api_client: add scroll_events method

Author: aviau

flareio/_ratelimit.py

@@ -0,0 +1,39 @@
+import time
+
+from datetime import datetime
+from datetime import timedelta
+
+import typing as t
+
+
+class Limiter:
+    def __init__(
+        self,
+        *,
+        tick_interval: timedelta,
+        _sleeper: t.Callable[[float], None] = time.sleep,
+    ) -> None:
+        self._tick_interval: timedelta = tick_interval
+        self._next_tick: datetime = datetime.now()
+        self._sleeper: t.Callable[[float], None] = _sleeper
+        self._slept_for: float = 0.0
+
+    def _push_next_tick(self) -> None:
+        self._next_tick = datetime.now() + self._tick_interval
+
+    @staticmethod
+    def _seconds_until(t: datetime) -> float:
+        td: timedelta = t - datetime.now()
+        return max(td.total_seconds(), 0.0)
+
+    def _sleep(self, seconds: float) -> None:
+        self._sleeper(seconds)
+        self._slept_for += seconds
+
+    def tick(self) -> None:
+        """
+        You should call this method before making a request.
+        The first time will be instantaneous.
+        """
+        self._sleep(self._seconds_until(self._next_tick))
+        self._push_next_tick()

flareio/api_client.py

@@ -11,6 +11,7 @@
 
 import typing as t
 
+from flareio._ratelimit import Limiter
 from flareio.exceptions import TokenError
 from flareio.version import __version__ as _flareio_version
 
@@ -263,3 +264,57 @@ def scroll(
                 params["from"] = next_page
             if json and from_in_json:
                 json["from"] = next_page
+
+    def scroll_events(
+        self,
+        *,
+        method: t.Literal[
+            "GET",
+            "POST",
+        ],
+        pages_url: str,
+        events_url: str,
+        params: t.Optional[t.Dict[str, t.Any]] = None,
+        json: t.Optional[t.Dict[str, t.Any]] = None,
+        _pages_limiter: t.Optional[Limiter] = None,
+        _events_limiter: t.Optional[Limiter] = None,
+    ) -> t.Iterator[
+        t.Tuple[
+            dict,
+            t.Optional[str],
+        ],
+    ]:
+        pages_limiter: Limiter = _pages_limiter or Limiter(
+            tick_interval=timedelta(seconds=1),
+        )
+        events_limiter: Limiter = _events_limiter or Limiter(
+            tick_interval=timedelta(seconds=0.25),
+        )
+
+        pages_limiter.tick()
+        for page_resp in self.scroll(
+            method=method,
+            url=pages_url,
+            params=params,
+            json=json,
+        ):
+            page_resp.raise_for_status()
+            page_items: t.List[dict] = page_resp.json()["items"]
+            page_next: t.Optional[str] = page_resp.json()["next"]
+
+            for page_item in page_items:
+                event_uid: str = page_item["metadata"]["uid"]
+
+                events_limiter.tick()
+                event_resp: requests.Response = self.get(
+                    url=events_url,
+                    params={
+                        "uid": event_uid,
+                    },
+                )
+                event_resp.raise_for_status()
+                event: dict = event_resp.json()
+
+                yield event, page_next
+
+            pages_limiter.tick()

tests/test_api_client_scroll_events.py

@@ -0,0 +1,68 @@
+import pytest
+import requests_mock
+
+from .utils import get_test_client
+from datetime import timedelta
+
+from flareio._ratelimit import Limiter
+
+
+def test_scroll_events() -> None:
+    api_client = get_test_client()
+
+    no_limit: Limiter = Limiter(
+        tick_interval=timedelta(seconds=0),
+    )
+
+    # This should make no http call.
+    with requests_mock.Mocker() as mocker:
+        events_iterator = api_client.scroll_events(
+            method="GET",
+            pages_url="https://api.flare.io/pages",
+            events_url="https://api.flare.io/events",
+            params={
+                "from": None,
+            },
+            _pages_limiter=no_limit,
+            _events_limiter=no_limit,
+        )
+        assert len(mocker.request_history) == 0
+
+    # First page
+    with requests_mock.Mocker() as mocker:
+        mocker.register_uri(
+            "GET",
+            "https://api.flare.io/pages",
+            json={
+                "items": [
+                    {"metadata": {"uid": "first_event_uid"}},
+                ],
+                "next": "second_page",
+            },
+            status_code=200,
+        )
+        mocker.register_uri(
+            "GET",
+            "https://api.flare.io/events",
+            json={"event": "hello"},
+            status_code=200,
+        )
+
+        item, cursor = next(events_iterator)
+        assert len(mocker.request_history) == 2
+        assert item == {"event": "hello"}
+        assert cursor == "second_page"
+
+    # Last page
+    with requests_mock.Mocker() as mocker:
+        mocker.register_uri(
+            "GET",
+            "https://api.flare.io/pages",
+            json={
+                "items": [],
+                "next": None,
+            },
+        )
+        with pytest.raises(StopIteration):
+            next(events_iterator)
+        assert len(mocker.request_history) == 1

tests/test_ratelimit.py

@@ -0,0 +1,37 @@
+from datetime import datetime
+from datetime import timedelta
+
+from flareio._ratelimit import Limiter
+
+
+def test_limiter() -> None:
+    # Setup limiter
+    limiter: Limiter = Limiter(
+        tick_interval=timedelta(seconds=35),
+        _sleeper=lambda _: None,
+    )
+
+    # The first tick is instantaneous. This is so that the limiter
+    # never sleeps if the requests are taking longer than the interval.
+    t_1: datetime = limiter._next_tick
+    limiter.tick()
+    t_2: datetime = limiter._next_tick
+    assert limiter._slept_for == 0
+    assert t_2 > t_1
+
+    # Second tick is delayed.
+    limiter.tick()
+    t_3: datetime = limiter._next_tick
+    assert t_3 > t_2
+    assert limiter._slept_for > 30  # Intentionally not exact to avoid test races.
+
+
+def test_seconds_until() -> None:
+    future: datetime = datetime.now() + timedelta(seconds=10)
+    assert Limiter._seconds_until(future) > 5
+
+
+def test_seconds_until_negative() -> None:
+    now: datetime = datetime.now()
+    past = now - timedelta(seconds=10)
+    assert Limiter._seconds_until(past) == 0.0