#!/usr/bin/env python2
#
# Copyright 2017 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Unittests for output archive plugin."""

from __future__ import print_function

import copy
import glob
import logging
import os
import resource
import shutil
import tarfile
import tempfile
import time
import unittest

import psutil
from six.moves import xrange

import instalog_common  # pylint: disable=unused-import
from instalog import datatypes
from instalog import log_utils
from instalog import plugin_sandbox
from instalog import testing


class TestOutputArchive(unittest.TestCase):

  def setUp(self):
    self.core = testing.MockCore()
    self.stream = self.core.GetStream(0)
    self.tmp_dir = tempfile.mkdtemp(prefix='output_archive_unittest_')
    self.event = datatypes.Event({'plugin': 'archive'})

  def tearDown(self):
    self.core.Close()
    shutil.rmtree(self.tmp_dir)

  def _GetMemoryUsage(self):
    """Returns current process's memory usage in bytes."""
    return resource.getrusage(resource.RUSAGE_SELF).ru_maxrss * 1024

  def testMemoryUsage(self):
    big_event = datatypes.Event({'1mb': 'x' * 1024 * 1024})
    event_size = len(big_event.Serialize())
    config = {
        'interval': 1000,  # arbitrary long time
        'threshold_size': 1024 * 1024 * 1024,  # arbitrary large value
    }
    sandbox = plugin_sandbox.PluginSandbox(
        'output_archive', config=config,
        data_dir=self.tmp_dir, core_api=self.core)
    sandbox.Start(True)

    mem_usage_start = self._GetMemoryUsage()
    logging.info('Initial memory usage: %d', mem_usage_start)
    # additional_memory = big_event(1mb) * 10 events * 20 iterations = ~200mb
    # maximum_memory = (original_memory + additional_memory) plus 10% padding
    mem_usage_max = (mem_usage_start + (event_size * 10 * 20)) * 1.1
    for _unused_i in xrange(20):
      events = [copy.deepcopy(big_event) for _unused_j in xrange(10)]
      self.stream.Queue(events)

    sandbox.Flush(1, False)  # trigger archive creation
    while not self.stream.Empty():
      mem_usage = self._GetMemoryUsage()
      logging.info('Current memory usage: %d/%d', mem_usage, mem_usage_max)
      if mem_usage >= mem_usage_max:
        # The test has failed, but we need to interrupt the archive plugin
        # and get it to stop as quickly as possible.
        # Stop new events from being accessed.
        del self.core.streams[0]
        # Force any open file handles shut so the plugin stops writing
        # to the archive on disk.
        proc = psutil.Process()
        for f in proc.get_open_files():
          os.close(f.fd)
        # Manually set the plugin state to STOPPING and advance into this
        # state.
        # pylint: disable=protected-access
        sandbox._state = plugin_sandbox.STOPPING
        sandbox.AdvanceState(True)
        # Once the plugin has really stopped, report our error.
        self.fail('Memory usage exceeded: %d/%d' % (mem_usage, mem_usage_max))
      time.sleep(0.1)
    # pylint: disable=protected-access
    sandbox._state = plugin_sandbox.STOPPING
    sandbox.AdvanceState(True)

  def testOneEvent(self):
    config = {
        'interval': 1}
    sandbox = plugin_sandbox.PluginSandbox(
        'output_archive', config=config,
        data_dir=self.tmp_dir, core_api=self.core)
    sandbox.Start(True)
    # pylint: disable=protected-access
    plugin = sandbox._plugin
    self.stream.Queue([self.event])
    plugin.PrepareAndProcess()
    sandbox.Flush(2, True)
    sandbox.Stop()

    # Inspect the disk archive.
    archive_path = glob.glob(os.path.join(self.tmp_dir, 'InstalogEvents*'))[0]
    with tarfile.open(archive_path, 'r:gz') as tar:
      events_member = [n for n in tar.getnames() if 'events.json' in n][0]
      events_file = tar.extractfile(events_member)
      lines = events_file.readlines()
      self.assertEqual(1, len(lines))
      event = datatypes.Event.Deserialize(lines[0])
      self.assertEqual(event, self.event)


if __name__ == '__main__':
  log_utils.InitLogging(log_utils.GetStreamHandler(logging.INFO))
  unittest.main()