perf: drop per-element copies in Clarity value deserialization

changelog.d/clarity-value-deser-perf.changed

@@ -0,0 +1 @@
+Reduced Clarity `Value` deserialization cost: ~57% lower peak memory for untyped reads of large lists and 15-55% less CPU across deserialization paths.

clarity-types/src/tests/types/serialization.rs

@@ -442,3 +442,36 @@ fn test_serialize_to_hex_returns_serialization_failure() {
         err
     );
 }
+
+/// Truncating after the first entry's value makes the unwind loop hit EOF
+/// while reading the next key of a partially-filled tuple frame.
+#[test]
+fn test_tuple_truncated_at_next_key_errors() {
+    let tuple = Value::from(
+        TupleData::from_data(vec![
+            (
+                ClarityName::try_from("a".to_string()).unwrap(),
+                Value::Bool(true),
+            ),
+            (
+                ClarityName::try_from("b".to_string()).unwrap(),
+                Value::Bool(false),
+            ),
+        ])
+        .unwrap(),
+    );
+    let mut bytes = vec![];
+    tuple.serialize_write(&mut bytes).unwrap();
+
+    // tuple prefix (1) + entry count (4) + key "a" (1-byte len + 1) +
+    // BoolTrue prefix (1) = 8 bytes; cut right before key "b".
+    bytes.truncate(8);
+
+    match Value::deserialize_read(&mut bytes.as_slice(), None, false) {
+        Ok(value) => panic!("accidentally parsed truncated tuple: {value}"),
+        Err(SerializationError::IOError(e)) => {
+            assert_eq!(e.err.kind(), std::io::ErrorKind::UnexpectedEof);
+        }
+        Err(other) => panic!("expected IOError(UnexpectedEof), got {other:?}"),
+    }
+}

clarity-types/src/tests/types/signatures.rs

@@ -14,6 +14,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 use std::collections::BTreeSet;
 
+use rstest::rstest;
 use stacks_common::types::StacksEpochId;
 
 use crate::errors::ClarityTypeError;
@@ -1059,3 +1060,165 @@ fn test_least_supertype() {
         );
     }
 }
+
+fn trait_id(contract: &str, name: &str) -> TraitIdentifier {
+    TraitIdentifier {
+        name: ClarityName::try_from(name.to_string()).unwrap(),
+        contract_identifier: QualifiedContractIdentifier::local(contract).unwrap(),
+    }
+}
+
+fn callable_principal_subtype(contract: &str) -> CallableSubtype {
+    CallableSubtype::Principal(QualifiedContractIdentifier::local(contract).unwrap())
+}
+
+fn callable_trait_subtype(contract: &str, name: &str) -> CallableSubtype {
+    CallableSubtype::Trait(trait_id(contract, name))
+}
+
+fn list_union_type(members: Vec<CallableSubtype>) -> TypeSignature {
+    TypeSignature::ListUnionType(members.into_iter().collect())
+}
+
+fn buff_type(len: u32) -> TypeSignature {
+    TypeSignature::SequenceType(SequenceSubtype::BufferType(
+        BufferLength::try_from(len).unwrap(),
+    ))
+}
+
+fn ascii_type(len: u32) -> TypeSignature {
+    TypeSignature::SequenceType(SequenceSubtype::StringType(StringSubtype::ASCII(
+        BufferLength::try_from(len).unwrap(),
+    )))
+}
+
+fn utf8_type(len: u32) -> TypeSignature {
+    TypeSignature::SequenceType(SequenceSubtype::StringType(StringSubtype::UTF8(
+        StringUTF8Length::try_from(len).unwrap(),
+    )))
+}
+
+/// The equal-type fast path in `parent_list_type_from_iter` is only sound if
+/// `least_supertype_v2_1(T, T) == Ok(T)` for every `T`. Each case seeds one
+/// leaf type; its nested compounds (~64 shapes) are generated in the body.
+#[rstest]
+#[case::no_type(TypeSignature::NoType)]
+#[case::int(TypeSignature::IntType)]
+#[case::uint(TypeSignature::UIntType)]
+#[case::bool(TypeSignature::BoolType)]
+#[case::principal(TypeSignature::PrincipalType)]
+#[case::buffer_zero_len(buff_type(0))]
+#[case::buffer(buff_type(17))]
+#[case::string_ascii(ascii_type(5))]
+#[case::string_utf8(utf8_type(3))]
+#[case::callable_principal(TypeSignature::CallableType(callable_principal_subtype("contract-a")))]
+#[case::callable_trait(TypeSignature::CallableType(callable_trait_subtype(
+    "contract-a",
+    "trait-a"
+)))]
+#[case::trait_reference(TypeSignature::TraitReferenceType(trait_id("contract-a", "trait-a")))]
+#[case::list_union_single(list_union_type(vec![callable_principal_subtype("contract-a")]))]
+#[case::list_union_mixed(list_union_type(vec![
+    callable_principal_subtype("contract-a"),
+    callable_principal_subtype("contract-b"),
+    callable_trait_subtype("contract-a", "trait-a"),
+    callable_trait_subtype("contract-b", "trait-b"),
+]))]
+#[case::empty_list(TypeSignature::from(TypeSignature::empty_list()))]
+fn test_least_supertype_v2_1_idempotent(#[case] leaf: TypeSignature) {
+    use crate::types::TypeSignature::*;
+
+    let mut corpus = vec![leaf];
+    // two wrapping rounds cover nested compounds
+    for _ in 0..2 {
+        let snapshot = corpus.clone();
+        for t in snapshot {
+            corpus.push(OptionalType(Box::new(t.clone())));
+            corpus.push(ResponseType(Box::new((t.clone(), NoType))));
+            corpus.push(ResponseType(Box::new((NoType, t.clone()))));
+            corpus.push(ResponseType(Box::new((t.clone(), t.clone()))));
+            corpus.push(TypeSignature::list_of(t.clone(), 0).unwrap());
+            corpus.push(TypeSignature::list_of(t.clone(), 4).unwrap());
+            corpus.push(
+                TupleTypeSignature::try_from(vec![(
+                    ClarityName::try_from("field-a".to_string()).unwrap(),
+                    t,
+                )])
+                .unwrap()
+                .into(),
+            );
+        }
+    }
+
+    for t in &corpus {
+        assert_eq!(
+            TypeSignature::least_supertype_v2_1(t, t).as_ref(),
+            Ok(t),
+            "least_supertype_v2_1 must be idempotent for {t:?}"
+        );
+    }
+}
+
+fn buff_value(len: usize) -> Value {
+    Value::buff_from(vec![0; len]).unwrap()
+}
+
+fn ascii_value(s: &str) -> Value {
+    Value::string_ascii_from_bytes(s.as_bytes().to_vec()).unwrap()
+}
+
+fn callable_value(contract: &str) -> Value {
+    Value::CallableContract(CallableData {
+        contract_identifier: QualifiedContractIdentifier::local(contract).unwrap(),
+        trait_identifier: None,
+    })
+}
+
+fn tuple_value(v: Value) -> Value {
+    Value::from(
+        TupleData::from_data(vec![(
+            ClarityName::try_from("field-a".to_string()).unwrap(),
+            v,
+        )])
+        .unwrap(),
+    )
+}
+
+/// `construct_parent_list_type` and `parent_list_type` must stay equivalent
+/// for values satisfying constructor invariants, including identical errors.
+#[rstest]
+#[case::empty(vec![])]
+#[case::homogeneous_bools(vec![Value::Bool(true), Value::Bool(false), Value::Bool(true)])]
+#[case::homogeneous_ints(vec![Value::Int(1), Value::Int(2)])]
+#[case::int_uint_mismatch(vec![Value::Int(1), Value::UInt(2)])]
+#[case::bool_int_mismatch(vec![Value::Bool(true), Value::Int(1)])]
+#[case::buffers_different_lengths(vec![buff_value(3), buff_value(5)])]
+#[case::ascii_different_lengths(vec![ascii_value("abc"), ascii_value("defgh")])]
+#[case::identical_callables(vec![callable_value("contract-a"), callable_value("contract-a")])]
+#[case::distinct_callables(vec![callable_value("contract-a"), callable_value("contract-b")])]
+#[case::callable_with_standard_principal(vec![
+    callable_value("contract-a"),
+    Value::from(StandardPrincipalData::transient()),
+])]
+#[case::optional_none_and_some(vec![Value::none(), Value::some(Value::Int(5)).unwrap()])]
+#[case::response_ok_and_err(vec![
+    Value::okay(Value::Int(1)).unwrap(),
+    Value::error(Value::Bool(false)).unwrap(),
+])]
+#[case::empty_and_nonempty_lists(vec![
+    Value::cons_list_unsanitized(vec![]).unwrap(),
+    Value::cons_list_unsanitized(vec![Value::Int(3)]).unwrap(),
+])]
+#[case::tuple_field_supertype(vec![tuple_value(buff_value(3)), tuple_value(buff_value(5))])]
+fn test_construct_parent_list_type_matches_parent_list_type(#[case] values: Vec<Value>) {
+    let streamed = TypeSignature::construct_parent_list_type(&values);
+    let children: Vec<_> = values
+        .iter()
+        .map(|v| TypeSignature::type_of(v).unwrap())
+        .collect();
+    let collected = TypeSignature::parent_list_type(&children);
+    assert_eq!(
+        streamed, collected,
+        "construct_parent_list_type diverged from parent_list_type for {values:?}"
+    );
+}