Updates

ETB-API/venv/lib/python3.12/site-packages/django_redis/client/herd.py

@@ -0,0 +1,169 @@
+import random
+import socket
+import time
+from collections import OrderedDict
+
+from django.conf import settings
+from redis.exceptions import ConnectionError as RedisConnectionError
+from redis.exceptions import ResponseError
+from redis.exceptions import TimeoutError as RedisTimeoutError
+
+from django_redis.client.default import DEFAULT_TIMEOUT, DefaultClient
+from django_redis.exceptions import ConnectionInterrupted
+
+_main_exceptions = (
+    RedisConnectionError,
+    RedisTimeoutError,
+    ResponseError,
+    socket.timeout,
+)
+
+
+class Marker:
+    """
+    Dummy class for use as
+    marker for herded keys.
+    """
+
+    pass
+
+
+def _is_expired(x, herd_timeout: int) -> bool:
+    if x >= herd_timeout:
+        return True
+    val = x + random.randint(1, herd_timeout)
+
+    return val >= herd_timeout
+
+
+class HerdClient(DefaultClient):
+    def __init__(self, *args, **kwargs):
+        self._marker = Marker()
+        self._herd_timeout = getattr(settings, "CACHE_HERD_TIMEOUT", 60)
+        super().__init__(*args, **kwargs)
+
+    def _pack(self, value, timeout):
+        herd_timeout = (timeout or self._backend.default_timeout) + int(time.time())
+        return self._marker, value, herd_timeout
+
+    def _unpack(self, value):
+        try:
+            marker, unpacked, herd_timeout = value
+        except (ValueError, TypeError):
+            return value, False
+
+        if not isinstance(marker, Marker):
+            return value, False
+
+        now = int(time.time())
+        if herd_timeout < now:
+            x = now - herd_timeout
+            return unpacked, _is_expired(x, self._herd_timeout)
+
+        return unpacked, False
+
+    def set(
+        self,
+        key,
+        value,
+        timeout=DEFAULT_TIMEOUT,
+        version=None,
+        client=None,
+        nx=False,
+        xx=False,
+    ):
+        if timeout is DEFAULT_TIMEOUT:
+            timeout = self._backend.default_timeout
+
+        if timeout is None or timeout <= 0:
+            return super().set(
+                key,
+                value,
+                timeout=timeout,
+                version=version,
+                client=client,
+                nx=nx,
+                xx=xx,
+            )
+
+        packed = self._pack(value, timeout)
+        real_timeout = timeout + self._herd_timeout
+
+        return super().set(
+            key, packed, timeout=real_timeout, version=version, client=client, nx=nx
+        )
+
+    def get(self, key, default=None, version=None, client=None):
+        packed = super().get(key, default=default, version=version, client=client)
+        val, refresh = self._unpack(packed)
+
+        if refresh:
+            return default
+
+        return val
+
+    def get_many(self, keys, version=None, client=None):
+        if client is None:
+            client = self.get_client(write=False)
+
+        if not keys:
+            return {}
+
+        recovered_data = OrderedDict()
+
+        new_keys = [self.make_key(key, version=version) for key in keys]
+        map_keys = dict(zip(new_keys, keys))
+
+        try:
+            results = client.mget(*new_keys)
+        except _main_exceptions as e:
+            raise ConnectionInterrupted(connection=client) from e
+
+        for key, value in zip(new_keys, results):
+            if value is None:
+                continue
+
+            val, refresh = self._unpack(self.decode(value))
+            recovered_data[map_keys[key]] = None if refresh else val
+
+        return recovered_data
+
+    def set_many(
+        self, data, timeout=DEFAULT_TIMEOUT, version=None, client=None, herd=True
+    ):
+        """
+        Set a bunch of values in the cache at once from a dict of key/value
+        pairs. This is much more efficient than calling set() multiple times.
+
+        If timeout is given, that timeout will be used for the key; otherwise
+        the default cache timeout will be used.
+        """
+        if client is None:
+            client = self.get_client(write=True)
+
+        set_function = self.set if herd else super().set
+
+        try:
+            pipeline = client.pipeline()
+            for key, value in data.items():
+                set_function(key, value, timeout, version=version, client=pipeline)
+            pipeline.execute()
+        except _main_exceptions as e:
+            raise ConnectionInterrupted(connection=client) from e
+
+    def incr(self, *args, **kwargs):
+        raise NotImplementedError
+
+    def decr(self, *args, **kwargs):
+        raise NotImplementedError
+
+    def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None, client=None):
+        if client is None:
+            client = self.get_client(write=True)
+
+        value = self.get(key, version=version, client=client)
+        if value is None:
+            return False
+
+        self.set(key, value, timeout=timeout, version=version, client=client)
+        return True