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      1 # Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
      2 # Use of this source code is governed by a BSD-style license that can be
      3 # found in the LICENSE file.
      4 
      5 import errno
      6 import os
      7 import shutil
      8 import urllib2
      9 
     10 from autotest_lib.client.common_lib import global_config
     11 
     12 def rm_dir_if_exists(dir_to_remove):
     13     """
     14     Removes a directory. Does not fail if the directory does NOT exist.
     15 
     16     @param dir_to_remove: path, directory to be removed.
     17 
     18     """
     19     try:
     20         shutil.rmtree(dir_to_remove)
     21     except OSError as e:
     22         if e.errno != errno.ENOENT:
     23             raise
     24 
     25 
     26 def rm_dirs_if_exist(dirs_to_remove):
     27     """
     28     Removes multiple directories. Does not fail if directories do NOT exist.
     29 
     30     @param dirs_to_remove: list of directory paths to be removed.
     31 
     32     """
     33     for dr in dirs_to_remove:
     34         rm_dir_if_exists(dr)
     35 
     36 
     37 def ensure_file_exists(filepath):
     38     """
     39     Verifies path given points to an existing file.
     40 
     41     @param filepath: path, path to check.
     42 
     43     @raises IOError if the path given does not point to a valid file.
     44 
     45     """
     46     error_msg = 'File %s does not exist.' % filepath
     47     if not os.path.isfile(filepath):
     48         raise IOError(error_msg)
     49 
     50 
     51 def ensure_all_files_exist(filepaths):
     52     """
     53     Verifies all paths given point to existing files.
     54 
     55     @param filepaths: List of paths to check.
     56 
     57     @raises IOError if given paths do not point to existing files.
     58 
     59     """
     60     for filepath in filepaths:
     61         ensure_file_exists(filepath)
     62 
     63 
     64 def ensure_dir_exists(dirpath):
     65     """
     66     Verifies path given points to an existing directory.
     67 
     68     @param dirpath: path, dir to check.
     69 
     70     @raises IOError if path does not point to an existing directory.
     71 
     72     """
     73     error_msg = 'Directory %s does not exist.' % dirpath
     74     if not os.path.isdir(dirpath):
     75         raise IOError(error_msg)
     76 
     77 
     78 def ensure_all_dirs_exist(dirpaths):
     79     """
     80     Verifies all paths given point to existing directories.
     81 
     82     @param dirpaths: list of directory paths to check.
     83 
     84     @raises IOError if given paths do not point to existing directories.
     85 
     86     """
     87     for dirpath in dirpaths:
     88         ensure_dir_exists(dirpath)
     89 
     90 
     91 def make_leaf_dir(dirpath):
     92     """
     93     Creates a directory, also creating parent directories if they do not exist.
     94 
     95     @param dirpath: path, directory to create.
     96 
     97     @raises whatever exception raised other than "path already exist".
     98 
     99     """
    100     try:
    101         os.makedirs(dirpath)
    102     except OSError as e:
    103         if e.errno != errno.EEXIST:
    104             raise
    105 
    106 
    107 def make_leaf_dirs(dirpaths):
    108     """
    109     Creates multiple directories building all respective parent directories if
    110     they do not exist.
    111 
    112     @param dirpaths: list of directory paths to create.
    113 
    114     @raises whatever exception raised other than "path already exists".
    115     """
    116     for dirpath in dirpaths:
    117         make_leaf_dir(dirpath)
    118 
    119 
    120 def download_file(remote_path, local_path):
    121     """
    122     Download file from a remote resource.
    123 
    124     @param remote_path: path, complete path to the remote file.
    125     @param local_path: path, complete path to save downloaded file.
    126 
    127     @raises: urllib2.HTTPError or urlib2.URLError exception. Both with added
    128             debug information
    129 
    130     """
    131     client_config = global_config.global_config.get_section_values('CLIENT')
    132     proxies = {}
    133 
    134     for name, value in client_config.items('CLIENT'):
    135         if value and name.endswith('_proxy'):
    136             proxies[name[:-6]] = value
    137 
    138     if proxies:
    139         proxy_handler = urllib2.ProxyHandler(proxies)
    140         opener = urllib2.build_opener(proxy_handler)
    141         urllib2.install_opener(opener)
    142 
    143     # Unlike urllib.urlopen urllib2.urlopen will immediately throw on error
    144     # If we could not find the file pointed by remote_path we will get an
    145     # exception, catch the exception to log useful information then re-raise
    146 
    147     try:
    148         remote_file = urllib2.urlopen(remote_path)
    149 
    150         # Catch exceptions, extract exception properties and then re-raise
    151         # This helps us with debugging what went wrong quickly as we get to see
    152         # test_that output immediately
    153 
    154     except urllib2.HTTPError as e:
    155         e.msg = (("""HTTPError raised while retrieving file %s\n.
    156                        Http Code = %s.\n. Reason = %s\n. Headers = %s.\n
    157                        Original Message = %s.\n""")
    158                  % (remote_path, e.code, e.reason, e.headers, e.msg))
    159         raise
    160 
    161     except urllib2.URLError as e:
    162         e.msg = (("""URLError raised while retrieving file %s\n.
    163                         Reason = %s\n. Original Message = %s\n.""")
    164                  % (remote_path, e.reason, e.msg))
    165         raise
    166 
    167     with open(local_path, 'wb') as local_file:
    168         local_file.write(remote_file.read())