Add response cache (#34)

aiopegelonline/__init__.py

@@ -8,7 +8,7 @@
 
 from .const import BASE_URL, CONNECT_ERRORS, LOGGER
 from .exceptions import PegelonlineDataError
-from .models import Station, StationMeasurements
+from .models import CacheEntry, Station, StationMeasurements
 
 
 class PegelOnline:
@@ -17,15 +17,34 @@ class PegelOnline:
  def __init__(self, aiohttp_session: ClientSession) -> None:
  """Pegelonline api init."""
  self.session: ClientSession = aiohttp_session
+ self.cache: dict[str, CacheEntry] = {}
 
  async def _async_do_request(self, url: str, params: dict):
  """Perform an async request."""
- LOGGER.debug("REQUEST url: %s params: %s", url, params)
+ cache_key = f"{url}_{params}"
+ if cache_key not in self.cache:
+ self.cache[cache_key] = CacheEntry(None, None)
+
+ cache_entry = self.cache[cache_key]
+
+ headers = {}
+ if (etag := cache_entry.etag) is not None:
+ headers = {"If-None-Match": etag}
+
+ LOGGER.debug("REQUEST url: %s params: %s headers: %s", url, params, headers)
  try:
- async with self.session.get(url, params=params) as resp:
+ async with self.session.get(url, params=params, headers=headers) as resp:
  result = await resp.text()
  LOGGER.debug("RESPONSE status: %s text: %s", resp.status, result)
+
+ if resp.status == 304: # 304 = not modified
+ return cache_entry.result
+
+ if cache_entry.etag is None:
+ cache_entry.etag = resp.headers.get("Etag")
+
  result = json.loads(result)
+ cache_entry.result = result
  if resp.status != 200:
  raise PegelonlineDataError(
  result.get("status"), result.get("message")

aiopegelonline/models.py

@@ -2,6 +2,8 @@
 
 from __future__ import annotations
 
+from dataclasses import dataclass
+
 
 class Station:
  """Representation of a station."""
@@ -93,3 +95,11 @@ def as_dict(self) -> dict[str, CurrentMeasurement | None]:
  "water_level": self.water_level,
  "water_temperature": self.water_temperature,
  }
+
+
+@dataclass
+class CacheEntry:
+ """Representation of response cache entry."""
+
+ etag: str | None
+ result: dict | None

tests/conftest.py

@@ -5,12 +5,12 @@
 
 import aiohttp
 import pytest
-from aioresponses import aioresponses
+from aioresponses import CallbackResult, aioresponses
 
 from aiopegelonline import PegelOnline
 from aiopegelonline.const import BASE_URL
 
-from .const import MOCK_DATA
+from .const import MOCK_DATA, MOCK_STATION_DATA_DRESDEN
 
 
 @pytest.fixture
@@ -29,7 +29,7 @@ async def mock_pegelonline():
 
 @pytest.fixture
 def mock_pegelonline_with_data(mock_aioresponse, mock_pegelonline):
- """Comfort fixture to initialize deCONZ session."""
+ """Comfort fixture to initialize pegelonline session."""
 
  async def data_to_pegelonline() -> PegelOnline:
  """Initialize PegelOnline session."""
@@ -43,3 +43,21 @@ async def data_to_pegelonline() -> PegelOnline:
  return mock_pegelonline
 
  return data_to_pegelonline
+
+@pytest.fixture
+def mock_pegelonline_with_cached_data(mock_aioresponse, mock_pegelonline):
+ """Comfort fixture to initialize pegelonline session with cached data."""
+
+ def cache_response(_, **kwargs) -> CallbackResult:
+ etag = "etag_station_dresden"
+ if (headers := kwargs.get("headers")) and headers.get("If-None-Match") == etag:
+ return CallbackResult(status=304, body="", headers={"Etag": etag})
+ return CallbackResult(status=200, body=json.dumps(MOCK_STATION_DATA_DRESDEN), headers={"Etag": etag})
+
+ async def data_to_pegelonline() -> PegelOnline:
+ """Initialize PegelOnline session."""
+ query = f"{BASE_URL}/stations/70272185-xxxx-xxxx-xxxx-43bea330dcae.json?prettyprint=false"
+ mock_aioresponse.get(query, callback=cache_response, repeat=True)
+ return mock_pegelonline
+
+ return data_to_pegelonline

tests/test_aiopegelonline.py

@@ -155,3 +155,31 @@ async def test_get_station_measurements(mock_pegelonline_with_data):
  "water_level": None,
  "water_temperature": None,
  }
+
+
+async def test_get_station_details_cached(mock_pegelonline_with_cached_data):
+ """Test response cache."""
+ api = await mock_pegelonline_with_cached_data()
+ station = await api.async_get_station_details(
+ "70272185-xxxx-xxxx-xxxx-43bea330dcae"
+ )
+ assert isinstance(station, Station)
+ assert station.uuid == "70272185-xxxx-xxxx-xxxx-43bea330dcae"
+ assert station.name == "DRESDEN"
+ assert station.agency == "STANDORT DRESDEN"
+ assert station.river_kilometer == 55.63
+ assert station.longitude == 13.738831783620384
+ assert station.latitude == 51.054459765598125
+ assert station.water_name == "ELBE"
+
+ station = await api.async_get_station_details(
+ "70272185-xxxx-xxxx-xxxx-43bea330dcae"
+ )
+ assert isinstance(station, Station)
+ assert station.uuid == "70272185-xxxx-xxxx-xxxx-43bea330dcae"
+ assert station.name == "DRESDEN"
+ assert station.agency == "STANDORT DRESDEN"
+ assert station.river_kilometer == 55.63
+ assert station.longitude == 13.738831783620384
+ assert station.latitude == 51.054459765598125
+ assert station.water_name == "ELBE"