From af6086182d98d284e4be72695be18ce3ddcbe671 Mon Sep 17 00:00:00 2001
From: Eh2406 <YeomanYaacov@gmail.com>
Date: Sat, 3 Mar 2018 21:33:23 -0500
Subject: [PATCH] use more Rc in the part of resolver that gets cloned a lot
In a test on https://github.com/rust-lang/cargo/issues/4810#issuecomment-357553286
Before we got to 1700000 ticks in ~(82 to 97) sec
After we got to 1700000 ticks in ~(63 to 67) sec
---
src/cargo/core/resolver/mod.rs | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/src/cargo/core/resolver/mod.rs b/src/cargo/core/resolver/mod.rs
index 264c32c82e6..b5ca6d9cba4 100644
--- a/src/cargo/core/resolver/mod.rs
+++ b/src/cargo/core/resolver/mod.rs
@@ -344,7 +344,7 @@ struct Context {
warnings: RcList<String>,
}
-type Activations = HashMap<String, HashMap<SourceId, Vec<Summary>>>;
+type Activations = HashMap<String, HashMap<SourceId, Rc<Vec<Summary>>>>;
/// Builds the list of all packages required to build the first argument.
pub fn resolve(summaries: &[(Summary, Method)],
@@ -1287,7 +1287,7 @@ impl Context {
.entry(id.name().to_string())
.or_insert_with(HashMap::new)
.entry(id.source_id().clone())
- .or_insert_with(Vec::new);
+ .or_insert_with(||Rc::new(Vec::new()));
if !prev.iter().any(|c| c == summary) {
self.resolve_graph.push(GraphNode::Add(id.clone()));
if let Some(link) = summary.links() {
@@ -1295,7 +1295,9 @@ impl Context {
"Attempting to resolve a with more then one crate with the links={}. \n\
This will not build as is. Consider rebuilding the .lock file.", link);
}
- prev.push(summary.clone());
+ let mut inner: Vec<_> = (**prev).clone();
+ inner.push(summary.clone());
+ *prev = Rc::new(inner);
return Ok(false)
}
debug!("checking if {} is already activated", summary.package_id());
@@ -1463,7 +1465,7 @@ fn check_cycles(resolve: &Resolve, activations: &Activations)
-> CargoResult<()> {
let summaries: HashMap<&PackageId, &Summary> = activations.values()
.flat_map(|v| v.values())
- .flat_map(|v| v)
+ .flat_map(|v| v.iter())
.map(|s| (s.package_id(), s))
.collect();