1pub mod wit;
2
3use crate::ExtensionManifest;
4use anyhow::{Context as _, Result, anyhow, bail};
5use async_trait::async_trait;
6use extension::{
7 CodeLabel, Command, Completion, ContextServerConfiguration, DebugAdapterBinary,
8 DebugTaskDefinition, ExtensionHostProxy, KeyValueStoreDelegate, ProjectDelegate, SlashCommand,
9 SlashCommandArgumentCompletion, SlashCommandOutput, Symbol, WorktreeDelegate,
10};
11use fs::{Fs, normalize_path};
12use futures::future::LocalBoxFuture;
13use futures::{
14 Future, FutureExt, StreamExt as _,
15 channel::{
16 mpsc::{self, UnboundedSender},
17 oneshot,
18 },
19 future::BoxFuture,
20};
21use gpui::{App, AsyncApp, BackgroundExecutor, Task};
22use http_client::HttpClient;
23use language::LanguageName;
24use lsp::LanguageServerName;
25use moka::sync::Cache;
26use node_runtime::NodeRuntime;
27use release_channel::ReleaseChannel;
28use semantic_version::SemanticVersion;
29use std::borrow::Cow;
30use std::sync::LazyLock;
31use std::{
32 path::{Path, PathBuf},
33 sync::Arc,
34};
35use wasmtime::{
36 CacheStore, Engine, Store,
37 component::{Component, ResourceTable},
38};
39use wasmtime_wasi::{self as wasi, WasiView};
40use wit::Extension;
41
42pub struct WasmHost {
43 engine: Engine,
44 release_channel: ReleaseChannel,
45 http_client: Arc<dyn HttpClient>,
46 node_runtime: NodeRuntime,
47 pub(crate) proxy: Arc<ExtensionHostProxy>,
48 fs: Arc<dyn Fs>,
49 pub work_dir: PathBuf,
50 _main_thread_message_task: Task<()>,
51 main_thread_message_tx: mpsc::UnboundedSender<MainThreadCall>,
52}
53
54#[derive(Clone)]
55pub struct WasmExtension {
56 tx: UnboundedSender<ExtensionCall>,
57 pub manifest: Arc<ExtensionManifest>,
58 pub work_dir: Arc<Path>,
59 #[allow(unused)]
60 pub zed_api_version: SemanticVersion,
61}
62
63#[async_trait]
64impl extension::Extension for WasmExtension {
65 fn manifest(&self) -> Arc<ExtensionManifest> {
66 self.manifest.clone()
67 }
68
69 fn work_dir(&self) -> Arc<Path> {
70 self.work_dir.clone()
71 }
72
73 async fn language_server_command(
74 &self,
75 language_server_id: LanguageServerName,
76 language_name: LanguageName,
77 worktree: Arc<dyn WorktreeDelegate>,
78 ) -> Result<Command> {
79 self.call(|extension, store| {
80 async move {
81 let resource = store.data_mut().table().push(worktree)?;
82 let command = extension
83 .call_language_server_command(
84 store,
85 &language_server_id,
86 &language_name,
87 resource,
88 )
89 .await?
90 .map_err(|err| store.data().extension_error(err))?;
91
92 Ok(command.into())
93 }
94 .boxed()
95 })
96 .await
97 }
98
99 async fn language_server_initialization_options(
100 &self,
101 language_server_id: LanguageServerName,
102 language_name: LanguageName,
103 worktree: Arc<dyn WorktreeDelegate>,
104 ) -> Result<Option<String>> {
105 self.call(|extension, store| {
106 async move {
107 let resource = store.data_mut().table().push(worktree)?;
108 let options = extension
109 .call_language_server_initialization_options(
110 store,
111 &language_server_id,
112 &language_name,
113 resource,
114 )
115 .await?
116 .map_err(|err| store.data().extension_error(err))?;
117 anyhow::Ok(options)
118 }
119 .boxed()
120 })
121 .await
122 }
123
124 async fn language_server_workspace_configuration(
125 &self,
126 language_server_id: LanguageServerName,
127 worktree: Arc<dyn WorktreeDelegate>,
128 ) -> Result<Option<String>> {
129 self.call(|extension, store| {
130 async move {
131 let resource = store.data_mut().table().push(worktree)?;
132 let options = extension
133 .call_language_server_workspace_configuration(
134 store,
135 &language_server_id,
136 resource,
137 )
138 .await?
139 .map_err(|err| store.data().extension_error(err))?;
140 anyhow::Ok(options)
141 }
142 .boxed()
143 })
144 .await
145 }
146
147 async fn language_server_additional_initialization_options(
148 &self,
149 language_server_id: LanguageServerName,
150 target_language_server_id: LanguageServerName,
151 worktree: Arc<dyn WorktreeDelegate>,
152 ) -> Result<Option<String>> {
153 self.call(|extension, store| {
154 async move {
155 let resource = store.data_mut().table().push(worktree)?;
156 let options = extension
157 .call_language_server_additional_initialization_options(
158 store,
159 &language_server_id,
160 &target_language_server_id,
161 resource,
162 )
163 .await?
164 .map_err(|err| store.data().extension_error(err))?;
165 anyhow::Ok(options)
166 }
167 .boxed()
168 })
169 .await
170 }
171
172 async fn language_server_additional_workspace_configuration(
173 &self,
174 language_server_id: LanguageServerName,
175 target_language_server_id: LanguageServerName,
176 worktree: Arc<dyn WorktreeDelegate>,
177 ) -> Result<Option<String>> {
178 self.call(|extension, store| {
179 async move {
180 let resource = store.data_mut().table().push(worktree)?;
181 let options = extension
182 .call_language_server_additional_workspace_configuration(
183 store,
184 &language_server_id,
185 &target_language_server_id,
186 resource,
187 )
188 .await?
189 .map_err(|err| store.data().extension_error(err))?;
190 anyhow::Ok(options)
191 }
192 .boxed()
193 })
194 .await
195 }
196
197 async fn labels_for_completions(
198 &self,
199 language_server_id: LanguageServerName,
200 completions: Vec<Completion>,
201 ) -> Result<Vec<Option<CodeLabel>>> {
202 self.call(|extension, store| {
203 async move {
204 let labels = extension
205 .call_labels_for_completions(
206 store,
207 &language_server_id,
208 completions.into_iter().map(Into::into).collect(),
209 )
210 .await?
211 .map_err(|err| store.data().extension_error(err))?;
212
213 Ok(labels
214 .into_iter()
215 .map(|label| label.map(Into::into))
216 .collect())
217 }
218 .boxed()
219 })
220 .await
221 }
222
223 async fn labels_for_symbols(
224 &self,
225 language_server_id: LanguageServerName,
226 symbols: Vec<Symbol>,
227 ) -> Result<Vec<Option<CodeLabel>>> {
228 self.call(|extension, store| {
229 async move {
230 let labels = extension
231 .call_labels_for_symbols(
232 store,
233 &language_server_id,
234 symbols.into_iter().map(Into::into).collect(),
235 )
236 .await?
237 .map_err(|err| store.data().extension_error(err))?;
238
239 Ok(labels
240 .into_iter()
241 .map(|label| label.map(Into::into))
242 .collect())
243 }
244 .boxed()
245 })
246 .await
247 }
248
249 async fn complete_slash_command_argument(
250 &self,
251 command: SlashCommand,
252 arguments: Vec<String>,
253 ) -> Result<Vec<SlashCommandArgumentCompletion>> {
254 self.call(|extension, store| {
255 async move {
256 let completions = extension
257 .call_complete_slash_command_argument(store, &command.into(), &arguments)
258 .await?
259 .map_err(|err| store.data().extension_error(err))?;
260
261 Ok(completions.into_iter().map(Into::into).collect())
262 }
263 .boxed()
264 })
265 .await
266 }
267
268 async fn run_slash_command(
269 &self,
270 command: SlashCommand,
271 arguments: Vec<String>,
272 delegate: Option<Arc<dyn WorktreeDelegate>>,
273 ) -> Result<SlashCommandOutput> {
274 self.call(|extension, store| {
275 async move {
276 let resource = if let Some(delegate) = delegate {
277 Some(store.data_mut().table().push(delegate)?)
278 } else {
279 None
280 };
281
282 let output = extension
283 .call_run_slash_command(store, &command.into(), &arguments, resource)
284 .await?
285 .map_err(|err| store.data().extension_error(err))?;
286
287 Ok(output.into())
288 }
289 .boxed()
290 })
291 .await
292 }
293
294 async fn context_server_command(
295 &self,
296 context_server_id: Arc<str>,
297 project: Arc<dyn ProjectDelegate>,
298 ) -> Result<Command> {
299 self.call(|extension, store| {
300 async move {
301 let project_resource = store.data_mut().table().push(project)?;
302 let command = extension
303 .call_context_server_command(store, context_server_id.clone(), project_resource)
304 .await?
305 .map_err(|err| store.data().extension_error(err))?;
306 anyhow::Ok(command.into())
307 }
308 .boxed()
309 })
310 .await
311 }
312
313 async fn context_server_configuration(
314 &self,
315 context_server_id: Arc<str>,
316 project: Arc<dyn ProjectDelegate>,
317 ) -> Result<Option<ContextServerConfiguration>> {
318 self.call(|extension, store| {
319 async move {
320 let project_resource = store.data_mut().table().push(project)?;
321 let Some(configuration) = extension
322 .call_context_server_configuration(
323 store,
324 context_server_id.clone(),
325 project_resource,
326 )
327 .await?
328 .map_err(|err| store.data().extension_error(err))?
329 else {
330 return Ok(None);
331 };
332
333 Ok(Some(configuration.try_into()?))
334 }
335 .boxed()
336 })
337 .await
338 }
339
340 async fn suggest_docs_packages(&self, provider: Arc<str>) -> Result<Vec<String>> {
341 self.call(|extension, store| {
342 async move {
343 let packages = extension
344 .call_suggest_docs_packages(store, provider.as_ref())
345 .await?
346 .map_err(|err| store.data().extension_error(err))?;
347
348 Ok(packages)
349 }
350 .boxed()
351 })
352 .await
353 }
354
355 async fn index_docs(
356 &self,
357 provider: Arc<str>,
358 package_name: Arc<str>,
359 kv_store: Arc<dyn KeyValueStoreDelegate>,
360 ) -> Result<()> {
361 self.call(|extension, store| {
362 async move {
363 let kv_store_resource = store.data_mut().table().push(kv_store)?;
364 extension
365 .call_index_docs(
366 store,
367 provider.as_ref(),
368 package_name.as_ref(),
369 kv_store_resource,
370 )
371 .await?
372 .map_err(|err| store.data().extension_error(err))?;
373
374 anyhow::Ok(())
375 }
376 .boxed()
377 })
378 .await
379 }
380
381 async fn get_dap_binary(
382 &self,
383 dap_name: Arc<str>,
384 config: DebugTaskDefinition,
385 user_installed_path: Option<PathBuf>,
386 worktree: Arc<dyn WorktreeDelegate>,
387 ) -> Result<DebugAdapterBinary> {
388 self.call(|extension, store| {
389 async move {
390 let resource = store.data_mut().table().push(worktree)?;
391 let dap_binary = extension
392 .call_get_dap_binary(store, dap_name, config, user_installed_path, resource)
393 .await?
394 .map_err(|err| store.data().extension_error(err))?;
395 let dap_binary = dap_binary.try_into()?;
396 Ok(dap_binary)
397 }
398 .boxed()
399 })
400 .await
401 }
402
403 async fn get_dap_schema(&self) -> Result<serde_json::Value> {
404 self.call(|extension, store| {
405 async move {
406 extension
407 .call_dap_schema(store)
408 .await
409 .and_then(|schema| serde_json::to_value(schema).map_err(|err| err.to_string()))
410 .map_err(|err| store.data().extension_error(err))
411 }
412 .boxed()
413 })
414 .await
415 }
416}
417
418pub struct WasmState {
419 manifest: Arc<ExtensionManifest>,
420 pub table: ResourceTable,
421 ctx: wasi::WasiCtx,
422 pub host: Arc<WasmHost>,
423}
424
425type MainThreadCall = Box<dyn Send + for<'a> FnOnce(&'a mut AsyncApp) -> LocalBoxFuture<'a, ()>>;
426
427type ExtensionCall = Box<
428 dyn Send + for<'a> FnOnce(&'a mut Extension, &'a mut Store<WasmState>) -> BoxFuture<'a, ()>,
429>;
430
431fn wasm_engine() -> wasmtime::Engine {
432 static WASM_ENGINE: LazyLock<wasmtime::Engine> = LazyLock::new(|| {
433 let mut config = wasmtime::Config::new();
434 config.wasm_component_model(true);
435 config.async_support(true);
436 config
437 .enable_incremental_compilation(cache_store())
438 .unwrap();
439 wasmtime::Engine::new(&config).unwrap()
440 });
441
442 WASM_ENGINE.clone()
443}
444
445fn cache_store() -> Arc<IncrementalCompilationCache> {
446 static CACHE_STORE: LazyLock<Arc<IncrementalCompilationCache>> =
447 LazyLock::new(|| Arc::new(IncrementalCompilationCache::new()));
448 CACHE_STORE.clone()
449}
450
451impl WasmHost {
452 pub fn new(
453 fs: Arc<dyn Fs>,
454 http_client: Arc<dyn HttpClient>,
455 node_runtime: NodeRuntime,
456 proxy: Arc<ExtensionHostProxy>,
457 work_dir: PathBuf,
458 cx: &mut App,
459 ) -> Arc<Self> {
460 let (tx, mut rx) = mpsc::unbounded::<MainThreadCall>();
461 let task = cx.spawn(async move |cx| {
462 while let Some(message) = rx.next().await {
463 message(cx).await;
464 }
465 });
466 Arc::new(Self {
467 engine: wasm_engine(),
468 fs,
469 work_dir,
470 http_client,
471 node_runtime,
472 proxy,
473 release_channel: ReleaseChannel::global(cx),
474 _main_thread_message_task: task,
475 main_thread_message_tx: tx,
476 })
477 }
478
479 pub fn load_extension(
480 self: &Arc<Self>,
481 wasm_bytes: Vec<u8>,
482 manifest: &Arc<ExtensionManifest>,
483 executor: BackgroundExecutor,
484 ) -> Task<Result<WasmExtension>> {
485 let this = self.clone();
486 let manifest = manifest.clone();
487 executor.clone().spawn(async move {
488 let zed_api_version = parse_wasm_extension_version(&manifest.id, &wasm_bytes)?;
489
490 let component = Component::from_binary(&this.engine, &wasm_bytes)
491 .context("failed to compile wasm component")?;
492
493 let mut store = wasmtime::Store::new(
494 &this.engine,
495 WasmState {
496 ctx: this.build_wasi_ctx(&manifest).await?,
497 manifest: manifest.clone(),
498 table: ResourceTable::new(),
499 host: this.clone(),
500 },
501 );
502
503 let mut extension = Extension::instantiate_async(
504 &mut store,
505 this.release_channel,
506 zed_api_version,
507 &component,
508 )
509 .await?;
510
511 extension
512 .call_init_extension(&mut store)
513 .await
514 .context("failed to initialize wasm extension")?;
515
516 let (tx, mut rx) = mpsc::unbounded::<ExtensionCall>();
517 executor
518 .spawn(async move {
519 while let Some(call) = rx.next().await {
520 (call)(&mut extension, &mut store).await;
521 }
522 })
523 .detach();
524
525 Ok(WasmExtension {
526 manifest: manifest.clone(),
527 work_dir: this.work_dir.join(manifest.id.as_ref()).into(),
528 tx,
529 zed_api_version,
530 })
531 })
532 }
533
534 async fn build_wasi_ctx(&self, manifest: &Arc<ExtensionManifest>) -> Result<wasi::WasiCtx> {
535 let extension_work_dir = self.work_dir.join(manifest.id.as_ref());
536 self.fs
537 .create_dir(&extension_work_dir)
538 .await
539 .context("failed to create extension work dir")?;
540
541 let file_perms = wasi::FilePerms::all();
542 let dir_perms = wasi::DirPerms::all();
543
544 Ok(wasi::WasiCtxBuilder::new()
545 .inherit_stdio()
546 .preopened_dir(&extension_work_dir, ".", dir_perms, file_perms)?
547 .preopened_dir(
548 &extension_work_dir,
549 extension_work_dir.to_string_lossy(),
550 dir_perms,
551 file_perms,
552 )?
553 .env("PWD", extension_work_dir.to_string_lossy())
554 .env("RUST_BACKTRACE", "full")
555 .build())
556 }
557
558 pub fn writeable_path_from_extension(&self, id: &Arc<str>, path: &Path) -> Result<PathBuf> {
559 let extension_work_dir = self.work_dir.join(id.as_ref());
560 let path = normalize_path(&extension_work_dir.join(path));
561 anyhow::ensure!(
562 path.starts_with(&extension_work_dir),
563 "cannot write to path {path:?}",
564 );
565 Ok(path)
566 }
567}
568
569pub fn parse_wasm_extension_version(
570 extension_id: &str,
571 wasm_bytes: &[u8],
572) -> Result<SemanticVersion> {
573 let mut version = None;
574
575 for part in wasmparser::Parser::new(0).parse_all(wasm_bytes) {
576 if let wasmparser::Payload::CustomSection(s) =
577 part.context("error parsing wasm extension")?
578 {
579 if s.name() == "zed:api-version" {
580 version = parse_wasm_extension_version_custom_section(s.data());
581 if version.is_none() {
582 bail!(
583 "extension {} has invalid zed:api-version section: {:?}",
584 extension_id,
585 s.data()
586 );
587 }
588 }
589 }
590 }
591
592 // The reason we wait until we're done parsing all of the Wasm bytes to return the version
593 // is to work around a panic that can happen inside of Wasmtime when the bytes are invalid.
594 //
595 // By parsing the entirety of the Wasm bytes before we return, we're able to detect this problem
596 // earlier as an `Err` rather than as a panic.
597 version.with_context(|| format!("extension {extension_id} has no zed:api-version section"))
598}
599
600fn parse_wasm_extension_version_custom_section(data: &[u8]) -> Option<SemanticVersion> {
601 if data.len() == 6 {
602 Some(SemanticVersion::new(
603 u16::from_be_bytes([data[0], data[1]]) as _,
604 u16::from_be_bytes([data[2], data[3]]) as _,
605 u16::from_be_bytes([data[4], data[5]]) as _,
606 ))
607 } else {
608 None
609 }
610}
611
612impl WasmExtension {
613 pub async fn load(
614 extension_dir: PathBuf,
615 manifest: &Arc<ExtensionManifest>,
616 wasm_host: Arc<WasmHost>,
617 cx: &AsyncApp,
618 ) -> Result<Self> {
619 let path = extension_dir.join("extension.wasm");
620
621 let mut wasm_file = wasm_host
622 .fs
623 .open_sync(&path)
624 .await
625 .context("failed to open wasm file")?;
626
627 let mut wasm_bytes = Vec::new();
628 wasm_file
629 .read_to_end(&mut wasm_bytes)
630 .context("failed to read wasm")?;
631
632 wasm_host
633 .load_extension(wasm_bytes, manifest, cx.background_executor().clone())
634 .await
635 .with_context(|| format!("failed to load wasm extension {}", manifest.id))
636 }
637
638 pub async fn call<T, Fn>(&self, f: Fn) -> T
639 where
640 T: 'static + Send,
641 Fn: 'static
642 + Send
643 + for<'a> FnOnce(&'a mut Extension, &'a mut Store<WasmState>) -> BoxFuture<'a, T>,
644 {
645 let (return_tx, return_rx) = oneshot::channel();
646 self.tx
647 .clone()
648 .unbounded_send(Box::new(move |extension, store| {
649 async {
650 let result = f(extension, store).await;
651 return_tx.send(result).ok();
652 }
653 .boxed()
654 }))
655 .expect("wasm extension channel should not be closed yet");
656 return_rx.await.expect("wasm extension channel")
657 }
658}
659
660impl WasmState {
661 fn on_main_thread<T, Fn>(&self, f: Fn) -> impl 'static + Future<Output = T>
662 where
663 T: 'static + Send,
664 Fn: 'static + Send + for<'a> FnOnce(&'a mut AsyncApp) -> LocalBoxFuture<'a, T>,
665 {
666 let (return_tx, return_rx) = oneshot::channel();
667 self.host
668 .main_thread_message_tx
669 .clone()
670 .unbounded_send(Box::new(move |cx| {
671 async {
672 let result = f(cx).await;
673 return_tx.send(result).ok();
674 }
675 .boxed_local()
676 }))
677 .expect("main thread message channel should not be closed yet");
678 async move { return_rx.await.expect("main thread message channel") }
679 }
680
681 fn work_dir(&self) -> PathBuf {
682 self.host.work_dir.join(self.manifest.id.as_ref())
683 }
684
685 fn extension_error(&self, message: String) -> anyhow::Error {
686 anyhow!(
687 "from extension \"{}\" version {}: {}",
688 self.manifest.name,
689 self.manifest.version,
690 message
691 )
692 }
693}
694
695impl wasi::WasiView for WasmState {
696 fn table(&mut self) -> &mut ResourceTable {
697 &mut self.table
698 }
699
700 fn ctx(&mut self) -> &mut wasi::WasiCtx {
701 &mut self.ctx
702 }
703}
704
705/// Wrapper around a mini-moka bounded cache for storing incremental compilation artifacts.
706/// Since wasm modules have many similar elements, this can save us a lot of work at the
707/// cost of a small memory footprint. However, we don't want this to be unbounded, so we use
708/// a LFU/LRU cache to evict less used cache entries.
709#[derive(Debug)]
710struct IncrementalCompilationCache {
711 cache: Cache<Vec<u8>, Vec<u8>>,
712}
713
714impl IncrementalCompilationCache {
715 fn new() -> Self {
716 let cache = Cache::builder()
717 // Cap this at 32 MB for now. Our extensions turn into roughly 512kb in the cache,
718 // which means we could store 64 completely novel extensions in the cache, but in
719 // practice we will more than that, which is more than enough for our use case.
720 .max_capacity(32 * 1024 * 1024)
721 .weigher(|k: &Vec<u8>, v: &Vec<u8>| (k.len() + v.len()).try_into().unwrap_or(u32::MAX))
722 .build();
723 Self { cache }
724 }
725}
726
727impl CacheStore for IncrementalCompilationCache {
728 fn get(&self, key: &[u8]) -> Option<Cow<'_, [u8]>> {
729 self.cache.get(key).map(|v| v.into())
730 }
731
732 fn insert(&self, key: &[u8], value: Vec<u8>) -> bool {
733 self.cache.insert(key.to_vec(), value);
734 true
735 }
736}