"""
Server implementation using the falcon webserver framework.
"""
-from typing import Optional, Mapping, cast
+from typing import Optional, Mapping, cast, Any, List
from pathlib import Path
+import datetime as dt
-import falcon
from falcon.asgi import App, Request, Response
from nominatim.api import NominatimAPIAsync
import nominatim.api.v1 as api_impl
+from nominatim.config import Configuration
+
+class HTTPNominatimError(Exception):
+ """ A special exception class for errors raised during processing.
+ """
+ def __init__(self, msg: str, status: int, content_type: str) -> None:
+ self.msg = msg
+ self.status = status
+ self.content_type = content_type
+
+
+async def nominatim_error_handler(req: Request, resp: Response, #pylint: disable=unused-argument
+ exception: HTTPNominatimError,
+ _: Any) -> None:
+ """ Special error handler that passes message and content type as
+ per exception info.
+ """
+ resp.status = exception.status
+ resp.text = exception.msg
+ resp.content_type = exception.content_type
+
+
+async def timeout_error_handler(req: Request, resp: Response, #pylint: disable=unused-argument
+ exception: TimeoutError, #pylint: disable=unused-argument
+ _: Any) -> None:
+ """ Special error handler that passes message and content type as
+ per exception info.
+ """
+ resp.status = 503
+ resp.text = "Query took too long to process."
+ resp.content_type = 'text/plain; charset=utf-8'
class ParamWrapper(api_impl.ASGIAdaptor):
""" Adaptor class for server glue to Falcon framework.
"""
- def __init__(self, req: Request, resp: Response) -> None:
+ def __init__(self, req: Request, resp: Response,
+ config: Configuration) -> None:
self.request = req
self.response = resp
+ self._config = config
def get(self, name: str, default: Optional[str] = None) -> Optional[str]:
return cast(Optional[str], self.request.get_header(name, default=default))
- def error(self, msg: str) -> falcon.HTTPBadRequest:
- return falcon.HTTPBadRequest(description=msg)
+ def error(self, msg: str, status: int = 400) -> HTTPNominatimError:
+ return HTTPNominatimError(msg, status, self.content_type)
- def create_response(self, status: int, output: str, content_type: str) -> None:
+ def create_response(self, status: int, output: str, num_results: int) -> None:
+ self.response.context.num_results = num_results
self.response.status = status
self.response.text = output
- self.response.content_type = content_type
+ self.response.content_type = self.content_type
+
+
+ def base_uri(self) -> str:
+ return cast (str, self.request.forwarded_prefix)
+
+ def config(self) -> Configuration:
+ return self._config
class EndpointWrapper:
""" Converter for server glue endpoint functions to Falcon request handlers.
"""
- def __init__(self, func: api_impl.EndpointFunc, api: NominatimAPIAsync) -> None:
+ def __init__(self, name: str, func: api_impl.EndpointFunc, api: NominatimAPIAsync) -> None:
+ self.name = name
self.func = func
self.api = api
async def on_get(self, req: Request, resp: Response) -> None:
""" Implementation of the endpoint.
"""
- await self.func(self.api, ParamWrapper(req, resp))
+ await self.func(self.api, ParamWrapper(req, resp, self.api.config))
+
+
+class FileLoggingMiddleware:
+ """ Middleware to log selected requests into a file.
+ """
+
+ def __init__(self, file_name: str):
+ self.fd = open(file_name, 'a', buffering=1, encoding='utf8') # pylint: disable=R1732
+
+
+ async def process_request(self, req: Request, _: Response) -> None:
+ """ Callback before the request starts timing.
+ """
+ req.context.start = dt.datetime.now(tz=dt.timezone.utc)
+
+
+ async def process_response(self, req: Request, resp: Response,
+ resource: Optional[EndpointWrapper],
+ req_succeeded: bool) -> None:
+ """ Callback after requests writes to the logfile. It only
+ writes logs for sucessful requests for search, reverse and lookup.
+ """
+ if not req_succeeded or resource is None or resp.status != 200\
+ or resource.name not in ('reverse', 'search', 'lookup', 'details'):
+ return
+
+ finish = dt.datetime.now(tz=dt.timezone.utc)
+ duration = (finish - req.context.start).total_seconds()
+ params = req.scope['query_string'].decode('utf8')
+ start = req.context.start.replace(tzinfo=None)\
+ .isoformat(sep=' ', timespec='milliseconds')
+
+ self.fd.write(f"[{start}] "
+ f"{duration:.4f} {getattr(resp.context, 'num_results', 0)} "
+ f'{resource.name} "{params}"\n')
+
+
+class APIShutdown:
+ """ Middleware that closes any open database connections.
+ """
+
+ def __init__(self, api: NominatimAPIAsync) -> None:
+ self.api = api
+
+ async def process_shutdown(self, *_: Any) -> None:
+ """Process the ASGI lifespan shutdown event.
+ """
+ await self.api.close()
def get_application(project_dir: Path,
"""
api = NominatimAPIAsync(project_dir, environ)
- app = App(cors_enable=api.config.get_bool('CORS_NOACCESSCONTROL'))
+ middleware: List[object] = [APIShutdown(api)]
+ log_file = api.config.LOG_FILE
+ if log_file:
+ middleware.append(FileLoggingMiddleware(log_file))
+
+ app = App(cors_enable=api.config.get_bool('CORS_NOACCESSCONTROL'),
+ middleware=middleware)
+ app.add_error_handler(HTTPNominatimError, nominatim_error_handler)
+ app.add_error_handler(TimeoutError, timeout_error_handler)
+
+ legacy_urls = api.config.get_bool('SERVE_LEGACY_URLS')
for name, func in api_impl.ROUTES:
- app.add_route('/' + name, EndpointWrapper(func, api))
+ endpoint = EndpointWrapper(name, func, api)
+ app.add_route(f"/{name}", endpoint)
+ if legacy_urls:
+ app.add_route(f"/{name}.php", endpoint)
return app
+
+
+def run_wsgi() -> App:
+ """ Entry point for uvicorn.
+
+ Make sure uvicorn is run from the project directory.
+ """
+ return get_application(Path('.'))