sql_crdt 0.0.8

sql_crdt: ^0.0.8 copied to clipboard

Dart implementation of Conflict-free Replicated Data Types (CRDTs) using SQL databases.
This project is a continuation of the crdt package and may depend on it in the future.

sql_crdt is based on the learnings from Libra, StoryArk and tudo.
Check tudo for a real world implementation.

⚠ The packages in this repository are still under development and may not be stable. The API may break at any time.

Notes #

sql_crdt is not an ORM. The API is essentially that of a plain old SQL database with a few behavioural changes:

• Every table gets 3 columns automatically added: is_deleted, hlc, and modified
• Deleted records aren't actually removed but rather flagged in the is_deleted column
• Features a reactive watch method to subscribe to database queries
• Adds convenience methods getChangeset, watchChangeset and merge to simplify syncing with remote nodes

⚠ Because deleted records are only flagged as deleted, they may need to be sanitized in order to be compliant with GDPR and similar legislation.

API #

The API is intentionally kept simple with a few methods:

• execute to run non-select SQL queries, e.g. inserts, updates, etc.
• query to perform a one-time query
• watch to receive query results whenever the database changes
• getChangeset to generate a serializable changeset of the local database
• watchChangeset a reactive alternative to get the changeset
• merge to apply a remote changeset to the local database
• transaction a blocking mechanism that avoids running simultaneous transactions in async code

Check the examples in sqlite_crdt and postgres_crdt for more details.

Features and bugs #

Please file feature requests and bugs in the issue tracker.