Merge #10810

10810: feat: Add toggle to disable cache priming r=jonas-schievink a=lnicola

Even if it doesn't prevent the rest of the features from working, cache priming tends to be quite CPU-intensive and can make people think that the load times are worse than they actually are.

It's also less useful in Code and `rust-tools` because the inlay hints and semantic highlighting trigger quite a bit of computation assuming you have a file open in the editor.

Co-authored-by: Laurențiu Nicola <lnicola@dend.ro>

crates/rust-analyzer/src/config.rs

@@ -58,6 +58,9 @@ config_data! {
         /// Whether to allow import insertion to merge new imports into single path glob imports like `use std::fmt::*;`.
         assist_allowMergingIntoGlobImports: bool           = "true",
 
+        /// Warm up caches on project load.
+        cache_warmup: bool = "true",
+
         /// Show function name and docs in parameter hints.
         callInfo_full: bool                                = "true",
 
@@ -545,6 +548,10 @@ impl Config {
         )
     }
 
+    pub fn prefill_caches(&self) -> bool {
+        self.data.cache_warmup
+    }
+
     pub fn location_link(&self) -> bool {
         try_or!(self.caps.text_document.as_ref()?.definition?.link_support?, false)
     }

crates/rust-analyzer/src/main_loop.rs

@@ -433,7 +433,9 @@ impl GlobalState {
                 for flycheck in &self.flycheck {
                     flycheck.update();
                 }
-                self.prime_caches_queue.request_op();
+                if self.config.prefill_caches() {
+                    self.prime_caches_queue.request_op();
+                }
             }
 
             if !was_quiescent || state_changed {