fix(python): remove unmaintained ratelimiter dependency (#1603)

The `ratelimiter` package hasn't been updated in ages and is no longer
maintained. This PR removes the dependency on `ratelimiter` and replaces
it with a custom rate limiter implementation.

---------

Co-authored-by: Will Jones <willjones127@gmail.com>

python/python/lancedb/embeddings/utils.py

@@ -16,6 +16,7 @@ import math
 import random
 import socket
 import sys
+import threading
 import time
 import urllib.error
 import weakref
@@ -38,6 +39,42 @@ IMAGES = Union[
 AUDIO = Union[str, bytes, List[str], List[bytes], pa.Array, pa.ChunkedArray, np.ndarray]
 
 
+class RateLimiter:
+    def __init__(self, max_calls: int = 1, period: float = 1.0):
+        self.period = period
+        self.max_calls = max(1, min(sys.maxsize, math.floor(max_calls)))
+
+        self._last_reset = time.time()
+        self._num_calls = 0
+        self._lock = threading.RLock()
+
+    def _check_sleep(self) -> float:
+        current_time = time.time()
+        elapsed = current_time - self._last_reset
+        period_remaining = self.period - elapsed
+
+        # If the time window has elapsed then reset.
+        if period_remaining <= 0:
+            self._num_calls = 0
+            self._last_reset = current_time
+
+        self._num_calls += 1
+
+        if self._num_calls > self.max_calls:
+            return period_remaining
+
+        return 0.0
+
+    def __call__(self, func):
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            with self._lock:
+                time.sleep(self._check_sleep())
+            return func(*args, **kwargs)
+
+        return wrapper
+
+
 @deprecated
 def with_embeddings(
     func: Callable,
@@ -109,21 +146,12 @@ class FunctionWrapper:
             def embed_func(c):
                 return self.func(c.tolist())
 
-        if len(self.rate_limiter_kwargs) > 0:
-            v = int(sys.version_info.minor)
-            if v >= 11:
-                print(
-                    "WARNING: rate limit only support up to 3.10, proceeding "
-                    "without rate limiter"
-                )
-            else:
-                import ratelimiter
-
-                max_calls = self.rate_limiter_kwargs["max_calls"]
-                limiter = ratelimiter.RateLimiter(
-                    max_calls, period=self.rate_limiter_kwargs["period"]
-                )
-                embed_func = limiter(embed_func)
+        if self.rate_limiter_kwargs:
+            limiter = RateLimiter(
+                max_calls=self.rate_limiter_kwargs["max_calls"],
+                period=self.rate_limiter_kwargs["period"],
+            )
+            embed_func = limiter(embed_func)
         batches = self.to_batches(text)
         embeds = [emb for c in batches for emb in embed_func(c)]
         return embeds

python/python/tests/test_embeddings.py

@@ -10,7 +10,6 @@
 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
-import sys
 from typing import List, Union
 
 import lance
@@ -35,9 +34,6 @@ def mock_embed_func(input_data):
 
 def test_with_embeddings():
     for wrap_api in [True, False]:
-        if wrap_api and sys.version_info.minor >= 11:
-            # ratelimiter package doesn't work on 3.11
-            continue
         data = pa.Table.from_arrays(
             [
                 pa.array(["foo", "bar"]),