Tools/Scripts/webkitpy/port/pulseaudio_sanitizer.py

# Copyright (C) 2010 Google Inc. All rights reserved.
# Copyrigth (C) 2012 Intel Corporation
#
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import logging
import os
import subprocess


_log = logging.getLogger(__name__)


# Shared by GTK and EFL for pulseaudio sanitizing before running tests.
class PulseAudioSanitizer:
    def __init__(self):
        self._pa_module_index = -1

    def unload_pulseaudio_module(self):
        # Unload pulseaudio's module-stream-restore, since it remembers
        # volume settings from different runs, and could affect
        # multimedia tests results
        self._pa_module_index = -1
        with open(os.devnull, 'w') as devnull:
            try:
                pactl_process = subprocess.Popen(["pactl", "list", "short", "modules"], stdout=subprocess.PIPE, stderr=devnull)
                pactl_process.wait()
            except OSError:
                # pactl might not be available.
                _log.debug('pactl not found. Please install pulseaudio-utils to avoid some potential media test failures.')
                return
        modules_list = pactl_process.communicate()[0]
        for module in modules_list.splitlines():
            if module.find("module-stream-restore") >= 0:
                # Some pulseaudio-utils versions don't provide
                # the index, just an empty string
                self._pa_module_index = module.split('\t')[0] or -1
                try:
                    # Since they could provide other stuff (not an index
                    # nor an empty string, let's make sure this is an int.
                    if int(self._pa_module_index) != -1:
                        pactl_process = subprocess.Popen(["pactl", "unload-module", self._pa_module_index])
                        pactl_process.wait()
                        if pactl_process.returncode == 0:
                            _log.debug('Unloaded module-stream-restore successfully')
                        else:
                            _log.debug('Unloading module-stream-restore failed')
                except ValueError:
                        # pactl should have returned an index if the module is found
                        _log.debug('Unable to parse module index. Please check if your pulseaudio-utils version is too old.')
                return

    def restore_pulseaudio_module(self):
        # If pulseaudio's module-stream-restore was previously unloaded,
        # restore it back. We shouldn't need extra checks here, since an
        # index != -1 here means we successfully unloaded it previously.
        if self._pa_module_index != -1:
            with open(os.devnull, 'w') as devnull:
                pactl_process = subprocess.Popen(["pactl", "load-module", "module-stream-restore"], stdout=devnull, stderr=devnull)
                pactl_process.wait()
                if pactl_process.returncode == 0:
                    _log.debug('Restored module-stream-restore successfully')
                else:
                    _log.debug('Restoring module-stream-restore failed')