feat: Add CircuitDiff

Cargo.toml

@@ -26,11 +26,11 @@ missing_docs = "warn"
 [patch.crates-io]
 
 # Uncomment to use unreleased versions of hugr
-# hugr = { git = "https://github.com/CQCL/hugr", rev = "09bd748398ce5afb39f5628d838756ccc03fc775" }
-# hugr-core = { git = "https://github.com/CQCL/hugr", rev = "09bd748398ce5afb39f5628d838756ccc03fc775" }
-# hugr-passes = { git = "https://github.com/CQCL/hugr", rev = "09bd748398ce5afb39f5628d838756ccc03fc775" }
-# hugr-cli = { git = "https://github.com/CQCL/hugr", rev = "09bd748398ce5afb39f5628d838756ccc03fc775" }
-# hugr-model = { git = "https://github.com/CQCL/hugr", rev = "09bd748398ce5afb39f5628d838756ccc03fc775" }
+hugr = { git = "https://github.com/CQCL/hugr", rev = "0efc806f" }
+hugr-core = { git = "https://github.com/CQCL/hugr", rev = "0efc806f" }
+hugr-passes = { git = "https://github.com/CQCL/hugr", rev = "0efc806f" }
+hugr-cli = { git = "https://github.com/CQCL/hugr", rev = "0efc806f" }
+hugr-model = { git = "https://github.com/CQCL/hugr", rev = "0efc806f" }
 # portgraph = { git = "https://github.com/CQCL/portgraph", rev = "68b96ac737e0c285d8c543b2d74a7aa80a18202c" }
 
 [workspace.dependencies]
@@ -53,9 +53,11 @@ crossbeam-channel = "0.5.14"
 csv = "1.3.1"
 delegate = "0.13.2"
 derive_more = "1.0.0"
+derive-where = "1.2.7"
 downcast-rs = "2.0.1"
 fxhash = "0.2.1"
 indexmap = "2.7.1"
+insta = "1.42.1"
 lazy_static = "1.5.0"
 num-complex = "0.4"
 num-rational = "0.4"
@@ -66,6 +68,7 @@ pest_derive = "2.7.15"
 petgraph = { version = "0.7.1", default-features = false }
 priority-queue = "2.1.2"
 rayon = "1.5"
+relrc = "0.3.0"
 rmp-serde = "1.1.2"
 rstest = "0.23.0"
 serde = "1.0"

tket2/Cargo.toml

@@ -72,11 +72,13 @@ tracing = { workspace = true }
 pest = { workspace = true }
 pest_derive = { workspace = true }
 zstd = { workspace = true, optional = true }
-
+derive-where = { workspace = true }
+relrc = { workspace = true }
 
 [dev-dependencies]
 rstest = { workspace = true }
 cool_asserts = { workspace = true }
+insta = { workspace = true }
 
 # Defined here so it can be overridden by the codspeed CI job
 # using `cargo add`.

tket2/src/circuit.rs

@@ -11,7 +11,7 @@ use std::collections::HashSet;
 use std::iter::Sum;
 
 pub use command::{Command, CommandIterator};
-pub use hash::CircuitHash;
+pub use hash::{CircuitHash, HashError, HashedCircuit};
 use hugr::extension::prelude::{LiftDef, NoopDef, TupleOpDef};
 use hugr::hugr::views::{DescendantsGraph, ExtractHugr, HierarchyView};
 use itertools::Either::{Left, Right};

tket2/src/circuit/hash.rs

@@ -6,7 +6,7 @@ use derive_more::{Display, Error};
 use fxhash::{FxHashMap, FxHasher64};
 use hugr::hugr::views::{HierarchyView, SiblingGraph};
 use hugr::ops::{NamedOp, OpType};
-use hugr::{HugrView, Node};
+use hugr::{Hugr, HugrView, Node};
 use petgraph::visit::{self as pg, Walker};
 
 use super::Circuit;
@@ -62,6 +62,46 @@ where
     }
 }
 
+/// A hashed circuit.
+///
+/// Unlike [`Circuit`], this wrapper type implements [`Hash`] by precomputing
+/// the hash and caching it.
+///
+/// Converting a [`Circuit`] to a [`HashedCircuit`] is done using its [`TryFrom`]
+/// implementation.
+#[derive(Clone, Debug)]
+pub struct HashedCircuit<H = Hugr> {
+    circuit: Circuit<H>,
+    hash: u64,
+}
+
+impl<H: HugrView> HashedCircuit<H> {
+    /// Get the underlying circuit.
+    pub fn circuit(&self) -> &Circuit<H> {
+        &self.circuit
+    }
+
+    /// Get the hash of the circuit.
+    pub fn hash(&self) -> u64 {
+        self.hash
+    }
+}
+
+impl<H: HugrView> TryFrom<Circuit<H>> for HashedCircuit<H> {
+    type Error = HashError;
+
+    fn try_from(circuit: Circuit<H>) -> Result<Self, Self::Error> {
+        let hash = circuit.circuit_hash()?;
+        Ok(Self { circuit, hash })
+    }
+}
+
+impl<H: HugrView> Hash for HashedCircuit<H> {
+    fn hash<Hasher: std::hash::Hasher>(&self, state: &mut Hasher) {
+        state.write_u64(self.hash);
+    }
+}
+
 /// Auxiliary data for circuit hashing.
 ///
 /// Contains previously computed hashes.
@@ -224,4 +264,21 @@ mod test {
         }
         assert_ne!(all_hashes[0], all_hashes[1]);
     }
+
+    #[test]
+    fn hashed_circuit_hash() {
+        let circ = build_simple_circuit(2, |circ| {
+            circ.append(Tk2Op::H, [0])?;
+            circ.append(Tk2Op::CX, [0, 1])?;
+            circ.append(Tk2Op::T, [1])?;
+            Ok(())
+        })
+        .unwrap();
+
+        let direct_hash = circ.circuit_hash().unwrap();
+        let hashed_circ = HashedCircuit::try_from(circ).unwrap();
+
+        // Check the cached hash matches direct computation
+        assert_eq!(direct_hash, hashed_circ.hash());
+    }
 }