⚡ Bolt: [성능 개선] 파일 내용을 가져오는 과정의 병렬화 (N+1 API 병목 현상 완화)

.jules/bolt.md

@@ -43,3 +43,6 @@
 ## 2026-07-09 - Avoid N+1 API blocking in SBOM aggregator
 **Learning:** The `collect_inventories` function in `scripts/ci/sbom_inventory_aggregator.py` was fetching SBOMs from the GitHub dependency graph synchronously for every repository in the organization. For large organizations (up to 500 repos), this N+1 network/CLI bottleneck significantly stalled the aggregation workflow.
 **Action:** Use `concurrent.futures.ThreadPoolExecutor` to fetch SBOMs concurrently when multiple repositories are provided, bounded by a `max_workers` limit (e.g., 10) to avoid overwhelming the CLI/API, while preserving the fast serial path for single-item inputs.
+## 2026-07-25 - Avoid N+1 API blocking in Noema review context fetching
+**Learning:** In `scripts/ci/noema_review_gate.py`, the `changed_file_context` function was fetching file contents from the GitHub API sequentially, causing an N+1 API bottleneck.
+**Action:** Use `concurrent.futures.ThreadPoolExecutor` to fetch bounded file contents concurrently, bounded by an explicit conservative `max_workers` limit (no more than 6), while preserving the fast serial path for single-item inputs and ensuring deterministic output order.

scripts/ci/noema_review_gate.py

@@ -5,6 +5,7 @@
 
 import argparse
 import base64
+import concurrent.futures
 import ipaddress
 import json
 import os
@@ -41,6 +42,7 @@
 MAX_FILE_CONTEXT_CHARS = 4000
 MAX_REVIEW_CONTEXT_CHARS = 24000
 MAX_THREAD_BODY_CHARS = 1200
+MAX_CONTEXT_WORKERS = 6
 
 # ⚡ Bolt: Pre-compiled regex patterns to avoid recompilation on every scrub_sensitive_data call.
 # Impact: Improves string processing performance in error reporting.
@@ -342,17 +344,26 @@ def changed_file_context(repo: str, number: int, head_sha: str) -> str:
     if not paths:
         return "Changed file context unavailable: PR reported no changed files."
     sections: list[str] = []
-    for path in paths[:MAX_CONTEXT_FILES]:
+    target_paths = paths[:MAX_CONTEXT_FILES]
+
+    def process_path(path: str) -> str:
+        """Fetch and truncate one changed file for the bounded review context."""
         try:
             content = fetch_head_file_content(repo, path, head_sha)
         except RuntimeError as exc:
             reason = scrub_sensitive_data(str(exc)) or "unknown error"
-            sections.append(f"### {path}\nUnavailable from head content API: {reason}")
-            continue
+            return f"### {path}\nUnavailable from head content API: {reason}"
         if not content:
-            sections.append(f"### {path}\nNo UTF-8 text content available from head content API.")
-            continue
-        sections.append(f"### {path}\n{truncate_text(content, MAX_FILE_CONTEXT_CHARS)}")
+            return f"### {path}\nNo UTF-8 text content available from head content API."
+        return f"### {path}\n{truncate_text(content, MAX_FILE_CONTEXT_CHARS)}"
+
+    if len(target_paths) <= 1:
+        sections.extend(process_path(path) for path in target_paths)
+    else:
+        max_workers = min(MAX_CONTEXT_WORKERS, len(target_paths))
+        with concurrent.futures.ThreadPoolExecutor(max_workers=max_workers) as executor:
+            sections.extend(executor.map(process_path, target_paths))
+
     if len(paths) > MAX_CONTEXT_FILES:
         sections.append(f"[{len(paths) - MAX_CONTEXT_FILES} changed files omitted from context budget]")
     return "\n\n".join(sections)

tests/test_noema_review_gate.py

@@ -309,6 +309,52 @@ def test_review_context_reports_omitted_files_and_missing_codegraph(monkeypatch,
     assert "1 changed files omitted from context budget" in context
 
 
+    paths = ["src/file_only.py"]
+    monkeypatch.setattr(noema, "fetch_changed_file_paths", lambda repo, number: paths)
+    context = noema.changed_file_context("owner/repo", 7, "head")
+    assert "src/file_only.py" in context
+
+
+def test_changed_file_context_concurrency_and_ordering(monkeypatch):
+    import time
+
+    paths = ["src/a.py", "src/b.py", "src/c.py", "src/empty.txt"]
+    monkeypatch.setattr(noema, "fetch_changed_file_paths", lambda repo, number: paths)
+
+    completion_order = []
+
+    def fake_fetch_head_file_content(repo, path, head_sha):
+        if path == "src/a.py":
+            completion_order.append(path)
+            raise RuntimeError("API error")
+        elif path == "src/b.py":
+            time.sleep(0.1)
+            completion_order.append(path)
+            return "b content"
+        elif path == "src/c.py":
+            completion_order.append(path)
+            return "c content"
+        elif path == "src/empty.txt":
+            completion_order.append(path)
+            return ""
+        return "content"
+
+    monkeypatch.setattr(noema, "fetch_head_file_content", fake_fetch_head_file_content)
+
+    context = noema.changed_file_context("owner/repo", 7, "head")
+
+    assert "### src/a.py\nUnavailable from head content API: API error" in context
+    assert "### src/b.py\nb content" in context
+    assert "### src/c.py\nc content" in context
+    assert "### src/empty.txt\nNo UTF-8 text content available" in context
+
+    pos_a = context.find("### src/a.py")
+    pos_b = context.find("### src/b.py")
+    pos_c = context.find("### src/c.py")
+
+    assert pos_a < pos_b < pos_c, "Output order does not match input order"
+
+
 class FakeResponse:
     """Small context-manager response for urllib monkeypatches."""
 

tests/test_noema_review_gate_concurrency_contract.py

@@ -0,0 +1,101 @@
+"""Focused contracts for changed-file review context concurrency."""
+
+from collections.abc import Callable, Iterable, Iterator
+from typing import Any
+
+from scripts.ci import noema_review_gate as noema
+
+
+class RecordingExecutor:
+    """Synchronous executor double that records worker and map contracts."""
+
+    instances: list["RecordingExecutor"] = []
+
+    def __init__(self, *, max_workers: int) -> None:
+        """Record the configured worker limit."""
+        self.max_workers = max_workers
+        self.map_inputs: list[tuple[str, ...]] = []
+        self.instances.append(self)
+
+    def __enter__(self) -> "RecordingExecutor":
+        """Return the executor double for context-manager use."""
+        return self
+
+    def __exit__(self, *args: object) -> bool:
+        """Propagate exceptions raised by the code under test."""
+        return False
+
+    def map(
+        self,
+        function: Callable[[str], str],
+        values: Iterable[str],
+    ) -> Iterator[str]:
+        """Record ordered inputs and evaluate them synchronously."""
+        ordered_values = tuple(values)
+        self.map_inputs.append(ordered_values)
+        return map(function, ordered_values)
+
+
+def install_recording_executor(monkeypatch: Any) -> None:
+    """Install a fresh recording executor double."""
+    RecordingExecutor.instances.clear()
+    monkeypatch.setattr(noema.concurrent.futures, "ThreadPoolExecutor", RecordingExecutor)
+
+
+def test_single_file_context_does_not_create_executor(monkeypatch: Any) -> None:
+    """Keep the one-file fast path strictly serial."""
+    install_recording_executor(monkeypatch)
+    monkeypatch.setattr(noema, "fetch_changed_file_paths", lambda repo, number: ["src/only.py"])
+    monkeypatch.setattr(noema, "fetch_head_file_content", lambda repo, path, head_sha: "only content")
+
+    context = noema.changed_file_context("owner/repo", 7, "head")
+
+    assert RecordingExecutor.instances == []
+    assert context == "### src/only.py\nonly content"
+
+
+def test_parallel_file_context_uses_bounded_map_and_scrubs_errors(monkeypatch: Any) -> None:
+    """Verify bounded parallel mapping, stable order, and error redaction."""
+    install_recording_executor(monkeypatch)
+    paths = [f"src/file_{index}.py" for index in range(noema.MAX_CONTEXT_WORKERS + 2)]
+    sensitive_value = "".join(("github_", "pat_", "123456789"))
+    monkeypatch.setattr(noema, "fetch_changed_file_paths", lambda repo, number: paths)
+
+    def fake_fetch_head_file_content(repo: str, path: str, head_sha: str) -> str:
+        """Return deterministic content while exercising error and empty paths."""
+        if path == paths[0]:
+            raise RuntimeError(f"API error token {sensitive_value}")
+        if path == paths[-1]:
+            return ""
+        return f"content for {path}"
+
+    monkeypatch.setattr(noema, "fetch_head_file_content", fake_fetch_head_file_content)
+
+    context = noema.changed_file_context("owner/repo", 7, "head")
+
+    assert len(RecordingExecutor.instances) == 1
+    executor = RecordingExecutor.instances[0]
+    assert executor.max_workers == min(noema.MAX_CONTEXT_WORKERS, len(paths))
+    assert executor.max_workers <= noema.MAX_CONTEXT_WORKERS
+    assert executor.max_workers <= len(paths)
+    assert executor.map_inputs == [tuple(paths)]
+    assert "Unavailable from head content API: API error token ***" in context
+    assert sensitive_value not in context
+    assert "No UTF-8 text content available from head content API." in context
+
+    section_positions = [context.index(f"### {path}") for path in paths]
+    assert section_positions == sorted(section_positions)
+
+
+def test_parallel_file_context_worker_count_tracks_small_batches(monkeypatch: Any) -> None:
+    """Limit worker creation to the number of files in a small batch."""
+    install_recording_executor(monkeypatch)
+    paths = ["src/first.py", "src/second.py"]
+    monkeypatch.setattr(noema, "fetch_changed_file_paths", lambda repo, number: paths)
+    monkeypatch.setattr(noema, "fetch_head_file_content", lambda repo, path, head_sha: path)
+
+    noema.changed_file_context("owner/repo", 7, "head")
+
+    executor = RecordingExecutor.instances[0]
+    assert executor.max_workers == len(paths)
+    assert executor.map_inputs == [tuple(paths)]