1 files changed, 79 insertions, 0 deletions
diff --git a/kafka/future.py b/kafka/future.py
new file mode 100644
index 0000000..06b8c3a
--- /dev/null
+++ b/kafka/future.py
@@ -0,0 +1,79 @@
+import functools
+import logging
+
+import kafka.common as Errors
+
+log = logging.getLogger(__name__)
+
+
+class Future(object):
+    def __init__(self):
+        self.is_done = False
+        self.value = None
+        self.exception = None
+        self._callbacks = []
+        self._errbacks = []
+
+    def succeeded(self):
+        return self.is_done and not self.exception
+
+    def failed(self):
+        return self.is_done and self.exception
+
+    def retriable(self):
+        try:
+            return self.exception.retriable
+        except AttributeError:
+            return False
+
+    def success(self, value):
+        assert not self.is_done, 'Future is already complete'
+        self.value = value
+        self.is_done = True
+        for f in self._callbacks:
+            try:
+                f(value)
+            except Exception:
+                log.exception('Error processing callback')
+        return self
+
+    def failure(self, e):
+        assert not self.is_done, 'Future is already complete'
+        self.exception = e if type(e) is not type else e()
+        assert isinstance(self.exception, BaseException), (
+            'future failed without an exception')
+        self.is_done = True
+        for f in self._errbacks:
+            try:
+                f(self.exception)
+            except Exception:
+                log.exception('Error processing errback')
+        return self
+
+    def add_callback(self, f, *args, **kwargs):
+        if args or kwargs:
+            f = functools.partial(f, *args, **kwargs)
+        if self.is_done and not self.exception:
+            f(self.value)
+        else:
+            self._callbacks.append(f)
+        return self
+
+    def add_errback(self, f, *args, **kwargs):
+        if args or kwargs:
+            f = functools.partial(f, *args, **kwargs)
+        if self.is_done and self.exception:
+            f(self.exception)
+        else:
+            self._errbacks.append(f)
+        return self
+
+    def add_both(self, f, *args, **kwargs):
+        self.add_callback(f, *args, **kwargs)
+        self.add_errback(f, *args, **kwargs)
+        return self
+
+    def chain(self, future):
+        self.add_callback(future.success)
+        self.add_errback(future.failure)
+        return self