slatedb 0.12.1

A cloud native embedded storage engine built on object storage.

SlateDB Python Binding

bindings/python contains the official UniFFI-based Python package for SlateDB.

Requirements

• Python 3.10 or newer

Install

pip install slatedb

API Model

• ObjectStore.resolve(...) opens an object store from a URL such as memory:///
• DbBuilder opens a writable database and DbReaderBuilder opens a read-only reader
• most database operations are async and should be used with asyncio
• WriteBatch is mutated synchronously and then consumed by db.write(...)
• db.shutdown() and reader.shutdown() explicitly close native resources

Quick Start

import asyncio

from slatedb.uniffi import (
    DbBuilder,
    IsolationLevel,
    ObjectStore,
    WriteBatch,
)


async def main() -> None:
    store = ObjectStore.resolve("memory:///")
    builder = DbBuilder("demo-db", store)
    db = await builder.build()

    try:
        await db.put(b"user:1", b"Alice")
        value = await db.get(b"user:1")
        assert value == b"Alice"

        batch = WriteBatch()
        batch.put(b"user:2", b"Bob")
        batch.put(b"user:3", b"Carol")
        await db.write(batch)

        scan = await db.scan_prefix(b"user:")
        while (row := await scan.next()) is not None:
            print(row.key, row.value)

        tx = await db.begin(IsolationLevel.SERIALIZABLE_SNAPSHOT)
        await tx.put(b"user:4", b"Dora")
        await tx.commit()
    finally:
        await db.shutdown()


asyncio.run(main())

Metrics

The Python binding exposes both custom metrics callbacks and the built-in DefaultMetricsRecorder:

• DbBuilder.with_metrics_recorder(...)
• DbReaderBuilder.with_metrics_recorder(...)
• DefaultMetricsRecorder.snapshot()
• DefaultMetricsRecorder.metrics_by_name(...)
• DefaultMetricsRecorder.metric_by_name_and_labels(...)

Example:

from slatedb.uniffi import DbBuilder, DefaultMetricsRecorder, ObjectStore

store = ObjectStore.resolve("memory:///")
recorder = DefaultMetricsRecorder()
builder = DbBuilder("metrics-demo", store)

builder.with_metrics_recorder(recorder)
db = await builder.build()

try:
    await db.put(b"hello", b"world")

    metric = recorder.metric_by_name_and_labels("slatedb.db.write_ops", [])
    if metric is not None and metric.value.is_counter():
        print(metric.value[0])
finally:
    await db.shutdown()

Local Development

This package reuses the shared Rust UniFFI crate at ../uniffi/Cargo.toml. The generated Python module under slatedb/uniffi/_slatedb_uniffi/ is build output and should not be edited by hand.

Editable Build

From the repository root:

cd bindings/python
python3 -m venv .venv
source .venv/bin/activate
pip install --upgrade pip
pip install maturin "uniffi-bindgen==0.31.0" ruff
maturin develop
ruff check .
python -c "import slatedb; import slatedb.uniffi; from slatedb.uniffi import *"

Run Tests

From bindings/python after building the extension with test extras:

maturin develop --extras test
pytest

Build Release Artifacts

From bindings/python:

maturin build
maturin sdist

Editable builds generate slatedb/uniffi/_slatedb_uniffi/ in-tree. If you switch from maturin develop to maturin build in the same checkout, remove that generated directory first or run the artifact build from a fresh checkout.

License

SlateDB is licensed under the Apache License, Version 2.0.