Added minimal version of watchdog

Sublime/fl0w/watchdog/utils/delayed_queue.py

@@ -0,0 +1,88 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2014 Thomas Amland <thomas.amland@gmail.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import time
+import threading
+from collections import deque
+
+
+class DelayedQueue(object):
+
+    def __init__(self, delay):
+        self.delay = delay
+        self._lock = threading.Lock()
+        self._not_empty = threading.Condition(self._lock)
+        self._queue = deque()
+        self._closed = False
+
+    def put(self, element):
+        """Add element to queue."""
+        self._lock.acquire()
+        self._queue.append((element, time.time()))
+        self._not_empty.notify()
+        self._lock.release()
+
+    def close(self):
+        """Close queue, indicating no more items will be added."""
+        self._closed = True
+        # Interrupt the blocking _not_empty.wait() call in get
+        self._not_empty.acquire()
+        self._not_empty.notify()
+        self._not_empty.release()
+
+    def get(self):
+        """Remove and return an element from the queue, or this queue has been
+        closed raise the Closed exception.
+        """
+        while True:
+            # wait for element to be added to queue
+            self._not_empty.acquire()
+            while len(self._queue) == 0 and not self._closed:
+                self._not_empty.wait()
+
+            if self._closed:
+                self._not_empty.release()
+                return None
+            head, insert_time = self._queue[0]
+            self._not_empty.release()
+
+            # wait for delay
+            time_left = insert_time + self.delay - time.time()
+            while time_left > 0:
+                time.sleep(time_left)
+                time_left = insert_time + self.delay - time.time()
+
+            # return element if it's still in the queue
+            self._lock.acquire()
+            try:
+                if len(self._queue) > 0 and self._queue[0][0] is head:
+                    self._queue.popleft()
+                    return head
+            finally:
+                self._lock.release()
+
+    def remove(self, predicate):
+        """Remove and return the first items for which predicate is True,
+        ignoring delay."""
+        try:
+            self._lock.acquire()
+            for i, (elem, t) in enumerate(self._queue):
+                if predicate(elem):
+                    del self._queue[i]
+                    return elem
+        finally:
+            self._lock.release()
+        return None