feat: better rate limiting logic (#317)

* feat: better rate-limiting logic

* fix: if -> while

* feat: better rate-limiting logic

* fix: suppress StopIteration warning

* chore: round log msg to 3 decimals

* chore: `black .`

* chore: suppress spammy logs

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: BobTheBuidler

dank_mids/brownie_patch/call.py

@@ -64,7 +64,7 @@
     *args: The arguments to be encoded.
 """
 
-# We do this so ypricemagic's checksum cache monkey patch will work,
+# We assign this variable so ypricemagic's checksum cache monkey patch will work,
 # This is only relevant to you if your project uses ypricemagic as well.
 to_checksum_address = Address.checksum
 

dank_mids/helpers/_session.py

@@ -5,6 +5,7 @@
 from itertools import chain
 from random import random
 from threading import get_ident
+from time import time
 from typing import Any, Callable, List, Optional, overload
 
 import msgspec
@@ -123,8 +124,18 @@ async def get_session() -> "DankClientSession":
     return await _get_session_for_thread(get_ident())
 
 
+_RETRY_AFTER = 1.0
+
+
 class DankClientSession(ClientSession):
-    async def post(self, endpoint: str, *args, loads: JSONDecoder = DEFAULT_JSON_DECODER, _retry_after: float = 1, **kwargs) -> bytes:  # type: ignore [override]
+    _limited = False
+    _last_rate_limited_at = 0
+    _continue_requests_at = 0
+
+    async def post(self, endpoint: str, *args, loads: JSONDecoder = DEFAULT_JSON_DECODER, **kwargs) -> bytes:  # type: ignore [override]
+        if (now := time()) < self._continue_requests_at:
+            await asyncio.sleep(self._continue_requests_at - now)
+
         # Process input arguments.
         if isinstance(kwargs.get("data"), PartialRequest):
             logger.debug("making request for %s", kwargs["data"])
@@ -142,40 +153,56 @@ async def post(self, endpoint: str, *args, loads: JSONDecoder = DEFAULT_JSON_DEC
                         return response_data
             except ClientResponseError as ce:
                 if ce.status == HTTPStatusExtended.TOO_MANY_REQUESTS:  # type: ignore [attr-defined]
-                    try_after = float(ce.headers.get("Retry-After", _retry_after * 1.5))  # type: ignore [union-attr]
-                    if self not in _limited:
-                        _limited.append(self)
-                        logger.info("You're being rate limited by your node provider")
-                        logger.info(
-                            "Its all good, dank_mids has this handled, but you might get results slower than you'd like"
-                        )
-                    logger.info(f"rate limited: retrying after {try_after}s")
-                    await asyncio.sleep(try_after)
-                    if try_after > 30:
-                        logger.warning("severe rate limiting from your provider")
-                    return await self.post(
-                        endpoint, *args, loads=loads, _retry_after=try_after, **kwargs
+                    await self.handle_too_many_requests(ce)
+                else:
+                    try:
+                        if ce.status not in RETRY_FOR_CODES or tried >= 5:
+                            logger.debug(
+                                "response failed with status %s", HTTPStatusExtended(ce.status)
+                            )
+                            raise ce
+                    except ValueError as ve:
+                        raise (
+                            ce if str(ve).endswith("is not a valid HTTPStatusExtended") else ve
+                        ) from ve
+
+                    sleep = random()
+                    await asyncio.sleep(sleep)
+                    logger.debug(
+                        "response failed with status %s, retrying in %ss",
+                        HTTPStatusExtended(ce.status),
+                        round(sleep, 2),
                     )
-
-                try:
-                    if ce.status not in RETRY_FOR_CODES or tried >= 5:
-                        logger.debug(
-                            "response failed with status %s", HTTPStatusExtended(ce.status)
-                        )
-                        raise ce
-                except ValueError as ve:
-                    raise (
-                        ce if str(ve).endswith("is not a valid HTTPStatusExtended") else ve
-                    ) from ve
-
-                sleep = random()
-                await asyncio.sleep(sleep)
-                logger.debug(
-                    "response failed with status %s, retrying in %ss",
-                    HTTPStatusExtended(ce.status),
-                    round(sleep, 2),
-                )
-                tried += 1
+                    tried += 1
+
+    async def handle_too_many_requests(self, error: ClientResponseError) -> None:
+        now = time()
+        self._last_rate_limited_at = now
+        retry_after = float(error.headers.get("Retry-After", _RETRY_AFTER))
+        resume_at = max(
+            self._continue_requests_at + retry_after,
+            self._last_rate_limited_at + retry_after,
+        )
+        retry_after = resume_at - now
+        self._continue_requests_at = resume_at
+
+        self._log_rate_limited(retry_after)
+        await asyncio.sleep(retry_after)
+
+        if retry_after > 30:
+            logger.warning("severe rate limiting from your provider")
+
+    def _log_rate_limited(self, try_after: float) -> None:
+        if not self._limited:
+            self._limited = True
+            logger.info("You're being rate limited by your node provider")
+            logger.info(
+                "Its all good, dank_mids has this handled, but you might get results slower than you'd like"
+            )
+        if try_after < 5:
+            logger.debug("rate limited: retrying after %.3fs", try_after)
+        else:
+            logger.info("rate limited: retrying after %.3fs", try_after)
 
 
 @alru_cache(maxsize=None)
@@ -191,6 +218,3 @@ async def _get_session_for_thread(thread_ident: int) -> DankClientSession:
         raise_for_status=True,
         read_bufsize=2**20,  # 1mb
     )
-
-
-_limited: List[DankClientSession] = []