client to re-sync instead of silently dropping the change.
• The awareness client no longer clobbers its own just-updated presence when a full state message arrives from the server.
• The awareness throttler now fires the trailing action in a burst (the last cursor position is no longer dropped).

0.4.0

Date: 2026-06-11

compare to previous release

Breaking changes

Wire protocol changed: Change, Snapshot, and VersionVector payloads are now transmitted as base64-encoded binary strings instead of JSON objects. Servers and clients running different versions are not compatible.

Affected message fields:

• HandshakeRequestMessage.versionVector — was Map<String, dynamic>, now a base64 string.
• HandshakeResponseMessage.versionVector, .snapshot, .changes[*] — same change.
• ChangeMessage.change — was Map<String, dynamic>, now a base64 string.
• ChangesMessage.changes[*] — was List<Map>, now List<String> (base64).
• DocumentStatusMessage.versionVector, .snapshot, .changes[*] — same change.
• DocumentStatusRequestMessage.versionVector — same change.

Updated crdt_lf dependency to ^3.0.0.

Changed

• All binary payloads in messages now use the compact binary format from crdt_lf 3.0.0 (Change.toBytes, VersionVector.toBytes, Snapshot.toBytes), reducing message size and eliminating JSON parsing overhead on the hot path.
• chore: improved documentation adding design diagrams
• chore: update tests

0.3.0

Date:

compare to previous release

Breaking changes

• CRDTServerRegistry.addDocument takes a documentId and author parameter
• CRDTServerRegistry methods now return a Future
• rename client requestSnapshot to requestSync

Added

• Feature: add messageCodec parameter to WebSocketServer and WebSocketClient
• Feature: JsonMessageCodec now supports toEncodable and reviver parameters
• Feature: added out of sync error handling
• Feature: added messageBroadcasted and messageSent server events
• Feature: added ChangesMessage

Changes

• Document status request can be sent without a version vector
• chore: added code coverage references

Fixed

• Fixed sync problems during client disconnection
• Fixed transporter subscription on connection error
• Fixed double call on "onNewSession"

0.2.0

Date: 2025-06-26

compare to previous release

Breaking changes

• encode and decode methods of MessageCodec have nullable return type

Added

• Feature: add plugin system
• Feature: add awareness plugin

Fixed

• Fixed: Fix a missing status update during first connection
• Fixed: Fix a bug where the connect start a reconnection loop if the connection is lost

0.1.0+1

Date: 2025-06-14

compare to previous release

Fixed

• Chore: update readme links

0.1.0

Date: 2025-06-14

Initial release