2 files changed, 171 insertions, 0 deletions
diff --git a/src/leap/util/check.py b/src/leap/util/check.py
new file mode 100644
index 00000000..9787341a
--- /dev/null
+++ b/src/leap/util/check.py
@@ -0,0 +1,61 @@
+# -*- coding: utf-8 -*-
+# check.py
+# Copyright (C) 2013 LEAP
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Set of functions to help checking situations
+"""
+import logging
+import inspect
+import traceback
+
+
+logger = logging.getLogger(__name__)
+
+
+def leap_assert(condition, message=""):
+    """
+    Asserts the condition and displays the message if that's not
+    met. It also logs the error and its backtrace.
+
+    @param condition: condition to check
+    @type condition: bool
+    @param message: message to display if the condition isn't met
+    @type message: str
+    """
+    if not condition:
+        logger.error("Bug: %s" % (message,))
+        try:
+            frame = inspect.currentframe()
+            stack_trace = traceback.format_stack(frame)
+            logger.error(''.join(stack_trace))
+        except Exception as e:
+            logger.error("Bug in leap_assert: %r" % (e,))
+    assert condition, message
+
+
+def leap_assert_type(var, expectedType):
+    """
+    Helper assert check for a variable's expected type
+
+    @param var: variable to check
+    @type var: any
+    @param expectedType: type to check agains
+    @type expectedType: type
+    """
+    leap_assert(isinstance(var, expectedType),
+                "Expected type %r instead of %r" %
+                (expectedType, type(var)))
diff --git a/src/leap/util/checkerthread.py b/src/leap/util/checkerthread.py
new file mode 100644
index 00000000..681c33e1
--- /dev/null
+++ b/src/leap/util/checkerthread.py
@@ -0,0 +1,110 @@
+# -*- coding: utf-8 -*-
+# providerbootstrapper.py
+# Copyright (C) 2013 LEAP
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Checker thread
+"""
+
+import logging
+
+from PySide import QtCore
+
+from leap.util.check import leap_assert_type
+
+logger = logging.getLogger(__name__)
+
+
+class CheckerThread(QtCore.QThread):
+    """
+    Generic checker thread that can perform any type of operation as
+    long as it returns a boolean value that identifies how the
+    execution went.
+    """
+
+    IDLE_SLEEP_INTERVAL = 1
+
+    def __init__(self):
+        QtCore.QThread.__init__(self)
+
+        self._checks = []
+        self._checks_lock = QtCore.QMutex()
+
+        self._should_quit = False
+        self._should_quit_lock = QtCore.QMutex()
+
+    def get_should_quit(self):
+        """
+        Returns wether this thread should quit
+
+        @rtype: bool
+        @return: True if the thread should terminate itself, Flase otherwise
+        """
+
+        QtCore.QMutexLocker(self._should_quit_lock)
+        return self._should_quit
+
+    def set_should_quit(self):
+        """
+        Sets the should_quit flag to True so that this thread
+        terminates the first chance it gets
+        """
+        QtCore.QMutexLocker(self._should_quit_lock)
+        self._should_quit = True
+        self.wait()
+
+    def start(self):
+        """
+        Starts the thread and resets the should_quit flag
+        """
+        with QtCore.QMutexLocker(self._should_quit_lock):
+            self._should_quit = False
+
+        QtCore.QThread.start(self)
+
+    def add_checks(self, checks):
+        """
+        Adds a list of checks to the ones being executed
+
+        @param checks: check functions to perform
+        @type checkes: list
+        """
+        with QtCore.QMutexLocker(self._checks_lock):
+            self._checks += checks
+
+    def run(self):
+        """
+        Main run loop for this thread. Executes the checks.
+        """
+        shouldContinue = False
+        while True:
+            if self.get_should_quit():
+                logger.debug("Quitting checker thread")
+                return
+            checkSomething = False
+            with QtCore.QMutexLocker(self._checks_lock):
+                if len(self._checks) > 0:
+                    check = self._checks.pop(0)
+                    shouldContinue = check()
+                    leap_assert_type(shouldContinue, bool)
+                    checkSomething = True
+                    if not shouldContinue:
+                        logger.debug("Something went wrong with the checks, "
+                                     "clearing...")
+                        self._checks = []
+                        checkSomething = False
+            if not checkSomething:
+                self.sleep(self.IDLE_SLEEP_INTERVAL)