chore: import upstream snapshot with attribution

code_review_graph/eval/benchmarks/build_performance.py

@@ -0,0 +1,60 @@
+"""Build performance benchmark: measures timing of graph operations."""
+
+from __future__ import annotations
+
+import logging
+import time
+from pathlib import Path
+
+logger = logging.getLogger(__name__)
+
+
+def run(repo_path: Path, store, config: dict) -> list[dict]:
+    """Run build performance benchmark."""
+    stats = store.get_stats()
+
+    # Time flow detection
+    try:
+        from code_review_graph.flows import store_flows, trace_flows
+        t0 = time.perf_counter()
+        flows = trace_flows(store)
+        store_flows(store, flows)
+        flow_time = time.perf_counter() - t0
+    except Exception as exc:
+        logger.warning("Flow detection failed: %s", exc)
+        flow_time = 0.0
+
+    # Time community detection
+    try:
+        from code_review_graph.communities import detect_communities, store_communities
+        t0 = time.perf_counter()
+        comms = detect_communities(store)
+        store_communities(store, comms)
+        community_time = time.perf_counter() - t0
+    except Exception as exc:
+        logger.warning("Community detection failed: %s", exc)
+        community_time = 0.0
+
+    # Time search (average of queries)
+    search_times: list[float] = []
+    for sq in config.get("search_queries", [])[:10]:
+        t0 = time.perf_counter()
+        store.search_nodes(sq["query"], limit=20)
+        search_times.append(time.perf_counter() - t0)
+
+    avg_search_ms = round(
+        sum(search_times) / max(len(search_times), 1) * 1000, 1
+    )
+
+    return [{
+        "repo": config["name"],
+        "file_count": stats.files_count,
+        "node_count": stats.total_nodes,
+        "edge_count": stats.total_edges,
+        "flow_detection_seconds": round(flow_time, 3),
+        "community_detection_seconds": round(community_time, 3),
+        "search_avg_ms": avg_search_ms,
+        "nodes_per_second": round(
+            stats.total_nodes / max(flow_time, 0.001)
+        ),
+    }]