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test(resolver-tests): Remove public dep support from SAT resolver
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@epage
epage committed Nov 29, 2023
1 parent 2f10699 commit 3b4f3b0
Showing 1 changed file with 8 additions and 123 deletions.
131 changes: 8 additions & 123 deletions crates/resolver-tests/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,7 @@ use cargo::core::{Dependency, PackageId, Registry, Summary};
use cargo::core::{GitReference, SourceId};
use cargo::sources::source::QueryKind;
use cargo::sources::IndexSummary;
use cargo::util::{CargoResult, Config, Graph, IntoUrl, RustVersion};
use cargo::util::{CargoResult, Config, IntoUrl, RustVersion};

use proptest::collection::{btree_map, vec};
use proptest::prelude::*;
Expand Down Expand Up @@ -195,17 +195,6 @@ fn log_bits(x: usize) -> usize {
}

fn sat_at_most_one(solver: &mut impl varisat::ExtendFormula, vars: &[varisat::Var]) {
if vars.len() <= 1 {
return;
} else if vars.len() == 2 {
solver.add_clause(&[vars[0].negative(), vars[1].negative()]);
return;
} else if vars.len() == 3 {
solver.add_clause(&[vars[0].negative(), vars[1].negative()]);
solver.add_clause(&[vars[0].negative(), vars[2].negative()]);
solver.add_clause(&[vars[1].negative(), vars[2].negative()]);
return;
}
// use the "Binary Encoding" from
// https://www.it.uu.se/research/group/astra/ModRef10/papers/Alan%20M.%20Frisch%20and%20Paul%20A.%20Giannoros.%20SAT%20Encodings%20of%20the%20At-Most-k%20Constraint%20-%20ModRef%202010.pdf
let bits: Vec<varisat::Var> = solver.new_var_iter(log_bits(vars.len())).collect();
Expand Down Expand Up @@ -254,7 +243,8 @@ impl SatResolve {
let mut cnf = varisat::CnfFormula::new();
let var_for_is_packages_used: HashMap<PackageId, varisat::Var> = registry
.iter()
.map(|s| (s.package_id(), cnf.new_var()))
.map(|s| s.package_id())
.zip(cnf.new_var_iter(registry.len()))
.collect();

// no two packages with the same links set
Expand All @@ -266,14 +256,6 @@ impl SatResolve {
.filter(|(l, _)| l.is_some()),
);

// no two semver compatible versions of the same package
let by_activations_keys = sat_at_most_one_by_key(
&mut cnf,
var_for_is_packages_used
.iter()
.map(|(p, &v)| (p.as_activations_key(), v)),
);

let mut by_name: HashMap<&'static str, Vec<PackageId>> = HashMap::new();

for p in registry.iter() {
Expand All @@ -285,119 +267,22 @@ impl SatResolve {

let empty_vec = vec![];

let mut graph: Graph<PackageId, ()> = Graph::new();

let mut version_selected_for: HashMap<
PackageId,
HashMap<Dependency, HashMap<_, varisat::Var>>,
> = HashMap::new();
// active packages need each of there `deps` to be satisfied
for p in registry.iter() {
graph.add(p.package_id());
for dep in p.dependencies() {
// This can more easily be written as:
// !is_active(p) or one of the things that match dep is_active
// All the complexity, from here to the end, is to support public and private dependencies!
let mut by_key: HashMap<_, Vec<varisat::Lit>> = HashMap::new();
for &m in by_name
let mut matches: Vec<varisat::Lit> = by_name
.get(dep.package_name().as_str())
.unwrap_or(&empty_vec)
.iter()
.filter(|&p| dep.matches_id(*p))
{
graph.link(p.package_id(), m);
by_key
.entry(m.as_activations_key())
.or_default()
.push(var_for_is_packages_used[&m].positive());
}
let keys: HashMap<_, _> = by_key.keys().map(|&k| (k, cnf.new_var())).collect();

// if `p` is active then we need to select one of the keys
let matches: Vec<_> = keys
.values()
.map(|v| v.positive())
.chain(Some(var_for_is_packages_used[&p.package_id()].negative()))
.map(|p| var_for_is_packages_used[&p].positive())
.collect();
// ^ the `dep` is satisfied or `p` is not active
matches.push(var_for_is_packages_used[&p.package_id()].negative());
cnf.add_clause(&matches);

// if a key is active then we need to select one of the versions
for (key, vars) in by_key.iter() {
let mut matches = vars.clone();
matches.push(keys[key].negative());
cnf.add_clause(&matches);
}

version_selected_for
.entry(p.package_id())
.or_default()
.insert(dep.clone(), keys);
}
}

let topological_order = graph.sort();

// we already ensure there is only one version for each `activations_key` so we can think of
// `publicly_exports` as being in terms of a set of `activations_key`s
let mut publicly_exports: HashMap<_, HashMap<_, varisat::Var>> = HashMap::new();

for &key in by_activations_keys.keys() {
// everything publicly depends on itself
let var = publicly_exports
.entry(key)
.or_default()
.entry(key)
.or_insert_with(|| cnf.new_var());
cnf.add_clause(&[var.positive()]);
}

// if a `dep` is public then `p` `publicly_exports` all the things that the selected version `publicly_exports`
for &p in topological_order.iter() {
if let Some(deps) = version_selected_for.get(&p) {
let mut p_exports = publicly_exports.remove(&p.as_activations_key()).unwrap();
for (_, versions) in deps.iter().filter(|(d, _)| d.is_public()) {
for (ver, sel) in versions {
for (&export_pid, &export_var) in publicly_exports[ver].iter() {
let our_var =
p_exports.entry(export_pid).or_insert_with(|| cnf.new_var());
cnf.add_clause(&[
sel.negative(),
export_var.negative(),
our_var.positive(),
]);
}
}
}
publicly_exports.insert(p.as_activations_key(), p_exports);
}
}

// we already ensure there is only one version for each `activations_key` so we can think of
// `can_see` as being in terms of a set of `activations_key`s
// and if `p` `publicly_exports` `export` then it `can_see` `export`
let mut can_see: HashMap<_, HashMap<_, varisat::Var>> = HashMap::new();

// if `p` has a `dep` that selected `ver` then it `can_see` all the things that the selected version `publicly_exports`
for (&p, deps) in version_selected_for.iter() {
let p_can_see = can_see.entry(p).or_default();
for (_, versions) in deps.iter() {
for (&ver, sel) in versions {
for (&export_pid, &export_var) in publicly_exports[&ver].iter() {
let our_var = p_can_see.entry(export_pid).or_insert_with(|| cnf.new_var());
cnf.add_clause(&[
sel.negative(),
export_var.negative(),
our_var.positive(),
]);
}
}
}
}

// a package `can_see` only one version by each name
for (_, see) in can_see.iter() {
sat_at_most_one_by_key(&mut cnf, see.iter().map(|((name, _, _), &v)| (name, v)));
}
let mut solver = varisat::Solver::new();
solver.add_formula(&cnf);

Expand Down Expand Up @@ -840,7 +725,7 @@ pub fn registry_strategy(
// => DepKind::Development, // Development has no impact so don't gen
_ => panic!("bad index for DepKind"),
},
p && k == 0,
p,
))
}

Expand Down

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