1 //! rust-analyzer is lazy and doesn't compute anything unless asked. This
2 //! sometimes is counter productive when, for example, the first goto definition
3 //! request takes longer to compute. This modules implemented prepopulation of
4 //! various caches, it's not really advanced at the moment.
7 use std::time::Duration;
9 use hir::db::DefDatabase;
12 salsa::{Database, ParallelDatabase, Snapshot},
13 Cancelled, CrateGraph, CrateId, SourceDatabase, SourceDatabaseExt,
15 FxHashSet, FxIndexMap,
18 use crate::RootDatabase;
20 /// We're indexing many crates.
22 pub struct ParallelPrimeCachesProgress {
23 /// the crates that we are currently priming.
24 pub crates_currently_indexing: Vec<String>,
25 /// the total number of crates we want to prime.
26 pub crates_total: usize,
27 /// the total number of crates that have finished priming
28 pub crates_done: usize,
31 pub(crate) fn parallel_prime_caches(
33 num_worker_threads: u8,
34 cb: &(dyn Fn(ParallelPrimeCachesProgress) + Sync),
36 let _p = profile::span("prime_caches");
38 let graph = db.crate_graph();
39 let mut crates_to_prime = {
40 let crate_ids = compute_crates_to_prime(db, &graph);
42 let mut builder = topologic_sort::TopologicalSortIter::builder();
44 for &crate_id in &crate_ids {
45 let crate_data = &graph[crate_id];
46 let dependencies = crate_data
50 .filter(|i| crate_ids.contains(i));
52 builder.add(crate_id, dependencies);
58 enum ParallelPrimeCacheWorkerProgress {
59 BeginCrate { crate_id: CrateId, crate_name: String },
60 EndCrate { crate_id: CrateId },
63 let (work_sender, progress_receiver) = {
64 let (progress_sender, progress_receiver) = crossbeam_channel::unbounded();
65 let (work_sender, work_receiver) = crossbeam_channel::unbounded();
66 let prime_caches_worker = move |db: Snapshot<RootDatabase>| {
67 while let Ok((crate_id, crate_name)) = work_receiver.recv() {
69 .send(ParallelPrimeCacheWorkerProgress::BeginCrate { crate_id, crate_name })?;
71 // This also computes the DefMap
72 db.import_map(crate_id);
74 progress_sender.send(ParallelPrimeCacheWorkerProgress::EndCrate { crate_id })?;
77 Ok::<_, crossbeam_channel::SendError<_>>(())
80 for _ in 0..num_worker_threads {
81 let worker = prime_caches_worker.clone();
82 let db = db.snapshot();
83 std::thread::spawn(move || Cancelled::catch(|| worker(db)));
86 (work_sender, progress_receiver)
89 let crates_total = crates_to_prime.pending();
90 let mut crates_done = 0;
92 // an index map is used to preserve ordering so we can sort the progress report in order of
93 // "longest crate to index" first
94 let mut crates_currently_indexing =
95 FxIndexMap::with_capacity_and_hasher(num_worker_threads as _, Default::default());
97 while crates_done < crates_total {
98 db.unwind_if_cancelled();
100 for crate_id in &mut crates_to_prime {
104 graph[crate_id].display_name.as_deref().unwrap_or_default().to_string(),
109 // recv_timeout is somewhat a hack, we need a way to from this thread check to see if the current salsa revision
110 // is cancelled on a regular basis. workers will only exit if they are processing a task that is cancelled, or
111 // if this thread exits, and closes the work channel.
112 let worker_progress = match progress_receiver.recv_timeout(Duration::from_millis(10)) {
114 Err(crossbeam_channel::RecvTimeoutError::Timeout) => {
117 Err(crossbeam_channel::RecvTimeoutError::Disconnected) => {
118 // our workers may have died from a cancelled task, so we'll check and re-raise here.
119 db.unwind_if_cancelled();
123 match worker_progress {
124 ParallelPrimeCacheWorkerProgress::BeginCrate { crate_id, crate_name } => {
125 crates_currently_indexing.insert(crate_id, crate_name);
127 ParallelPrimeCacheWorkerProgress::EndCrate { crate_id } => {
128 crates_currently_indexing.remove(&crate_id);
129 crates_to_prime.mark_done(crate_id);
134 let progress = ParallelPrimeCachesProgress {
135 crates_currently_indexing: crates_currently_indexing.values().cloned().collect(),
144 fn compute_crates_to_prime(db: &RootDatabase, graph: &CrateGraph) -> FxHashSet<CrateId> {
145 // We're only interested in the workspace crates and the `ImportMap`s of their direct
146 // dependencies, though in practice the latter also compute the `DefMap`s.
147 // We don't prime transitive dependencies because they're generally not visible in
148 // the current workspace.
152 let file_id = graph[id].root_file_id;
153 let root_id = db.file_source_root(file_id);
154 !db.source_root(root_id).is_library
156 .flat_map(|id| graph[id].dependencies.iter().map(|krate| krate.crate_id))