init

2026-02-12 23:22:11 +08:00
parent 7b09eb3d89
commit 89660bba4e
5988 changed files with 2517516 additions and 0 deletions
@@ -0,0 +1,94 @@
+from __future__ import absolute_import
+
+import functools
+import logging
+import threading
+
+log = logging.getLogger(__name__)
+
+
+class Future(object):
+    error_on_callbacks = False # and errbacks
+
+    def __init__(self):
+        self.is_done = False
+        self.value = None
+        self.exception = None
+        self._callbacks = []
+        self._errbacks = []
+        self._lock = threading.Lock()
+
+    def succeeded(self):
+        return self.is_done and not bool(self.exception)
+
+    def failed(self):
+        return self.is_done and bool(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'
+        with self._lock:
+            self.value = value
+            self.is_done = True
+        if self._callbacks:
+            self._call_backs('callback', self._callbacks, self.value)
+        return self
+
+    def failure(self, e):
+        assert not self.is_done, 'Future is already complete'
+        exception = e if type(e) is not type else e()
+        assert isinstance(exception, BaseException), (
+            'future failed without an exception')
+        with self._lock:
+            self.exception = exception
+            self.is_done = True
+        self._call_backs('errback', self._errbacks, self.exception)
+        return self
+
+    def add_callback(self, f, *args, **kwargs):
+        if args or kwargs:
+            f = functools.partial(f, *args, **kwargs)
+        with self._lock:
+            if not self.is_done:
+                self._callbacks.append(f)
+            elif self.succeeded():
+                self._lock.release()
+                self._call_backs('callback', [f], self.value)
+                self._lock.acquire()
+        return self
+
+    def add_errback(self, f, *args, **kwargs):
+        if args or kwargs:
+            f = functools.partial(f, *args, **kwargs)
+        with self._lock:
+            if not self.is_done:
+                self._errbacks.append(f)
+            elif self.failed():
+                self._lock.release()
+                self._call_backs('errback', [f], self.exception)
+                self._lock.acquire()
+        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
+
+    def _call_backs(self, back_type, backs, value):
+        for f in backs:
+            try:
+                f(value)
+            except Exception as e:
+                log.exception('Error processing %s', back_type)
+                if self.error_on_callbacks:
+                    raise e