Refactor of caching & data storage part 6 #118

staticdataproviders/file_download_static_data_provider.py

@@ -0,0 +1,77 @@
+import logging
+from datetime import datetime
+from threading import Thread, Event
+
+import pytz
+from requests import ReadTimeout
+from requests.exceptions import ConnectionError, ConnectTimeout
+
+from core.constants import HTTP_HEADERS
+from core.url_data_cache import URLDataCache
+from staticdataproviders.static_data_provider import StaticDataProvider
+
+
+class FileDownloadStaticDataProvider(StaticDataProvider):
+    """Generic static reference data provider class for providers that fetch their data from the web by downloading a
+     file."""
+
+    def __init__(self, name, provider_config, url, poll_interval):
+        """ Set up the provider, note poll_interval is in *days*."""
+        super().__init__(name, provider_config)
+        self._url = url
+        self._poll_interval = poll_interval
+        self._thread = None
+        self._stop_event = Event()
+        self._url_data_cache = URLDataCache("staticdata_" + name)
+
+    def start(self):
+        # Fire off the polling thread. It will poll immediately on startup, then sleep for poll_interval between
+        # subsequent polls, so start() returns immediately and the application can continue starting.
+        logging.info(
+            "Set up query of " + self.name + " static reference data every " + str(self._poll_interval) + " days.")
+        self._thread = Thread(target=self._run, daemon=True)
+        self._thread.start()
+
+    def stop(self):
+        self._stop_event.set()
+
+    def _run(self):
+        while True:
+            self._poll()
+            if self._stop_event.wait(timeout=self._poll_interval * 60 * 60 * 24):
+                break
+
+    def _poll(self):
+        try:
+            # Request data from API. Use the data cache (with a TTL of 1 day) here, not as the main mechanism for
+            # caching, but just so continual restarts of the software during testing don't hammer the servers.
+            logging.debug("Downloading " + self.name + " static reference data...")
+            http_response = self._url_data_cache.get(self._url, headers=HTTP_HEADERS)
+            # Check response code was good
+            if http_response.ok:
+                # Pass off to the subclass for processing
+                ok = self._handle_http_response(http_response)
+                if ok:
+                    self.status = "OK"
+                    self.last_update_time = datetime.now(pytz.UTC)
+                    logging.info("Updated static reference data for " + self.name)
+            else:
+                self.status = "Error"
+                logging.warning(f"HTTP {http_response.status_code} when downloading static reference data for {self.name}.")
+
+        except ConnectionError:
+            self.status = "Error"
+            logging.warning(f"Connection error when downloading static reference data for {self.name}.")
+        except (ConnectTimeout, ReadTimeout):
+            self.status = "Error"
+            logging.warning(f"Timeout when downloading static reference data for {self.name}.")
+        except Exception:
+            self.status = "Error"
+            logging.exception("Exception in HTTP static reference data provider (" + self.name + ")")
+            self._stop_event.wait(timeout=1)
+
+    def _handle_http_response(self, http_response):
+        """Handle an HTTP response returned by the server and load the data from it. Return true if successful,
+         false otherwise."""
+
+        raise NotImplementedError("Subclasses must implement this method")

staticdataproviders/k0swe.py

@@ -0,0 +1,40 @@
+import logging
+import re
+
+from core.data_store import DATA_STORE
+from staticdataproviders.file_download_static_data_provider import FileDownloadStaticDataProvider
+
+
+class K0SWE(FileDownloadStaticDataProvider):
+    """Static data provider for K0SWE's dxcc.json, which provides callsign regex to DXCC entity mapping, plus DXCC to
+    continent, flag emoji etc."""
+
+    POLL_INTERVAL_DAYS = 7
+    DATA_URL = "https://raw.githubusercontent.com/k0swe/dxcc-json/refs/heads/main/dxcc.json"
+
+    def __init__(self, provider_config):
+        super().__init__("K0SWE DXCC JSON", provider_config, self.DATA_URL, self.POLL_INTERVAL_DAYS)
+
+    def _handle_http_response(self, http_response):
+        try:
+            dxcc_list = http_response.json()["dxcc"]
+            # Reformat as a map for to place in the data store
+            dxcc_map = {}
+            for dxcc in dxcc_list:
+                dxcc_map[dxcc["entityCode"]] = dxcc
+
+            # Precompile regex matches for DXCCs to improve efficiency when iterating through them
+            for dxcc in dxcc_map.values():
+                dxcc["_prefixRegexCompiled"] = re.compile(dxcc["prefixRegex"])
+
+            # Add to data store
+            for k, v in dxcc_map.items():
+                DATA_STORE.dxcc_data[k] = v
+
+            return True
+
+        except Exception as e:
+            logging.error("Exception when loading K0SWE dxcc.json.", e, exc_info=True)
+            return False
+
+

staticdataproviders/local_file_static_data_provider.py

@@ -0,0 +1,36 @@
+import logging
+from datetime import datetime
+
+import pytz
+
+from staticdataproviders.static_data_provider import StaticDataProvider
+
+
+class LocalFileStaticDataProvider(StaticDataProvider):
+    """Generic static reference data provider class for providers that fetch their data from a local file on startup."""
+
+    def __init__(self, name, provider_config, path):
+        super().__init__(name, provider_config)
+        self._path = path
+
+    def start(self):
+        logging.debug("Loading " + self.name + " static reference data from file.")
+        try:
+            ok = self._load_data(self._path)
+            if ok:
+                self.status = "OK"
+                self.last_update_time = datetime.now(pytz.UTC)
+            else:
+                self.status = "Error"
+                logging.info("Failed to load data for " + self.name)
+        except Exception as e:
+            self.status = "Error"
+            logging.error("Exception in local file Static Data Provider (" + self.name + ")", e, exc_info=True)
+
+    def stop(self):
+        pass
+
+    def _load_data(self, path):
+        """Load data from the given file path. Return true if successful, false otherwise."""
+
+        raise NotImplementedError("Subclasses must implement this method")

staticdataproviders/static_data_provider.py

@@ -0,0 +1,31 @@
+import logging
+from datetime import datetime
+
+import pytz
+
+from core.data_store import DATA_STORE
+
+
+class StaticDataProvider:
+    """Generic static reference data provider class. Subclasses of this query the individual URLs or files for data."""
+
+    def __init__(self, name, provider_config):
+        """Constructor"""
+
+        self.name = name
+        self.enabled = provider_config["enabled"]
+        self.last_update_time = datetime.min.replace(tzinfo=pytz.UTC)
+        self.status = "Not Started" if self.enabled else "Disabled"
+        self.reference_count = 0
+
+
+    def start(self):
+        """Start the provider. This should return immediately after spawning threads to access the remote resources"""
+
+        raise NotImplementedError("Subclasses must implement this method")
+
+
+    def stop(self):
+        """Stop any threads and prepare for application shutdown"""
+
+        raise NotImplementedError("Subclasses must implement this method")