tools/patman/tout.py

   1 # Copyright (c) 2016 Google, Inc
   2 #
   3 # SPDX-License-Identifier:            GPL-2.0+
   4 #
   5 # Terminal output logging.
   6 #
   7
   8 import sys
   9
  10 import terminal
  11
  12 # Output verbosity levels that we support
  13 ERROR = 0
  14 WARNING = 1
  15 NOTICE = 2
  16 INFO = 3
  17 DEBUG = 4
  18
  19 """
  20 This class handles output of progress and other useful information
  21 to the user. It provides for simple verbosity level control and can
  22 output nothing but errors at verbosity zero.
  23
  24 The idea is that modules set up an Output object early in their years and pass
  25 it around to other modules that need it. This keeps the output under control
  26 of a single class.
  27
  28 Public properties:
  29     verbose: Verbosity level: 0=silent, 1=progress, 3=full, 4=debug
  30 """
  31 def __enter__():
  32     return
  33
  34 def __exit__(unused1, unused2, unused3):
  35     """Clean up and remove any progress message."""
  36     ClearProgress()
  37     return False
  38
  39 def UserIsPresent():
  40     """This returns True if it is likely that a user is present.
  41
  42     Sometimes we want to prompt the user, but if no one is there then this
  43     is a waste of time, and may lock a script which should otherwise fail.
  44
  45     Returns:
  46         True if it thinks the user is there, and False otherwise
  47     """
  48     return stdout_is_tty and verbose > 0
  49
  50 def ClearProgress():
  51     """Clear any active progress message on the terminal."""
  52     if verbose > 0 and stdout_is_tty:
  53         _stdout.write('\r%s\r' % (" " * len (_progress)))
  54         _stdout.flush()
  55
  56 def Progress(msg, warning=False, trailer='...'):
  57     """Display progress information.
  58
  59     Args:
  60         msg: Message to display.
  61         warning: True if this is a warning."""
  62     ClearProgress()
  63     if verbose > 0:
  64         _progress = msg + trailer
  65         if stdout_is_tty:
  66             col = _color.YELLOW if warning else _color.GREEN
  67             _stdout.write('\r' + _color.Color(col, _progress))
  68             _stdout.flush()
  69         else:
  70             _stdout.write(_progress + '\n')
  71
  72 def _Output(level, msg, color=None):
  73     """Output a message to the terminal.
  74
  75     Args:
  76         level: Verbosity level for this message. It will only be displayed if
  77                 this as high as the currently selected level.
  78         msg; Message to display.
  79         error: True if this is an error message, else False.
  80     """
  81     if verbose >= level:
  82         ClearProgress()
  83         if color:
  84             msg = _color.Color(color, msg)
  85         _stdout.write(msg + '\n')
  86
  87 def DoOutput(level, msg):
  88     """Output a message to the terminal.
  89
  90     Args:
  91         level: Verbosity level for this message. It will only be displayed if
  92                 this as high as the currently selected level.
  93         msg; Message to display.
  94     """
  95     _Output(level, msg)
  96
  97 def Error(msg):
  98     """Display an error message
  99
 100     Args:
 101         msg; Message to display.
 102     """
 103     _Output(0, msg, _color.RED)
 104
 105 def Warning(msg):
 106     """Display a warning message
 107
 108     Args:
 109         msg; Message to display.
 110     """
 111     _Output(1, msg, _color.YELLOW)
 112
 113 def Notice(msg):
 114     """Display an important infomation message
 115
 116     Args:
 117         msg; Message to display.
 118     """
 119     _Output(2, msg)
 120
 121 def Info(msg):
 122     """Display an infomation message
 123
 124     Args:
 125         msg; Message to display.
 126     """
 127     _Output(3, msg)
 128
 129 def Debug(msg):
 130     """Display a debug message
 131
 132     Args:
 133         msg; Message to display.
 134     """
 135     _Output(4, msg)
 136
 137 def UserOutput(msg):
 138     """Display a message regardless of the current output level.
 139
 140     This is used when the output was specifically requested by the user.
 141     Args:
 142         msg; Message to display.
 143     """
 144     _Output(0, msg)
 145
 146 def Init(_verbose=WARNING, stdout=sys.stdout):
 147     """Initialize a new output object.
 148
 149     Args:
 150         verbose: Verbosity level (0-4).
 151         stdout: File to use for stdout.
 152     """
 153     global verbose, _progress, _color, _stdout, stdout_is_tty
 154
 155     verbose = _verbose
 156     _progress = ''                    # Our last progress message
 157     _color = terminal.Color()
 158     _stdout = stdout
 159
 160     # TODO(sjg): Move this into Chromite libraries when we have them
 161     stdout_is_tty = hasattr(sys.stdout, 'isatty') and sys.stdout.isatty()
 162
 163 def Uninit():
 164     ClearProgress()
 165
 166 Init()