(raulenrique) | dfdda47 | 2018-06-04 12:02:29 -0700 | [diff] [blame^] | 1 | # Copyright (C) 2018 The Android Open Source Project |
| 2 | # |
| 3 | # Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | # you may not use this file except in compliance with the License. |
| 5 | # You may obtain a copy of the License at |
| 6 | # |
| 7 | # http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | # |
| 9 | # Unless required by applicable law or agreed to in writing, software |
| 10 | # distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | # See the License for the specific language governing permissions and |
| 13 | # limitations under the License. |
| 14 | """Functions to process archive files.""" |
| 15 | |
| 16 | import os |
| 17 | import tempfile |
| 18 | import tarfile |
| 19 | import urllib.parse |
| 20 | import zipfile |
| 21 | |
| 22 | |
| 23 | class ZipFileWithPermission(zipfile.ZipFile): |
| 24 | """Subclassing Zipfile to preserve file permission. |
| 25 | |
| 26 | See https://bugs.python.org/issue15795 |
| 27 | """ |
| 28 | |
| 29 | def extract(self, member, path=None, pwd=None): |
| 30 | ret_val = super().extract(member, path, pwd) |
| 31 | |
| 32 | if not isinstance(member, zipfile.ZipInfo): |
| 33 | member = self.getinfo(member) |
| 34 | attr = member.external_attr >> 16 |
| 35 | if attr != 0: |
| 36 | os.chmod(ret_val, attr) |
| 37 | return ret_val |
| 38 | |
| 39 | |
| 40 | def unzip(archive_path, target_path): |
| 41 | """Extracts zip file to a path. |
| 42 | |
| 43 | Args: |
| 44 | archive_path: Path to the zip file. |
| 45 | target_path: Path to extract files to. |
| 46 | """ |
| 47 | |
| 48 | with ZipFileWithPermission(archive_path) as zfile: |
| 49 | zfile.extractall(target_path) |
| 50 | |
| 51 | |
| 52 | def untar(archive_path, target_path): |
| 53 | """Extracts tar file to a path. |
| 54 | |
| 55 | Args: |
| 56 | archive_path: Path to the tar file. |
| 57 | target_path: Path to extract files to. |
| 58 | """ |
| 59 | |
| 60 | with tarfile.open(archive_path, mode='r') as tfile: |
| 61 | tfile.extractall(target_path) |
| 62 | |
| 63 | |
| 64 | ARCHIVE_TYPES = { |
| 65 | '.zip': unzip, |
| 66 | '.tar.gz': untar, |
| 67 | '.tar.bz2': untar, |
| 68 | '.tar.xz': untar, |
| 69 | } |
| 70 | |
| 71 | |
| 72 | def is_supported_archive(url): |
| 73 | """Checks whether the url points to a supported archive.""" |
| 74 | return get_extract_func(url) is not None |
| 75 | |
| 76 | |
| 77 | def get_extract_func(url): |
| 78 | """Gets the function to extract an archive. |
| 79 | |
| 80 | Args: |
| 81 | url: The url to the archive file. |
| 82 | |
| 83 | Returns: |
| 84 | A function to extract the archive. None if not found. |
| 85 | """ |
| 86 | |
| 87 | parsed_url = urllib.parse.urlparse(url) |
| 88 | filename = os.path.basename(parsed_url.path) |
| 89 | for ext, func in ARCHIVE_TYPES.items(): |
| 90 | if filename.endswith(ext): |
| 91 | return func |
| 92 | return None |
| 93 | |
| 94 | |
| 95 | def download_and_extract(url): |
| 96 | """Downloads and extracts an archive file to a temporary directory. |
| 97 | |
| 98 | Args: |
| 99 | url: Url to download. |
| 100 | |
| 101 | Returns: |
| 102 | Path to the temporary directory. |
| 103 | """ |
| 104 | |
| 105 | print('Downloading {}'.format(url)) |
| 106 | archive_file, _headers = urllib.request.urlretrieve(url) |
| 107 | |
| 108 | temporary_dir = tempfile.mkdtemp() |
| 109 | print('Extracting {} to {}'.format(archive_file, temporary_dir)) |
| 110 | get_extract_func(url)(archive_file, temporary_dir) |
| 111 | |
| 112 | return temporary_dir |
| 113 | |
| 114 | |
| 115 | def find_archive_root(path): |
| 116 | """Finds the real root of an extracted archive. |
| 117 | |
| 118 | Sometimes archives has additional layers of directories. This function tries |
| 119 | to guess the right 'root' path by entering all single sub-directories. |
| 120 | |
| 121 | Args: |
| 122 | path: Path to the extracted archive. |
| 123 | |
| 124 | Returns: |
| 125 | The root path we found. |
| 126 | """ |
| 127 | for root, dirs, files in os.walk(path): |
| 128 | if files or len(dirs) > 1: |
| 129 | return root |
| 130 | return path |