lttng_ivc/utils/utils.py

   1 import signal
   2 import hashlib
   3 import os
   4 import time
   5
   6 def line_count(file_path):
   7     line_count = 0
   8     with open(file_path) as f:
   9         for line in f:
  10             line_count += 1
  11     return line_count
  12
  13
  14 def sha256_checksum(filename, block_size=65536):
  15     sha256 = hashlib.sha256()
  16     with open(filename, 'rb') as f:
  17         for block in iter(lambda: f.read(block_size), b''):
  18             sha256.update(block)
  19     return sha256.hexdigest()
  20
  21
  22 # TODO: timeout as a parameter or Settings
  23 # TODO: Custom exception
  24 def wait_for_file(path):
  25     i = 0
  26     timeout = 60
  27     while not os.path.exists(path):
  28         time.sleep(1)
  29         i = i + 1
  30         if i > timeout:
  31             raise Exception("File still does not exists. Timeout expired")
  32
  33
  34 # TODO: find better exception
  35 def create_empty_file(path):
  36     if os.path.exists(path):
  37         raise Exception("Path already exist")
  38     open(path, 'w').close()
  39
  40
  41 def __dummy_sigusr1_handler():
  42     pass
  43
  44
  45 def sessiond_spawn(runtime):
  46     previous_handler = signal.signal(signal.SIGUSR1, __dummy_sigusr1_handler)
  47     sessiond = runtime.spawn_subprocess("lttng-sessiond -vvv -S")
  48     signal.sigtimedwait({signal.SIGUSR1}, 60)
  49     previous_handler = signal.signal(signal.SIGUSR1, previous_handler)
  50     return sessiond
  51
  52
  53
  54
  55 def file_contains(stderr_file, list_of_string):
  56     with open(stderr_file, 'r') as stderr:
  57         for line in stderr:
  58             for s in list_of_string:
  59                 if s in line:
  60                     return True