[feat] add a zmq based logger, change log window

- Add a new handler for a zmq/thread-safe log send between components.
- Update the log window to use this new handler.
- Remove old custom handler
  We have implemented a new handler that uses logbook, so this one is no
  longer needed.
- Adapt log silencer to new handler
- Use log file always as default

- Related: #6733

1 files changed, 360 insertions, 0 deletions

diff --git a/src/leap/bitmask/gui/logwindow.py b/src/leap/bitmask/gui/logwindow.py
new file mode 100644
index 00000000..123f14cc
--- /dev/null
+++ b/src/leap/bitmask/gui/logwindow.py
@@ -0,0 +1,360 @@
+# -*- coding: utf-8 -*-
+# logwindow.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/>.
+
+"""
+History log window
+"""
+import cgi
+
+from PySide import QtCore, QtGui
+
+import logbook
+from logbook.queues import ZeroMQSubscriber
+
+from ui_loggerwindow import Ui_LoggerWindow
+
+from leap.bitmask.logs import LOG_FORMAT
+from leap.bitmask.logs.utils import get_logger
+from leap.bitmask.util.constants import PASTEBIN_API_DEV_KEY
+from leap.bitmask.util import pastebin
+
+logger = get_logger()
+
+# log history global variable used to store received logs through different
+# opened instances of this window
+_LOGS_HISTORY = []
+
+
+class QtLogHandler(logbook.Handler,  logbook.StringFormatterHandlerMixin):
+    """
+    Custom log handler which emits a log record with the message properly
+    formatted using a Qt Signal.
+    """
+
+    class _QtSignaler(QtCore.QObject):
+        """
+        inline class used to hold the `new_log` Signal, if this is used
+        directly in the outside class it fails due how PySide works.
+
+        This is the message we get if not use this method:
+        TypeError: Error when calling the metaclass bases
+            metaclass conflict: the metaclass of a derived class must be a
+            (non-strict) subclass of the metaclasses of all its bases
+
+        """
+        new_log = QtCore.Signal(object)
+
+        def emit(self, data):
+            """
+            emit the `new_log` Signal with the given `data` parameter.
+
+            :param data: the data to emit along with the signal.
+            :type data: object
+            """
+            # WARNING: the new-style connection does NOT work because PySide
+            # translates the emit method to self.emit, and that collides with
+            # the emit method for logging.Handler
+            # self.new_log.emit(log_item)
+            QtCore.QObject.emit(self, QtCore.SIGNAL('new_log(PyObject)'), data)
+
+    def __init__(self, level=logbook.NOTSET, format_string=None,
+                 encoding=None, filter=None, bubble=False):
+
+        logbook.Handler.__init__(self, level, filter, bubble)
+        logbook.StringFormatterHandlerMixin.__init__(self, format_string)
+
+        self.qt = self._QtSignaler()
+
+    def __enter__(self):
+        return logbook.Handler.__enter__(self)
+
+    def __exit__(self, exc_type, exc_value, tb):
+        return logbook.Handler.__exit__(self, exc_type, exc_value, tb)
+
+    def emit(self, record):
+        """
+        Emit the specified logging record using a Qt Signal.
+        Also add it to the history in order to be able to access it later.
+
+        :param record: the record to emit
+        :type record: logbook.LogRecord
+        """
+        global _LOGS_HISTORY
+        record.msg = self.format(record)
+        # NOTE: not optimal approach, we may want to look at
+        # bisect.insort with a custom approach to use key or
+        # http://code.activestate.com/recipes/577197-sortedcollection/
+        # Sort logs on arrival, logs transmitted over zmq may arrive unsorted.
+        _LOGS_HISTORY.append(record)
+        _LOGS_HISTORY = sorted(_LOGS_HISTORY, key=lambda r: r.time)
+
+        # XXX: emitting the record on arrival does not allow us to sort here so
+        # in the GUI the logs may arrive with with some time sort problem.
+        # We should implement a sort-on-arrive for the log window.
+        # Maybe we should switch to a tablewidget item that sort automatically
+        # by timestamp.
+        # As a user workaround you can close/open the log window
+        self.qt.emit(record)
+
+
+class LoggerWindow(QtGui.QDialog):
+    """
+    Window that displays a history of the logged messages in the app.
+    """
+    _paste_ok = QtCore.Signal(object)
+    _paste_error = QtCore.Signal(object)
+
+    def __init__(self, parent):
+        """
+        Initialize the widget.
+        """
+        QtGui.QDialog.__init__(self, parent)
+
+        # Load UI
+        self.ui = Ui_LoggerWindow()
+        self.ui.setupUi(self)
+
+        # Make connections
+        self.ui.btnSave.clicked.connect(self._save_log_to_file)
+        self.ui.btnDebug.toggled.connect(self._load_history),
+        self.ui.btnInfo.toggled.connect(self._load_history),
+        self.ui.btnWarning.toggled.connect(self._load_history),
+        self.ui.btnError.toggled.connect(self._load_history),
+        self.ui.btnCritical.toggled.connect(self._load_history)
+        self.ui.leFilterBy.textEdited.connect(self._filter_by)
+        self.ui.cbCaseInsensitive.stateChanged.connect(self._load_history)
+        self.ui.btnPastebin.clicked.connect(self._pastebin_this)
+
+        self._paste_ok.connect(self._pastebin_ok)
+        self._paste_error.connect(self._pastebin_err)
+
+        self._current_filter = ""
+        self._current_history = ""
+
+        self._set_logs_to_display()
+
+        self._my_handler = QtLogHandler(format_string=LOG_FORMAT)
+        self._my_handler.qt.new_log.connect(self._add_log_line)
+
+        self._load_history()
+        self._connect_to_logbook()
+
+    def _connect_to_logbook(self):
+        """
+        Run in the background the log receiver.
+        """
+        subscriber = ZeroMQSubscriber('tcp://127.0.0.1:5000', multi=True)
+        self._logbook_controller = subscriber.dispatch_in_background(
+            self._my_handler)
+
+    def _add_log_line(self, log):
+        """
+        Adds a line to the history, only if it's in the desired levels to show.
+
+        :param log: a log record to be inserted in the widget
+        :type log: Logbook.LogRecord.
+        """
+        html_style = {
+            logbook.DEBUG: "background: #CDFFFF;",
+            logbook.INFO: "background: white;",
+            logbook.WARNING: "background: #FFFF66;",
+            logbook.ERROR: "background: red; color: white;",
+            logbook.CRITICAL: "background: red; color: white; font: bold;"
+        }
+        level = log.level
+        message = cgi.escape(log.msg)
+
+        if self._logs_to_display[level]:
+            open_tag = "<tr style='" + html_style[level] + "'>"
+            open_tag += "<td width='100%' style='padding: 5px;'>"
+            close_tag = "</td></tr>"
+            message = open_tag + message + close_tag
+
+            filter_by = self._current_filter
+            msg = message
+            if self.ui.cbCaseInsensitive.isChecked():
+                msg = msg.upper()
+                filter_by = filter_by.upper()
+
+            if msg.find(filter_by) != -1:
+                self.ui.txtLogHistory.append(message)
+
+    def _load_history(self):
+        """
+        Load the previous logged messages in the widget.
+        They are stored in the custom handler.
+        """
+        self._set_logs_to_display()
+        self.ui.txtLogHistory.clear()
+        current_history = []
+        for record in _LOGS_HISTORY:
+            self._add_log_line(record)
+            current_history.append(record.msg)
+
+        self._current_history = "\n".join(current_history)
+
+    def _set_logs_to_display(self):
+        """
+        Sets the logs_to_display dict getting the toggled options from the ui
+        """
+        self._logs_to_display = {
+            logbook.DEBUG: self.ui.btnDebug.isChecked(),
+            logbook.INFO: self.ui.btnInfo.isChecked(),
+            logbook.WARNING: self.ui.btnWarning.isChecked(),
+            logbook.ERROR: self.ui.btnError.isChecked(),
+            logbook.CRITICAL: self.ui.btnCritical.isChecked()
+        }
+
+    def _filter_by(self, text):
+        """
+        Sets the text to use for filtering logs in the log window.
+
+        :param text: the text to compare with the logs when filtering.
+        :type text: str
+        """
+        self._current_filter = text
+        self._load_history()
+
+    def _save_log_to_file(self):
+        """
+        Lets the user save the current log to a file
+        """
+        fileName, filtr = QtGui.QFileDialog.getSaveFileName(
+            self, self.tr("Save As"),
+            options=QtGui.QFileDialog.DontUseNativeDialog)
+
+        if fileName:
+            try:
+                with open(fileName, 'w') as output:
+                    history = self.ui.txtLogHistory.toPlainText()
+                    # Chop some \n.
+                    # html->plain adds several \n because the html is made
+                    # using table cells.
+                    history = history.replace('\n\n\n', '\n')
+
+                    output.write(history)
+                logger.debug('Log saved in %s' % (fileName, ))
+            except IOError, e:
+                logger.error("Error saving log file: %r" % (e, ))
+        else:
+            logger.debug('Log not saved!')
+
+    def _set_pastebin_sending(self, sending):
+        """
+        Define the status of the pastebin button.
+        Change the text and enable/disable according to the current action.
+
+        :param sending: if we are sending to pastebin or not.
+        :type sending: bool
+        """
+        if sending:
+            self.ui.btnPastebin.setText(self.tr("Sending to pastebin..."))
+            self.ui.btnPastebin.setEnabled(False)
+        else:
+            self.ui.btnPastebin.setText(self.tr("Send to Pastebin.com"))
+            self.ui.btnPastebin.setEnabled(True)
+
+    def _pastebin_ok(self, link):
+        """
+        Handle a successful paste.
+
+        :param link: the recently created pastebin link.
+        :type link: str
+        """
+        self._set_pastebin_sending(False)
+        msg = self.tr("Your pastebin link <a href='{0}'>{0}</a>")
+        msg = msg.format(link)
+
+        # We save the dialog in an instance member to avoid dialog being
+        # deleted right after we exit this method
+        self._msgBox = msgBox = QtGui.QMessageBox(
+            QtGui.QMessageBox.Information, self.tr("Pastebin OK"), msg)
+        msgBox.setWindowModality(QtCore.Qt.NonModal)
+        msgBox.show()
+
+    def _pastebin_err(self, failure):
+        """
+        Handle a failure in paste.
+
+        :param failure: the exception that made the paste fail.
+        :type failure: Exception
+        """
+        self._set_pastebin_sending(False)
+        logger.error(repr(failure))
+
+        msg = self.tr("Sending logs to Pastebin failed!")
+        if isinstance(failure, pastebin.PostLimitError):
+            msg = self.tr('Maximum amount of submissions reached for today.')
+
+        # We save the dialog in an instance member to avoid dialog being
+        # deleted right after we exit this method
+        self._msgBox = msgBox = QtGui.QMessageBox(
+            QtGui.QMessageBox.Critical, self.tr("Pastebin Error"), msg)
+        msgBox.setWindowModality(QtCore.Qt.NonModal)
+        msgBox.show()
+
+    def _pastebin_this(self):
+        """
+        Send the current log history to pastebin.com and gives the user a link
+        to see it.
+        """
+        def do_pastebin():
+            """
+            Send content to pastebin and return the link.
+            """
+            content = self._current_history
+            pb = pastebin.PastebinAPI()
+            try:
+                link = pb.paste(PASTEBIN_API_DEV_KEY, content,
+                                paste_name="Bitmask log",
+                                paste_expire_date='1M')
+                # convert to 'raw' link
+                link = "http://pastebin.com/raw.php?i=" + link.split('/')[-1]
+
+                self._paste_ok.emit(link)
+            except Exception as e:
+                self._paste_error.emit(e)
+
+        self._set_pastebin_sending(True)
+
+        self._paste_thread = QtCore.QThread()
+        self._paste_thread.run = lambda: do_pastebin()
+        self._paste_thread.start()
+
+    def closeEvent(self, e):
+        """
+        Disconnect logger on close.
+        """
+        self._disconnect_logger()
+        e.accept()
+
+    def reject(self):
+        """
+        Disconnect logger on reject.
+        """
+        self._disconnect_logger()
+        QtGui.QDialog.reject(self)
+
+    def _disconnect_logger(self):
+        """
+        Stop the background thread that receives messages through zmq, also
+        close the subscriber socket.
+        This allows us to re-create the subscriber when we reopen this window
+        without getting an error at trying to connect twice to the zmq port.
+        """
+        self._logbook_controller.stop()
+        self._logbook_controller.subscriber.close()