The Tor Browser / file revision

 # This Source Code Form is subject to the terms of the Mozilla Public

 # License, v. 2.0. If a copy of the MPL was not distributed with this

 # file, You can obtain one at http://mozilla.org/MPL/2.0/.

 from __future__ import unicode_literals

 from contextlib import contextmanager

 import json

 from .files import (

     AbsoluteSymlinkFile,

     ExistingFile,

     File,

     FileFinder,

     PreprocessedFile,

 )

 import mozpack.path as mozpath

 # This probably belongs in a more generic module. Where?

 @contextmanager

 def _auto_fileobj(path, fileobj, mode='r'):

     if path and fileobj:

         raise AssertionError('Only 1 of path or fileobj may be defined.')

     if not path and not fileobj:

         raise AssertionError('Must specified 1 of path or fileobj.')

     if path:

         fileobj = open(path, mode)

     try:

         yield fileobj

     finally:

         if path:

             fileobj.close()

 class UnreadableInstallManifest(Exception):

     """Raised when an invalid install manifest is parsed."""

 class InstallManifest(object):

     """Describes actions to be used with a copier.FileCopier instance.

     This class facilitates serialization and deserialization of data used to

     construct a copier.FileCopier and to perform copy operations.

     The manifest defines source paths, destination paths, and a mechanism by

     which the destination file should come into existence.

     Entries in the manifest correspond to the following types:

       copy -- The file specified as the source path will be copied to the

           destination path.

       symlink -- The destination path will be a symlink to the source path.

           If symlinks are not supported, a copy will be performed.

       exists -- The destination path is accounted for and won't be deleted by

           the FileCopier. If the destination path doesn't exist, an error is

           raised.

       optional -- The destination path is accounted for and won't be deleted by

           the FileCopier. No error is raised if the destination path does not

           exist.

       patternsymlink -- Paths matched by the expression in the source path

           will be symlinked to the destination directory.

       patterncopy -- Similar to patternsymlink except files are copied, not

           symlinked.

       preprocess -- The file specified at the source path will be run through

           the preprocessor, and the output will be written to the destination

           path.

     Version 1 of the manifest was the initial version.

     Version 2 added optional path support

     Version 3 added support for pattern entries.

     Version 4 added preprocessed file support.

     """

     CURRENT_VERSION = 4

     FIELD_SEPARATOR = '\x1f'

     SYMLINK = 1

     COPY = 2

     REQUIRED_EXISTS = 3

     OPTIONAL_EXISTS = 4

     PATTERN_SYMLINK = 5

     PATTERN_COPY = 6

     PREPROCESS = 7

     def __init__(self, path=None, fileobj=None):

         """Create a new InstallManifest entry.

         If path is defined, the manifest will be populated with data from the

         file path.

         If fileobj is defined, the manifest will be populated with data read

         from the specified file object.

         Both path and fileobj cannot be defined.

         """

         self._dests = {}

         self._source_file = None

         if path or fileobj:

             with _auto_fileobj(path, fileobj, 'rb') as fh:

                 self._source_file = fh.name

                 self._load_from_fileobj(fh)

     def _load_from_fileobj(self, fileobj):

         version = fileobj.readline().rstrip()

         if version not in ('1', '2', '3', '4'):

             raise UnreadableInstallManifest('Unknown manifest version: ' %

                 version)

         for line in fileobj:

             line = line.rstrip()

             fields = line.split(self.FIELD_SEPARATOR)

             record_type = int(fields[0])

             if record_type == self.SYMLINK:

                 dest, source = fields[1:]

                 self.add_symlink(source, dest)

                 continue

             if record_type == self.COPY:

                 dest, source = fields[1:]

                 self.add_copy(source, dest)

                 continue

             if record_type == self.REQUIRED_EXISTS:

                 _, path = fields

                 self.add_required_exists(path)

                 continue

             if record_type == self.OPTIONAL_EXISTS:

                 _, path = fields

                 self.add_optional_exists(path)

                 continue

             if record_type == self.PATTERN_SYMLINK:

                 _, base, pattern, dest = fields[1:]

                 self.add_pattern_symlink(base, pattern, dest)

                 continue

             if record_type == self.PATTERN_COPY:

                 _, base, pattern, dest = fields[1:]

                 self.add_pattern_copy(base, pattern, dest)

                 continue

             if record_type == self.PREPROCESS:

                 dest, source, deps, marker, defines = fields[1:]

                 self.add_preprocess(source, dest, deps, marker,

                     self._decode_field_entry(defines))

                 continue

             raise UnreadableInstallManifest('Unknown record type: %d' %

                 record_type)

     def __len__(self):

         return len(self._dests)

     def __contains__(self, item):

         return item in self._dests

     def __eq__(self, other):

         return isinstance(other, InstallManifest) and self._dests == other._dests

     def __neq__(self, other):

         return not self.__eq__(other)

     def __ior__(self, other):

         if not isinstance(other, InstallManifest):

             raise ValueError('Can only | with another instance of InstallManifest.')

         for dest in sorted(other._dests):

             self._add_entry(dest, other._dests[dest])

         return self

     def _encode_field_entry(self, data):

         """Converts an object into a format that can be stored in the manifest file.

         Complex data types, such as ``dict``, need to be converted into a text

         representation before they can be written to a file.

         """

         return json.dumps(data, sort_keys=True)

     def _decode_field_entry(self, data):

         """Restores an object from a format that can be stored in the manifest file.

         Complex data types, such as ``dict``, need to be converted into a text

         representation before they can be written to a file.

         """

         return json.loads(data)

     def write(self, path=None, fileobj=None):

         """Serialize this manifest to a file or file object.

         If path is specified, that file will be written to. If fileobj is specified,

         the serialized content will be written to that file object.

         It is an error if both are specified.

         """

         with _auto_fileobj(path, fileobj, 'wb') as fh:

             fh.write('%d\n' % self.CURRENT_VERSION)

             for dest in sorted(self._dests):

                 entry = self._dests[dest]

                 parts = ['%d' % entry[0], dest]

                 parts.extend(entry[1:])

                 fh.write('%s\n' % self.FIELD_SEPARATOR.join(

                     p.encode('utf-8') for p in parts))

     def add_symlink(self, source, dest):

         """Add a symlink to this manifest.

         dest will be a symlink to source.

         """

         self._add_entry(dest, (self.SYMLINK, source))

     def add_copy(self, source, dest):

         """Add a copy to this manifest.

         source will be copied to dest.

         """

         self._add_entry(dest, (self.COPY, source))

     def add_required_exists(self, dest):

         """Record that a destination file must exist.

         This effectively prevents the listed file from being deleted.

         """

         self._add_entry(dest, (self.REQUIRED_EXISTS,))

     def add_optional_exists(self, dest):

         """Record that a destination file may exist.

         This effectively prevents the listed file from being deleted. Unlike a

         "required exists" file, files of this type do not raise errors if the

         destination file does not exist.

         """

         self._add_entry(dest, (self.OPTIONAL_EXISTS,))

     def add_pattern_symlink(self, base, pattern, dest):

         """Add a pattern match that results in symlinks being created.

         A ``FileFinder`` will be created with its base set to ``base``

         and ``FileFinder.find()`` will be called with ``pattern`` to discover

         source files. Each source file will be symlinked under ``dest``.

         Filenames under ``dest`` are constructed by taking the path fragment

         after ``base`` and concatenating it with ``dest``. e.g.

            <base>/foo/bar.h -> <dest>/foo/bar.h

         """

         self._add_entry(mozpath.join(base, pattern, dest),

             (self.PATTERN_SYMLINK, base, pattern, dest))

     def add_pattern_copy(self, base, pattern, dest):

         """Add a pattern match that results in copies.

         See ``add_pattern_symlink()`` for usage.

         """

         self._add_entry(mozpath.join(base, pattern, dest),

             (self.PATTERN_COPY, base, pattern, dest))

     def add_preprocess(self, source, dest, deps, marker='#', defines={}):

         """Add a preprocessed file to this manifest.

         ``source`` will be passed through preprocessor.py, and the output will be

         written to ``dest``.

         """

         self._add_entry(dest,

             (self.PREPROCESS, source, deps, marker, self._encode_field_entry(defines)))

     def _add_entry(self, dest, entry):

         if dest in self._dests:

             raise ValueError('Item already in manifest: %s' % dest)

         self._dests[dest] = entry

     def _get_deps(self, dest):

         return {self._source_file} if self._source_file else set()

     def populate_registry(self, registry):

         """Populate a mozpack.copier.FileRegistry instance with data from us.

         The caller supplied a FileRegistry instance (or at least something that

         conforms to its interface) and that instance is populated with data

         from this manifest.

         """

         for dest in sorted(self._dests):

             entry = self._dests[dest]

             install_type = entry[0]

             if install_type == self.SYMLINK:

                 registry.add(dest, AbsoluteSymlinkFile(entry[1]))

                 continue

             if install_type == self.COPY:

                 registry.add(dest, File(entry[1]))

                 continue

             if install_type == self.REQUIRED_EXISTS:

                 registry.add(dest, ExistingFile(required=True))

                 continue

             if install_type == self.OPTIONAL_EXISTS:

                 registry.add(dest, ExistingFile(required=False))

                 continue

             if install_type in (self.PATTERN_SYMLINK, self.PATTERN_COPY):

                 _, base, pattern, dest = entry

                 finder = FileFinder(base, find_executables=False)

                 paths = [f[0] for f in finder.find(pattern)]

                 if install_type == self.PATTERN_SYMLINK:

                     cls = AbsoluteSymlinkFile

                 else:

                     cls = File

                 for path in paths:

                     source = mozpath.join(base, path)

                     registry.add(mozpath.join(dest, path), cls(source))

                 continue

             if install_type == self.PREPROCESS:

                 registry.add(dest, PreprocessedFile(entry[1],

                     depfile_path=entry[2],

                     marker=entry[3],

                     defines=self._decode_field_entry(entry[4]),

                     extra_depends=self._get_deps(dest)))

                 continue

             raise Exception('Unknown install type defined in manifest: %d' %

                 install_type)