profilergui.py

# -*- coding: utf-8 -*-
#
# Copyright © Spyder Project Contributors
# based on pylintgui.py by Pierre Raybaut
#
# Licensed under the terms of the MIT License
# (see spyder/__init__.py for details)

"""
Profiler widget

See the official documentation on python profiling:
https://docs.python.org/3/library/profile.html
"""

# Standard library imports
from __future__ import with_statement
import os
import os.path as osp
from itertools import islice
import sys
import time
import re
import logging

# Third party imports
from qtpy.compat import getopenfilename, getsavefilename
from qtpy.QtCore import QByteArray, QProcess, QProcessEnvironment, Qt, Signal
from qtpy.QtGui import QColor
from qtpy.QtWidgets import (QApplication, QHBoxLayout, QLabel, QMessageBox,
                            QTreeWidget, QTreeWidgetItem, QVBoxLayout, QWidget)

# Local imports
from spyder.config.base import get_conf_path, get_translation
from spyder.py3compat import to_text_string
from spyder.utils import icon_manager as ima
from spyder.utils.qthelpers import (create_toolbutton, get_item_user_text,
                                    set_item_user_text)
from spyder.utils.programs import shell_split
from spyder.widgets.comboboxes import PythonModulesComboBox
from spyder.utils.misc import add_pathlist_to_PYTHONPATH, getcwd_or_home
from spyder.plugins.variableexplorer.widgets.texteditor import TextEditor

# This is needed for testing this module as a stand alone script
try:
    _ = get_translation("profiler", "spyder_profiler")
except KeyError as error:
    import gettext
    _ = gettext.gettext


logger = logging.getLogger(__name__)
def is_profiler_installed():
    from spyder.utils.programs import is_module_installed
    return is_module_installed('cProfile') and is_module_installed('pstats')


class ProfilerWidget(QWidget):
    """
    Profiler widget
    """
    DATAPATH = get_conf_path('profiler.results')
    VERSION = '0.0.1'
    redirect_stdio = Signal(bool)

    def __init__(self, parent, max_entries=100, options_button=None,
                 text_color=None):
        QWidget.__init__(self, parent)

        self.setWindowTitle("Profiler")

        self.output = None
        self.error_output = None

        self.text_color = text_color

        self._last_wdir = None
        self._last_args = None
        self._last_pythonpath = None

        self.filecombo = PythonModulesComboBox(self)

        self.start_button = create_toolbutton(self, icon=ima.icon('run'),
                                    text=_("Profile"),
                                    tip=_("Run profiler"),
                                    triggered=lambda : self.start(),
                                    text_beside_icon=True)
        self.stop_button = create_toolbutton(self,
                                             icon=ima.icon('stop'),
                                             text=_("Stop"),
                                             tip=_("Stop current profiling"),
                                             text_beside_icon=True)
        self.filecombo.valid.connect(self.start_button.setEnabled)
        #self.connect(self.filecombo, SIGNAL('valid(bool)'), self.show_data)
        # FIXME: The combobox emits this signal on almost any event
        #        triggering show_data() too early, too often.

        browse_button = create_toolbutton(self, icon=ima.icon('fileopen'),
                                          tip=_('Select Python script'),
                                          triggered=self.select_file)

        self.datelabel = QLabel()

        self.log_button = create_toolbutton(self, icon=ima.icon('log'),
                                            text=_("Output"),
                                            text_beside_icon=True,
                                            tip=_("Show program's output"),
                                            triggered=self.show_log)

        self.datatree = ProfilerDataTree(self)

        self.collapse_button = create_toolbutton(self,
                                                 icon=ima.icon('collapse'),
                                                 triggered=lambda dD:
                                                 self.datatree.change_view(-1),
                                                 tip=_('Collapse one level up'))
        self.expand_button = create_toolbutton(self,
                                               icon=ima.icon('expand'),
                                               triggered=lambda dD:
                                               self.datatree.change_view(1),
                                               tip=_('Expand one level down'))

        self.save_button = create_toolbutton(self, text_beside_icon=True,
                                             text=_("Save data"),
                                             icon=ima.icon('filesave'),
                                             triggered=self.save_data,
                                             tip=_('Save profiling data'))
        self.load_button = create_toolbutton(self, text_beside_icon=True,
                            text=_("Load data"),
                            icon=ima.icon('fileimport'),
                            triggered=self.compare,
                            tip=_('Load profiling data for comparison'))
        self.clear_button = create_toolbutton(self, text_beside_icon=True,
                                              text=_("Clear comparison"),
                                              icon=ima.icon('editdelete'),
                                              triggered=self.clear)

        hlayout1 = QHBoxLayout()
        hlayout1.addWidget(self.filecombo)
        hlayout1.addWidget(browse_button)
        hlayout1.addWidget(self.start_button)
        hlayout1.addWidget(self.stop_button)
        if options_button:
            hlayout1.addWidget(options_button)

        hlayout2 = QHBoxLayout()
        hlayout2.addWidget(self.collapse_button)
        hlayout2.addWidget(self.expand_button)
        hlayout2.addStretch()
        hlayout2.addWidget(self.datelabel)
        hlayout2.addStretch()
        hlayout2.addWidget(self.log_button)
        hlayout2.addWidget(self.save_button)
        hlayout2.addWidget(self.load_button)
        hlayout2.addWidget(self.clear_button)

        layout = QVBoxLayout()
        layout.addLayout(hlayout1)
        layout.addLayout(hlayout2)
        layout.addWidget(self.datatree)
        self.setLayout(layout)

        self.process = None
        self.set_running_state(False)
        self.start_button.setEnabled(False)
        self.clear_button.setEnabled(False)

        if not is_profiler_installed():
            # This should happen only on certain GNU/Linux distributions
            # or when this a home-made Python build because the Python
            # profilers are included in the Python standard library
            for widget in (self.datatree, self.filecombo,
                           self.start_button, self.stop_button):
                widget.setDisabled(True)
            url = 'https://docs.python.org/3/library/profile.html'
            text = '%s <a href=%s>%s</a>' % (_('Please install'), url,
                                             _("the Python profiler modules"))
            self.datelabel.setText(text)
        else:
            pass # self.show_data()

    def save_data(self):
        """Save data"""
        title = _( "Save profiler result")
        filename, _selfilter = getsavefilename(
                self, title, getcwd_or_home(),
                _("Profiler result")+" (*.Result)")
        if filename:
            self.datatree.save_data(filename)

    def compare(self):
        filename, _selfilter = getopenfilename(
                self, _("Select script to compare"),
                getcwd_or_home(), _("Profiler result")+" (*.Result)")
        if filename:
            self.datatree.compare(filename)
            self.show_data()
            self.clear_button.setEnabled(True)

    def clear(self):
        self.datatree.compare(None)
        self.datatree.hide_diff_cols(True)
        self.show_data()
        self.clear_button.setEnabled(False)

    def analyze(self, filename, wdir=None, args=None, pythonpath=None):
        if not is_profiler_installed():
            return
        self.kill_if_running()
        #index, _data = self.get_data(filename)
        index = None # FIXME: storing data is not implemented yet
        if index is None:
            self.filecombo.addItem(filename)
            self.filecombo.setCurrentIndex(self.filecombo.count()-1)
        else:
            self.filecombo.setCurrentIndex(self.filecombo.findText(filename))
        self.filecombo.selected()
        if self.filecombo.is_valid():
            if wdir is None:
                wdir = osp.dirname(filename)
            self.start(wdir, args, pythonpath)

    def select_file(self):
        self.redirect_stdio.emit(False)
        filename, _selfilter = getopenfilename(
                self, _("Select Python script"),
                getcwd_or_home(), _("Python scripts")+" (*.py ; *.pyw)")
        self.redirect_stdio.emit(True)
        if filename:
            self.analyze(filename)

    def show_log(self):
        if self.output:
            TextEditor(self.output, title=_("Profiler output"),
                       readonly=True, size=(700, 500), parent=self).exec_()

    def show_errorlog(self):
        if self.error_output:
            TextEditor(self.error_output, title=_("Profiler output"),
                       readonly=True, size=(700, 500), parent=self).exec_()

    def start(self, wdir=None, args=None, pythonpath=None):
        filename = to_text_string(self.filecombo.currentText())
        if wdir is None:
            wdir = self._last_wdir
            if wdir is None:
                wdir = osp.basename(filename)
        if args is None:
            args = self._last_args
            if args is None:
                args = []
        if pythonpath is None:
            pythonpath = self._last_pythonpath
        self._last_wdir = wdir
        self._last_args = args
        self._last_pythonpath = pythonpath

        self.datelabel.setText(_('Profiling, please wait...'))

        self.process = QProcess(self)
        self.process.setProcessChannelMode(QProcess.SeparateChannels)
        self.process.setWorkingDirectory(wdir)
        self.process.readyReadStandardOutput.connect(self.read_output)
        self.process.readyReadStandardError.connect(
                                          lambda: self.read_output(error=True))
        self.process.finished.connect(lambda ec, es=QProcess.ExitStatus:
                                      self.finished(ec, es))
        self.stop_button.clicked.connect(self.kill)

        if pythonpath is not None:
            env = [to_text_string(_pth)
                   for _pth in self.process.systemEnvironment()]
            add_pathlist_to_PYTHONPATH(env, pythonpath)
            processEnvironment = QProcessEnvironment()
            for envItem in env:
                envName, separator, envValue = envItem.partition('=')
                processEnvironment.insert(envName, envValue)
            processEnvironment.insert("PYTHONIOENCODING", "utf8")
            self.process.setProcessEnvironment(processEnvironment)

        self.output = ''
        self.error_output = ''
        self.stopped = False

        p_args = ['-m', 'cProfile', '-o', self.DATAPATH]
        if os.name == 'nt':
            # On Windows, one has to replace backslashes by slashes to avoid
            # confusion with escape characters (otherwise, for example, '\t'
            # will be interpreted as a tabulation):
            p_args.append(osp.normpath(filename).replace(os.sep, '/'))
        else:
            p_args.append(filename)
        if args:
            p_args.extend(shell_split(args))
        executable = sys.executable
        if executable.endswith("spyder.exe"):
            # py2exe distribution
            executable = "python.exe"
        self.process.start(executable, p_args)

        running = self.process.waitForStarted()
        self.set_running_state(running)
        if not running:
            QMessageBox.critical(self, _("Error"),
                                 _("Process failed to start"))

    def kill(self):
        """Stop button pressed."""
        self.process.kill()
        self.stopped = True

    def set_running_state(self, state=True):
        self.start_button.setEnabled(not state)
        self.stop_button.setEnabled(state)

    def read_output(self, error=False):
        if error:
            self.process.setReadChannel(QProcess.StandardError)
        else:
            self.process.setReadChannel(QProcess.StandardOutput)
        qba = QByteArray()
        while self.process.bytesAvailable():
            if error:
                qba += self.process.readAllStandardError()
            else:
                qba += self.process.readAllStandardOutput()
        text = to_text_string(qba.data(), encoding='utf-8')
        if error:
            self.error_output += text
        else:
            self.output += text

    def finished(self, exit_code, exit_status):
        self.set_running_state(False)
        self.show_errorlog()  # If errors occurred, show them.
        self.output = self.error_output + self.output
        # FIXME: figure out if show_data should be called here or
        #        as a signal from the combobox
        self.show_data(justanalyzed=True)

    def kill_if_running(self):
        if self.process is not None:
            if self.process.state() == QProcess.Running:
                self.process.kill()
                self.process.waitForFinished()

    def show_data(self, justanalyzed=False):
        if not justanalyzed:
            self.output = None
        self.log_button.setEnabled(self.output is not None
                                   and len(self.output) > 0)
        self.kill_if_running()
        filename = to_text_string(self.filecombo.currentText())
        if not filename:
            return

        if self.stopped:
            self.datelabel.setText(_('Run stopped by user.'))
            self.datatree.initialize_view()
            return

        self.datelabel.setText(_('Sorting data, please wait...'))
        QApplication.processEvents()

        self.datatree.load_data(self.DATAPATH)
        self.datatree.show_tree()

        text_style = "<span style=\'color: %s\'><b>%s </b></span>"
        date_text = text_style % (self.text_color,
                                  time.strftime("%Y-%m-%d %H:%M:%S",
                                                time.localtime()))
        self.datelabel.setText(date_text)


def gettime_s(text):
    """
    Parse text and return a time in seconds.

    The text is of the format 0h : 0.min:0.0s:0 ms:0us:0 ns.
    Spaces are not taken into account and any of the specifiers can be ignored.
    """
    pattern = r'([+-]?\d+\.?\d*) ?([munsecinh]+)'
    matches = re.findall(pattern, text)
    if len(matches) == 0:
        return None
    time = 0.
    for res in matches:
        tmp = float(res[0])
        if res[1] == 'ns':
            tmp *= 1e-9
        elif res[1] == 'us':
            tmp *= 1e-6
        elif res[1] == 'ms':
            tmp *= 1e-3
        elif res[1] == 'min':
            tmp *= 60
        elif res[1] == 'h':
            tmp *= 3600
        time += tmp
    return time

class TreeWidgetItem( QTreeWidgetItem ):
    def __init__(self, parent=None):
        QTreeWidgetItem.__init__(self, parent)

    def __lt__(self, otherItem):
        column = self.treeWidget().sortColumn()
        try:
            if column == 1 or column == 3: #TODO: Hardcoded Column
                t0 = gettime_s(self.text(column))
                t1 = gettime_s(otherItem.text(column))
                if t0 is not None and t1 is not None:
                    return t0 > t1

            return float( self.text(column) ) > float( otherItem.text(column) )
        except ValueError:
            return self.text(column) > otherItem.text(column)

class ProfilerDataTree(QTreeWidget):
    """
    Convenience tree widget (with built-in model)
    to store and view profiler data.

    The quantities calculated by the profiler are as follows
    (from profile.Profile):
    [0] = The number of times this function was called, not counting direct
          or indirect recursion,
    [1] = Number of times this function appears on the stack, minus one
    [2] = Total time spent internal to this function
    [3] = Cumulative time that this function was present on the stack.  In
          non-recursive functions, this is the total execution time from start
          to finish of each invocation of a function, including time spent in
          all subfunctions.
    [4] = A dictionary indicating for each function name, the number of times
          it was called by us.
    """

    sig_edit_goto = Signal(str, int, str)

    SEP = r"<[=]>"  # separator between filename and linenumber
    # (must be improbable as a filename to avoid splitting the filename itself)

    def __init__(self, parent=None):
        QTreeWidget.__init__(self, parent)
        self.header_list = [_('Function/Module'), _('Total Time'), _('Diff'),
                            _('Local Time'), _('Diff'), _('Calls'), _('Diff'),
                            _('File:line')]
        self.icon_list = {'module': ima.icon('python'),
                         'function': ima.icon('function'),
                         'builtin': ima.icon('python'),
                         'constructor': ima.icon('class')}
        self.profdata = None   # To be filled by self.load_data()
        self.stats = None      # To be filled by self.load_data()
        self.item_depth = None
        self.item_list = None
        self.items_to_be_shown = None
        self.current_view_depth = None
        self.compare_file = None
        self.setColumnCount(len(self.header_list))
        self.setHeaderLabels(self.header_list)
        self.initialize_view()
        self.itemActivated.connect(self.item_activated)
        self.itemExpanded.connect(self.item_expanded)

    def set_item_data(self, item, filename, line_number):
        """Set tree item user data: filename (string) and line_number (int)"""
        set_item_user_text(item, '%s%s%d' % (filename, self.SEP, line_number))

    def get_item_data(self, item):
        """Get tree item user data: (filename, line_number)"""
        filename, line_number_str = get_item_user_text(item).split(self.SEP)
        return filename, int(line_number_str)

    def initialize_view(self):
        """Clean the tree and view parameters"""
        self.clear()
        self.item_depth = 0   # To be use for collapsing/expanding one level
        self.item_list = []  # To be use for collapsing/expanding one level
        self.items_to_be_shown = {}
        self.current_view_depth = 0

    def load_data(self, profdatafile):
        """Load profiler data saved by profile/cProfile module"""
        import pstats
        # Fixes spyder-ide/spyder#6220.
        try:
            stats_indi = [pstats.Stats(profdatafile), ]
        except (OSError, IOError):
            self.profdata = None
            return
        self.profdata = stats_indi[0]

        if self.compare_file is not None:
            # Fixes spyder-ide/spyder#5587.
            try:
                stats_indi.append(pstats.Stats(self.compare_file))
            except (OSError, IOError) as e:
                QMessageBox.critical(
                    self, _("Error"),
                    _("Error when trying to load profiler results. "
                      "The error was<br><br>"
                      "<tt>{0}</tt>").format(e))
                self.compare_file = None
        map(lambda x: x.calc_callees(), stats_indi)
        self.profdata.calc_callees()
        self.stats1 = stats_indi
        self.stats = stats_indi[0].stats

    def compare(self,filename):
        self.hide_diff_cols(False)
        self.compare_file = filename

    def hide_diff_cols(self, hide):
        for i in (2,4,6):
            self.setColumnHidden(i, hide)

    def save_data(self, filename):
        """Save profiler data."""
        self.stats1[0].dump_stats(filename)

    def find_root(self):
        """Find a function without a caller"""
        # Fixes spyder-ide/spyder#8336.
        if self.profdata is not None:
            self.profdata.sort_stats("cumulative")
        else:
            return
        for func in self.profdata.fcn_list:
            if ('~', 0) != func[0:2] and not func[2].startswith(
                    '<built-in method exec>'):
                # This skips the profiler function at the top of the list
                # it does only occur in Python 3
                return func

    def find_callees(self, parent):
        """Find all functions called by (parent) function."""
        # FIXME: This implementation is very inneficient, because it
        #        traverses all the data to find children nodes (callees)
        return self.profdata.all_callees[parent]

    def show_tree(self):
        """Populate the tree with profiler data and display it."""
        self.initialize_view() # Clear before re-populating
        self.setItemsExpandable(True)
        self.setSortingEnabled(False)
        rootkey = self.find_root()  # This root contains profiler overhead
        if rootkey is not None:
            self.populate_tree(self, self.find_callees(rootkey))
            self.resizeColumnToContents(0)
            self.setSortingEnabled(True)
            self.sortItems(1, Qt.AscendingOrder) # FIXME: hardcoded index
            self.change_view(1)

    def function_info(self, functionKey):
        """Returns processed information about the function's name and file."""
        node_type = 'function'
        filename, line_number, function_name = functionKey
        if function_name == '<module>':
            modulePath, moduleName = osp.split(filename)
            node_type = 'module'
            if moduleName == '__init__.py':
                modulePath, moduleName = osp.split(modulePath)
            function_name = '<' + moduleName + '>'
        if not filename or filename == '~':
            file_and_line = '(built-in)'
            node_type = 'builtin'
        else:
            if function_name == '__init__':
                node_type = 'constructor'
            file_and_line = '%s : %d' % (filename, line_number)
        return filename, line_number, function_name, file_and_line, node_type

    @staticmethod
    def format_measure(measure):
        """Get format and units for data coming from profiler task."""
        # Convert to a positive value.
        measure = abs(measure)

        # For number of calls
        if isinstance(measure, int):
            return to_text_string(measure)

        # For time measurements
        if 1.e-9 < measure <= 1.e-6:
            measure = u"{0:.2f} ns".format(measure / 1.e-9)
        elif 1.e-6 < measure <= 1.e-3:
            measure = u"{0:.2f} us".format(measure / 1.e-6)
        elif 1.e-3 < measure <= 1:
            measure = u"{0:.2f} ms".format(measure / 1.e-3)
        elif 1 < measure <= 60:
            measure = u"{0:.2f} sec".format(measure)
        elif 60 < measure <= 3600:
            m, s = divmod(measure, 3600)
            if s > 60:
                m, s = divmod(measure, 60)
                s = to_text_string(s).split(".")[-1]
            measure = u"{0:.0f}.{1:.2s} min".format(m, s)
        else:
            h, m = divmod(measure, 3600)
            if m > 60:
                m /= 60
            measure = u"{0:.0f}h:{1:.0f}min".format(h, m)
        return measure

    def color_string(self, x):
        """Return a string formatted delta for the values in x.

        Args:
            x: 2-item list of integers (representing number of calls) or
               2-item list of floats (representing seconds of runtime).

        Returns:
            A list with [formatted x[0], [color, formatted delta]], where
            color reflects whether x[1] is lower, greater, or the same as
            x[0].
        """
        diff_str = ""
        color = "black"

        if len(x) == 2 and self.compare_file is not None:
            difference = x[0] - x[1]
            if difference:
                color, sign = ('green', '-') if difference < 0 else ('red', '+')
                diff_str = '{}{}'.format(sign, self.format_measure(difference))
        return [self.format_measure(x[0]), [diff_str, color]]

    def format_output(self, child_key):
        """ Formats the data.

        self.stats1 contains a list of one or two pstat.Stats() instances, with
        the first being the current run and the second, the saved run, if it
        exists.  Each Stats instance is a dictionary mapping a function to
        5 data points - cumulative calls, number of calls, total time,
        cumulative time, and callers.

        format_output() converts the number of calls, total time, and
        cumulative time to a string format for the child_key parameter.
        """
        data = [x.stats.get(child_key, [0, 0, 0, 0, {}]) for x in self.stats1]
        return (map(self.color_string, islice(zip(*data), 1, 4)))

    def populate_tree(self, parentItem, children_list):
        """Recursive method to create each item (and associated data) in the tree."""
        for child_key in children_list:
            self.item_depth += 1
            (filename, line_number, function_name, file_and_line, node_type
             ) = self.function_info(child_key)

            ((total_calls, total_calls_dif), (loc_time, loc_time_dif), (cum_time,
             cum_time_dif)) = self.format_output(child_key)

            child_item = TreeWidgetItem(parentItem)
            self.item_list.append(child_item)
            self.set_item_data(child_item, filename, line_number)

            # FIXME: indexes to data should be defined by a dictionary on init
            child_item.setToolTip(0, _('Function or module name'))
            child_item.setData(0, Qt.DisplayRole, function_name)
            child_item.setIcon(0, self.icon_list[node_type])

            child_item.setToolTip(1, _('Time in function '\
                                       '(including sub-functions)'))
            child_item.setData(1, Qt.DisplayRole, cum_time)
            child_item.setTextAlignment(1, Qt.AlignRight)

            child_item.setData(2, Qt.DisplayRole, cum_time_dif[0])
            child_item.setForeground(2, QColor(cum_time_dif[1]))
            child_item.setTextAlignment(2, Qt.AlignLeft)

            child_item.setToolTip(3, _('Local time in function '\
                                      '(not in sub-functions)'))

            child_item.setData(3, Qt.DisplayRole, loc_time)
            child_item.setTextAlignment(3, Qt.AlignRight)

            child_item.setData(4, Qt.DisplayRole, loc_time_dif[0])
            child_item.setForeground(4, QColor(loc_time_dif[1]))
            child_item.setTextAlignment(4, Qt.AlignLeft)

            child_item.setToolTip(5, _('Total number of calls '\
                                       '(including recursion)'))

            child_item.setData(5, Qt.DisplayRole, total_calls)
            child_item.setTextAlignment(5, Qt.AlignRight)

            child_item.setData(6, Qt.DisplayRole, total_calls_dif[0])
            child_item.setForeground(6, QColor(total_calls_dif[1]))
            child_item.setTextAlignment(6, Qt.AlignLeft)

            child_item.setToolTip(7, _('File:line '\
                                       'where function is defined'))
            child_item.setData(7, Qt.DisplayRole, file_and_line)
            #child_item.setExpanded(True)
            if self.is_recursive(child_item):
                child_item.setData(7, Qt.DisplayRole, '(%s)' % _('recursion'))
                child_item.setDisabled(True)
            else:
                callees = self.find_callees(child_key)
                if self.item_depth < 3:
                    self.populate_tree(child_item, callees)
                elif callees:
                    child_item.setChildIndicatorPolicy(child_item.ShowIndicator)
                    self.items_to_be_shown[id(child_item)] = callees
            self.item_depth -= 1

    def item_activated(self, item):
        filename, line_number = self.get_item_data(item)
        self.sig_edit_goto.emit(filename, line_number, '')

    def item_expanded(self, item):
        if item.childCount() == 0 and id(item) in self.items_to_be_shown:
            callees = self.items_to_be_shown[id(item)]
            self.populate_tree(item, callees)

    def is_recursive(self, child_item):
        """Returns True is a function is a descendant of itself."""
        ancestor = child_item.parent()
        # FIXME: indexes to data should be defined by a dictionary on init
        while ancestor:
            if (child_item.data(0, Qt.DisplayRole
                                ) == ancestor.data(0, Qt.DisplayRole) and
                child_item.data(7, Qt.DisplayRole
                                ) == ancestor.data(7, Qt.DisplayRole)):
                return True
            else:
                ancestor = ancestor.parent()
        return False

    def get_top_level_items(self):
        """Iterate over top level items"""
        return [self.topLevelItem(_i) for _i in range(self.topLevelItemCount())]

    def get_items(self, maxlevel):
        """Return all items with a level <= `maxlevel`"""
        itemlist = []
        def add_to_itemlist(item, maxlevel, level=1):
            level += 1
            for index in range(item.childCount()):
                citem = item.child(index)
                itemlist.append(citem)
                if level <= maxlevel:
                    add_to_itemlist(citem, maxlevel, level)
        for tlitem in self.get_top_level_items():
            itemlist.append(tlitem)
            if maxlevel > 0:
                add_to_itemlist(tlitem, maxlevel=maxlevel)
        return itemlist

    def change_view(self, change_in_depth):
        """Change the view depth by expand or collapsing all same-level nodes"""
        self.current_view_depth += change_in_depth
        if self.current_view_depth < 0:
            self.current_view_depth = 0
        self.collapseAll()
        if self.current_view_depth > 0:
            for item in self.get_items(maxlevel=self.current_view_depth-1):
                item.setExpanded(True)


#==============================================================================
# Tests
#==============================================================================
def primes(n):
    """
    Simple test function
    Taken from http://www.huyng.com/posts/python-performance-analysis/
    """
    if n==2:
        return [2]
    elif n<2:
        return []
    s=list(range(3,n+1,2))
    mroot = n ** 0.5
    half=(n+1)//2-1
    i=0
    m=3
    while m <= mroot:
        if s[i]:
            j=(m*m-3)//2
            s[j]=0
            while j<half:
                s[j]=0
                j+=m
        i=i+1
        m=2*i+3
    return [2]+[x for x in s if x]


def test():
    """Run widget test"""
    import inspect
    import tempfile
    from spyder.utils.qthelpers import qapplication

    primes_sc = inspect.getsource(primes)
    fd, script = tempfile.mkstemp(suffix='.py')
    with os.fdopen(fd, 'w') as f:
        f.write("# -*- coding: utf-8 -*-" + "\n\n")
        f.write(primes_sc + "\n\n")
        f.write("primes(100000)")

    app = qapplication(test_time=5)
    widget = ProfilerWidget(None)
    widget.resize(800, 600)
    widget.show()
    widget.analyze(script)
    sys.exit(app.exec_())


if __name__ == '__main__':
    test()