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      1 # Copyright (c) 2009, Google Inc. All rights reserved.
      2 # Copyright (c) 2009 Apple Inc. All rights reserved.
      3 #
      4 # Redistribution and use in source and binary forms, with or without
      5 # modification, are permitted provided that the following conditions are
      6 # met:
      7 #
      8 #     * Redistributions of source code must retain the above copyright
      9 # notice, this list of conditions and the following disclaimer.
     10 #     * Redistributions in binary form must reproduce the above
     11 # copyright notice, this list of conditions and the following disclaimer
     12 # in the documentation and/or other materials provided with the
     13 # distribution.
     14 #     * Neither the name of Google Inc. nor the names of its
     15 # contributors may be used to endorse or promote products derived from
     16 # this software without specific prior written permission.
     17 #
     18 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29 
     30 import codecs
     31 import os
     32 import sys
     33 
     34 
     35 # Simple class to split output between multiple destinations
     36 class Tee:
     37     def __init__(self, *files):
     38         self.files = files
     39 
     40     # Callers should pass an already encoded string for writing.
     41     def write(self, bytes):
     42         for file in self.files:
     43             file.write(bytes)
     44 
     45 
     46 class OutputTee:
     47     def __init__(self):
     48         self._original_stdout = None
     49         self._original_stderr = None
     50         self._files_for_output = []
     51 
     52     def add_log(self, path):
     53         log_file = self._open_log_file(path)
     54         self._files_for_output.append(log_file)
     55         self._tee_outputs_to_files(self._files_for_output)
     56         return log_file
     57 
     58     def remove_log(self, log_file):
     59         self._files_for_output.remove(log_file)
     60         self._tee_outputs_to_files(self._files_for_output)
     61         log_file.close()
     62 
     63     @staticmethod
     64     def _open_log_file(log_path):
     65         (log_directory, log_name) = os.path.split(log_path)
     66         if log_directory and not os.path.exists(log_directory):
     67             os.makedirs(log_directory)
     68         return codecs.open(log_path, "a+", "utf-8")
     69 
     70     def _tee_outputs_to_files(self, files):
     71         if not self._original_stdout:
     72             self._original_stdout = sys.stdout
     73             self._original_stderr = sys.stderr
     74         if files and len(files):
     75             sys.stdout = Tee(self._original_stdout, *files)
     76             sys.stderr = Tee(self._original_stderr, *files)
     77         else:
     78             sys.stdout = self._original_stdout
     79             sys.stderr = self._original_stderr
     80