#!/usr/bin/env python

# Copyright (C) 2017 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import argparse
import atexit
import hashlib
import os
import signal
import subprocess
import sys
import tempfile
import time
import urllib

TRACE_TO_TEXT_SHAS = {
  'linux': '02b80116b5873dc00d82ff50c79f89909e054e78',
  'mac': 'f0fcf2e9adaacd28c1b712b241d5f02e9f746741',
}
TRACE_TO_TEXT_PATH = tempfile.gettempdir()
TRACE_TO_TEXT_BASE_URL = (
    'https://storage.googleapis.com/perfetto/')

def check_hash(file_name, sha_value):
  with open(file_name, 'rb') as fd:
    # TODO(fmayer): Chunking.
    file_hash = hashlib.sha1(fd.read()).hexdigest()
    return file_hash == sha_value


def load_trace_to_text(platform):
  sha_value = TRACE_TO_TEXT_SHAS[platform]
  file_name = 'trace_to_text-' + platform + '-' + sha_value
  local_file = os.path.join(TRACE_TO_TEXT_PATH, file_name)

  if os.path.exists(local_file):
    if not check_hash(local_file, sha_value):
      os.remove(local_file)
    else:
      return local_file

  url = TRACE_TO_TEXT_BASE_URL + file_name
  urllib.urlretrieve(url, local_file)
  if not check_hash(local_file, sha_value):
    os.remove(local_file)
    raise ValueError("Invalid signature.")
  os.chmod(local_file, 0o755)
  return local_file


NULL = open('/dev/null', 'r')

CFG_IDENT = '      '
CFG='''buffers {{
  size_kb: 32768
}}

data_sources {{
  config {{
    name: "android.heapprofd"
    heapprofd_config {{

      all: {all}
      sampling_interval_bytes: {interval}
{target_cfg}
      continuous_dump_config {{
        dump_phase_ms: 0
        dump_interval_ms: 1000
      }}
    }}
  }}
}}

duration_ms: {duration}
'''

PERFETTO_CMD=('CFG=\'{}\'; echo ${{CFG}} | '
              'perfetto --txt -c - -o /data/misc/perfetto-traces/profile -d')
IS_INTERRUPTED = False
def sigint_handler(sig, frame):
  global IS_INTERRUPTED
  IS_INTERRUPTED = True


def main(argv):
  parser = argparse.ArgumentParser()
  parser.add_argument("-i", "--interval", help="Sampling interval. "
                      "Default 128000 (128kB)", type=int, default=128000)
  parser.add_argument("-d", "--duration", help="Duration of profile (ms). "
                      "Default 1 minute", type=int, default=60000)
  parser.add_argument("-a", "--all", help="Profile the whole system",
                      action='store_true')
  parser.add_argument("--no-start", help="Do not start heapprofd",
                      action='store_true')
  parser.add_argument("-p", "--pid", help="PIDs to profile", nargs='+',
                      type=int)
  parser.add_argument("-n", "--name", help="Process names to profile",
                      nargs='+')
  parser.add_argument("-t", "--trace-to-text-binary",
                      help="Path to local trace to text. For debugging.")
  parser.add_argument("--disable-selinux", action="store_true",
                      help="Disable SELinux enforcement for duration of "
                      "profile")

  args = parser.parse_args()

  fail = False
  if args.all is None and args.pid is None and args.name is None:
    print("FATAL: Neither --all nor PID nor NAME given.", file=sys.stderr)
    fail = True
  if args.duration is None:
    print("FATAL: No duration given.", file=sys.stderr)
    fail = True
  if args.interval is None:
    print("FATAL: No interval given.", file=sys.stderr)
    fail = True
  if fail:
    parser.print_help()
    return 1
  target_cfg = ""
  if args.pid:
    for pid in args.pid:
      target_cfg += '{}pid: {}\n'.format(CFG_IDENT, pid)
  if args.name:
    for name in args.name:
      target_cfg += '{}process_cmdline: "{}"\n'.format(CFG_IDENT, name)

  trace_to_text_binary = args.trace_to_text_binary
  if trace_to_text_binary is None:
    platform = None
    if sys.platform.startswith('linux'):
      platform = 'linux'
    elif sys.platform.startswith('darwin'):
      platform = 'mac'
    else:
      print("Invalid platform: {}".format(sys.platform), file=sys.stderr)
      return 1

    trace_to_text_binary = load_trace_to_text(platform)

  cfg = CFG.format(all=str(args.all == True).lower(), interval=args.interval,
                   duration=args.duration, target_cfg=target_cfg)

  if args.disable_selinux:
    enforcing = subprocess.check_output(['adb', 'shell', 'getenforce'])
    atexit.register(subprocess.check_call,
        ['adb', 'shell', 'su root setenforce %s' % enforcing])
    subprocess.check_call(['adb', 'shell', 'su root setenforce 0'])

  if not args.no_start:
    atexit.register(subprocess.check_call,
                    ['adb', 'shell', 'su root stop heapprofd'])
    subprocess.check_call(['adb', 'shell', 'su root start heapprofd'])

  perfetto_pid = subprocess.check_output(
      ['adb', 'exec-out', PERFETTO_CMD.format(cfg)]).strip()

  old_handler = signal.signal(signal.SIGINT, sigint_handler)
  print("Profiling active. Press Ctrl+C to terminate.")
  exists = True
  while exists and not IS_INTERRUPTED:
    exists = subprocess.call(
        ['adb', 'shell', '[ -d /proc/{} ]'.format(perfetto_pid)]) == 0
    time.sleep(1)
  signal.signal(signal.SIGINT, old_handler)
  if IS_INTERRUPTED:
    # Not check_call because it could have existed in the meantime.
    subprocess.call(['adb', 'shell', 'kill', '-INT', perfetto_pid])

  # Wait for perfetto cmd to return.
  while exists:
    exists = subprocess.call(
        ['adb', 'shell', '[ -d /proc/{} ]'.format(perfetto_pid)]) == 0
    time.sleep(1)

  subprocess.check_call(['adb', 'pull', '/data/misc/perfetto-traces/profile',
                         '/tmp/profile'], stdout=NULL)
  trace_to_text_output = subprocess.check_output(
      [trace_to_text_binary, 'profile', '/tmp/profile'],
      stderr=NULL)
  profile_path = None
  for word in trace_to_text_output.split():
    if 'heap_profile-' in word:
      profile_path = word
  if profile_path is None:
    print("Could not find trace_to_text output path.", file=sys.stderr)
    return 1

  profile_files = os.listdir(profile_path)
  if not profile_files:
    print("No profiles generated", file=sys.stderr)
    return 1

  subprocess.check_call(['gzip'] + [os.path.join(profile_path, x) for x in
                                    os.listdir(profile_path)])

  symlink_path = os.path.join(os.path.dirname(profile_path),
                                        "heap_profile-latest")
  os.unlink(symlink_path)
  os.symlink(profile_path, symlink_path)

  print("Wrote profiles to {} (symlink {})".format(profile_path, symlink_path))
  print("These can be viewed using pprof. Googlers: head to pprof/ and "
        "upload them.")


if __name__ == '__main__':
  sys.exit(main(sys.argv))