Rate limiting added to core client (#315)

* Rate limiting added to core client

* Ratelimit added to reqs

requirements.txt

@@ -5,3 +5,4 @@ maggma==0.29.4
 requests==2.25.1
 monty==2021.6.10
 emmet-core==0.4.1
+ratelimit==2.2.1

setup.py

@@ -31,6 +31,7 @@
         "monty",
         "emmet-core",
         "maggma",
+        "ratelimit",
     ],
     extras_require={
         "server": [

src/mp_api/core/client.py

@@ -23,6 +23,8 @@
 from emmet.core.utils import jsanitize
 from maggma.api.utils import api_sanitize
 
+from mp_api.core.ratelimit import check_limit
+
 try:
     from pymatgen.core import __version__ as pmg_version  # type: ignore
 except ImportError:  # pragma: no cover
@@ -148,6 +150,8 @@ def _post_resource(
             available.
         """
 
+        check_limit()
+
         payload = jsanitize(body)
 
         try:
@@ -223,6 +227,8 @@ def _query_resource(
             available.
         """
 
+        check_limit()
+
         if criteria:
             criteria = {k: v for k, v in criteria.items() if v is not None}
         else:

src/mp_api/core/ratelimit.py

@@ -0,0 +1,11 @@
+from ratelimit import sleep_and_retry, limits
+from mp_api.core.settings import MAPISettings
+
+
+@sleep_and_retry
+@limits(calls=MAPISettings().requests_per_min, period=60)
+def check_limit():
+    """
+    Empty function for enabling global rate limiting.
+    """
+    return

src/mp_api/core/settings.py

@@ -22,5 +22,9 @@ class MAPISettings(BaseSettings):
 
     db_version: str = Field("2021_04_26", description="Database version")
 
+    requests_per_min: int = Field(
+        60, description="Number of requests per minute to for rate limit."
+    )
+
     class Config:
         env_prefix = "mapi_"