WebKitTools/Scripts/webkitpy/tool/bot/queueengine.py
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebKitTools/Scripts/webkitpy/tool/bot/queueengine.py	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,156 @@
+# Copyright (c) 2009 Google Inc. All rights reserved.
+# Copyright (c) 2009 Apple Inc. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+# 
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import os
+import time
+import traceback
+
+from datetime import datetime, timedelta
+
+from webkitpy.common.net.statusserver import StatusServer
+from webkitpy.common.system.executive import ScriptError
+from webkitpy.common.system.deprecated_logging import log, OutputTee
+
+
+class TerminateQueue(Exception):
+    pass
+
+
+class QueueEngineDelegate:
+    def queue_log_path(self):
+        raise NotImplementedError, "subclasses must implement"
+
+    def work_item_log_path(self, work_item):
+        raise NotImplementedError, "subclasses must implement"
+
+    def begin_work_queue(self):
+        raise NotImplementedError, "subclasses must implement"
+
+    def should_continue_work_queue(self):
+        raise NotImplementedError, "subclasses must implement"
+
+    def next_work_item(self):
+        raise NotImplementedError, "subclasses must implement"
+
+    def should_proceed_with_work_item(self, work_item):
+        # returns (safe_to_proceed, waiting_message, patch)
+        raise NotImplementedError, "subclasses must implement"
+
+    def process_work_item(self, work_item):
+        raise NotImplementedError, "subclasses must implement"
+
+    def handle_unexpected_error(self, work_item, message):
+        raise NotImplementedError, "subclasses must implement"
+
+
+class QueueEngine:
+    def __init__(self, name, delegate, wakeup_event):
+        self._name = name
+        self._delegate = delegate
+        self._wakeup_event = wakeup_event
+        self._output_tee = OutputTee()
+
+    log_date_format = "%Y-%m-%d %H:%M:%S"
+    sleep_duration_text = "2 mins"  # This could be generated from seconds_to_sleep
+    seconds_to_sleep = 120
+    handled_error_code = 2
+
+    # Child processes exit with a special code to the parent queue process can detect the error was handled.
+    @classmethod
+    def exit_after_handled_error(cls, error):
+        log(error)
+        exit(cls.handled_error_code)
+
+    def run(self):
+        self._begin_logging()
+
+        self._delegate.begin_work_queue()
+        while (self._delegate.should_continue_work_queue()):
+            try:
+                self._ensure_work_log_closed()
+                work_item = self._delegate.next_work_item()
+                if not work_item:
+                    self._sleep("No work item.")
+                    continue
+                if not self._delegate.should_proceed_with_work_item(work_item):
+                    self._sleep("Not proceeding with work item.")
+                    continue
+
+                # FIXME: Work logs should not depend on bug_id specificaly.
+                #        This looks fixed, no?
+                self._open_work_log(work_item)
+                try:
+                    if not self._delegate.process_work_item(work_item):
+                        self._sleep("Unable to process work item.")
+                except ScriptError, e:
+                    # Use a special exit code to indicate that the error was already
+                    # handled in the child process and we should just keep looping.
+                    if e.exit_code == self.handled_error_code:
+                        continue
+                    message = "Unexpected failure when processing patch!  Please file a bug against webkit-patch.\n%s" % e.message_with_output()
+                    self._delegate.handle_unexpected_error(work_item, message)
+            except TerminateQueue, e:
+                log("\nTerminateQueue exception received.")
+                return 0
+            except KeyboardInterrupt, e:
+                log("\nUser terminated queue.")
+                return 1
+            except Exception, e:
+                traceback.print_exc()
+                # Don't try tell the status bot, in case telling it causes an exception.
+                self._sleep("Exception while preparing queue")
+        # Never reached.
+        self._ensure_work_log_closed()
+
+    def _begin_logging(self):
+        self._queue_log = self._output_tee.add_log(self._delegate.queue_log_path())
+        self._work_log = None
+
+    def _open_work_log(self, work_item):
+        work_item_log_path = self._delegate.work_item_log_path(work_item)
+        self._work_log = self._output_tee.add_log(work_item_log_path)
+
+    def _ensure_work_log_closed(self):
+        # If we still have a bug log open, close it.
+        if self._work_log:
+            self._output_tee.remove_log(self._work_log)
+            self._work_log = None
+
+    def _now(self):
+        """Overriden by the unit tests to allow testing _sleep_message"""
+        return datetime.now()
+
+    def _sleep_message(self, message):
+        wake_time = self._now() + timedelta(seconds=self.seconds_to_sleep)
+        return "%s Sleeping until %s (%s)." % (message, wake_time.strftime(self.log_date_format), self.sleep_duration_text)
+
+    def _sleep(self, message):
+        log(self._sleep_message(message))
+        self._wakeup_event.wait(self.seconds_to_sleep)
+        self._wakeup_event.clear()