refactor(dependencies): share package using Rc instead of cloning ♻️

Although Rc is used, it is still cloned in
dependency::DependencyProvider as it needs to sort the releases

Author: andho

compiler-cli/src/dependencies.rs

@@ -1,6 +1,7 @@
 use std::{
     cell::RefCell,
     collections::{HashMap, HashSet},
+    rc::Rc,
     time::Instant,
 };
 
@@ -1045,7 +1046,7 @@ async fn lookup_package(
 }
 
 struct PackageFetcher {
-    runtime_cache: RefCell<HashMap<String, hexpm::Package>>,
+    runtime_cache: RefCell<HashMap<String, Rc<hexpm::Package>>>,
     runtime: tokio::runtime::Handle,
     http: HttpClient,
 }
@@ -1062,7 +1063,7 @@ impl PackageFetcher {
     /// Caches the result of `get_dependencies` so that we don't need to make a network request.
     /// Currently dependencies are fetched during initial version resolution, and then during check
     /// for major version availability.
-    fn cache_package(&self, package: &str, result: hexpm::Package) {
+    fn cache_package(&self, package: &str, result: Rc<hexpm::Package>) {
         let mut runtime_cache = self.runtime_cache.borrow_mut();
         let _ = runtime_cache.insert(package.to_string(), result);
     }
@@ -1098,7 +1099,7 @@ impl dependency::PackageFetcher for PackageFetcher {
     fn get_dependencies(
         &self,
         package: &str,
-    ) -> Result<hexpm::Package, Box<dyn std::error::Error>> {
+    ) -> Result<Rc<hexpm::Package>, Box<dyn std::error::Error>> {
         {
             let runtime_cache = self.runtime_cache.borrow();
             let result = runtime_cache.get(package);
@@ -1117,9 +1118,11 @@ impl dependency::PackageFetcher for PackageFetcher {
             .map_err(Box::new)?;
 
         match hexpm::get_package_response(response, HEXPM_PUBLIC_KEY) {
-            Ok(a) => {
-                self.cache_package(package, a.clone());
-                Ok(a)
+            Ok(pkg) => {
+                let pkg = Rc::new(pkg);
+                let pkg_ref = Rc::clone(&pkg);
+                self.cache_package(package, pkg);
+                Ok(pkg_ref)
             }
             Err(e) => match e {
                 hexpm::ApiError::NotFound => {

compiler-core/src/dependency.rs

@@ -1,4 +1,4 @@
-use std::{borrow::Borrow, cell::RefCell, collections::HashMap, error::Error as StdError};
+use std::{borrow::Borrow, cell::RefCell, collections::HashMap, error::Error as StdError, rc::Rc};
 
 use crate::{manifest, Error, Result};
 
@@ -197,7 +197,7 @@ but it is locked to {locked_version}, which is incompatible.",
 }
 
 pub trait PackageFetcher {
-    fn get_dependencies(&self, package: &str) -> Result<hexpm::Package, Box<dyn StdError>>;
+    fn get_dependencies(&self, package: &str) -> Result<Rc<hexpm::Package>, Box<dyn StdError>>;
 }
 
 struct DependencyProvider<'a, T: PackageFetcher> {
@@ -247,7 +247,9 @@ where
     ) -> Result<(), Box<dyn StdError>> {
         let mut packages = self.packages.borrow_mut();
         if packages.get(name).is_none() {
-            let mut package = self.remote.get_dependencies(name)?;
+            let package = self.remote.get_dependencies(name)?;
+            // mut (therefore clone) is required here in order to sort the releases
+            let mut package = (*package).clone();
             // Sort the packages from newest to oldest, pres after all others
             package.releases.sort_by(|a, b| a.version.cmp(&b.version));
             package.releases.reverse();
@@ -362,14 +364,14 @@ mod tests {
     use super::*;
 
     struct Remote {
-        deps: HashMap<String, hexpm::Package>,
+        deps: HashMap<String, Rc<hexpm::Package>>,
     }
 
     impl PackageFetcher for Remote {
-        fn get_dependencies(&self, package: &str) -> Result<hexpm::Package, Box<dyn StdError>> {
+        fn get_dependencies(&self, package: &str) -> Result<Rc<hexpm::Package>, Box<dyn StdError>> {
             self.deps
                 .get(package)
-                .cloned()
+                .map(Rc::clone)
                 .ok_or(Box::new(hexpm::ApiError::NotFound))
         }
     }
@@ -411,7 +413,8 @@ mod tests {
                         meta: (),
                     },
                 ],
-            },
+            }
+            .into(),
         );
         let _ = deps.insert(
             "gleam_otp".into(),
@@ -484,7 +487,8 @@ mod tests {
                         meta: (),
                     },
                 ],
-            },
+            }
+            .into(),
         );
         let _ = deps.insert(
             "package_with_retired".into(),
@@ -510,7 +514,8 @@ mod tests {
                         meta: (),
                     },
                 ],
-            },
+            }
+            .into(),
         );
 
         let _ = deps.insert(
@@ -534,7 +539,8 @@ mod tests {
                     outer_checksum: vec![1, 2, 3],
                     meta: (),
                 }],
-            },
+            }
+            .into(),
         );
 
         let simple_deps_for_major_version_check = vec![
@@ -577,7 +583,7 @@ mod tests {
 
     fn insert_simplified_deps(
         simple_deps: Vec<(&str, Vec<(&str, Vec<(&str, &str)>)>)>,
-        deps: &mut HashMap<String, hexpm::Package>,
+        deps: &mut HashMap<String, Rc<hexpm::Package>>,
     ) {
         for (name, releases) in simple_deps {
             let _ = deps.insert(
@@ -608,7 +614,8 @@ mod tests {
                             meta: (),
                         })
                         .collect(),
-                },
+                }
+                .into(),
             );
         }
     }