Use an arena for packages

Author: x-hgg-x

README.md

@@ -29,10 +29,6 @@ So, because root depends on both menu >=1.0.0 and intl >=5.0.0,
 ```
 
 This pubgrub crate provides a Rust implementation of PubGrub.
-It is generic and works for any type of dependency system
-as long as packages (P) and versions (V) implement
-the provided `Package` and `Version` traits.
-
 
 ## Using the pubgrub crate
 

benches/backtracking.rs

@@ -26,7 +26,7 @@ fn backtracking_singletons(c: &mut Criterion, package_count: u32, version_count:
 
     c.bench_function("backtracking_singletons", |b| {
         b.iter(|| {
-            let _ = pubgrub::resolve(&dependency_provider, 0u32, 0u32);
+            let _ = pubgrub::resolve(&mut dependency_provider, 0u32, 0u32);
         })
     });
 }
@@ -59,7 +59,7 @@ fn backtracking_disjoint_versions(c: &mut Criterion, package_count: u32, version
 
     c.bench_function("backtracking_disjoint_versions", |b| {
         b.iter(|| {
-            let _ = pubgrub::resolve(&dependency_provider, 0u32, 0u32);
+            let _ = pubgrub::resolve(&mut dependency_provider, 0u32, 0u32);
         })
     });
 }
@@ -83,7 +83,7 @@ fn backtracking_ranges(c: &mut Criterion, package_count: u32, version_count: u32
 
     c.bench_function("backtracking_ranges", |b| {
         b.iter(|| {
-            let _ = pubgrub::resolve(&dependency_provider, 0u32, 0u32);
+            let _ = pubgrub::resolve(&mut dependency_provider, 0u32, 0u32);
         })
     });
 }

benches/large_case.rs

@@ -1,24 +1,41 @@
 // SPDX-License-Identifier: MPL-2.0
+use std::fmt::{Debug, Display};
+use std::hash::Hash;
 
 use std::time::Duration;
 
 use criterion::*;
 use serde::de::Deserialize;
 
-use pubgrub::{resolve, OfflineDependencyProvider, Package, Range, SemanticVersion, VersionSet};
+use pubgrub::{resolve, Map, OfflineDependencyProvider, Range, SemanticVersion, VersionSet};
 
-fn bench<'a, P: Package + Deserialize<'a>, VS: VersionSet + Deserialize<'a>>(
+fn bench<
+    'a,
+    P: Debug + Display + Clone + Eq + Hash + Deserialize<'a>,
+    VS: VersionSet + Deserialize<'a>,
+>(
     b: &mut Bencher,
     case: &'a str,
 ) where
     <VS as VersionSet>::V: Deserialize<'a>,
 {
-    let dependency_provider: OfflineDependencyProvider<P, VS> = ron::de::from_str(case).unwrap();
+    let mut dependency_provider: OfflineDependencyProvider<P, VS> =
+        ron::de::from_str(case).unwrap();
+
+    let dependencies = dependency_provider
+        .packages()
+        .map(|p| {
+            (
+                p.clone(),
+                dependency_provider.versions(p).unwrap().cloned().collect(),
+            )
+        })
+        .collect::<Map<_, Vec<_>>>();
 
     b.iter(|| {
-        for p in dependency_provider.packages() {
-            for n in dependency_provider.versions(p).unwrap() {
-                let _ = resolve(&dependency_provider, p.clone(), n.clone());
+        for (p, versions) in &dependencies {
+            for n in versions {
+                let _ = resolve(&mut dependency_provider, p.clone(), n.clone());
             }
         }
     });

benches/sudoku.rs

@@ -123,11 +123,15 @@ fn solve(board: Vec<(SudokuPackage, Ranges<Arc<usize>>)>) -> SelectedDependencie
     let mut dependency_provider = DP::new();
     encode_constraints(&mut dependency_provider);
     dependency_provider.add_dependencies(SudokuPackage::Root, Arc::new(1usize), board);
-    match resolve(&dependency_provider, SudokuPackage::Root, Arc::new(1usize)) {
+    match resolve(
+        &mut dependency_provider,
+        SudokuPackage::Root,
+        Arc::new(1usize),
+    ) {
         Ok(sol) => sol,
-        Err(PubGrubError::NoSolution(mut derivation_tree)) => {
-            derivation_tree.collapse_no_versions();
-            eprintln!("{}", DefaultStringReporter::report(&derivation_tree));
+        Err(PubGrubError::NoSolution(mut error)) => {
+            error.derivation_tree.collapse_no_versions();
+            eprintln!("{}", DefaultStringReporter::report(&error));
             std::process::exit(1);
         }
         Err(err) => panic!("{:?}", err),

examples/branching_error_reporting.rs

@@ -54,11 +54,11 @@ fn main() {
     dependency_provider.add_dependencies("y", (2, 0, 0), []);
 
     // Run the algorithm.
-    match resolve(&dependency_provider, "root", (1, 0, 0)) {
+    match resolve(&mut dependency_provider, "root", (1, 0, 0)) {
         Ok(sol) => println!("{:?}", sol),
-        Err(PubGrubError::NoSolution(mut derivation_tree)) => {
-            derivation_tree.collapse_no_versions();
-            eprintln!("{}", DefaultStringReporter::report(&derivation_tree));
+        Err(PubGrubError::NoSolution(mut error)) => {
+            error.derivation_tree.collapse_no_versions();
+            eprintln!("{}", DefaultStringReporter::report(&error));
             std::process::exit(1);
         }
         Err(err) => panic!("{:?}", err),

examples/caching_dependency_provider.rs

@@ -1,64 +1,93 @@
 // SPDX-License-Identifier: MPL-2.0
 
 use std::cell::RefCell;
+use std::collections::BTreeMap;
+use std::fmt::{Debug, Display};
+use std::hash::Hash;
 
-use pubgrub::{resolve, Dependencies, DependencyProvider, OfflineDependencyProvider, Ranges};
+use pubgrub::{
+    resolve, Dependencies, DependencyConstraints, DependencyProvider, Map,
+    OfflineDependencyProvider, PackageArena, PackageId, Ranges,
+};
 
 type NumVS = Ranges<u32>;
+type CachedDeps<V, VS> = RefCell<Map<PackageId, BTreeMap<V, DependencyConstraints<VS>>>>;
 
 // An example implementing caching dependency provider that will
 // store queried dependencies in memory and check them before querying more from remote.
-struct CachingDependencyProvider<DP: DependencyProvider> {
+struct CachingDependencyProvider<DP: DependencyProvider>
+where
+    DP::P: Debug + Display + Clone + Eq + Hash,
+{
     remote_dependencies: DP,
-    cached_dependencies: RefCell<OfflineDependencyProvider<DP::P, DP::VS>>,
+    cached_dependencies: CachedDeps<DP::V, DP::VS>,
 }
 
-impl<DP: DependencyProvider> CachingDependencyProvider<DP> {
+impl<DP: DependencyProvider> CachingDependencyProvider<DP>
+where
+    DP::P: Debug + Display + Clone + Eq + Hash,
+{
     pub fn new(remote_dependencies_provider: DP) -> Self {
         CachingDependencyProvider {
             remote_dependencies: remote_dependencies_provider,
-            cached_dependencies: RefCell::new(OfflineDependencyProvider::new()),
+            cached_dependencies: Default::default(),
         }
     }
 }
 
-impl<DP: DependencyProvider<M = String>> DependencyProvider for CachingDependencyProvider<DP> {
-    // Caches dependencies if they were already queried
+impl<DP: DependencyProvider<M = &'static str>> DependencyProvider for CachingDependencyProvider<DP>
+where
+    DP::P: Debug + Display + Clone + Eq + Hash,
+{
+    // Cache dependencies if they were already queried
     fn get_dependencies(
-        &self,
-        package: &DP::P,
+        &mut self,
+        package_id: PackageId,
         version: &DP::V,
-    ) -> Result<Dependencies<DP::P, DP::VS, DP::M>, DP::Err> {
+        package_store: &mut PackageArena<Self::P>,
+    ) -> Result<Dependencies<DP::VS, DP::M>, DP::Err> {
         let mut cache = self.cached_dependencies.borrow_mut();
-        match cache.get_dependencies(package, version) {
-            Ok(Dependencies::Unavailable(_)) => {
-                let dependencies = self.remote_dependencies.get_dependencies(package, version);
-                match dependencies {
-                    Ok(Dependencies::Available(dependencies)) => {
-                        cache.add_dependencies(
-                            package.clone(),
-                            version.clone(),
-                            dependencies.clone(),
-                        );
-                        Ok(Dependencies::Available(dependencies))
-                    }
-                    Ok(Dependencies::Unavailable(reason)) => Ok(Dependencies::Unavailable(reason)),
-                    error @ Err(_) => error,
-                }
+        if let Some(deps) = cache.get(&package_id).and_then(|vmap| vmap.get(version)) {
+            return Ok(Dependencies::Available(deps.clone()));
+        }
+
+        match self
+            .remote_dependencies
+            .get_dependencies(package_id, version, package_store)
+        {
+            Ok(Dependencies::Available(deps)) => {
+                cache
+                    .entry(package_id)
+                    .or_default()
+                    .insert(version.clone(), deps.clone());
+                Ok(Dependencies::Available(deps))
             }
-            Ok(dependencies) => Ok(dependencies),
-            Err(_) => unreachable!(),
+
+            Ok(Dependencies::Unavailable(reason)) => Ok(Dependencies::Unavailable(reason)),
+            error @ Err(_) => error,
         }
     }
 
-    fn choose_version(&self, package: &DP::P, ranges: &DP::VS) -> Result<Option<DP::V>, DP::Err> {
-        self.remote_dependencies.choose_version(package, ranges)
+    fn choose_version(
+        &mut self,
+        package_id: PackageId,
+        ranges: &DP::VS,
+        package_store: &PackageArena<Self::P>,
+    ) -> Result<Option<DP::V>, DP::Err> {
+        self.remote_dependencies
+            .choose_version(package_id, ranges, package_store)
     }
 
     type Priority = DP::Priority;
 
-    fn prioritize(&self, package: &DP::P, ranges: &DP::VS) -> Self::Priority {
-        self.remote_dependencies.prioritize(package, ranges)
+    fn prioritize(
+        &mut self,
+        package_id: PackageId,
+        ranges: &DP::VS,
+        package_store: &PackageArena<Self::P>,
+    ) -> Self::Priority {
+        self.remote_dependencies
+            .prioritize(package_id, ranges, package_store)
     }
 
     type Err = DP::Err;
@@ -76,9 +105,9 @@ fn main() {
     // Add dependencies as needed. Here only root package is added.
     remote_dependencies_provider.add_dependencies("root", 1u32, Vec::new());
 
-    let caching_dependencies_provider =
+    let mut caching_dependencies_provider =
         CachingDependencyProvider::new(remote_dependencies_provider);
 
-    let solution = resolve(&caching_dependencies_provider, "root", 1u32);
+    let solution = resolve(&mut caching_dependencies_provider, "root", 1u32);
     println!("Solution: {:?}", solution);
 }

examples/doc_interface.rs

@@ -19,6 +19,6 @@ fn main() {
     dependency_provider.add_dependencies("icons", 1u32, []);
 
     // Run the algorithm.
-    let solution = resolve(&dependency_provider, "root", 1u32);
+    let solution = resolve(&mut dependency_provider, "root", 1u32);
     println!("Solution: {:?}", solution);
 }

examples/doc_interface_error.rs

@@ -71,11 +71,11 @@ fn main() {
     dependency_provider.add_dependencies("intl", (5, 0, 0), []);
 
     // Run the algorithm.
-    match resolve(&dependency_provider, "root", (1, 0, 0)) {
+    match resolve(&mut dependency_provider, "root", (1, 0, 0)) {
         Ok(sol) => println!("{:?}", sol),
-        Err(PubGrubError::NoSolution(mut derivation_tree)) => {
-            derivation_tree.collapse_no_versions();
-            eprintln!("{}", DefaultStringReporter::report(&derivation_tree));
+        Err(PubGrubError::NoSolution(mut error)) => {
+            error.derivation_tree.collapse_no_versions();
+            eprintln!("{}", DefaultStringReporter::report(&error));
         }
         Err(err) => panic!("{:?}", err),
     };

examples/doc_interface_semantic.rs

@@ -62,11 +62,11 @@ fn main() {
     dependency_provider.add_dependencies("icons", (2, 0, 0), []);
 
     // Run the algorithm.
-    match resolve(&dependency_provider, "root", (1, 0, 0)) {
+    match resolve(&mut dependency_provider, "root", (1, 0, 0)) {
         Ok(sol) => println!("{:?}", sol),
-        Err(PubGrubError::NoSolution(mut derivation_tree)) => {
-            derivation_tree.collapse_no_versions();
-            eprintln!("{}", DefaultStringReporter::report(&derivation_tree));
+        Err(PubGrubError::NoSolution(mut error)) => {
+            error.derivation_tree.collapse_no_versions();
+            eprintln!("{}", DefaultStringReporter::report(&error));
         }
         Err(err) => panic!("{:?}", err),
     };

examples/linear_error_reporting.rs

@@ -36,11 +36,11 @@ fn main() {
     dependency_provider.add_dependencies("baz", (3, 0, 0), []);
 
     // Run the algorithm.
-    match resolve(&dependency_provider, "root", (1, 0, 0)) {
+    match resolve(&mut dependency_provider, "root", (1, 0, 0)) {
         Ok(sol) => println!("{:?}", sol),
-        Err(PubGrubError::NoSolution(mut derivation_tree)) => {
-            derivation_tree.collapse_no_versions();
-            eprintln!("{}", DefaultStringReporter::report(&derivation_tree));
+        Err(PubGrubError::NoSolution(mut error)) => {
+            error.derivation_tree.collapse_no_versions();
+            eprintln!("{}", DefaultStringReporter::report(&error));
             std::process::exit(1);
         }
         Err(err) => panic!("{:?}", err),