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Diffstat (limited to '')
-rw-r--r-- | src/tools/rust-analyzer/crates/ide/src/prime_caches.rs | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/src/tools/rust-analyzer/crates/ide/src/prime_caches.rs b/src/tools/rust-analyzer/crates/ide/src/prime_caches.rs new file mode 100644 index 000000000..296270036 --- /dev/null +++ b/src/tools/rust-analyzer/crates/ide/src/prime_caches.rs @@ -0,0 +1,158 @@ +//! rust-analyzer is lazy and doesn't compute anything unless asked. This +//! sometimes is counter productive when, for example, the first goto definition +//! request takes longer to compute. This modules implemented prepopulation of +//! various caches, it's not really advanced at the moment. +mod topologic_sort; + +use std::time::Duration; + +use hir::db::DefDatabase; +use ide_db::{ + base_db::{ + salsa::{Database, ParallelDatabase, Snapshot}, + Cancelled, CrateGraph, CrateId, SourceDatabase, SourceDatabaseExt, + }, + FxHashSet, FxIndexMap, +}; + +use crate::RootDatabase; + +/// We're indexing many crates. +#[derive(Debug)] +pub struct ParallelPrimeCachesProgress { + /// the crates that we are currently priming. + pub crates_currently_indexing: Vec<String>, + /// the total number of crates we want to prime. + pub crates_total: usize, + /// the total number of crates that have finished priming + pub crates_done: usize, +} + +pub(crate) fn parallel_prime_caches( + db: &RootDatabase, + num_worker_threads: u8, + cb: &(dyn Fn(ParallelPrimeCachesProgress) + Sync), +) { + let _p = profile::span("prime_caches"); + + let graph = db.crate_graph(); + let mut crates_to_prime = { + let crate_ids = compute_crates_to_prime(db, &graph); + + let mut builder = topologic_sort::TopologicalSortIter::builder(); + + for &crate_id in &crate_ids { + let crate_data = &graph[crate_id]; + let dependencies = crate_data + .dependencies + .iter() + .map(|d| d.crate_id) + .filter(|i| crate_ids.contains(i)); + + builder.add(crate_id, dependencies); + } + + builder.build() + }; + + enum ParallelPrimeCacheWorkerProgress { + BeginCrate { crate_id: CrateId, crate_name: String }, + EndCrate { crate_id: CrateId }, + } + + let (work_sender, progress_receiver) = { + let (progress_sender, progress_receiver) = crossbeam_channel::unbounded(); + let (work_sender, work_receiver) = crossbeam_channel::unbounded(); + let prime_caches_worker = move |db: Snapshot<RootDatabase>| { + while let Ok((crate_id, crate_name)) = work_receiver.recv() { + progress_sender + .send(ParallelPrimeCacheWorkerProgress::BeginCrate { crate_id, crate_name })?; + + // This also computes the DefMap + db.import_map(crate_id); + + progress_sender.send(ParallelPrimeCacheWorkerProgress::EndCrate { crate_id })?; + } + + Ok::<_, crossbeam_channel::SendError<_>>(()) + }; + + for _ in 0..num_worker_threads { + let worker = prime_caches_worker.clone(); + let db = db.snapshot(); + std::thread::spawn(move || Cancelled::catch(|| worker(db))); + } + + (work_sender, progress_receiver) + }; + + let crates_total = crates_to_prime.pending(); + let mut crates_done = 0; + + // an index map is used to preserve ordering so we can sort the progress report in order of + // "longest crate to index" first + let mut crates_currently_indexing = + FxIndexMap::with_capacity_and_hasher(num_worker_threads as _, Default::default()); + + while crates_done < crates_total { + db.unwind_if_cancelled(); + + for crate_id in &mut crates_to_prime { + work_sender + .send(( + crate_id, + graph[crate_id].display_name.as_deref().unwrap_or_default().to_string(), + )) + .ok(); + } + + // recv_timeout is somewhat a hack, we need a way to from this thread check to see if the current salsa revision + // is cancelled on a regular basis. workers will only exit if they are processing a task that is cancelled, or + // if this thread exits, and closes the work channel. + let worker_progress = match progress_receiver.recv_timeout(Duration::from_millis(10)) { + Ok(p) => p, + Err(crossbeam_channel::RecvTimeoutError::Timeout) => { + continue; + } + Err(crossbeam_channel::RecvTimeoutError::Disconnected) => { + // our workers may have died from a cancelled task, so we'll check and re-raise here. + db.unwind_if_cancelled(); + break; + } + }; + match worker_progress { + ParallelPrimeCacheWorkerProgress::BeginCrate { crate_id, crate_name } => { + crates_currently_indexing.insert(crate_id, crate_name); + } + ParallelPrimeCacheWorkerProgress::EndCrate { crate_id } => { + crates_currently_indexing.remove(&crate_id); + crates_to_prime.mark_done(crate_id); + crates_done += 1; + } + }; + + let progress = ParallelPrimeCachesProgress { + crates_currently_indexing: crates_currently_indexing.values().cloned().collect(), + crates_done, + crates_total, + }; + + cb(progress); + } +} + +fn compute_crates_to_prime(db: &RootDatabase, graph: &CrateGraph) -> FxHashSet<CrateId> { + // We're only interested in the workspace crates and the `ImportMap`s of their direct + // dependencies, though in practice the latter also compute the `DefMap`s. + // We don't prime transitive dependencies because they're generally not visible in + // the current workspace. + graph + .iter() + .filter(|&id| { + let file_id = graph[id].root_file_id; + let root_id = db.file_source_root(file_id); + !db.source_root(root_id).is_library + }) + .flat_map(|id| graph[id].dependencies.iter().map(|krate| krate.crate_id)) + .collect() +} |