Personal Computer World 2009 February/PCWFEB09.iso/Software/Linux/Kubuntu 8.10/kubuntu-8.10-desktop-i386.iso/casper/filesystem.squashfs/usr/lib/python2.5/imputil.pyc

Python Compiled Bytecode | 2008-10-29 | 16KB | 550 lines

# Source Generated with Decompyle++
# File: in.pyc (Python 2.5)

'''
Import utilities

Exported classes:
    ImportManager   Manage the import process

    Importer        Base class for replacing standard import functions
    BuiltinImporter Emulate the import mechanism for builtin and frozen modules

    DynLoadSuffixImporter
'''
import imp
import sys
import __builtin__
import struct
import marshal
__all__ = [
    'ImportManager',
    'Importer',
    'BuiltinImporter']
_StringType = type('')
_ModuleType = type(sys)

class ImportManager:
    '''Manage the import process.'''

    def install(self, namespace = vars(__builtin__)):
        '''Install this ImportManager into the specified namespace.'''
        if isinstance(namespace, _ModuleType):
            namespace = vars(namespace)

        self.previous_importer = namespace['__import__']
        self.namespace = namespace
        namespace['__import__'] = self._import_hook


    def uninstall(self):
        '''Restore the previous import mechanism.'''
        self.namespace['__import__'] = self.previous_importer


    def add_suffix(self, suffix, importFunc):
        if not callable(importFunc):
            raise AssertionError
        self.fs_imp.add_suffix(suffix, importFunc)

    clsFilesystemImporter = None

    def __init__(self, fs_imp = None):
        if not _os_stat:
            _os_bootstrap()

        if fs_imp is None:
            if not self.clsFilesystemImporter:
                pass
            cls = _FilesystemImporter
            fs_imp = cls()

        self.fs_imp = fs_imp
        for desc in imp.get_suffixes():
            if desc[2] == imp.C_EXTENSION:
                self.add_suffix(desc[0], DynLoadSuffixImporter(desc).import_file)
                continue

        self.add_suffix('.py', py_suffix_importer)


    def _import_hook(self, fqname, globals = None, locals = None, fromlist = None):
        '''Python calls this hook to locate and import a module.'''
        parts = fqname.split('.')
        parent = self._determine_import_context(globals)
        if parent:
            module = parent.__importer__._do_import(parent, parts, fromlist)
            if module:
                return module



        try:
            top_module = sys.modules[parts[0]]
        except KeyError:
            top_module = self._import_top_module(parts[0])
            if not top_module:
                raise ImportError, 'No module named ' + fqname

        except:
            top_module

        if len(parts) == 1:
            if not fromlist:
                return top_module

            if not top_module.__dict__.get('__ispkg__'):
                return top_module


        importer = top_module.__dict__.get('__importer__')
        if importer:
            return importer._finish_import(top_module, parts[1:], fromlist)

        if len(parts) == 2 and hasattr(top_module, parts[1]):
            if fromlist:
                return getattr(top_module, parts[1])
            else:
                return top_module

        raise ImportError, 'No module named ' + fqname


    def _determine_import_context(self, globals):
        '''Returns the context in which a module should be imported.

        The context could be a loaded (package) module and the imported module
        will be looked for within that package. The context could also be None,
        meaning there is no context -- the module should be looked for as a
        "top-level" module.
        '''
        if not globals or not globals.get('__importer__'):
            return None

        parent_fqname = globals['__name__']
        if globals['__ispkg__']:
            parent = sys.modules[parent_fqname]
            if not globals is parent.__dict__:
                raise AssertionError
            return parent

        i = parent_fqname.rfind('.')
        if i == -1:
            return None

        parent_fqname = parent_fqname[:i]
        parent = sys.modules[parent_fqname]
        if not parent.__name__ == parent_fqname:
            raise AssertionError
        return parent


    def _import_top_module(self, name):
        for item in sys.path:
            if isinstance(item, _StringType):
                module = self.fs_imp.import_from_dir(item, name)
            else:
                module = item.import_top(name)
            if module:
                return module
                continue



    def _reload_hook(self, module):
        '''Python calls this hook to reload a module.'''
        importer = module.__dict__.get('__importer__')
        if not importer:
            pass

        raise SystemError, 'reload not yet implemented'



class Importer:
    '''Base class for replacing standard import functions.'''

    def import_top(self, name):
        '''Import a top-level module.'''
        return self._import_one(None, name, name)


    def _finish_import(self, top, parts, fromlist):
        bottom = self._load_tail(top, parts)
        if not fromlist:
            return top

        if bottom.__ispkg__:
            self._import_fromlist(bottom, fromlist)

        return bottom


    def _import_one(self, parent, modname, fqname):
        '''Import a single module.'''

        try:
            return sys.modules[fqname]
        except KeyError:
            pass

        result = self.get_code(parent, modname, fqname)
        if result is None:
            return None

        module = self._process_result(result, fqname)
        if parent:
            setattr(parent, modname, module)

        return module


    def _process_result(self, .1, fqname):
        (ispkg, code, values) = .1
        is_module = isinstance(code, _ModuleType)
        if is_module:
            module = code
        else:
            module = imp.new_module(fqname)
        module.__importer__ = self
        module.__ispkg__ = ispkg
        module.__dict__.update(values)
        sys.modules[fqname] = module
        if not is_module:

            try:
                exec code in module.__dict__
            if fqname in sys.modules:
                del sys.modules[fqname]


            raise

        is_module
        module = sys.modules[fqname]
        module.__name__ = fqname
        return module


    def _load_tail(self, m, parts):
        '''Import the rest of the modules, down from the top-level module.

        Returns the last module in the dotted list of modules.
        '''
        for part in parts:
            fqname = '%s.%s' % (m.__name__, part)
            m = self._import_one(m, part, fqname)
            if not m:
                raise ImportError, 'No module named ' + fqname
                continue

        return m


    def _import_fromlist(self, package, fromlist):
        '''Import any sub-modules in the "from" list.'''
        if '*' in fromlist:
            fromlist = list(fromlist) + list(package.__dict__.get('__all__', []))

        for sub in fromlist:
            if sub != '*' and not hasattr(package, sub):
                subname = '%s.%s' % (package.__name__, sub)
                submod = self._import_one(package, sub, subname)
                if not submod:
                    raise ImportError, 'cannot import name ' + subname

            submod



    def _do_import(self, parent, parts, fromlist):
        '''Attempt to import the module relative to parent.

        This method is used when the import context specifies that <self>
        imported the parent module.
        '''
        top_name = parts[0]
        top_fqname = parent.__name__ + '.' + top_name
        top_module = self._import_one(parent, top_name, top_fqname)
        if not top_module:
            return None

        return self._finish_import(top_module, parts[1:], fromlist)


    def get_code(self, parent, modname, fqname):
        '''Find and retrieve the code for the given module.

        parent specifies a parent module to define a context for importing. It
        may be None, indicating no particular context for the search.

        modname specifies a single module (not dotted) within the parent.

        fqname specifies the fully-qualified module name. This is a
        (potentially) dotted name from the "root" of the module namespace
        down to the modname.
        If there is no parent, then modname==fqname.

        This method should return None, or a 3-tuple.

        * If the module was not found, then None should be returned.

        * The first item of the 2- or 3-tuple should be the integer 0 or 1,
            specifying whether the module that was found is a package or not.

        * The second item is the code object for the module (it will be
            executed within the new module\'s namespace). This item can also
            be a fully-loaded module object (e.g. loaded from a shared lib).

        * The third item is a dictionary of name/value pairs that will be
            inserted into new module before the code object is executed. This
            is provided in case the module\'s code expects certain values (such
            as where the module was found). When the second item is a module
            object, then these names/values will be inserted *after* the module
            has been loaded/initialized.
        '''
        raise RuntimeError, 'get_code not implemented'


if not __debug__ or 'c':
    pass
_suffix_char = 'o'
_suffix = '.py' + _suffix_char

def _compile(pathname, timestamp):
    """Compile (and cache) a Python source file.

    The file specified by <pathname> is compiled to a code object and
    returned.

    Presuming the appropriate privileges exist, the bytecodes will be
    saved back to the filesystem for future imports. The source file's
    modification timestamp must be provided as a Long value.
    """
    codestring = open(pathname, 'rU').read()
    if codestring and codestring[-1] != '\n':
        codestring = codestring + '\n'

    code = __builtin__.compile(codestring, pathname, 'exec')

    try:
        f = open(pathname + _suffix_char, 'wb')
    except IOError:
        pass

    f.write('\x00\x00\x00\x00')
    f.write(struct.pack('<I', timestamp))
    marshal.dump(code, f)
    f.flush()
    f.seek(0, 0)
    f.write(imp.get_magic())
    f.close()
    return code

_os_stat = None
_os_path_join = None

def _os_bootstrap():
    """Set up 'os' module replacement functions for use during import bootstrap."""
    global _os_stat, _os_path_join
    names = sys.builtin_module_names
    join = None
    if 'posix' in names:
        sep = '/'
        stat = stat
        import posix
    elif 'nt' in names:
        sep = '\\'
        stat = stat
        import nt
    elif 'dos' in names:
        sep = '\\'
        stat = stat
        import dos
    elif 'os2' in names:
        sep = '\\'
        stat = stat
        import os2
    elif 'mac' in names:
        stat = stat
        import mac

        def join(a, b):
            if a == '':
                return b

            if ':' not in a:
                a = ':' + a

            if a[-1:] != ':':
                a = a + ':'

            return a + b

    else:
        raise ImportError, 'no os specific module found'
    if join is None:

        def join(a, b, sep = sep):
            if a == '':
                return b

            lastchar = a[-1:]
            if lastchar == '/' or lastchar == sep:
                return a + b

            return a + sep + b


    _os_stat = stat
    _os_path_join = join


def _os_path_isdir(pathname):
    '''Local replacement for os.path.isdir().'''

    try:
        s = _os_stat(pathname)
    except OSError:
        return None

    return s.st_mode & 61440 == 16384


def _timestamp(pathname):
    '''Return the file modification time as a Long.'''

    try:
        s = _os_stat(pathname)
    except OSError:
        return None

    return long(s.st_mtime)


class BuiltinImporter(Importer):

    def get_code(self, parent, modname, fqname):
        if parent:
            return None

        if imp.is_builtin(modname):
            type = imp.C_BUILTIN
        elif imp.is_frozen(modname):
            type = imp.PY_FROZEN
        else:
            return None
        module = imp.load_module(modname, None, modname, ('', '', type))
        return (0, module, { })



class _FilesystemImporter(Importer):

    def __init__(self):
        self.suffixes = []


    def add_suffix(self, suffix, importFunc):
        if not callable(importFunc):
            raise AssertionError
        self.suffixes.append((suffix, importFunc))


    def import_from_dir(self, dir, fqname):
        result = self._import_pathname(_os_path_join(dir, fqname), fqname)
        if result:
            return self._process_result(result, fqname)



    def get_code(self, parent, modname, fqname):
        if not parent:
            raise AssertionError
        for submodule_path in parent.__path__:
            code = self._import_pathname(_os_path_join(submodule_path, modname), fqname)
            if code is not None:
                return code
                continue

        return self._import_pathname(_os_path_join(parent.__pkgdir__, modname), fqname)


    def _import_pathname(self, pathname, fqname):
        if _os_path_isdir(pathname):
            result = self._import_pathname(_os_path_join(pathname, '__init__'), fqname)
            if result:
                values = result[2]
                values['__pkgdir__'] = pathname
                values['__path__'] = [
                    pathname]
                return (1, result[1], values)

            return None

        for suffix, importFunc in self.suffixes:
            filename = pathname + suffix

            try:
                finfo = _os_stat(filename)
            except OSError:
                continue

            return importFunc(filename, finfo, fqname)




def py_suffix_importer(filename, finfo, fqname):
    file = filename[:-3] + _suffix
    t_py = long(finfo[8])
    t_pyc = _timestamp(file)
    code = None
    if t_pyc is not None and t_pyc >= t_py:
        f = open(file, 'rb')
        if f.read(4) == imp.get_magic():
            t = struct.unpack('<I', f.read(4))[0]
            if t == t_py:
                code = marshal.load(f)


        f.close()

    if code is None:
        file = filename
        code = _compile(file, t_py)

    return (0, code, {
        '__file__': file })


class DynLoadSuffixImporter:

    def __init__(self, desc):
        self.desc = desc


    def import_file(self, filename, finfo, fqname):
        fp = open(filename, self.desc[1])
        module = imp.load_module(fqname, fp, filename, self.desc)
        module.__file__ = filename
        return (0, module, { })



def _print_importers():
    items = sys.modules.items()
    items.sort()
    for name, module in items:
        if module:
            print name, module.__dict__.get('__importer__', '-- no importer')
            continue
        print name, '-- non-existent module'



def _test_revamp():
    ImportManager().install()
    sys.path.insert(0, BuiltinImporter())