all: Switch to deterministic IndexMap

While testing ccache I noticed that cache hit rate was extremely low. After some debugging I noticed that the CFLAGS and other environmental variables and macro scripts were not being set deterministically. This is problematic for ccache as it hashes the compiler arguments as part of the key and the order matters to get the same key on a future run.

The cause of this non-determinism is the Rust stdlib HashMap and HashSet, which intentionally do not guarantee reproducible hashing and ordering. To solve this switch to IndexMap and IndexSet, drop-in compatible replacements for HashMap and HashSet respectively. Since non-determinism is just generally a bad idea for build tools and package management software replace ALL uses of HashMap and HashSet repo-wide except for one use in `moss/src/db/meta/mod.rs` which I do not know enough Rust to resolve the compile errors.

Tested by building a package with ccache enabled and using `ccache --show-stats` in the package recipe to verify that the hit rate was now 100% and that the build stage time had dropped to just the time it spent linking.

Signed-off-by: Reilly Brogan <reilly@reillybrogan.com>

Cargo.toml

@@ -19,7 +19,7 @@ clap = { version = "4.5.1", features = ["derive", "string"] }
 crossterm = "0.27.0"
 derive_more = "0.99"
 dialoguer = "0.11.0"
-diesel = { version = "2.1.4", features = ["sqlite","returning_clauses_for_sqlite_3_35"] }
+diesel = { version = "2.1.4", features = ["sqlite", "returning_clauses_for_sqlite_3_35"] }
 diesel_migrations = "2.1.0"
 dirs = "5.0"
 elf = "0.7.4"
@@ -28,6 +28,7 @@ itertools = "0.12.1"
 futures = "0.3.30"
 glob = "0.3.1"
 hex = "0.4.3"
+indexmap = { version = "2.2.6", features = ["serde", "std"] }
 libsqlite3-sys = { version = "0.25.2", features = ["bundled"] }
 log = "0.4"
 nom = "7.1.3"
@@ -48,7 +49,7 @@ tokio-stream = { version = "0.1.14", features = ["time"] }
 tokio-util = { version = "0.7.9", features = ["io"] }
 url = { version = "2.5.0", features = ["serde"] }
 xxhash-rust = { version = "0.8.10", features = ["xxh3"] }
-zstd = { version = "0.12.4", features = [ "zstdmt" ] }
+zstd = { version = "0.12.4", features = ["zstdmt"] }
 
 [profile.release]
 lto = 'thin'

boulder/Cargo.toml

@@ -22,6 +22,7 @@ elf.workspace = true
 glob.workspace = true
 futures.workspace = true
 hex.workspace = true
+indexmap.workspace = true
 itertools.workspace = true
 nix.workspace = true
 rayon.workspace = true

boulder/src/build/job/phase.rs

@@ -2,21 +2,21 @@
 //
 // SPDX-License-Identifier: MPL-2.0
 
-use std::collections::HashSet;
-
+use indexmap::IndexSet;
 use itertools::Itertools;
+
 use stone_recipe::{
     script,
     tuning::{self, Toolchain},
     Script,
 };
-
 use tui::Styled;
 
-use super::{work_dir, Error};
 use crate::build::pgo;
 use crate::{architecture::BuildTarget, util, Macros, Paths, Recipe};
 
+use super::{work_dir, Error};
+
 pub fn list(pgo_stage: Option<pgo::Stage>) -> Vec<Phase> {
     if matches!(pgo_stage, Some(pgo::Stage::One | pgo::Stage::Two)) {
         Phase::WORKLOAD.to_vec()
@@ -316,7 +316,7 @@ fn add_tuning(
         flags
             .map(|s| s.trim())
             .filter(|s| s.len() > 1)
-            .collect::<HashSet<_>>()
+            .collect::<IndexSet<_>>()
             .into_iter()
             .join(" ")
     }

boulder/src/build/root.rs

@@ -2,12 +2,13 @@
 //
 // SPDX-License-Identifier: MPL-2.0
 
-use std::collections::HashSet;
 use std::{fs, io};
 
+use indexmap::IndexSet;
+use thiserror::Error;
+
 use moss::{repository, runtime, Installation};
 use stone_recipe::{tuning::Toolchain, Upstream};
-use thiserror::Error;
 
 use crate::build::Builder;
 use crate::{container, timing, util, Timing};
@@ -149,7 +150,7 @@ fn packages(builder: &Builder) -> Vec<&str> {
         .into_iter()
         .chain(extra_deps)
         // Remove dupes
-        .collect::<HashSet<_>>()
+        .collect::<IndexSet<_>>()
         .into_iter()
         .collect()
 }

boulder/src/cli/profile.rs

@@ -2,15 +2,17 @@
 //
 // SPDX-License-Identifier: MPL-2.0
 
-use std::{collections::HashMap, io};
+use std::io;
 
-use boulder::{profile, Env, Profile};
 use clap::Parser;
+use indexmap::IndexMap;
 use itertools::Itertools;
-use moss::{repository, runtime, Installation, Repository};
 use thiserror::Error;
 use url::Url;
 
+use boulder::{profile, Env, Profile};
+use moss::{repository, runtime, Installation, Repository};
+
 #[derive(Debug, Parser)]
 #[command(about = "Manage boulder profiles")]
 pub struct Command {
@@ -27,13 +29,13 @@ pub enum Subcommand {
         #[arg(help = "profile name")]
         name: String,
         #[arg(
-            short = 'r',
-            long = "repo",
-            required = true,
-            help = "profile repositories",
-            value_parser = parse_repository,
-            help = "repository to add to profile, can be passed multiple times",
-            long_help = "repository to add to profile\n\nExample: --repo name=volatile,uri=https://dev.serpentos.com/volatile/x86_64/stone.index,priority=100"
+        short = 'r',
+        long = "repo",
+        required = true,
+        help = "profile repositories",
+        value_parser = parse_repository,
+        help = "repository to add to profile, can be passed multiple times",
+        long_help = "repository to add to profile\n\nExample: --repo name=volatile,uri=https://dev.serpentos.com/volatile/x86_64/stone.index,priority=100"
         )]
         repos: Vec<(repository::Id, Repository)>,
     },
@@ -49,7 +51,7 @@ fn parse_repository(s: &str) -> Result<(repository::Id, Repository), String> {
     let key_values = s
         .split(',')
         .filter_map(|kv| kv.split_once('='))
-        .collect::<HashMap<_, _>>();
+        .collect::<IndexMap<_, _>>();
 
     let id = repository::Id::new(key_values.get("name").ok_or("missing name")?.to_string());
     let uri = key_values
@@ -140,6 +142,7 @@ pub fn update<'a>(env: &'a Env, manager: profile::Manager<'a>, profile: &profile
 
     Ok(())
 }
+
 #[derive(Debug, Error)]
 pub enum Error {
     #[error("config")]

boulder/src/draft/build.rs

@@ -1,11 +1,9 @@
 // SPDX-FileCopyrightText: Copyright © 2020-2024 Serpent OS Developers
 //
 // SPDX-License-Identifier: MPL-2.0
-use std::{
-    collections::{HashMap, HashSet},
-    fmt,
-    num::NonZeroU64,
-};
+use std::{fmt, num::NonZeroU64};
+
+use indexmap::{IndexMap, IndexSet};
 
 use moss::Dependency;
 
@@ -102,7 +100,7 @@ impl fmt::Display for Phases {
 /// State passed to each system when processing paths
 struct State<'a> {
     /// Any dependencies that need to be recorded
-    dependencies: &'a mut HashSet<Dependency>,
+    dependencies: &'a mut IndexSet<Dependency>,
     /// Total confidence level of the current build [`System`]
     confidence: u64,
 }
@@ -124,14 +122,14 @@ pub struct Analysis {
     /// The detected build [`System`], if any
     pub detected_system: Option<System>,
     /// All detected dependencies
-    pub dependencies: HashSet<Dependency>,
+    pub dependencies: IndexSet<Dependency>,
 }
 
 /// Analyze the provided paths to determine which build [`System`]
 /// the project uses and any dependencies that are identified
 pub fn analyze(files: &[File]) -> Result<Analysis, Error> {
-    let mut dependencies = HashSet::new();
-    let mut confidences = HashMap::new();
+    let mut dependencies = IndexSet::new();
+    let mut confidences = IndexMap::new();
 
     for system in System::ALL {
         let mut state = State {

boulder/src/macros.rs

@@ -2,15 +2,16 @@
 //
 // SPDX-License-Identifier: MPL-2.0
 
-use std::{collections::HashMap, fs, io, path::Path};
+use std::{fs, io, path::Path};
 
+use indexmap::IndexMap;
 use thiserror::Error;
 
 use crate::{util, Env};
 
 #[derive(Debug)]
 pub struct Macros {
-    pub arch: HashMap<String, stone_recipe::Macros>,
+    pub arch: IndexMap<String, stone_recipe::Macros>,
     pub actions: Vec<stone_recipe::Macros>,
 }
 
@@ -25,7 +26,7 @@ impl Macros {
         let arch_files = util::enumerate_files(&arch_dir, matcher).map_err(Error::ArchFiles)?;
         let action_files = util::enumerate_files(&actions_dir, matcher).map_err(Error::ActionFiles)?;
 
-        let mut arch = HashMap::new();
+        let mut arch = IndexMap::new();
         let mut actions = vec![];
 
         for file in arch_files {

boulder/src/package.rs

@@ -1,16 +1,14 @@
 // SPDX-FileCopyrightText: Copyright © 2020-2024 Serpent OS Developers
 //
 // SPDX-License-Identifier: MPL-2.0
-use std::{
-    collections::{hash_map, HashMap},
-    fs, io,
-    num::NonZeroU64,
-};
+use std::{fs, io, num::NonZeroU64};
 
+use indexmap::IndexMap;
 use itertools::Itertools;
+use thiserror::Error;
+
 use stone::write::digest;
 use stone_recipe::{script, Package};
-use thiserror::Error;
 
 use crate::{build, container, timing, util, Macros, Paths, Recipe, Timing};
 
@@ -24,7 +22,7 @@ mod emit;
 pub struct Packager<'a> {
     paths: &'a Paths,
     recipe: &'a Recipe,
-    packages: HashMap<String, Package>,
+    packages: IndexMap<String, Package>,
     collector: Collector,
     build_release: NonZeroU64,
 }
@@ -90,7 +88,7 @@ impl<'a> Packager<'a> {
             .packages
             .iter()
             .filter_map(|(name, package)| {
-                let bucket = analysis.buckets.remove(name)?;
+                let bucket = analysis.buckets.swap_remove(name)?;
 
                 Some(emit::Package::new(
                     name,
@@ -119,13 +117,13 @@ fn resolve_packages(
     macros: &Macros,
     recipe: &Recipe,
     collector: &mut Collector,
-) -> Result<HashMap<String, Package>, Error> {
+) -> Result<IndexMap<String, Package>, Error> {
     let mut parser = script::Parser::new();
     parser.add_definition("name", &recipe.parsed.source.name);
     parser.add_definition("version", &recipe.parsed.source.version);
     parser.add_definition("release", recipe.parsed.source.release);
 
-    let mut packages = HashMap::new();
+    let mut packages = IndexMap::new();
 
     // Add a package, ensuring it's fully expanded
     //
@@ -165,11 +163,11 @@ fn resolve_packages(
         }
 
         match packages.entry(name.clone()) {
-            hash_map::Entry::Vacant(entry) => {
+            indexmap::map::Entry::Vacant(entry) => {
                 entry.insert(package);
             }
-            hash_map::Entry::Occupied(entry) => {
-                let prev = entry.remove();
+            indexmap::map::Entry::Occupied(entry) => {
+                let prev = entry.swap_remove();
 
                 package.run_deps = package.run_deps.into_iter().chain(prev.run_deps).sorted().collect();
                 package.paths = package

boulder/src/package/analysis.rs

@@ -3,17 +3,20 @@
 // SPDX-License-Identifier: MPL-2.0
 
 use std::{
-    collections::{BTreeSet, HashMap, VecDeque},
+    collections::{BTreeSet, VecDeque},
     path::PathBuf,
 };
 
+use indexmap::IndexMap;
+
 use moss::{Dependency, Provider};
 use stone::write::digest;
 use tui::{ProgressBar, ProgressStyle, Styled};
 
-use super::collect::{Collector, PathInfo};
 use crate::{Paths, Recipe};
 
+use super::collect::{Collector, PathInfo};
+
 mod handler;
 
 pub type BoxError = Box<dyn std::error::Error>;
@@ -24,7 +27,7 @@ pub struct Chain<'a> {
     paths: &'a Paths,
     collector: &'a Collector,
     hasher: &'a mut digest::Hasher,
-    pub buckets: HashMap<String, Bucket>,
+    pub buckets: IndexMap<String, Bucket>,
 }
 
 impl<'a> Chain<'a> {