Files
2025-04-24 11:44:23 +02:00

490 lines
18 KiB
Python

from __future__ import annotations
import datetime
import time
from abc import ABC, abstractmethod
from deprecated.sphinx import versionadded, versionchanged
from limits.typing import (
MongoClient,
MongoCollection,
MongoDatabase,
cast,
)
from ..util import get_dependency
from .base import MovingWindowSupport, SlidingWindowCounterSupport, Storage
class MongoDBStorageBase(
Storage, MovingWindowSupport, SlidingWindowCounterSupport, ABC
):
"""
Rate limit storage with MongoDB as backend.
Depends on :pypi:`pymongo`.
"""
DEPENDENCIES = ["pymongo"]
def __init__(
self,
uri: str,
database_name: str = "limits",
counter_collection_name: str = "counters",
window_collection_name: str = "windows",
wrap_exceptions: bool = False,
**options: int | str | bool,
) -> None:
"""
:param uri: uri of the form ``mongodb://[user:password]@host:port?...``,
This uri is passed directly to :class:`~pymongo.mongo_client.MongoClient`
:param database_name: The database to use for storing the rate limit
collections.
:param counter_collection_name: The collection name to use for individual counters
used in fixed window strategies
:param window_collection_name: The collection name to use for sliding & moving window
storage
:param wrap_exceptions: Whether to wrap storage exceptions in
:exc:`limits.errors.StorageError` before raising it.
:param options: all remaining keyword arguments are passed to the
constructor of :class:`~pymongo.mongo_client.MongoClient`
:raise ConfigurationError: when the :pypi:`pymongo` library is not available
"""
super().__init__(uri, wrap_exceptions=wrap_exceptions, **options)
self._database_name = database_name
self._collection_mapping = {
"counters": counter_collection_name,
"windows": window_collection_name,
}
self.lib = self.dependencies["pymongo"].module
self.lib_errors, _ = get_dependency("pymongo.errors")
self._storage_uri = uri
self._storage_options = options
self._storage: MongoClient | None = None
@property
def storage(self) -> MongoClient:
if self._storage is None:
self._storage = self._init_mongo_client(
self._storage_uri, **self._storage_options
)
self.__initialize_database()
return self._storage
@property
def _database(self) -> MongoDatabase:
return self.storage[self._database_name]
@property
def counters(self) -> MongoCollection:
return self._database[self._collection_mapping["counters"]]
@property
def windows(self) -> MongoCollection:
return self._database[self._collection_mapping["windows"]]
@abstractmethod
def _init_mongo_client(
self, uri: str | None, **options: int | str | bool
) -> MongoClient:
raise NotImplementedError()
@property
def base_exceptions(
self,
) -> type[Exception] | tuple[type[Exception], ...]: # pragma: no cover
return self.lib_errors.PyMongoError # type: ignore
def __initialize_database(self) -> None:
self.counters.create_index("expireAt", expireAfterSeconds=0)
self.windows.create_index("expireAt", expireAfterSeconds=0)
def reset(self) -> int | None:
"""
Delete all rate limit keys in the rate limit collections (counters, windows)
"""
num_keys = self.counters.count_documents({}) + self.windows.count_documents({})
self.counters.drop()
self.windows.drop()
return int(num_keys)
def clear(self, key: str) -> None:
"""
:param key: the key to clear rate limits for
"""
self.counters.find_one_and_delete({"_id": key})
self.windows.find_one_and_delete({"_id": key})
def get_expiry(self, key: str) -> float:
"""
:param key: the key to get the expiry for
"""
counter = self.counters.find_one({"_id": key})
return (
(counter["expireAt"] if counter else datetime.datetime.now())
.replace(tzinfo=datetime.timezone.utc)
.timestamp()
)
def get(self, key: str) -> int:
"""
:param key: the key to get the counter value for
"""
counter = self.counters.find_one(
{
"_id": key,
"expireAt": {"$gte": datetime.datetime.now(datetime.timezone.utc)},
},
projection=["count"],
)
return counter and counter["count"] or 0
def incr(self, key: str, expiry: int, amount: int = 1) -> int:
"""
increments the counter for a given rate limit key
:param key: the key to increment
:param expiry: amount in seconds for the key to expire in
:param amount: the number to increment by
"""
expiration = datetime.datetime.now(datetime.timezone.utc) + datetime.timedelta(
seconds=expiry
)
return int(
self.counters.find_one_and_update(
{"_id": key},
[
{
"$set": {
"count": {
"$cond": {
"if": {"$lt": ["$expireAt", "$$NOW"]},
"then": amount,
"else": {"$add": ["$count", amount]},
}
},
"expireAt": {
"$cond": {
"if": {"$lt": ["$expireAt", "$$NOW"]},
"then": expiration,
"else": "$expireAt",
}
},
}
},
],
upsert=True,
projection=["count"],
return_document=self.lib.ReturnDocument.AFTER,
)["count"]
)
def check(self) -> bool:
"""
Check if storage is healthy by calling :meth:`pymongo.mongo_client.MongoClient.server_info`
"""
try:
self.storage.server_info()
return True
except: # noqa: E722
return False
def get_moving_window(self, key: str, limit: int, expiry: int) -> tuple[float, int]:
"""
returns the starting point and the number of entries in the moving
window
:param key: rate limit key
:param expiry: expiry of entry
:return: (start of window, number of acquired entries)
"""
timestamp = time.time()
if result := list(
self.windows.aggregate(
[
{"$match": {"_id": key}},
{
"$project": {
"filteredEntries": {
"$filter": {
"input": "$entries",
"as": "entry",
"cond": {"$gte": ["$$entry", timestamp - expiry]},
}
}
}
},
{
"$project": {
"min": {"$min": "$filteredEntries"},
"count": {"$size": "$filteredEntries"},
}
},
]
)
):
return result[0]["min"], result[0]["count"]
return timestamp, 0
def acquire_entry(self, key: str, limit: int, expiry: int, amount: int = 1) -> bool:
"""
:param key: rate limit key to acquire an entry in
:param limit: amount of entries allowed
:param expiry: expiry of the entry
:param amount: the number of entries to acquire
"""
if amount > limit:
return False
timestamp = time.time()
try:
updates: dict[
str,
dict[str, datetime.datetime | dict[str, list[float] | int]],
] = {
"$push": {
"entries": {
"$each": [timestamp] * amount,
"$position": 0,
"$slice": limit,
}
},
"$set": {
"expireAt": (
datetime.datetime.now(datetime.timezone.utc)
+ datetime.timedelta(seconds=expiry)
)
},
}
self.windows.update_one(
{
"_id": key,
f"entries.{limit - amount}": {"$not": {"$gte": timestamp - expiry}},
},
updates,
upsert=True,
)
return True
except self.lib.errors.DuplicateKeyError:
return False
def get_sliding_window(
self, key: str, expiry: int
) -> tuple[int, float, int, float]:
expiry_ms = expiry * 1000
if result := self.windows.find_one_and_update(
{"_id": key},
[
{
"$set": {
"previousCount": {
"$cond": {
"if": {
"$lte": [
{"$subtract": ["$expireAt", "$$NOW"]},
expiry_ms,
]
},
"then": {"$ifNull": ["$currentCount", 0]},
"else": {"$ifNull": ["$previousCount", 0]},
}
},
"currentCount": {
"$cond": {
"if": {
"$lte": [
{"$subtract": ["$expireAt", "$$NOW"]},
expiry_ms,
]
},
"then": 0,
"else": {"$ifNull": ["$currentCount", 0]},
}
},
"expireAt": {
"$cond": {
"if": {
"$lte": [
{"$subtract": ["$expireAt", "$$NOW"]},
expiry_ms,
]
},
"then": {
"$add": ["$expireAt", expiry_ms],
},
"else": "$expireAt",
}
},
}
}
],
return_document=self.lib.ReturnDocument.AFTER,
projection=["currentCount", "previousCount", "expireAt"],
):
expires_at = (
(result["expireAt"].replace(tzinfo=datetime.timezone.utc).timestamp())
if result.get("expireAt")
else time.time()
)
current_ttl = max(0, expires_at - time.time())
prev_ttl = max(0, current_ttl - expiry if result["previousCount"] else 0)
return (
result["previousCount"],
prev_ttl,
result["currentCount"],
current_ttl,
)
return 0, 0.0, 0, 0.0
def acquire_sliding_window_entry(
self, key: str, limit: int, expiry: int, amount: int = 1
) -> bool:
expiry_ms = expiry * 1000
result = self.windows.find_one_and_update(
{"_id": key},
[
{
"$set": {
"previousCount": {
"$cond": {
"if": {
"$lte": [
{"$subtract": ["$expireAt", "$$NOW"]},
expiry_ms,
]
},
"then": {"$ifNull": ["$currentCount", 0]},
"else": {"$ifNull": ["$previousCount", 0]},
}
},
}
},
{
"$set": {
"currentCount": {
"$cond": {
"if": {
"$lte": [
{"$subtract": ["$expireAt", "$$NOW"]},
expiry_ms,
]
},
"then": 0,
"else": {"$ifNull": ["$currentCount", 0]},
}
},
"expireAt": {
"$cond": {
"if": {
"$lte": [
{"$subtract": ["$expireAt", "$$NOW"]},
expiry_ms,
]
},
"then": {
"$cond": {
"if": {"$gt": ["$expireAt", 0]},
"then": {"$add": ["$expireAt", expiry_ms]},
"else": {"$add": ["$$NOW", 2 * expiry_ms]},
}
},
"else": "$expireAt",
}
},
}
},
{
"$set": {
"curWeightedCount": {
"$floor": {
"$add": [
{
"$multiply": [
"$previousCount",
{
"$divide": [
{
"$max": [
0,
{
"$subtract": [
"$expireAt",
{
"$add": [
"$$NOW",
expiry_ms,
]
},
]
},
]
},
expiry_ms,
]
},
]
},
"$currentCount",
]
}
}
}
},
{
"$set": {
"currentCount": {
"$cond": {
"if": {
"$lte": [
{"$add": ["$curWeightedCount", amount]},
limit,
]
},
"then": {"$add": ["$currentCount", amount]},
"else": "$currentCount",
}
}
}
},
{
"$set": {
"_acquired": {
"$lte": [{"$add": ["$curWeightedCount", amount]}, limit]
}
}
},
{"$unset": ["curWeightedCount"]},
],
return_document=self.lib.ReturnDocument.AFTER,
upsert=True,
)
return cast(bool, result["_acquired"])
def __del__(self) -> None:
if self.storage:
self.storage.close()
@versionadded(version="2.1")
@versionchanged(
version="3.14.0",
reason="Added option to select custom collection names for windows & counters",
)
class MongoDBStorage(MongoDBStorageBase):
STORAGE_SCHEME = ["mongodb", "mongodb+srv"]
def _init_mongo_client(
self, uri: str | None, **options: int | str | bool
) -> MongoClient:
return cast(MongoClient, self.lib.MongoClient(uri, **options))