ZIm/crates/extension_host/src/wasm_host.rs
2025-03-31 20:55:27 +02:00

620 lines
19 KiB
Rust

pub mod wit;
use crate::ExtensionManifest;
use anyhow::{Context as _, Result, anyhow, bail};
use async_trait::async_trait;
use extension::{
CodeLabel, Command, Completion, ExtensionHostProxy, KeyValueStoreDelegate, ProjectDelegate,
SlashCommand, SlashCommandArgumentCompletion, SlashCommandOutput, Symbol, WorktreeDelegate,
};
use fs::{Fs, normalize_path};
use futures::future::LocalBoxFuture;
use futures::{
Future, FutureExt, StreamExt as _,
channel::{
mpsc::{self, UnboundedSender},
oneshot,
},
future::BoxFuture,
};
use gpui::{App, AsyncApp, BackgroundExecutor, Task};
use http_client::HttpClient;
use language::LanguageName;
use lsp::LanguageServerName;
use node_runtime::NodeRuntime;
use release_channel::ReleaseChannel;
use semantic_version::SemanticVersion;
use std::{
path::{Path, PathBuf},
sync::{Arc, OnceLock},
};
use wasmtime::{
Engine, Store,
component::{Component, ResourceTable},
};
use wasmtime_wasi::{self as wasi, WasiView};
use wit::Extension;
pub struct WasmHost {
engine: Engine,
release_channel: ReleaseChannel,
http_client: Arc<dyn HttpClient>,
node_runtime: NodeRuntime,
pub(crate) proxy: Arc<ExtensionHostProxy>,
fs: Arc<dyn Fs>,
pub work_dir: PathBuf,
_main_thread_message_task: Task<()>,
main_thread_message_tx: mpsc::UnboundedSender<MainThreadCall>,
}
#[derive(Clone)]
pub struct WasmExtension {
tx: UnboundedSender<ExtensionCall>,
pub manifest: Arc<ExtensionManifest>,
pub work_dir: Arc<Path>,
#[allow(unused)]
pub zed_api_version: SemanticVersion,
}
#[async_trait]
impl extension::Extension for WasmExtension {
fn manifest(&self) -> Arc<ExtensionManifest> {
self.manifest.clone()
}
fn work_dir(&self) -> Arc<Path> {
self.work_dir.clone()
}
async fn language_server_command(
&self,
language_server_id: LanguageServerName,
language_name: LanguageName,
worktree: Arc<dyn WorktreeDelegate>,
) -> Result<Command> {
self.call(|extension, store| {
async move {
let resource = store.data_mut().table().push(worktree)?;
let command = extension
.call_language_server_command(
store,
&language_server_id,
&language_name,
resource,
)
.await?
.map_err(|err| anyhow!("{err}"))?;
Ok(command.into())
}
.boxed()
})
.await
}
async fn language_server_initialization_options(
&self,
language_server_id: LanguageServerName,
language_name: LanguageName,
worktree: Arc<dyn WorktreeDelegate>,
) -> Result<Option<String>> {
self.call(|extension, store| {
async move {
let resource = store.data_mut().table().push(worktree)?;
let options = extension
.call_language_server_initialization_options(
store,
&language_server_id,
&language_name,
resource,
)
.await?
.map_err(|err| anyhow!("{err}"))?;
anyhow::Ok(options)
}
.boxed()
})
.await
}
async fn language_server_workspace_configuration(
&self,
language_server_id: LanguageServerName,
worktree: Arc<dyn WorktreeDelegate>,
) -> Result<Option<String>> {
self.call(|extension, store| {
async move {
let resource = store.data_mut().table().push(worktree)?;
let options = extension
.call_language_server_workspace_configuration(
store,
&language_server_id,
resource,
)
.await?
.map_err(|err| anyhow!("{err}"))?;
anyhow::Ok(options)
}
.boxed()
})
.await
}
async fn language_server_additional_initialization_options(
&self,
language_server_id: LanguageServerName,
target_language_server_id: LanguageServerName,
worktree: Arc<dyn WorktreeDelegate>,
) -> Result<Option<String>> {
self.call(|extension, store| {
async move {
let resource = store.data_mut().table().push(worktree)?;
let options = extension
.call_language_server_additional_initialization_options(
store,
&language_server_id,
&target_language_server_id,
resource,
)
.await?
.map_err(|err| anyhow!("{err}"))?;
anyhow::Ok(options)
}
.boxed()
})
.await
}
async fn language_server_additional_workspace_configuration(
&self,
language_server_id: LanguageServerName,
target_language_server_id: LanguageServerName,
worktree: Arc<dyn WorktreeDelegate>,
) -> Result<Option<String>> {
self.call(|extension, store| {
async move {
let resource = store.data_mut().table().push(worktree)?;
let options = extension
.call_language_server_additional_workspace_configuration(
store,
&language_server_id,
&target_language_server_id,
resource,
)
.await?
.map_err(|err| anyhow!("{err}"))?;
anyhow::Ok(options)
}
.boxed()
})
.await
}
async fn labels_for_completions(
&self,
language_server_id: LanguageServerName,
completions: Vec<Completion>,
) -> Result<Vec<Option<CodeLabel>>> {
self.call(|extension, store| {
async move {
let labels = extension
.call_labels_for_completions(
store,
&language_server_id,
completions.into_iter().map(Into::into).collect(),
)
.await?
.map_err(|err| anyhow!("{err}"))?;
Ok(labels
.into_iter()
.map(|label| label.map(Into::into))
.collect())
}
.boxed()
})
.await
}
async fn labels_for_symbols(
&self,
language_server_id: LanguageServerName,
symbols: Vec<Symbol>,
) -> Result<Vec<Option<CodeLabel>>> {
self.call(|extension, store| {
async move {
let labels = extension
.call_labels_for_symbols(
store,
&language_server_id,
symbols.into_iter().map(Into::into).collect(),
)
.await?
.map_err(|err| anyhow!("{err}"))?;
Ok(labels
.into_iter()
.map(|label| label.map(Into::into))
.collect())
}
.boxed()
})
.await
}
async fn complete_slash_command_argument(
&self,
command: SlashCommand,
arguments: Vec<String>,
) -> Result<Vec<SlashCommandArgumentCompletion>> {
self.call(|extension, store| {
async move {
let completions = extension
.call_complete_slash_command_argument(store, &command.into(), &arguments)
.await?
.map_err(|err| anyhow!("{err}"))?;
Ok(completions.into_iter().map(Into::into).collect())
}
.boxed()
})
.await
}
async fn run_slash_command(
&self,
command: SlashCommand,
arguments: Vec<String>,
delegate: Option<Arc<dyn WorktreeDelegate>>,
) -> Result<SlashCommandOutput> {
self.call(|extension, store| {
async move {
let resource = if let Some(delegate) = delegate {
Some(store.data_mut().table().push(delegate)?)
} else {
None
};
let output = extension
.call_run_slash_command(store, &command.into(), &arguments, resource)
.await?
.map_err(|err| anyhow!("{err}"))?;
Ok(output.into())
}
.boxed()
})
.await
}
async fn context_server_command(
&self,
context_server_id: Arc<str>,
project: Arc<dyn ProjectDelegate>,
) -> Result<Command> {
self.call(|extension, store| {
async move {
let project_resource = store.data_mut().table().push(project)?;
let command = extension
.call_context_server_command(store, context_server_id.clone(), project_resource)
.await?
.map_err(|err| anyhow!("{err}"))?;
anyhow::Ok(command.into())
}
.boxed()
})
.await
}
async fn suggest_docs_packages(&self, provider: Arc<str>) -> Result<Vec<String>> {
self.call(|extension, store| {
async move {
let packages = extension
.call_suggest_docs_packages(store, provider.as_ref())
.await?
.map_err(|err| anyhow!("{err:?}"))?;
Ok(packages)
}
.boxed()
})
.await
}
async fn index_docs(
&self,
provider: Arc<str>,
package_name: Arc<str>,
kv_store: Arc<dyn KeyValueStoreDelegate>,
) -> Result<()> {
self.call(|extension, store| {
async move {
let kv_store_resource = store.data_mut().table().push(kv_store)?;
extension
.call_index_docs(
store,
provider.as_ref(),
package_name.as_ref(),
kv_store_resource,
)
.await?
.map_err(|err| anyhow!("{err:?}"))?;
anyhow::Ok(())
}
.boxed()
})
.await
}
}
pub struct WasmState {
manifest: Arc<ExtensionManifest>,
pub table: ResourceTable,
ctx: wasi::WasiCtx,
pub host: Arc<WasmHost>,
}
type MainThreadCall = Box<dyn Send + for<'a> FnOnce(&'a mut AsyncApp) -> LocalBoxFuture<'a, ()>>;
type ExtensionCall = Box<
dyn Send + for<'a> FnOnce(&'a mut Extension, &'a mut Store<WasmState>) -> BoxFuture<'a, ()>,
>;
fn wasm_engine() -> wasmtime::Engine {
static WASM_ENGINE: OnceLock<wasmtime::Engine> = OnceLock::new();
WASM_ENGINE
.get_or_init(|| {
let mut config = wasmtime::Config::new();
config.wasm_component_model(true);
config.async_support(true);
wasmtime::Engine::new(&config).unwrap()
})
.clone()
}
impl WasmHost {
pub fn new(
fs: Arc<dyn Fs>,
http_client: Arc<dyn HttpClient>,
node_runtime: NodeRuntime,
proxy: Arc<ExtensionHostProxy>,
work_dir: PathBuf,
cx: &mut App,
) -> Arc<Self> {
let (tx, mut rx) = mpsc::unbounded::<MainThreadCall>();
let task = cx.spawn(async move |cx| {
while let Some(message) = rx.next().await {
message(cx).await;
}
});
Arc::new(Self {
engine: wasm_engine(),
fs,
work_dir,
http_client,
node_runtime,
proxy,
release_channel: ReleaseChannel::global(cx),
_main_thread_message_task: task,
main_thread_message_tx: tx,
})
}
pub fn load_extension(
self: &Arc<Self>,
wasm_bytes: Vec<u8>,
manifest: &Arc<ExtensionManifest>,
executor: BackgroundExecutor,
) -> Task<Result<WasmExtension>> {
let this = self.clone();
let manifest = manifest.clone();
executor.clone().spawn(async move {
let zed_api_version = parse_wasm_extension_version(&manifest.id, &wasm_bytes)?;
let component = Component::from_binary(&this.engine, &wasm_bytes)
.context("failed to compile wasm component")?;
let mut store = wasmtime::Store::new(
&this.engine,
WasmState {
ctx: this.build_wasi_ctx(&manifest).await?,
manifest: manifest.clone(),
table: ResourceTable::new(),
host: this.clone(),
},
);
let mut extension = Extension::instantiate_async(
&mut store,
this.release_channel,
zed_api_version,
&component,
)
.await?;
extension
.call_init_extension(&mut store)
.await
.context("failed to initialize wasm extension")?;
let (tx, mut rx) = mpsc::unbounded::<ExtensionCall>();
executor
.spawn(async move {
while let Some(call) = rx.next().await {
(call)(&mut extension, &mut store).await;
}
})
.detach();
Ok(WasmExtension {
manifest: manifest.clone(),
work_dir: this.work_dir.join(manifest.id.as_ref()).into(),
tx,
zed_api_version,
})
})
}
async fn build_wasi_ctx(&self, manifest: &Arc<ExtensionManifest>) -> Result<wasi::WasiCtx> {
let extension_work_dir = self.work_dir.join(manifest.id.as_ref());
self.fs
.create_dir(&extension_work_dir)
.await
.context("failed to create extension work dir")?;
let file_perms = wasi::FilePerms::all();
let dir_perms = wasi::DirPerms::all();
Ok(wasi::WasiCtxBuilder::new()
.inherit_stdio()
.preopened_dir(&extension_work_dir, ".", dir_perms, file_perms)?
.preopened_dir(
&extension_work_dir,
extension_work_dir.to_string_lossy(),
dir_perms,
file_perms,
)?
.env("PWD", extension_work_dir.to_string_lossy())
.env("RUST_BACKTRACE", "full")
.build())
}
pub fn writeable_path_from_extension(&self, id: &Arc<str>, path: &Path) -> Result<PathBuf> {
let extension_work_dir = self.work_dir.join(id.as_ref());
let path = normalize_path(&extension_work_dir.join(path));
if path.starts_with(&extension_work_dir) {
Ok(path)
} else {
Err(anyhow!("cannot write to path {}", path.display()))
}
}
}
pub fn parse_wasm_extension_version(
extension_id: &str,
wasm_bytes: &[u8],
) -> Result<SemanticVersion> {
let mut version = None;
for part in wasmparser::Parser::new(0).parse_all(wasm_bytes) {
if let wasmparser::Payload::CustomSection(s) =
part.context("error parsing wasm extension")?
{
if s.name() == "zed:api-version" {
version = parse_wasm_extension_version_custom_section(s.data());
if version.is_none() {
bail!(
"extension {} has invalid zed:api-version section: {:?}",
extension_id,
s.data()
);
}
}
}
}
// The reason we wait until we're done parsing all of the Wasm bytes to return the version
// is to work around a panic that can happen inside of Wasmtime when the bytes are invalid.
//
// By parsing the entirety of the Wasm bytes before we return, we're able to detect this problem
// earlier as an `Err` rather than as a panic.
version.ok_or_else(|| anyhow!("extension {} has no zed:api-version section", extension_id))
}
fn parse_wasm_extension_version_custom_section(data: &[u8]) -> Option<SemanticVersion> {
if data.len() == 6 {
Some(SemanticVersion::new(
u16::from_be_bytes([data[0], data[1]]) as _,
u16::from_be_bytes([data[2], data[3]]) as _,
u16::from_be_bytes([data[4], data[5]]) as _,
))
} else {
None
}
}
impl WasmExtension {
pub async fn load(
extension_dir: PathBuf,
manifest: &Arc<ExtensionManifest>,
wasm_host: Arc<WasmHost>,
cx: &AsyncApp,
) -> Result<Self> {
let path = extension_dir.join("extension.wasm");
let mut wasm_file = wasm_host
.fs
.open_sync(&path)
.await
.context("failed to open wasm file")?;
let mut wasm_bytes = Vec::new();
wasm_file
.read_to_end(&mut wasm_bytes)
.context("failed to read wasm")?;
wasm_host
.load_extension(wasm_bytes, manifest, cx.background_executor().clone())
.await
.with_context(|| format!("failed to load wasm extension {}", manifest.id))
}
pub async fn call<T, Fn>(&self, f: Fn) -> T
where
T: 'static + Send,
Fn: 'static
+ Send
+ for<'a> FnOnce(&'a mut Extension, &'a mut Store<WasmState>) -> BoxFuture<'a, T>,
{
let (return_tx, return_rx) = oneshot::channel();
self.tx
.clone()
.unbounded_send(Box::new(move |extension, store| {
async {
let result = f(extension, store).await;
return_tx.send(result).ok();
}
.boxed()
}))
.expect("wasm extension channel should not be closed yet");
return_rx.await.expect("wasm extension channel")
}
}
impl WasmState {
fn on_main_thread<T, Fn>(&self, f: Fn) -> impl 'static + Future<Output = T>
where
T: 'static + Send,
Fn: 'static + Send + for<'a> FnOnce(&'a mut AsyncApp) -> LocalBoxFuture<'a, T>,
{
let (return_tx, return_rx) = oneshot::channel();
self.host
.main_thread_message_tx
.clone()
.unbounded_send(Box::new(move |cx| {
async {
let result = f(cx).await;
return_tx.send(result).ok();
}
.boxed_local()
}))
.expect("main thread message channel should not be closed yet");
async move { return_rx.await.expect("main thread message channel") }
}
fn work_dir(&self) -> PathBuf {
self.host.work_dir.join(self.manifest.id.as_ref())
}
}
impl wasi::WasiView for WasmState {
fn table(&mut self) -> &mut ResourceTable {
&mut self.table
}
fn ctx(&mut self) -> &mut wasi::WasiCtx {
&mut self.ctx
}
}