Replace custom blob gRPC API with ByteStream

client/third_party/cachetools/keys.py

Index: client/third_party/cachetools/keys.py
diff --git a/client/third_party/cachetools/keys.py b/client/third_party/cachetools/keys.py
new file mode 100644
index 0000000000000000000000000000000000000000..ba1e2fc2bee6d9b06096513d3bea6ec00d82bcc1
--- /dev/null
+++ b/client/third_party/cachetools/keys.py
@@ -0,0 +1,42 @@
+"""Key functions for memoizing decorators."""
+
+from __future__ import absolute_import
+
+__all__ = ('hashkey', 'typedkey')
+
+
+class _HashedTuple(tuple):
+
+    __hashvalue = None
+
+    def __hash__(self, hash=tuple.__hash__):
+        hashvalue = self.__hashvalue
+        if hashvalue is None:
+            self.__hashvalue = hashvalue = hash(self)
+        return hashvalue
+
+    def __add__(self, other, add=tuple.__add__):
+        return _HashedTuple(add(self, other))
+
+    def __radd__(self, other, add=tuple.__add__):
+        return _HashedTuple(add(other, self))
+
+_kwmark = (object(),)
+
+
+def hashkey(*args, **kwargs):
+    """Return a cache key for the specified hashable arguments."""
+
+    if kwargs:
+        return _HashedTuple(args + sum(sorted(kwargs.items()), _kwmark))
+    else:
+        return _HashedTuple(args)
+
+
+def typedkey(*args, **kwargs):
+    """Return a typed cache key for the specified hashable arguments."""
+
+    key = hashkey(*args, **kwargs)
+    key += tuple(type(v) for v in args)
+    key += tuple(type(v) for _, v in sorted(kwargs.items()))
+    return key