From 7ecd563beb2eed5db8cc4efcdc9e2bedf6cf33b9 Mon Sep 17 00:00:00 2001
From: Erik Schamper <1254028+Schamper@users.noreply.github.com>
Date: Tue, 3 Mar 2026 14:35:58 +0000
Subject: [PATCH] Add expression and parser benchmarks

---
 tests/test_benchmark.py | 89 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

diff --git a/tests/test_benchmark.py b/tests/test_benchmark.py
index 15e0415..443f9d1 100644
--- a/tests/test_benchmark.py
+++ b/tests/test_benchmark.py
@@ -1,9 +1,12 @@
 from __future__ import annotations
 
+from functools import partial
 from typing import TYPE_CHECKING
 
 import pytest
 
+from dissect.cstruct.expression import Expression
+
 if TYPE_CHECKING:
     from pytest_benchmark.fixture import BenchmarkFixture
 
@@ -85,3 +88,89 @@ def test_benchmark_getattr_typedefs(cs: cstruct, benchmark: BenchmarkFixture) ->
     cs.load(cdef)
 
     benchmark(lambda: cs.my_uint8)
+
+
+@pytest.mark.benchmark
+def test_benchmark_expression_parse(cs: cstruct, benchmark: BenchmarkFixture) -> None:
+    """Benchmark the parsing of expressions."""
+    cs.load("#define a 5\n#define b 10")
+
+    benchmark(lambda: Expression("a * 2 + b * (3 + 4) >> 1"))
+
+
+@pytest.mark.benchmark
+def test_benchmark_expression_evaluate(cs: cstruct, benchmark: BenchmarkFixture) -> None:
+    """Benchmark the evaluation of expressions."""
+    cs.load("#define a 5\n#define b 10")
+
+    expression = Expression("a * 2 + b * (3 + 4) >> 1")
+    benchmark(lambda: expression.evaluate(cs))
+
+
+@pytest.mark.benchmark
+def test_benchmark_expression_parse_and_evaluate(cs: cstruct, benchmark: BenchmarkFixture) -> None:
+    """Benchmark the parsing and evaluation of expressions."""
+    cs.load("#define a 5\n#define b 10")
+
+    benchmark(lambda: Expression("a * 2 + b * (3 + 4) >> 1").evaluate(cs))
+
+
+_BENCHMARK_CDEF = """
+struct SECURITY_DESCRIPTOR {
+    uint8   Revision;
+    uint8   Sbz1;
+    uint16  Control;
+    uint32  OffsetOwner;
+    uint32  OffsetGroup;
+    uint32  OffsetSacl;
+    uint32  OffsetDacl;
+};
+
+struct LDAP_SID_IDENTIFIER_AUTHORITY {
+    char    Value[6];
+};
+
+struct LDAP_SID {
+    uint8   Revision;
+    uint8   SubAuthorityCount;
+    LDAP_SID_IDENTIFIER_AUTHORITY   IdentifierAuthority;
+    uint32  SubAuthority[SubAuthorityCount];
+};
+
+struct ACL {
+    uint8   AclRevision;
+    uint8   Sbz1;
+    uint16  AclSize;
+    uint16  AceCount;
+    uint16  Sbz2;
+    char    Data[AclSize - 8];
+};
+
+struct ACE {
+    uint8   AceType;
+    uint8   AceFlags;
+    uint16  AceSize;
+    char    Data[AceSize - 4];
+};
+
+struct ACCESS_ALLOWED_ACE {
+    uint16  Mask;
+    LDAP_SID Sid;
+};
+
+struct ACCESS_ALLOWED_OBJECT_ACE {
+    uint32  Mask;
+    uint32  Flags;
+    char    ObjectType[(Flags & 1) * 16];
+    char    InheritedObjectType[(Flags & 2) * 8];
+    LDAP_SID Sid;
+};
+"""
+
+
+@pytest.mark.benchmark
+def test_benchmark_lexer_and_parser(cs: cstruct, benchmark: BenchmarkFixture) -> None:
+    """Benchmark tokenizing and parsing a realistic set of struct definitions."""
+    cs.add_type = partial(cs.add_type, replace=True)
+
+    benchmark(lambda: cs.load(_BENCHMARK_CDEF))