Start of change to use asynchronous services. need to update to Flask 2.0 and use python 3.8 first.

assets/package-lock.json

 {
   "name": "waterdataui-assets",
-  "version": "0.49.0dev",
+  "version": "0.50.0dev",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {

wdfn-server/waterdata/services/nwissite.py

@@ -3,117 +3,105 @@ Class and functions for calling NWIS services and working with
 the returned data.
 
 """
-from requests import exceptions as request_exceptions, Session
 from ..utils import parse_rdb
 
 from .. import app
 
 
-class SiteService:
+async def get(session, params):
+    # pylint: disable=no-member
     """
-    Provides access to the NWIS site service
+    Returns a tuple containing the request status code and a list of dictionaries that represent the contents of
+    RDB file
+    :param session - instance aiohttp.ClientSession
+    :param dict params:
+    :yields
+        - status_code - status code returned from the service request
+        - reason - string
+        - site_data - list of dictionaries
     """
-
-    def __init__(self, endpoint):
-        """
-        Constructor method.
-
-        :param str endpoint: the scheme, host and path to the NWIS site service
-        """
-        self.endpoint = endpoint
-        self.session = Session()
-
-    def get(self, params):
-        # pylint: disable=no-member
-        """
-        Returns a tuple containing the request status code and a list of dictionaries that represent the contents of
-        RDB file
-
-        :param dict params:
-        :returns
-            - status_code - status code returned from the service request
-            - reason - string
-            - site_data - list of dictionaries
-        """
-        app.logger.debug(f'Requesting data from {self.endpoint}')
-        default_params = {
-            'format': 'rdb'
-        }
-        default_params.update(params)
-        try:
-            response = self.session.get(self.endpoint, params=default_params)
-        except (request_exceptions.Timeout, request_exceptions.ConnectionError) as err:
-            app.logger.error(repr(err))
-            return 500, repr(err), None
+    endpoint = app.config["SITE_DATA_ENDPOINT"]
+    app.logger.debug(f'Requesting data from {endpoint}')
+    default_params = {
+        'format': 'rdb'
+    }
+    default_params.update(params)
+    async with session.get(endpoint, params=default_params) as response:
         if response.status_code == 200:
-            return 200, response.reason, list(parse_rdb(response.iter_lines(decode_unicode=True)))
+            async with response.iter_lines(decode_unicode=True) as lines:
+                return 200, response.reason, list(parse_rdb(lines))
 
         return response.status_code, response.reason, []
 
-    def get_site_data(self, site_no, agency_cd=''):
-        """
-        Get the metadata for site_no, agency_cd (which may be blank) using the additional query parameters, param
-        Note that more than one dictionary can be returned if agency_cd is empty.
-        :param str site_no: site identifier
-        :param str agency_cd: identifier for the agency that owns the site
-        :returns:
-            - status - status code from response
-            - reason - string
-            - site_metadata - list of dict representing the data returned in the rdb file
-        """
-        params = {
-            'sites': site_no,
-            'siteOutput': 'expanded'
-        }
-        if agency_cd:
-            params['agencyCd'] = agency_cd
-        return self.get(params)
 
-    def get_period_of_record(self, site_no, agency_cd=''):
-        """
-        Get the parameters measured at the site(s).
+async def get_site_data(session, site_no, agency_cd=''):
+    """
+    Get the metadata for site_no, agency_cd (which may be blank) using the additional query parameters, param
+    Note that more than one dictionary can be returned if agency_cd is empty.
+    :param session: instance of aiohttp.ClientSession
+    :param str site_no: site identifier
+    :param str agency_cd: identifier for the agency that owns the site
+    :yields:
+        - status - status code from response
+        - reason - string
+        - site_metadata - list of dict representing the data returned in the rdb file
+    """
+    params = {
+        'sites': site_no,
+        'siteOutput': 'expanded'
+    }
+    if agency_cd:
+        params['agencyCd'] = agency_cd
+    return await get(session, params)
+
 
-        :param str site_no: site identifier
-        :param str agency_cd: identifier for the agency that owns the site:
-        :returns:
-            - status - status code from response
-            - reason - string
-            - periodOfRecord - list of dict representing the period of record for the data available at the site
-        """
-        params = {
-            'sites': site_no,
-            'seriesCatalogOutput': True,
-            'siteStatus': 'all'
-        }
-        if agency_cd:
-            params['agencyCd'] = agency_cd
-        return self.get(params)
+async def get_period_of_record(session, site_no, agency_cd=''):
+    """
+    Get the parameters measured at the site(s).
+    :param session: instance of aiohttp.ClientSession
+    :param str site_no: site identifier
+    :param str agency_cd: identifier for the agency that owns the site:
+    :returns:
+        - status - status code from response
+        - reason - string
+        - periodOfRecord - list of dict representing the period of record for the data available at the site
+    """
+    params = {
+        'sites': site_no,
+        'seriesCatalogOutput': True,
+        'siteStatus': 'all'
+    }
+    if agency_cd:
+        params['agencyCd'] = agency_cd
+    return await get(session, params)
 
-    def get_huc_sites(self, huc_cd):
-        """
-        Get all sites within a hydrologic unit as identified by its
-        hydrologic unit code (HUC).
 
-        :param str huc_cd: hydrologic unit code
-        :returns: all sites in the specified HUC
-            - status - status code from response
-            - reason - string
-            - sites - list of dict representing the sites in huc_cd
-        """
-        return self.get({
-            'huc': huc_cd
-        })
+async def get_huc_sites(session, huc_cd):
+    """
+    Get all sites within a hydrologic unit as identified by its
+    hydrologic unit code (HUC).
+    :param session: instance of aiohttp.ClientSession
+    :param str huc_cd: hydrologic unit code
+    :returns: all sites in the specified HUC
+        - status - status code from response
+        - reason - string
+        - sites - list of dict representing the sites in huc_cd
+    """
+    return await get(session, {
+        'huc': huc_cd
+    })
 
-    def get_county_sites(self, state_county_cd):
-        """
-        Get all sites within a county.
 
-        :param str state_county_cd: FIPS ID for a statecounty
-        :returns: all sites in the specified county
-            - status - status code from response
-            - reason - string
-            - sites - list of dict representing the site in state_county_cd
-         """
-        return self.get({
-            'countyCd': state_county_cd
-        })
+def get_county_sites(session, state_county_cd):
+    """
+    Get all sites within a county.
+    :param session: instance of aiohttp.ClientSession
+    :param str state_county_cd: FIPS ID for a statecounty
+    :returns: all sites in the specified county
+        - status - status code from response
+        - reason - string
+        - sites - list of dict representing the site in state_county_cd
+     """
+    return get(session, {
+        'countyCd': state_county_cd
+    })

wdfn-server/waterdata/services/sifta.py

 """
 Helpers to retrieve SIFTA cooperator data.
 """
-from requests import exceptions as request_exceptions, Session
 
 from .. import app
 
 
-class SiftaService:
-    # pylint: disable=too-few-public-methods, no-member
+async def get_cooperators(session, site_no):
     """
-    Provide access to a service that returns cooperator data
-    """
-    def __init__(self, endpoint):
-        self.endpoint = endpoint
-        self.session = Session()
+    Gets the cooperator data from the SIFTA service
 
-    def get_cooperators(self, site_no):
-        """
-        Gets the cooperator data from the SIFTA service
+    :param session - instance aiohttp.ClientSession
+    :param str site_no: USGS site number
+    :yields Array of dict
+    """
+    url = f'{app.config["COOPERATOR_SERVICE_ENDPOINT"]}{site_no}'
+    app.logger.debug(f'Requesting data from {url}')  # pylint: disable=no-member
 
-        :param site_no: USGS site number
-        :return Array of dict
-        """
-        url = f'{self.endpoint}{site_no}'
-        try:
-            response = self.session.get(url)
-        except (request_exceptions.Timeout, request_exceptions.ConnectionError) as err:
-            app.logger.error(repr(err))
-            return []
+    async with session.get(url) as response:
+        # TODO: Add exception handling
+        app.logger.debug(f'Retrieved data from {url}')  # pylint: disable=no-member
 
         if response.status_code != 200:
             return []

wdfn-server/waterdata/views.py

 """
 Main application views.
 """
+import asyncio
 import datetime
 import json
 import smtplib
@@ -16,17 +17,15 @@ from .utils import defined_when, set_cookie_for_banner_message, create_message
 from .services.camera import get_monitoring_location_camera_details
 from .services.nwissite import SiteService
 from .services.ogc import MonitoringLocationNetworkService
-from .services.sifta import SiftaService
+from .services.sifta import get_cooperators
 from .services.timezone import TimeZoneService
 
 # Station Fields Mapping to Descriptions
 from .constants import STATION_FIELDS_D
 
-site_service = SiteService(app.config['SITE_DATA_ENDPOINT'])
 monitoring_location_network_service = \
     MonitoringLocationNetworkService(app.config['MONITORING_LOCATIONS_OBSERVATIONS_ENDPOINT'])
 time_zone_service = TimeZoneService(app.config['WEATHER_SERVICE_ENDPOINT'])
-sifta_service = SiftaService(app.config['COOPERATOR_SERVICE_ENDPOINT'])
 
 
 @app.context_processor
@@ -98,18 +97,21 @@ def iv_data_availability():
     """Render the IV data availability statement page."""
     return render_template('iv_data_availability_statement.html')
 
-
 @app.route('/monitoring-location/<site_no>/', methods=['GET'])
-def monitoring_location(site_no):
+async def monitoring_location(site_no):
     # pylint: disable=too-many-locals
     # TODO: refactor to use more utility functions so that this doesn't have too many locals # pylint: disable=fixme
     """
     Monitoring Location view
-
     :param site_no: USGS site number
-
     """
     agency_cd = request.args.get('agency_cd', '')
+
+    async with aiohttp.ClientSession()
+
+    loop = asyncio.get_event_loop()
+    coroutines = [get_cooperators(sifta_endpoint, site_no)]
+    results = loop.run_until_complete(asyncio.gather(*coroutines))
     site_status, site_status_reason, site_data = site_service.get_site_data(site_no, agency_cd)
     json_ld = None