Add pylint to depot_tools.

third_party/logilab/common/tasksqueue.py

+# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of logilab-common.
+#
+# logilab-common is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option) any
+# later version.
+#
+# logilab-common is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with logilab-common.  If not, see <http://www.gnu.org/licenses/>.
+"""Prioritized tasks queue"""
+
+__docformat__ = "restructuredtext en"
+
+from bisect import insort_left
+from Queue import Queue
+
+LOW = 0
+MEDIUM = 10
+HIGH = 100
+
+PRIORITY = {
+    'LOW': LOW,
+    'MEDIUM': MEDIUM,
+    'HIGH': HIGH,
+    }
+REVERSE_PRIORITY = dict((values, key) for key, values in PRIORITY.iteritems())
+
+
+
+class PrioritizedTasksQueue(Queue):
+
+    def _init(self, maxsize):
+        """Initialize the queue representation"""
+        self.maxsize = maxsize
+        # ordered list of task, from the lowest to the highest priority
+        self.queue = []
+
+    def _put(self, item):
+        """Put a new item in the queue"""
+        for i, task in enumerate(self.queue):
+            # equivalent task
+            if task == item:
+                # if new task has a higher priority, remove the one already
+                # queued so the new priority will be considered
+                if task < item:
+                    item.merge(task)
+                    del self.queue[i]
+                    break
+                # else keep it so current order is kept
+                task.merge(item)
+                return
+        insort_left(self.queue, item)
+
+    def _get(self):
+        """Get an item from the queue"""
+        return self.queue.pop()
+
+    def __iter__(self):
+        return iter(self.queue)
+
+    def remove(self, tid):
+        """remove a specific task from the queue"""
+        # XXX acquire lock
+        for i, task in enumerate(self):
+            if task.id == tid:
+                self.queue.pop(i)
+                return
+        raise ValueError('not task of id %s in queue' % tid)
+
+class Task(object):
+    def __init__(self, tid, priority=LOW):
+        # task id
+        self.id = tid
+        # task priority
+        self.priority = priority
+
+    def __repr__(self):
+        return '<Task %s @%#x>' % (self.id, id(self))
+
+    def __cmp__(self, other):
+        return cmp(self.priority, other.priority)
+
+    def __lt__(self, other):
+        return self.priority < other.priority
+
+    def __eq__(self, other):
+        return self.id == other.id
+
+    def merge(self, other):
+        pass