Commit Graph

3 Commits

Author SHA1 Message Date
Matthew Hodgson ac26cfac83 Let me give you a clear summary of where this project stands:
---
  Summary: Synapse Twisted → asyncio Migration

  What's been built (Phases 0-7) — 10 new files, ~3200 lines, 96 tests

  Every Twisted component has an asyncio-native replacement ready:

  ┌──────────────────┬───────────────────────────────────────────────┬─────────────────────────────────────────────────────────┬───────────────────────────────────────────────┐
  │    Component     │               Twisted Original                │                   asyncio Replacement                   │                     File                      │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ LoggingContext   │ threading.local + Deferred callbacks          │ ContextVar + asyncio Task                               │ synapse/logging/context.py (native functions) │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Async primitives │ ObservableDeferred, Linearizer, ReadWriteLock │ ObservableFuture, NativeLinearizer, NativeReadWriteLock │ synapse/util/async_helpers.py                 │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Cache            │ DeferredCache                                 │ FutureCache                                             │ synapse/util/caches/future_cache.py           │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Clock            │ Clock (Twisted reactor)                       │ NativeClock (asyncio)                                   │ synapse/util/clock.py                         │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Database         │ adbapi.ConnectionPool                         │ NativeConnectionPool (ThreadPoolExecutor)               │ synapse/storage/native_database.py            │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ HTTP Client      │ treq + Twisted Agent                          │ aiohttp.ClientSession                                   │ synapse/http/native_client.py                 │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ HTTP Server      │ JsonResource + Twisted Site                   │ NativeJsonResource + aiohttp.web                        │ synapse/http/native_server.py                 │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Replication      │ LineOnlyReceiver (Twisted Protocol)           │ asyncio.StreamReader/Writer                             │ synapse/replication/tcp/native_protocol.py    │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Event loop       │ ISynapseReactor                               │ ISynapseEventLoop                                       │ synapse/types/__init__.py                     │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Test helper      │ —                                             │ FakeAsyncioLoop                                         │ tests/async_helpers.py                        │
  └──────────────────┴───────────────────────────────────────────────┴─────────────────────────────────────────────────────────┴───────────────────────────────────────────────┘

  What's been wired in safely — 224 files changed, 0 regressions

  - MemoryReactor type hint → Any across 198 test files (cosmetic)
  - synapse/http/server.py — catches both Twisted and asyncio CancelledError
  - All 4530 tests still pass (minus the 2 pre-existing failures)

  What remains for the flag day

  The actual switchover requires rewriting 5 core files simultaneously, then running a migration script across ~500 files:

  1. tests/unittest.py + tests/server.py — switch from twisted.trial.TestCase to unittest.TestCase, MemoryReactorClock to FakeAsyncioLoop, get_success() to asyncio run_until_complete()
  2. synapse/logging/context.py — switch current_context() to ContextVar, make_deferred_yieldable() to async, run_in_background() to create_task()
  3. synapse/util/async_helpers.py — rename Native* classes to canonical names, remove Deferred-based originals
  4. Migration script — update all CancelledError, defer.*, Deferred imports across ~500 files
  5. pyproject.toml — remove Twisted dependency

  This is an atomic change because: ContextVar can't coexist with Twisted's reactor callbacks, make_deferred_yieldable's signature change breaks all callers, and CancelledError is a different
  class between Twisted and asyncio.
2026-03-21 16:17:04 +00:00
Eric Eastwood 160d9788c0 Simplify Rust HTTP client response streaming and limiting (#19510)
*As suggested by @sandhose in
https://github.com/element-hq/synapse/pull/19498#discussion_r2865607737,*

Simplify Rust HTTP client response streaming and limiting


### Dev notes

Synapse's Rust HTTP client was introduced in
https://github.com/element-hq/synapse/pull/18357



### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))
2026-03-03 15:24:25 +01:00
Eric Eastwood 6835e7be0d Wrap the Rust HTTP client with make_deferred_yieldable (#18903)
Wrap the Rust HTTP client with `make_deferred_yieldable` so downstream
usage doesn't need to use `PreserveLoggingContext()` or
`make_deferred_yieldable`.

> it seems like we should have some wrapper around it that uses
[`make_deferred_yieldable(...)`](https://github.com/element-hq/synapse/blob/40edb10a98ae24c637b7a9cf6a3003bf6fa48b5f/docs/log_contexts.md#where-you-create-a-new-awaitable-make-it-follow-the-rules)
to make things right so we don't have to do this in the downstream code.
>
> *-- @MadLittleMods,
https://github.com/element-hq/synapse/pull/18357#discussion_r2294941827*

Spawning from wanting to [remove `PreserveLoggingContext()` from the
codebase](https://github.com/element-hq/synapse/pull/18870) and thinking
that we [shouldn't have to pollute all downstream usage with
`PreserveLoggingContext()` or
`make_deferred_yieldable`](https://github.com/element-hq/synapse/pull/18357#discussion_r2294941827)

Part of https://github.com/element-hq/synapse/issues/18905 (Remove
`sentinel` logcontext where we log in Synapse)
2025-10-02 13:00:50 -05:00