[Py2exe-checkins] py2exe zipextimporter.py,NONE,1.1

[Thomas H. <th...@us...>]

Update of /cvsroot/py2exe/py2exe
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv23675

Added Files:
	zipextimporter.py 
Log Message:
The zipextimporter, which allows to load dlls and pyds from zip
archives, without unpacking them to the file system.


--- NEW FILE: zipextimporter.py ---
"""zipextimporter - an importer which can import extension modules from zipfiles

Overview
========

zipextimporter.py contains the ZipExtImporter class which allows to
load Python binary extension modules contained in a zip.archive,
without unpacking them to the file system.

Call the zipextimporter.install() function to install the import hook,
add a zip-file containing .pyd or .dll extension modules to sys.path,
and import them.

It uses the _memimporter extension which uses code from Joachim
Bauch's MemoryModule library.  This library emulates the win32 api
function LoadLibrary.

Sample usage
============

>>> import zipextimporter
>>> zipextimporter.install()
>>> import sys
>>> sys.path.append("lib.zip")
>>> import _socket
>>> _socket.__file__
'c:\\sf\\py2exe\\hacks\\memimp\\lib.zip\\_socket.pyd'
>>> _socket.__loader__
<ZipExtensionImporter at a74480>
>>>

Bugs
====

reload() on already imported extension modules does not work
correctly: It happily loads the extension a second time.
"""
import imp, sys
import zipimport
import _memimporter

class ZipExtensionImporter(zipimport.zipimporter):
    _suffixes = [s[0] for s in imp.get_suffixes() if s[2] == imp.C_EXTENSION]

    def find_module(self, fullname, path=None):
        result = zipimport.zipimporter.find_module(self, fullname, path)
        if result:
            return result
        if fullname in ("pywintypes", "pythoncom"):
            fullname = fullname + "%d%d" % sys.version_info[:2]
        fullname = fullname.replace(".", "\\")
        for s in self._suffixes:
            if (fullname + s) in self._files:
                return self
        return None

    def locate_dll_image(self, name):
        # A callback function for_memimporter.import_module.  Tries to
        # locate additional dlls.  Returns the image as Python string,
        # or None if not found.
        if name in self._files:
            return self.get_data(name)
        return None

    def load_module(self, fullname):
        _memimporter.set_find_proc(self.locate_dll_image)
        try:
            return zipimport.zipimporter.load_module(self, fullname)
        except zipimport.ZipImportError:
            pass
        initname = fullname.split(".")[-1]
        fullname = fullname.replace(".", "\\")
        if fullname in ("pywintypes", "pythoncom"):
            fullname = fullname + "%d%d" % sys.version_info[:2]
        for s in self._suffixes:
            path = fullname + s
            if path in self._files:
                # XXX should check sys.modules first ? See PEP302 on reload
                # XXX maybe in C code...
                code = self.get_data(path)
                mod = _memimporter.import_module(code, "init" + initname, path)
                mod.__file__ = "%s\\%s" % (self.archive, path)
                mod.__loader__ = self
                if _memimporter.get_verbose_flag():
                    sys.stderr.write("import %s # loaded from zipfile %s\n" % (fullname, mod.__file__))
                return mod
        raise zipimport.ZipImportError, "can't find module %s" % fullname

    def __repr__(self):
        return "<%s object %r>" % (self.__class__.__name__, self.archive)

def install():
    "Install the zipextimporter"
    sys.path_hooks.insert(0, ZipExtensionImporter)
    sys.path_importer_cache.clear()

##if __name__ == "__main__":
##    print ZipExtensionImporter("lib.zip")