diff options
Diffstat (limited to 'platform_utils.py')
-rw-r--r-- | platform_utils.py | 183 |
1 files changed, 16 insertions, 167 deletions
diff --git a/platform_utils.py b/platform_utils.py index 06ef9b18..0203249a 100644 --- a/platform_utils.py +++ b/platform_utils.py | |||
@@ -1,5 +1,3 @@ | |||
1 | # -*- coding:utf-8 -*- | ||
2 | # | ||
3 | # Copyright (C) 2016 The Android Open Source Project | 1 | # Copyright (C) 2016 The Android Open Source Project |
4 | # | 2 | # |
5 | # Licensed under the Apache License, Version 2.0 (the "License"); | 3 | # Licensed under the Apache License, Version 2.0 (the "License"); |
@@ -17,18 +15,9 @@ | |||
17 | import errno | 15 | import errno |
18 | import os | 16 | import os |
19 | import platform | 17 | import platform |
20 | import select | ||
21 | import shutil | 18 | import shutil |
22 | import stat | 19 | import stat |
23 | 20 | ||
24 | from pyversion import is_python3 | ||
25 | if is_python3(): | ||
26 | from queue import Queue | ||
27 | else: | ||
28 | from Queue import Queue | ||
29 | |||
30 | from threading import Thread | ||
31 | |||
32 | 21 | ||
33 | def isWindows(): | 22 | def isWindows(): |
34 | """ Returns True when running with the native port of Python for Windows, | 23 | """ Returns True when running with the native port of Python for Windows, |
@@ -39,145 +28,6 @@ def isWindows(): | |||
39 | return platform.system() == "Windows" | 28 | return platform.system() == "Windows" |
40 | 29 | ||
41 | 30 | ||
42 | class FileDescriptorStreams(object): | ||
43 | """ Platform agnostic abstraction enabling non-blocking I/O over a | ||
44 | collection of file descriptors. This abstraction is required because | ||
45 | fctnl(os.O_NONBLOCK) is not supported on Windows. | ||
46 | """ | ||
47 | @classmethod | ||
48 | def create(cls): | ||
49 | """ Factory method: instantiates the concrete class according to the | ||
50 | current platform. | ||
51 | """ | ||
52 | if isWindows(): | ||
53 | return _FileDescriptorStreamsThreads() | ||
54 | else: | ||
55 | return _FileDescriptorStreamsNonBlocking() | ||
56 | |||
57 | def __init__(self): | ||
58 | self.streams = [] | ||
59 | |||
60 | def add(self, fd, dest, std_name): | ||
61 | """ Wraps an existing file descriptor as a stream. | ||
62 | """ | ||
63 | self.streams.append(self._create_stream(fd, dest, std_name)) | ||
64 | |||
65 | def remove(self, stream): | ||
66 | """ Removes a stream, when done with it. | ||
67 | """ | ||
68 | self.streams.remove(stream) | ||
69 | |||
70 | @property | ||
71 | def is_done(self): | ||
72 | """ Returns True when all streams have been processed. | ||
73 | """ | ||
74 | return len(self.streams) == 0 | ||
75 | |||
76 | def select(self): | ||
77 | """ Returns the set of streams that have data available to read. | ||
78 | The returned streams each expose a read() and a close() method. | ||
79 | When done with a stream, call the remove(stream) method. | ||
80 | """ | ||
81 | raise NotImplementedError | ||
82 | |||
83 | def _create_stream(self, fd, dest, std_name): | ||
84 | """ Creates a new stream wrapping an existing file descriptor. | ||
85 | """ | ||
86 | raise NotImplementedError | ||
87 | |||
88 | |||
89 | class _FileDescriptorStreamsNonBlocking(FileDescriptorStreams): | ||
90 | """ Implementation of FileDescriptorStreams for platforms that support | ||
91 | non blocking I/O. | ||
92 | """ | ||
93 | class Stream(object): | ||
94 | """ Encapsulates a file descriptor """ | ||
95 | def __init__(self, fd, dest, std_name): | ||
96 | self.fd = fd | ||
97 | self.dest = dest | ||
98 | self.std_name = std_name | ||
99 | self.set_non_blocking() | ||
100 | |||
101 | def set_non_blocking(self): | ||
102 | import fcntl | ||
103 | flags = fcntl.fcntl(self.fd, fcntl.F_GETFL) | ||
104 | fcntl.fcntl(self.fd, fcntl.F_SETFL, flags | os.O_NONBLOCK) | ||
105 | |||
106 | def fileno(self): | ||
107 | return self.fd.fileno() | ||
108 | |||
109 | def read(self): | ||
110 | return self.fd.read(4096) | ||
111 | |||
112 | def close(self): | ||
113 | self.fd.close() | ||
114 | |||
115 | def _create_stream(self, fd, dest, std_name): | ||
116 | return self.Stream(fd, dest, std_name) | ||
117 | |||
118 | def select(self): | ||
119 | ready_streams, _, _ = select.select(self.streams, [], []) | ||
120 | return ready_streams | ||
121 | |||
122 | |||
123 | class _FileDescriptorStreamsThreads(FileDescriptorStreams): | ||
124 | """ Implementation of FileDescriptorStreams for platforms that don't support | ||
125 | non blocking I/O. This implementation requires creating threads issuing | ||
126 | blocking read operations on file descriptors. | ||
127 | """ | ||
128 | def __init__(self): | ||
129 | super(_FileDescriptorStreamsThreads, self).__init__() | ||
130 | # The queue is shared accross all threads so we can simulate the | ||
131 | # behavior of the select() function | ||
132 | self.queue = Queue(10) # Limit incoming data from streams | ||
133 | |||
134 | def _create_stream(self, fd, dest, std_name): | ||
135 | return self.Stream(fd, dest, std_name, self.queue) | ||
136 | |||
137 | def select(self): | ||
138 | # Return only one stream at a time, as it is the most straighforward | ||
139 | # thing to do and it is compatible with the select() function. | ||
140 | item = self.queue.get() | ||
141 | stream = item.stream | ||
142 | stream.data = item.data | ||
143 | return [stream] | ||
144 | |||
145 | class QueueItem(object): | ||
146 | """ Item put in the shared queue """ | ||
147 | def __init__(self, stream, data): | ||
148 | self.stream = stream | ||
149 | self.data = data | ||
150 | |||
151 | class Stream(object): | ||
152 | """ Encapsulates a file descriptor """ | ||
153 | def __init__(self, fd, dest, std_name, queue): | ||
154 | self.fd = fd | ||
155 | self.dest = dest | ||
156 | self.std_name = std_name | ||
157 | self.queue = queue | ||
158 | self.data = None | ||
159 | self.thread = Thread(target=self.read_to_queue) | ||
160 | self.thread.daemon = True | ||
161 | self.thread.start() | ||
162 | |||
163 | def close(self): | ||
164 | self.fd.close() | ||
165 | |||
166 | def read(self): | ||
167 | data = self.data | ||
168 | self.data = None | ||
169 | return data | ||
170 | |||
171 | def read_to_queue(self): | ||
172 | """ The thread function: reads everything from the file descriptor into | ||
173 | the shared queue and terminates when reaching EOF. | ||
174 | """ | ||
175 | for line in iter(self.fd.readline, b''): | ||
176 | self.queue.put(_FileDescriptorStreamsThreads.QueueItem(self, line)) | ||
177 | self.fd.close() | ||
178 | self.queue.put(_FileDescriptorStreamsThreads.QueueItem(self, None)) | ||
179 | |||
180 | |||
181 | def symlink(source, link_name): | 31 | def symlink(source, link_name): |
182 | """Creates a symbolic link pointing to source named link_name. | 32 | """Creates a symbolic link pointing to source named link_name. |
183 | Note: On Windows, source must exist on disk, as the implementation needs | 33 | Note: On Windows, source must exist on disk, as the implementation needs |
@@ -274,31 +124,30 @@ def rename(src, dst): | |||
274 | else: | 124 | else: |
275 | raise | 125 | raise |
276 | else: | 126 | else: |
277 | os.rename(src, dst) | 127 | shutil.move(src, dst) |
278 | 128 | ||
279 | 129 | ||
280 | def remove(path): | 130 | def remove(path, missing_ok=False): |
281 | """Remove (delete) the file path. This is a replacement for os.remove that | 131 | """Remove (delete) the file path. This is a replacement for os.remove that |
282 | allows deleting read-only files on Windows, with support for long paths and | 132 | allows deleting read-only files on Windows, with support for long paths and |
283 | for deleting directory symbolic links. | 133 | for deleting directory symbolic links. |
284 | 134 | ||
285 | Availability: Unix, Windows.""" | 135 | Availability: Unix, Windows.""" |
286 | if isWindows(): | 136 | longpath = _makelongpath(path) if isWindows() else path |
287 | longpath = _makelongpath(path) | 137 | try: |
288 | try: | 138 | os.remove(longpath) |
289 | os.remove(longpath) | 139 | except OSError as e: |
290 | except OSError as e: | 140 | if e.errno == errno.EACCES: |
291 | if e.errno == errno.EACCES: | 141 | os.chmod(longpath, stat.S_IWRITE) |
292 | os.chmod(longpath, stat.S_IWRITE) | 142 | # Directory symbolic links must be deleted with 'rmdir'. |
293 | # Directory symbolic links must be deleted with 'rmdir'. | 143 | if islink(longpath) and isdir(longpath): |
294 | if islink(longpath) and isdir(longpath): | 144 | os.rmdir(longpath) |
295 | os.rmdir(longpath) | ||
296 | else: | ||
297 | os.remove(longpath) | ||
298 | else: | 145 | else: |
299 | raise | 146 | os.remove(longpath) |
300 | else: | 147 | elif missing_ok and e.errno == errno.ENOENT: |
301 | os.remove(path) | 148 | pass |
149 | else: | ||
150 | raise | ||
302 | 151 | ||
303 | 152 | ||
304 | def walk(top, topdown=True, onerror=None, followlinks=False): | 153 | def walk(top, topdown=True, onerror=None, followlinks=False): |