filesystem.py revision 2bde8e466a4451c7319e3a072d118917957d6554 
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28
29"""Wrapper object for the file system / source tree."""
30
31from __future__ import with_statement
32
33import codecs
34import errno
35import exceptions
36import glob
37import os
38import shutil
39import tempfile
40import time
41
42from webkitpy.common.system import ospath
43
44class FileSystem(object):
45    """FileSystem interface for webkitpy.
46
47    Unless otherwise noted, all paths are allowed to be either absolute
48    or relative."""
49    def __init__(self):
50        self._sep = os.sep
51
52    def _get_sep(self):
53        return self._sep
54
55    sep = property(_get_sep, doc="pathname separator")
56
57    def abspath(self, path):
58        return os.path.abspath(path)
59
60    def basename(self, path):
61        """Wraps os.path.basename()."""
62        return os.path.basename(path)
63
64    def copyfile(self, source, destination):
65        """Copies the contents of the file at the given path to the destination
66        path."""
67        shutil.copyfile(source, destination)
68
69    def dirname(self, path):
70        """Wraps os.path.dirname()."""
71        return os.path.dirname(path)
72
73    def exists(self, path):
74        """Return whether the path exists in the filesystem."""
75        return os.path.exists(path)
76
77    def files_under(self, path, dirs_to_skip=[], file_filter=None):
78        """Return the list of all files under the given path in topdown order.
79
80        Args:
81            dirs_to_skip: a list of directories to skip over during the
82                traversal (e.g., .svn, resources, etc.)
83            file_filter: if not None, the filter will be invoked
84                with the filesystem object and the dirname and basename of
85                each file found. The file is included in the result if the
86                callback returns True.
87        """
88        def filter_all(fs, dirpath, basename):
89            return True
90
91        file_filter = file_filter or filter_all
92        files = []
93        if self.isfile(path):
94            if file_filter(self, self.dirname(path), self.basename(path)):
95                files.append(path)
96            return files
97
98        if self.basename(path) in dirs_to_skip:
99            return []
100
101        for (dirpath, dirnames, filenames) in os.walk(path):
102            for d in dirs_to_skip:
103                if d in dirnames:
104                    dirnames.remove(d)
105
106            for filename in filenames:
107                if file_filter(self, dirpath, filename):
108                    files.append(self.join(dirpath, filename))
109        return files
110
111    def glob(self, path):
112        """Wraps glob.glob()."""
113        return glob.glob(path)
114
115    def isabs(self, path):
116        """Return whether the path is an absolute path."""
117        return os.path.isabs(path)
118
119    def isfile(self, path):
120        """Return whether the path refers to a file."""
121        return os.path.isfile(path)
122
123    def isdir(self, path):
124        """Return whether the path refers to a directory."""
125        return os.path.isdir(path)
126
127    def join(self, *comps):
128        """Return the path formed by joining the components."""
129        return os.path.join(*comps)
130
131    def listdir(self, path):
132        """Return the contents of the directory pointed to by path."""
133        return os.listdir(path)
134
135    def mkdtemp(self, **kwargs):
136        """Create and return a uniquely named directory.
137
138        This is like tempfile.mkdtemp, but if used in a with statement
139        the directory will self-delete at the end of the block (if the
140        directory is empty; non-empty directories raise errors). The
141        directory can be safely deleted inside the block as well, if so
142        desired.
143
144        Note that the object returned is not a string and does not support all of the string
145        methods. If you need a string, coerce the object to a string and go from there.
146        """
147        class TemporaryDirectory(object):
148            def __init__(self, **kwargs):
149                self._kwargs = kwargs
150                self._directory_path = tempfile.mkdtemp(**self._kwargs)
151
152            def __str__(self):
153                return self._directory_path
154
155            def __enter__(self):
156                return self._directory_path
157
158            def __exit__(self, type, value, traceback):
159                # Only self-delete if necessary.
160
161                # FIXME: Should we delete non-empty directories?
162                if os.path.exists(self._directory_path):
163                    os.rmdir(self._directory_path)
164
165        return TemporaryDirectory(**kwargs)
166
167    def maybe_make_directory(self, *path):
168        """Create the specified directory if it doesn't already exist."""
169        try:
170            os.makedirs(self.join(*path))
171        except OSError, e:
172            if e.errno != errno.EEXIST:
173                raise
174
175    def move(self, source, destination):
176        shutil.move(source, destination)
177
178    def mtime(self, path):
179        return os.stat(path).st_mtime
180
181    def normpath(self, path):
182        """Wraps os.path.normpath()."""
183        return os.path.normpath(path)
184
185    def open_binary_tempfile(self, suffix):
186        """Create, open, and return a binary temp file. Returns a tuple of the file and the name."""
187        temp_fd, temp_name = tempfile.mkstemp(suffix)
188        f = os.fdopen(temp_fd, 'wb')
189        return f, temp_name
190
191    def open_text_file_for_writing(self, path, append=False):
192        """Returns a file handle suitable for writing to."""
193        mode = 'w'
194        if append:
195            mode = 'a'
196        return codecs.open(path, mode, 'utf8')
197
198    def open_binary_file_for_reading(self, path):
199        return codecs.open(path, 'rb')
200
201    def read_binary_file(self, path):
202        """Return the contents of the file at the given path as a byte string."""
203        with file(path, 'rb') as f:
204            return f.read()
205
206    def read_text_file(self, path):
207        """Return the contents of the file at the given path as a Unicode string.
208
209        The file is read assuming it is a UTF-8 encoded file with no BOM."""
210        with codecs.open(path, 'r', 'utf8') as f:
211            return f.read()
212
213    def relpath(self, path, start='.'):
214        return ospath.relpath(path, start)
215
216    class _WindowsError(exceptions.OSError):
217        """Fake exception for Linux and Mac."""
218        pass
219
220    def remove(self, path, osremove=os.remove):
221        """On Windows, if a process was recently killed and it held on to a
222        file, the OS will hold on to the file for a short while.  This makes
223        attempts to delete the file fail.  To work around that, this method
224        will retry for a few seconds until Windows is done with the file."""
225        try:
226            exceptions.WindowsError
227        except AttributeError:
228            exceptions.WindowsError = FileSystem._WindowsError
229
230        retry_timeout_sec = 3.0
231        sleep_interval = 0.1
232        while True:
233            try:
234                osremove(path)
235                return True
236            except exceptions.WindowsError, e:
237                time.sleep(sleep_interval)
238                retry_timeout_sec -= sleep_interval
239                if retry_timeout_sec < 0:
240                    raise e
241
242    def rmtree(self, path):
243        """Delete the directory rooted at path, empty or no."""
244        shutil.rmtree(path, ignore_errors=True)
245
246    def read_binary_file(self, path):
247        """Return the contents of the file at the given path as a byte string."""
248        with file(path, 'rb') as f:
249            return f.read()
250
251    def read_text_file(self, path):
252        """Return the contents of the file at the given path as a Unicode string.
253
254        The file is read assuming it is a UTF-8 encoded file with no BOM."""
255        with codecs.open(path, 'r', 'utf8') as f:
256            return f.read()
257
258    def splitext(self, path):
259        """Return (dirname + os.sep + basename, '.' + ext)"""
260        return os.path.splitext(path)
261
262    def write_binary_file(self, path, contents):
263        """Write the contents to the file at the given location."""
264        with file(path, 'wb') as f:
265            f.write(contents)
266
267    def write_text_file(self, path, contents):
268        """Write the contents to the file at the given location.
269
270        The file is written encoded as UTF-8 with no BOM."""
271        with codecs.open(path, 'w', 'utf8') as f:
272            f.write(contents)
273