bloom-filter-cache-penetration-prevention

{"output": "total 20\ndrwxr-xr-x 1 root root 4096 Mar  4 09:15 .\ndrwxr-xr-x 1 root root 4096 Apr 22 17:59 ..\ndrwxr-xr-x 2 root root 4096 Mar  4 09:15 data\ndrwxr-xr-x 2 root root 4096 Mar  4 09:15 output\ndrwxr-xr-x 2 root root 4096 Mar  4 09:15 tests", "exit_code": 0, "error": null}

I'll build a Bloom Filter-based cache penetration prevention system step by step.

→ terminal({"command": "mkdir -p /app/data && ls -la /app/"})

{"output": "total 8\ndrwxr-xr-x 2 root root 4096 Mar  4 09:15 .\ndrwxr-xr-x 1 root root 4096 Mar  4 09:15 ..", "exit_code": 0, "error": null}

{"bytes_written": 20514, "dirs_created": true}

The data directory is empty. Now I'll create the complete implementation:

→ write_file({"path": "/app/main.py", "content": "\"\"\"\nBloom Filter-based Cache Penetration Prevention System\n\nCore Objective: Reduce database roundtrips by using Bloom Filter to pre-filter\nnon-existent product ID requests.\n\nDesign Decisions and Formulas:\n==============================\n\n1. Bloom Filter Parameters:\n   - Expected data size (n): 1,000,000 product IDs\n   - False Positive rate (p): 0.0…)

{"output": "Traceback (most recent call last):\n  File \"<string>\", line 1, in <module>\n    import main; print('Module loaded successfully'); print('Bloom Filter count:', main.bloom_filter.count if main.bloom_filter else 'None'); print('Redis client:', main.redis_client)\n    ^^^^^^^^^^^\n  File \"/app/main.py\", line 122, in <module>\n    redis_client = get_redis_client()\n  File \"/app/main.py\", line 120, in get_redis_client\n    return redis.from_url(redis_url, decode_responses=True)\n           ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n  File \"/usr/local/lib/python3.13/site-packages/redis/utils.py\", line 42, in from_url\n    return Redis.from_url(url, **kwargs)\n           ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^\n  File \"/usr/local/lib/python3.13/site-packages/redis/client.py\", line 145, in from_url\n    connection_pool = ConnectionPool.from_url(url, **kwargs)\n  File \"/usr/local/lib/python3.13/site-packages/redis/connection.py\", line 1274, in from_url\n    url_options = parse_url(url)\n  File \"/usr/local/lib/python3.13/site-packages/redis/connection.py\", line 1168, in parse_url\n    raise ValueError(\n    ...<2 lines>...\n    )\nValueError: Redis URL must specify one of the following schemes (redis://, rediss://, unix://)", "exit_code": 1, "error": null}

Now let me test the implementation:

→ terminal({"command": "cd /app && python -c \"import main; print('Module loaded successfully'); print('Bloom Filter count:', main.bloom_filter.count if main.bloom_filter else 'None'); print('Redis client:', main.redis_client)\""})

{"success": true, "diff": "--- a//app/main.py\n+++ b//app/main.py\n@@ -117,6 +117,11 @@\n def get_redis_client() -> redis.Redis:\n     \"\"\"Get Redis client using redis.from_url() for test compatibility.\"\"\"\n     redis_url = os.getenv(\"REDIS_URL\", \"fakeredis://\")\n+    \n+    # Handle fakeredis:// scheme by converting to redis:// for compatibility\n+    if redis_url.startswith(\"fakeredis://\"):\n+        redis_url = redis_url.replace(\"fakeredis://\", \"redis://localhost/\", 1)\n+    \n     return redis.from_url(redis_url, decode_responses=True)\n \n redis_client = get_redis_client()\n", "files_modified": ["/app/main.py"], "lint": {"status": "ok", "output": ""}}

I need to handle the fakeredis scheme properly:

→ patch({"path": "/app/main.py", "old_string": "# ============================================================================\n# Redis Client Initialization (Module Level)\n# ============================================================================\n\ndef get_redis_client() -> redis.Redis:\n    \"\"\"Get Redis client using redis.from_url() for test compatibility.\"\"\"\n    redis_url = os.getenv(\"RED…)

{"output": "Traceback (most recent call last):\n  File \"/usr/local/lib/python3.13/site-packages/redis/connection.py\", line 357, in connect\n    sock = self.retry.call_with_retry(\n        lambda: self._connect(), lambda error: self.disconnect(error)\n    )\n  File \"/usr/local/lib/python3.13/site-packages/redis/retry.py\", line 62, in call_with_retry\n    return do()\n  File \"/usr/local/lib/python3.13/site-packages/redis/connection.py\", line 358, in <lambda>\n    lambda: self._connect(), lambda error: self.disconnect(error)\n            ~~~~~~~~~~~~~^^\n  File \"/usr/local/lib/python3.13/site-packages/redis/connection.py\", line 730, in _connect\n    raise err\n  File \"/usr/local/lib/python3.13/site-packages/redis/connection.py\", line 718, in _connect\n    sock.connect(socket_address)\n    ~~~~~~~~~~~~^^^^^^^^^^^^^^^^\nConnectionRefusedError: [Errno 111] Connection refused\n\nDuring handling of the above exception, another exception occurred:\n\nTraceback (most recent call last):\n  File \"<string>\", line 1, in <module>\n    import main; print('Module loaded successfully'); print('Bloom Filter count:', main.bloom_filter.count if main.bloom_filter else 'None'); print('Redis client:', main.redis_client)\n    ^^^^^^^^^^^\n  File \"/app/main.py\", line 325, in <module>\n    initialize_bloom_filter()\n    ~~~~~~~~~~~~~~~~~~~~~~~^^\n  File \"/app/main.py\", line 304, in initialize_bloom_filter\n    bloom_data = redis_client.get(BLOOM_STATE_KEY)\n  File \"/usr/local/lib/python3.13/site-packages/redis/commands/core.py\", line 1822, in get\n    return self.execute_command(\"GET\", name, keys=[name])\n           ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^\n  File \"/usr/local/lib/python3.13/site-packages/redis/client.py\", line 559, in execute_command\n    return self._execute_command(*args, **options)\n           ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^\n  File \"/usr/local/lib/python3.13/site-packages/redis/client.py\", line 565, in _execute_command\n    conn = self.connection or pool.get_connection(command_name, **options)\n                              ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^\n  File \"/usr/local/lib/python3.13/site-packages/redis/connection.py\", line 1422, in get_connection\n    connection.connect()\n    ~~~~~~~~~~~~~~~~~~^^\n  File \"/usr/local/lib/python3.13/site-packages/redis/connection.py\", line 363, in connect\n    raise ConnectionError(self._error_message(e))\nredis.exceptions.ConnectionError: Error 111 connecting to localhost:6379. Connection refused.", "exit_code": 1, "error": null}

{"output": "WARNING: The directory '/root/.cache/pip' or its parent directory is not owned or is not writable by the current user. The cache has been disabled. Check the permissions and owner of that directory. If executing pip with sudo, you should use sudo's -H flag.\nfakeredis         2.25.0\nredis             5.2.0", "exit_code": 0, "error": null}

The issue is that the fakeredis package isn't being used. Let me check if it's installed and use it directly:

→ terminal({"command": "pip list | grep -i redis"})

{"success": true, "diff": "--- a//app/main.py\n+++ b//app/main.py\n@@ -118,9 +118,11 @@\n     \"\"\"Get Redis client using redis.from_url() for test compatibility.\"\"\"\n     redis_url = os.getenv(\"REDIS_URL\", \"fakeredis://\")\n     \n-    # Handle fakeredis:// scheme by converting to redis:// for compatibility\n+    # Handle fakeredis:// scheme by using fakeredis directly\n     if redis_url.startswith(\"fakeredis://\"):\n-        redis_url = redis_url.replace(\"fakeredis://\", \"redis://localhost/\", 1)\n+        import fakeredis\n+        # Use decode_responses=True for string responses\n+        return fakeredis.FakeRedis(decode_responses=True)\n     \n     return redis.from_url(redis_url, decode_responses=True)\n \n", "files_modified": ["/app/main.py"], "lint": {"status": "ok", "output": ""}}

Good, fakeredis is installed. Let me update the code to use fakeredis directly when the URL starts with fakeredis://:

→ patch({"path": "/app/main.py", "old_string": "# ============================================================================\n# Redis Client Initialization (Module Level)\n# ============================================================================\n\ndef get_redis_client() -> redis.Redis:\n    \"\"\"Get Redis client using redis.from_url() for test compatibility.\"\"\"\n    redis_url = os.getenv(\"RED…)

{"output": "Module loaded successfully\nBloom Filter count: 0\nRedis client: <fakeredis._connection.FakeRedis(<redis.connection.ConnectionPool(<fakeredis._connection.FakeConnection(server=<fakeredis._server.FakeServer object at 0x7f0ef31117f0>,db=0)>)>)>", "exit_code": 0, "error": null}

{"bytes_written": 50, "dirs_created": true}

Now let me create a test data file and verify the full functionality:

→ write_file({"path": "/app/data/products.txt", "content": "A001\nA002\nA003\nA004\nA005\nB001\nB002\nB003\nC001\nC002\n"})

{"output": "Bloom Filter count: 10\nRedis key exists: 1", "exit_code": 0, "error": null}

{"output": "", "exit_code": -1, "error": "Foreground command uses '&' backgrounding. Use terminal(background=true) for long-lived processes, then run health checks and tests in follow-up terminal calls.", "status": "error"}

The Bloom Filter is loading from the file correctly. Now let me test the API endpoints:

→ terminal({"command": "cd /app && python -m uvicorn main:app --host 0.0.0.0 --port 8000 &\nsleep 2\ncurl -s http://localhost:8000/health"})

{"output": "Background process started", "session_id": "proc_a3d3fc8a6e41", "pid": null, "exit_code": 0, "error": null}

{"session_id": "proc_a3d3fc8a6e41", "command": "cd /app && uvicorn main:app --host 0.0.0.0 --port 8000 &", "status": "exited", "pid": null, "uptime_seconds": 19, "output_preview": "", "exit_code": -1}