Files
lancedb/python/src/lib.rs
T
Dan RammerandClaude Opus 5 fe34eb3549 refactor!: rename LSM APIs to MemWAL and align SSTable/table shard naming (#4075)
## What

Renames the MemWAL surface in two passes, across Rust, Python,
TypeScript, and Java, including the wire format.

### 1. MemWAL APIs drop "LSM"

The write path these APIs drive is Lance's MemWAL; "LSM" described its
shape rather than naming it. Turning it on and off now reads as enabling
a feature rather than installing a spec.

| Before | After |
|---|---|
| `set_lsm_write_spec` | `enable_memwal` |
| `unset_lsm_write_spec` | `disable_memwal` |
| `get_lsm_write_spec` | `get_memwal_spec` |
| `flush_lsm` / `compact_lsm` / `checkpoint_lsm` | `flush_memwal` /
`compact_memwal` / `checkpoint_memwal` |
| `get_lsm_stats` | `get_memwal_stats` |
| `close_lsm_writers` | `close_memwal_writers` |
| `use_lsm` (query, merge insert) | `use_memwal` |
| `LsmWriteSpec` / `LsmStats` | `MemWalWriteSpec` / `MemWalStats` |
| Java `LanceDbTableLsm` | `LanceDbTableMemWal` |

TypeScript and Java use camelCase (`enableMemWal`, `getMemWalStats`,
...); the napi methods set `js_name` so the generated names keep the
`MemWal` casing. flush/compact/checkpoint keep a `_memwal` suffix so
`compact_memwal` is not confused with `compact_files` / `optimize`,
which compact the base table.

Internal names (`LsmMode`, `LsmScanner`, the `merge::lsm` / `query::lsm`
modules) are unchanged.

### 2. Stats use SSTable and table shard

Aligns the stats surface with the MemWAL naming settled upstream in
lance-format/lance#7943 and #7957, where the persisted unit became an
**SSTable**.

**Generation → SSTable.** A `GenerationStats` describes one flushed
MemTable, which is an SSTable. The generation *number* is kept — an
SSTable is identified by its generation — so only the noun moved.

**Bucket → table shard.** Each entry is one MemWAL shard. "Bucket" names
only the hash sharding *transform*, so it was already wrong for
`identity` and `year` sharding, which produce shards and no buckets at
all.

| Before | After |
|---|---|
| `GenerationStats` | `SsTableStats` |
| `BucketStats` | `TableShardStats` |
| `stats.buckets` | `stats.table_shards` |
| `BucketStats.generations` | `TableShardStats.sstables` |
| `include_generation_rows` | `include_sstable_rows` |
| `newest_generation` | `newest_sstable_generation` |
| `outstanding_generations` | `outstanding_sstables` |

Docs and comments follow suit: "seal" → "freeze", "L0" / "flushed
generations" → SSTables, "bucket" (meaning a shard) → table shard.

`MemWalWriteSpec::bucket`, `num_buckets`, and the `"Sealed"` shard
status value are **unchanged** — those name the sharding transform or a
server value, not the shard.

## Compatibility

Breaking, for an experimental API. The wire format changes with the
SDKs, so this must roll out together with the matching server change:

- Routes: `/set_lsm_write_spec/` → `/enable_memwal/`,
`/unset_lsm_write_spec/` → `/disable_memwal/`, `/get_lsm_write_spec/` →
`/get_memwal_spec/`, `/flush_lsm/` → `/flush_memwal/`, `/compact_lsm/` →
`/compact_memwal/`, `/get_lsm_stats/` → `/get_memwal_stats/`
- Response keys: `lsm_write_spec` → `memwal_spec`, `lsm_stats` →
`memwal_stats`, `buckets` → `table_shards`, `generations` → `sstables`
- Request fields: `include_generation_rows` → `include_sstable_rows`;
`use_lsm` → `use_memwal` on query and merge-insert bodies

## Validation

- Rust: `cargo test --features remote -p lancedb --lib --tests` — 1467
lib tests and all integration test targets pass; `cargo clippy` clean
- Python: rebuilt the extension; `test_remote_db`, `test_memwal_spec`,
`test_merge_insert_lsm`, `test_query`, `test_permutation`, `test_table`
— 655 passed; `ruff format` / `ruff check` clean
- TypeScript: `pnpm build`; `table`, `merge`, `query` tests — 593
passed; `biome check` clean; `docs/src/js` regenerated with `npm run
docs`
- Java: `mvn test` — 37 passed (Spotless applied with JDK 11; the pinned
google-java-format does not run on JDK 21)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-10-16 13:33:57 -05:00

141 lines
5.4 KiB
Rust

// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: Copyright The LanceDB Authors
use arrow::RecordBatchStream;
use connection::{Connection, connect, connect_namespace, connect_namespace_client};
use env_logger::Env;
use expr::{PyExpr, expr_col, expr_func, expr_lit};
use index::IndexConfig;
use permutation::{PyAsyncPermutationBuilder, PyPermutationReader};
use pyo3::{
Bound, PyResult, Python, pyfunction, pymodule,
types::{PyAnyMethods, PyModule, PyModuleMethods},
wrap_pyfunction,
};
use query::{FTSQuery, HybridQuery, Query, VectorQuery};
use session::Session;
use table::{
AddColumnsResult, AddResult, AlterColumnsResult, DeleteResult, DropColumnsResult, FtsToken,
FunctionErrorFragment, FunctionErrorRecord, FunctionErrors, MemWalWriteSpec, MergeResult,
PyBlobFile, RefreshColumnResult, RefreshMaterializedViewResult, Table,
UpdateFieldMetadataResult, UpdateResult,
};
pub mod arrow;
pub mod authz;
pub mod catalog;
pub mod connection;
pub mod error;
pub mod expr;
pub mod header;
pub mod index;
pub mod job;
mod listing;
pub mod namespace;
pub mod oauth;
pub mod otel;
pub mod permutation;
pub mod query;
pub mod runtime;
pub mod session;
pub mod sql;
pub mod table;
pub mod util;
/// Shut down the shared Tokio runtime (see `runtime::shutdown`).
///
/// Registered below as a Python `atexit` callback rather than called
/// directly: `atexit` runs while the interpreter is still fully valid,
/// which is the coordinated, bounded exit the runtime otherwise never gets.
///
/// Runs the actual wait with the GIL released (`Python::detach`): shutdown
/// blocks the calling thread waiting on the runtime's own worker threads,
/// and if any in-flight task needs the GIL to finish (e.g. one that calls
/// back into Python), holding it here while waiting on that same task would
/// deadlock rather than time out.
#[pyfunction]
fn shutdown_runtime(py: Python<'_>) {
py.detach(|| runtime::shutdown(std::time::Duration::from_secs(5)));
}
#[pymodule]
pub fn _lancedb(py: Python, m: &Bound<'_, PyModule>) -> PyResult<()> {
let env = Env::new()
.filter_or("LANCEDB_LOG", "warn")
.write_style("LANCEDB_LOG_STYLE");
env_logger::init_from_env(env);
m.add_class::<Connection>()?;
m.add_class::<catalog::Catalog>()?;
m.add_class::<catalog::DatabaseNames>()?;
m.add_class::<listing::NameListing>()?;
m.add_class::<listing::FunctionListing>()?;
m.add_class::<listing::JobListing>()?;
m.add_class::<authz::AuthorizationClient>()?;
m.add_class::<authz::AuthzSubject>()?;
m.add_class::<authz::AuthzObject>()?;
m.add_class::<authz::AuthzPrivilege>()?;
m.add_function(wrap_pyfunction!(catalog::connect_catalog, m)?)?;
m.add_class::<Session>()?;
m.add_class::<Table>()?;
m.add_class::<crate::oauth::PyOAuthSession>()?;
m.add_class::<crate::oauth::PySessionStatus>()?;
m.add_class::<crate::oauth::PySessionLogout>()?;
m.add_class::<crate::job::Job>()?;
m.add_class::<crate::job::JobInfo>()?;
m.add_class::<crate::job::JobDescription>()?;
m.add_class::<crate::job::JobFailureInfo>()?;
m.add_class::<crate::sql::Query>()?;
m.add_class::<crate::sql::QueryDescription>()?;
m.add_class::<PyBlobFile>()?;
m.add_class::<IndexConfig>()?;
m.add_class::<Query>()?;
m.add_class::<FTSQuery>()?;
m.add_class::<HybridQuery>()?;
m.add_class::<VectorQuery>()?;
m.add_class::<RecordBatchStream>()?;
m.add_class::<AddColumnsResult>()?;
m.add_class::<RefreshColumnResult>()?;
m.add_class::<FunctionErrors>()?;
m.add_class::<FunctionErrorRecord>()?;
m.add_class::<FunctionErrorFragment>()?;
m.add_class::<RefreshMaterializedViewResult>()?;
m.add_class::<AlterColumnsResult>()?;
m.add_class::<UpdateFieldMetadataResult>()?;
m.add_class::<AddResult>()?;
m.add_class::<MergeResult>()?;
m.add_class::<MemWalWriteSpec>()?;
m.add_class::<DeleteResult>()?;
m.add_class::<DropColumnsResult>()?;
m.add_class::<UpdateResult>()?;
m.add_class::<FtsToken>()?;
m.add_class::<PyAsyncPermutationBuilder>()?;
m.add_class::<PyPermutationReader>()?;
m.add_class::<PyExpr>()?;
// OpenTelemetry metrics bridge
m.add_class::<otel::PyMetricPoint>()?;
m.add_class::<otel::PyMetricDescription>()?;
m.add_function(wrap_pyfunction!(
otel::register_lancedb_metrics_recorder,
m
)?)?;
m.add_function(wrap_pyfunction!(otel::lancedb_metrics_catalog, m)?)?;
m.add_function(wrap_pyfunction!(otel::snapshot_lancedb_metrics, m)?)?;
m.add_function(wrap_pyfunction!(connect, m)?)?;
m.add_function(wrap_pyfunction!(connect_namespace, m)?)?;
m.add_function(wrap_pyfunction!(connect_namespace_client, m)?)?;
m.add_function(wrap_pyfunction!(table::tokenize, m)?)?;
m.add_function(wrap_pyfunction!(permutation::async_permutation_builder, m)?)?;
m.add_function(wrap_pyfunction!(util::validate_table_name, m)?)?;
m.add_function(wrap_pyfunction!(query::fts_query_to_json, m)?)?;
m.add_function(wrap_pyfunction!(expr_col, m)?)?;
m.add_function(wrap_pyfunction!(expr_lit, m)?)?;
m.add_function(wrap_pyfunction!(expr_func, m)?)?;
m.add("__version__", env!("CARGO_PKG_VERSION"))?;
// Give the shared runtime a coordinated, bounded shutdown at normal
// process exit -- see `shutdown_runtime` and `runtime::shutdown` for why.
py.import("atexit")?
.call_method1("register", (wrap_pyfunction!(shutdown_runtime, m)?,))?;
Ok(())
}