[meta] switch to AHashMap

Switch to ahash, which promises to be faster at lookups.

Overall, iteration through the hash map is a bit slower but
`make_package_graph` and other queries are faster.

```

make_package_graph      time:   [6.9865 ms 7.0088 ms 7.0313 ms]
                        change: [-4.0527% -3.5680% -3.1149%] (p = 0.00 < 0.05)
                        Performance has improved.

depends_on              time:   [110.99 µs 111.12 µs 111.27 µs]
                        change: [-12.629% -12.282% -11.952%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 5 outliers among 100 measurements (5.00%)
  2 (2.00%) low mild
  3 (3.00%) high mild

depends_on_cache        time:   [92.296 µs 92.522 µs 92.777 µs]
                        change: [-18.680% -18.438% -18.227%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 6 outliers among 100 measurements (6.00%)
  2 (2.00%) low mild
  3 (3.00%) high mild
  1 (1.00%) high severe

into_ids                time:   [164.61 µs 164.74 µs 164.87 µs]
                        change: [-9.3113% -8.9215% -8.5783%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 5 outliers among 100 measurements (5.00%)
  2 (2.00%) low mild
  1 (1.00%) high mild
  2 (2.00%) high severe

resolve_package_name    time:   [1.4308 µs 1.4327 µs 1.4351 µs]
                        change: [+12.664% +12.952% +13.227%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 1 outliers among 100 measurements (1.00%)
  1 (1.00%) high mild

make_package_name_hashmap
                        time:   [50.083 µs 50.112 µs 50.144 µs]
                        change: [-0.0379% +0.0879% +0.2012%] (p = 0.16 > 0.05)
                        No change in performance detected.
Found 5 outliers among 100 measurements (5.00%)
  3 (3.00%) high mild
  2 (2.00%) high severe

make_cycles             time:   [55.688 µs 55.770 µs 55.871 µs]
                        change: [+6.9990% +7.4064% +7.7971%] (p = 0.00 < 0.05)
                        Performance has regressed.
```

Cargo.toml

@@ -19,6 +19,7 @@ members = [
 ]
 
 [workspace.dependencies]
+ahash = "0.8.6"
 guppy-workspace-hack = "0.1.0"
 
 [patch.crates-io.guppy-workspace-hack]

cargo-guppy/Cargo.toml

@@ -6,6 +6,7 @@ license = "MIT OR Apache-2.0"
 edition = "2018"
 
 [dependencies]
+ahash.workspace = true
 camino = "1.1.6"
 # disable tracing integration since we don't use it
 color-eyre = { version = "0.6.2", default-features = false }

cargo-guppy/src/lib.rs

@@ -42,6 +42,7 @@ mod mv;
 
 pub use crate::{core::*, mv::*};
 
+use ahash::AHashMap;
 use camino::Utf8PathBuf;
 use clap::{ArgEnum, Parser};
 use color_eyre::eyre::{bail, Result, WrapErr};
@@ -58,15 +59,7 @@ use guppy::{
 use guppy_cmdlib::{
     string_to_platform_spec, CargoMetadataOptions, CargoResolverOpts, PackagesAndFeatures,
 };
-use std::{
-    borrow::Cow,
-    cmp,
-    collections::{HashMap, HashSet},
-    fmt, fs,
-    io::Write,
-    iter,
-    path::PathBuf,
-};
+use std::{borrow::Cow, cmp, collections::HashSet, fmt, fs, io::Write, iter, path::PathBuf};
 
 pub fn cmd_diff(json: bool, old: &str, new: &str) -> Result<()> {
     let old_json = fs::read_to_string(old)?;
@@ -140,7 +133,7 @@ pub fn cmd_dups(opts: &DupsOptions) -> Result<()> {
     let resolver = opts.filter_opts.make_resolver(&pkg_graph)?;
     let selection = pkg_graph.query_workspace();
 
-    let mut dupe_map: HashMap<_, Vec<_>> = HashMap::new();
+    let mut dupe_map: AHashMap<_, Vec<_>> = AHashMap::new();
     for package in selection
         .resolve_with_fn(resolver)
         .packages(DependencyDirection::Forward)
@@ -387,7 +380,7 @@ pub fn cmd_subtree_size(options: &SubtreeSizeOptions) -> Result<()> {
         pkg_graph.query_workspace()
     };
 
-    let mut unique_deps: HashMap<&PackageId, HashSet<&PackageId>> = HashMap::new();
+    let mut unique_deps: AHashMap<&PackageId, HashSet<&PackageId>> = AHashMap::new();
     for package_id in selection
         .resolve_with_fn(&resolver)
         .package_ids(DependencyDirection::Forward)

clippy.toml

@@ -0,0 +1,5 @@
+disallowed-methods = [
+    # use ahash everywhere instead
+    "std::collections::hash::map::HashMap::new",
+    "std::collections::hash::map::HashMap::with_capacity",
+]

fixtures/Cargo.toml

@@ -6,6 +6,7 @@ publish = false
 edition = "2018"
 
 [dependencies]
+ahash.workspace = true
 camino = "1.1.6"
 guppy = { path = "../guppy" }
 once_cell = "1.18.0"

fixtures/src/details.rs

@@ -8,6 +8,7 @@ use crate::{
     },
     package_id,
 };
+use ahash::AHashMap;
 use camino::Utf8PathBuf;
 use guppy::{
     errors::FeatureGraphWarning,
@@ -19,24 +20,24 @@ use guppy::{
     DependencyKind, PackageId, Version,
 };
 use pretty_assertions::assert_eq;
-use std::collections::{BTreeMap, HashMap};
+use std::collections::BTreeMap;
 
 /// This captures metadata fields that are relevant for tests. They are meant to be written out
 /// lazily as tests are filled out -- feel free to add more details as necessary!
 pub struct FixtureDetails {
     workspace_members: Option<BTreeMap<Utf8PathBuf, PackageId>>,
-    package_details: HashMap<PackageId, PackageDetails>,
-    link_details: HashMap<(PackageId, PackageId), LinkDetails>,
+    package_details: AHashMap<PackageId, PackageDetails>,
+    link_details: AHashMap<(PackageId, PackageId), LinkDetails>,
     feature_graph_warnings: Vec<FeatureGraphWarning>,
     cycles: Vec<Vec<PackageId>>,
 }
 
 impl FixtureDetails {
-    pub fn new(package_details: HashMap<PackageId, PackageDetails>) -> Self {
+    pub fn new(package_details: AHashMap<PackageId, PackageDetails>) -> Self {
         Self {
             workspace_members: None,
             package_details,
-            link_details: HashMap::new(),
+            link_details: AHashMap::new(),
             feature_graph_warnings: vec![],
             cycles: vec![],
         }
@@ -57,7 +58,7 @@ impl FixtureDetails {
 
     pub fn with_link_details(
         mut self,
-        link_details: HashMap<(PackageId, PackageId), LinkDetails>,
+        link_details: AHashMap<(PackageId, PackageId), LinkDetails>,
     ) -> Self {
         self.link_details = link_details;
         self
@@ -456,7 +457,7 @@ impl PackageDetails {
         self
     }
 
-    pub fn insert_into(self, map: &mut HashMap<PackageId, PackageDetails>) {
+    pub fn insert_into(self, map: &mut AHashMap<PackageId, PackageDetails>) {
         map.insert(self.id.clone(), self);
     }
 
@@ -543,7 +544,7 @@ impl LinkDetails {
         self
     }
 
-    pub fn insert_into(self, map: &mut HashMap<(PackageId, PackageId), Self>) {
+    pub fn insert_into(self, map: &mut AHashMap<(PackageId, PackageId), Self>) {
         map.insert((self.from.clone(), self.to.clone()), self);
     }
 
@@ -601,7 +602,7 @@ pub struct PlatformResults {
     // Each pair stands for (required on, enabled on).
     status: (EnabledTernary, EnabledTernary),
     default_features: (EnabledTernary, EnabledTernary),
-    feature_statuses: HashMap<String, (EnabledTernary, EnabledTernary)>,
+    feature_statuses: AHashMap<String, (EnabledTernary, EnabledTernary)>,
 }
 
 impl PlatformResults {
@@ -612,7 +613,7 @@ impl PlatformResults {
         Self {
             status,
             default_features,
-            feature_statuses: HashMap::new(),
+            feature_statuses: AHashMap::new(),
         }
     }