factstr

factstr is the shared Rust contract crate for FACTSTR.

It defines the public event store contract and core types. It does not implement a store by itself.

Store implementations live in separate crates:

• factstr-memory
• factstr-sqlite
• factstr-postgres

Core operations

The core contract currently includes:

• append
• query
• append_if
• stream_all
• stream_to
• stream_all_durable
• stream_to_durable

Core types

The public contract includes:

• NewEvent
• EventRecord
• EventQuery
• EventFilter
• QueryResult
• AppendResult
• DurableStream
• EventStream
• EventStore
• EventStoreError

Related stream handler types are also part of the crate:

• HandleStream
• StreamHandlerError

Semantics

Important contract semantics:

• facts are append-only
• sequence numbers are global and monotonically increasing
• one committed batch receives one consecutive sequence range
• min_sequence_number is a read cursor only
• current_context_version describes the full matching conflict context
• append_if checks the full matching context
• durable streams resume strictly after the stored cursor

Related crates

• factstr-memory for the in-memory implementation
• factstr-sqlite for the SQLite implementation
• factstr-postgres for the PostgreSQL implementation