Files
Nominatim/src/nominatim_api/server/falcon/server.py
2025-11-16 14:41:25 +01:00

226 lines
7.9 KiB
Python

# SPDX-License-Identifier: GPL-3.0-or-later
#
# This file is part of Nominatim. (https://nominatim.org)
#
# Copyright (C) 2025 by the Nominatim developer community.
# For a full list of authors see the git log.
"""
Server implementation using the falcon webserver framework.
"""
from __future__ import annotations
from typing import Optional, Mapping, Any, List, cast
from pathlib import Path
import asyncio
import datetime as dt
from falcon.asgi import App, Request, Response
from ...config import Configuration
from ...core import NominatimAPIAsync
from ...types import QueryStatistics
from ... import v1 as api_impl
from ...result_formatting import FormatDispatcher, load_format_dispatcher
from ... import logging as loglib
from ..asgi_adaptor import ASGIAdaptor, EndpointFunc
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,
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,
exception: TimeoutError,
_: Any) -> None:
""" Special error handler that passes message and content type as
per exception info.
"""
resp.status = 503
loglib.log().comment('Aborted: Query took too long to process.')
logdata = loglib.get_and_disable()
if logdata:
resp.text = logdata
resp.content_type = 'text/html; charset=utf-8'
else:
resp.text = "Query took too long to process."
resp.content_type = 'text/plain; charset=utf-8'
class ParamWrapper(ASGIAdaptor):
""" Adaptor class for server glue to Falcon framework.
"""
def __init__(self, req: Request, resp: Response,
config: Configuration, formatter: FormatDispatcher) -> None:
self.request = req
self.response = resp
self._config = config
self._formatter = formatter
def get(self, name: str, default: Optional[str] = None) -> Optional[str]:
return self.request.get_param(name, default=default)
def get_header(self, name: str, default: Optional[str] = None) -> Optional[str]:
return self.request.get_header(name, default=default)
def error(self, msg: str, status: int = 400) -> HTTPNominatimError:
return HTTPNominatimError(msg, status, self.content_type)
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 = self.content_type
def base_uri(self) -> str:
return self.request.forwarded_prefix
def config(self) -> Configuration:
return self._config
def formatting(self) -> FormatDispatcher:
return self._formatter
def query_stats(self) -> Optional[QueryStatistics]:
return cast(Optional[QueryStatistics], getattr(self.request.context, 'query_stats', None))
class EndpointWrapper:
""" Converter for server glue endpoint functions to Falcon request handlers.
"""
def __init__(self, name: str, func: EndpointFunc, api: NominatimAPIAsync,
formatter: FormatDispatcher) -> None:
self.name = name
self.func = func
self.api = api
self.formatter = formatter
async def on_get(self, req: Request, resp: Response) -> None:
""" Implementation of the endpoint.
"""
await self.func(self.api, ParamWrapper(req, resp, self.api.config,
self.formatter))
class FileLoggingMiddleware:
""" Middleware to log selected requests into a file.
"""
def __init__(self, file_name: str, logstr: str):
self.logstr = logstr + '\n'
self.fd = open(file_name, 'a', buffering=1, encoding='utf8')
async def process_request(self, req: Request, _: Response) -> None:
""" Callback before the request starts timing.
"""
req.context.query_stats = QueryStatistics()
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 successful requests for search, reverse and lookup.
"""
qs = req.context.query_stats
if not req_succeeded or 'start' not in qs\
or resource is None or resp.status != 200\
or resource.name not in ('reverse', 'search', 'lookup', 'details'):
return
qs['endpoint'] = resource.name
qs['query_string'] = req.scope['query_string'].decode('utf8')
qs['results_total'] = getattr(resp.context, 'num_results', 0)
for param in ('start', 'end', 'start_query'):
if isinstance(qs.get(param), dt.datetime):
qs[param] = qs[param].replace(tzinfo=None)\
.isoformat(sep=' ', timespec='milliseconds')
self.fd.write(self.logstr.format_map(qs))
class APIMiddleware:
""" Middleware managing the Nominatim database connection.
"""
def __init__(self, project_dir: Path, environ: Optional[Mapping[str, str]]) -> None:
self.api = NominatimAPIAsync(project_dir, environ)
self.app: Optional[App[Request, Response]] = None
@property
def config(self) -> Configuration:
""" Get the configuration for Nominatim.
"""
return self.api.config
def set_app(self, app: App[Request, Response]) -> None:
""" Set the Falcon application this middleware is connected to.
"""
self.app = app
async def process_startup(self, *_: Any) -> None:
""" Process the ASGI lifespan startup event.
"""
assert self.app is not None
legacy_urls = self.api.config.get_bool('SERVE_LEGACY_URLS')
formatter = load_format_dispatcher('v1', self.api.config.project_dir)
for name, func in await api_impl.get_routes(self.api):
endpoint = EndpointWrapper(name, func, self.api, formatter)
self.app.add_route(f"/{name}", endpoint)
if legacy_urls:
self.app.add_route(f"/{name}.php", endpoint)
async def process_shutdown(self, *_: Any) -> None:
"""Process the ASGI lifespan shutdown event.
"""
await self.api.close()
def get_application(project_dir: Path,
environ: Optional[Mapping[str, str]] = None) -> App[Request, Response]:
""" Create a Nominatim Falcon ASGI application.
"""
apimw = APIMiddleware(project_dir, environ)
middleware: List[Any] = [apimw]
log_file = apimw.config.LOG_FILE
if log_file:
middleware.append(FileLoggingMiddleware(log_file, apimw.config.LOG_FORMAT))
app = App(cors_enable=apimw.config.get_bool('CORS_NOACCESSCONTROL'),
middleware=middleware)
apimw.set_app(app)
app.add_error_handler(HTTPNominatimError, nominatim_error_handler)
app.add_error_handler(TimeoutError, timeout_error_handler)
# different from TimeoutError in Python <= 3.10
app.add_error_handler(asyncio.TimeoutError, timeout_error_handler) # type: ignore[arg-type]
return app
def run_wsgi() -> App[Request, Response]:
""" Entry point for uvicorn.
Make sure uvicorn is run from the project directory.
"""
return get_application(Path('.'))