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mirror of https://github.com/ellmau/adf-obdd.git synced 2025-12-19 09:29:36 +01:00

Add path-counting functionality to the obdd

This commit is contained in:
Stefan Ellmauthaler 2022-04-04 10:34:47 +02:00
parent ccb82318d5
commit 904d0b107e
Failed to extract signature
3 changed files with 111 additions and 30 deletions

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@ -7,7 +7,7 @@ This module describes the abstract dialectical framework
use std::collections::HashSet;
use serde::{ser::SerializeMap, Deserialize, Serialize};
use serde::{Deserialize, Serialize};
use crate::{
datatypes::{

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@ -185,7 +185,7 @@ impl BddNode {
}
}
/// Type alias for the pair of counter-models and models
/// Represents the pair of counts, related to counter-models and models.
#[derive(Debug, Clone, Copy, Eq, PartialEq, PartialOrd, Ord)]
pub struct ModelCounts {
/// Contains the number of counter-models
@ -225,8 +225,8 @@ impl From<(usize, usize)> for ModelCounts {
}
}
}
/// Type alias for the Modelcounts and the depth of a given Node in a BDD
pub type CountNode = (ModelCounts, usize);
/// Type alias for the Modelcounts, Count of paths to bot resp top, and the depth of a given Node in a BDD
pub type CountNode = (ModelCounts, ModelCounts, usize);
/// Type alias for Facet counts, which contains number of facets and counter facets.
pub type FacetCounts = (usize, usize);

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@ -51,11 +51,11 @@ impl Bdd {
result
.count_cache
.borrow_mut()
.insert(Term::TOP, (ModelCounts::top(), 0));
.insert(Term::TOP, (ModelCounts::top(), ModelCounts::top(), 0));
result
.count_cache
.borrow_mut()
.insert(Term::BOT, (ModelCounts::bot(), 0));
.insert(Term::BOT, (ModelCounts::bot(), ModelCounts::bot(), 0));
result
}
}
@ -228,22 +228,28 @@ impl Bdd {
var_set.insert(var);
self.var_deps.push(var_set);
}
log::debug!("newterm: {} as {:?}", new_term, node);
#[cfg(feature = "adhoccounting")]
{
log::debug!("newterm: {} as {:?}", new_term, node);
let mut count_cache = self.count_cache.borrow_mut();
let (lo_counts, lodepth) = *count_cache.get(&lo).expect("Cache corrupted");
let (hi_counts, hidepth) = *count_cache.get(&hi).expect("Cache corrupted");
let (lo_counts, lo_paths, lodepth) =
*count_cache.get(&lo).expect("Cache corrupted");
let (hi_counts, hi_paths, hidepth) =
*count_cache.get(&hi).expect("Cache corrupted");
log::debug!(
"lo (cm: {}, mo: {}, dp: {})",
"lo (cm: {}, mo: {}, p-: {}, p+: {}, dp: {})",
lo_counts.cmodels,
lo_counts.models,
lo_paths.cmodels,
lo_paths.models,
lodepth
);
log::debug!(
"hi (cm: {}, mo: {}, dp: {})",
"hi (cm: {}, mo: {}, p-: {}, p+: {}, dp: {})",
hi_counts.cmodels,
hi_counts.models,
hi_paths.cmodels,
hi_paths.models,
hidepth
);
let (lo_exp, hi_exp) = if lodepth > hidepth {
@ -260,6 +266,11 @@ impl Bdd {
lo_counts.models * lo_exp + hi_counts.models * hi_exp,
)
.into(),
(
lo_paths.cmodels + hi_paths.cmodels,
lo_paths.models + hi_paths.models,
)
.into(),
std::cmp::max(lodepth, hidepth) + 1,
),
);
@ -270,7 +281,7 @@ impl Bdd {
}
}
/// Computes the number of counter-models and models for a given BDD-tree
/// Computes the number of counter-models and models for a given BDD-tree.
///
/// Use the flag `_memoization` to choose between using the memoization approach or not. (This flag does nothing if the feature `adhoccounting` is used)
pub fn models(&self, term: Term, _memoization: bool) -> ModelCounts {
@ -286,12 +297,29 @@ impl Bdd {
}
}
pub fn max_depth(&self, term: Term) -> usize {
/// Computes the number of paths which lead to Bot respectively Top.
///
/// Use the flag `_memoization` to choose between using the memoization approach or not. (This flag does nothing if the feature `adhoccounting` is used)
pub fn paths(&self, term: Term, _memoization: bool) -> ModelCounts {
#[cfg(feature = "adhoccounting")]
{
return self.count_cache.borrow().get(&term).expect("The term should be originating from this bdd, otherwise the result would be inconsistent anyways").1;
}
#[cfg(not(feature = "adhoccounting"))]
if _memoization {
self.modelcount_memoization(term).1
} else {
self.modelcount_naive(term).1
}
}
/// Computes the maximal depth of the given sub-tree.
pub fn max_depth(&self, term: Term) -> usize {
#[cfg(feature = "adhoccounting")]
{
return self.count_cache.borrow().get(&term).expect("The term should be originating from this bdd, otherwise the result would be inconsistent anyways").2;
}
#[cfg(not(feature = "adhoccounting"))]
match self.count_cache.borrow().get(&term) {
Some((mc, depth)) => *depth,
None => {
@ -309,15 +337,15 @@ impl Bdd {
/// Computes the number of counter-models, models, and variables for a given BDD-tree
fn modelcount_naive(&self, term: Term) -> CountNode {
if term == Term::TOP {
(ModelCounts::top(), 0)
(ModelCounts::top(), ModelCounts::top(), 0)
} else if term == Term::BOT {
(ModelCounts::bot(), 0)
(ModelCounts::bot(), ModelCounts::bot(), 0)
} else {
let node = &self.nodes[term.0];
let mut lo_exp = 0u32;
let mut hi_exp = 0u32;
let (lo_counts, lodepth) = self.modelcount_naive(node.lo());
let (hi_counts, hidepth) = self.modelcount_naive(node.hi());
let (lo_counts, lo_paths, lodepth) = self.modelcount_naive(node.lo());
let (hi_counts, hi_paths, hidepth) = self.modelcount_naive(node.hi());
if lodepth > hidepth {
hi_exp = (lodepth - hidepth) as u32;
} else {
@ -329,6 +357,11 @@ impl Bdd {
lo_counts.models * 2usize.pow(lo_exp) + hi_counts.models * 2usize.pow(hi_exp),
)
.into(),
(
lo_paths.cmodels + hi_paths.cmodels,
lo_paths.models + hi_paths.models,
)
.into(),
std::cmp::max(lodepth, hidepth) + 1,
)
}
@ -336,9 +369,9 @@ impl Bdd {
fn modelcount_memoization(&self, term: Term) -> CountNode {
if term == Term::TOP {
(ModelCounts::top(), 0)
(ModelCounts::top(), ModelCounts::top(), 0)
} else if term == Term::BOT {
(ModelCounts::bot(), 0)
(ModelCounts::bot(), ModelCounts::bot(), 0)
} else {
if let Some(result) = self.count_cache.borrow().get(&term) {
return *result;
@ -347,8 +380,8 @@ impl Bdd {
let node = &self.nodes[term.0];
let mut lo_exp = 0u32;
let mut hi_exp = 0u32;
let (lo_counts, lodepth) = self.modelcount_memoization(node.lo());
let (hi_counts, hidepth) = self.modelcount_memoization(node.hi());
let (lo_counts, lo_paths, lodepth) = self.modelcount_memoization(node.lo());
let (hi_counts, hi_paths, hidepth) = self.modelcount_memoization(node.hi());
if lodepth > hidepth {
hi_exp = (lodepth - hidepth) as u32;
} else {
@ -362,6 +395,11 @@ impl Bdd {
+ hi_counts.models * 2usize.pow(hi_exp),
)
.into(),
(
lo_paths.cmodels + hi_paths.cmodels,
lo_paths.models + hi_paths.models,
)
.into(),
std::cmp::max(lodepth, hidepth) + 1,
)
};
@ -377,10 +415,10 @@ impl Bdd {
{
self.count_cache
.borrow_mut()
.insert(Term::TOP, (ModelCounts::top(), 0));
.insert(Term::TOP, (ModelCounts::top(), ModelCounts::top(), 0));
self.count_cache
.borrow_mut()
.insert(Term::BOT, (ModelCounts::bot(), 0));
.insert(Term::BOT, (ModelCounts::bot(), ModelCounts::bot(), 0));
for i in 0..self.nodes.len() {
log::debug!("fixing Term({})", i);
self.modelcount_memoization(Term(i));
@ -583,13 +621,46 @@ mod test {
assert_eq!(bdd.models(Term::TOP, true), (0, 1).into());
assert_eq!(bdd.models(Term::BOT, true), (1, 0).into());
assert_eq!(bdd.modelcount_naive(v1), ((1, 1).into(), 1));
assert_eq!(bdd.modelcount_naive(formula1), ((3, 1).into(), 2));
assert_eq!(bdd.modelcount_naive(formula2), ((1, 3).into(), 2));
assert_eq!(bdd.modelcount_naive(formula3), ((2, 2).into(), 2));
assert_eq!(bdd.modelcount_naive(formula4), ((5, 3).into(), 3));
assert_eq!(bdd.modelcount_naive(Term::TOP), ((0, 1).into(), 0));
assert_eq!(bdd.modelcount_naive(Term::BOT), ((1, 0).into(), 0));
assert_eq!(bdd.paths(formula1, false), (2, 1).into());
assert_eq!(bdd.paths(formula2, false), (1, 2).into());
assert_eq!(bdd.paths(formula3, false), (2, 2).into());
assert_eq!(bdd.paths(formula4, false), (3, 2).into());
assert_eq!(bdd.paths(Term::TOP, false), (0, 1).into());
assert_eq!(bdd.paths(Term::BOT, false), (1, 0).into());
assert_eq!(bdd.paths(v1, true), (1, 1).into());
assert_eq!(bdd.paths(formula1, true), (2, 1).into());
assert_eq!(bdd.paths(formula2, true), (1, 2).into());
assert_eq!(bdd.paths(formula3, true), (2, 2).into());
assert_eq!(bdd.paths(formula4, true), (3, 2).into());
assert_eq!(bdd.paths(Term::TOP, true), (0, 1).into());
assert_eq!(bdd.paths(Term::BOT, true), (1, 0).into());
assert_eq!(bdd.modelcount_naive(v1), ((1, 1).into(), (1, 1).into(), 1));
assert_eq!(
bdd.modelcount_naive(formula1),
((3, 1).into(), (2, 1).into(), 2)
);
assert_eq!(
bdd.modelcount_naive(formula2),
((1, 3).into(), (1, 2).into(), 2)
);
assert_eq!(
bdd.modelcount_naive(formula3),
((2, 2).into(), (2, 2).into(), 2)
);
assert_eq!(
bdd.modelcount_naive(formula4),
((5, 3).into(), (3, 2).into(), 3)
);
assert_eq!(
bdd.modelcount_naive(Term::TOP),
((0, 1).into(), (0, 1).into(), 0)
);
assert_eq!(
bdd.modelcount_naive(Term::BOT),
((1, 0).into(), (1, 0).into(), 0)
);
assert_eq!(
bdd.modelcount_naive(formula4),
@ -651,6 +722,16 @@ mod test {
.for_each(|(left, right)| {
assert!(left == right);
});
assert_eq!(
bdd.var_impact(Var(0), &[formula1, formula2, formula3, formula4]),
4
);
assert_eq!(
bdd.var_impact(Var(2), &[formula1, formula2, formula3, formula4]),
1
);
assert_eq!(bdd.var_impact(Var(2), &[formula1, formula2, formula3]), 0);
}
#[test]