diff --git a/econtext/compat/__init__.py b/econtext/compat/__init__.py new file mode 100644 index 00000000..e69de29b diff --git a/econtext/compat/pkgutil.py b/econtext/compat/pkgutil.py new file mode 100644 index 00000000..ce072ec9 --- /dev/null +++ b/econtext/compat/pkgutil.py @@ -0,0 +1,591 @@ +"""Utilities to support packages.""" + +# NOTE: This module must remain compatible with Python 2.3, as it is shared +# by setuptools for distribution with Python 2.3 and up. + +import os +import sys +import imp +import os.path +from types import ModuleType + +__all__ = [ + 'get_importer', 'iter_importers', 'get_loader', 'find_loader', + 'walk_packages', 'iter_modules', 'get_data', + 'ImpImporter', 'ImpLoader', 'read_code', 'extend_path', +] + +def read_code(stream): + # This helper is needed in order for the PEP 302 emulation to + # correctly handle compiled files + import marshal + + magic = stream.read(4) + if magic != imp.get_magic(): + return None + + stream.read(4) # Skip timestamp + return marshal.load(stream) + + +def simplegeneric(func): + """Make a trivial single-dispatch generic function""" + registry = {} + def wrapper(*args, **kw): + ob = args[0] + try: + cls = ob.__class__ + except AttributeError: + cls = type(ob) + try: + mro = cls.__mro__ + except AttributeError: + try: + class cls(cls, object): + pass + mro = cls.__mro__[1:] + except TypeError: + mro = object, # must be an ExtensionClass or some such :( + for t in mro: + if t in registry: + return registry[t](*args, **kw) + else: + return func(*args, **kw) + try: + wrapper.__name__ = func.__name__ + except (TypeError, AttributeError): + pass # Python 2.3 doesn't allow functions to be renamed + + def register(typ, func=None): + if func is None: + return lambda f: register(typ, f) + registry[typ] = func + return func + + wrapper.__dict__ = func.__dict__ + wrapper.__doc__ = func.__doc__ + wrapper.register = register + return wrapper + + +def walk_packages(path=None, prefix='', onerror=None): + """Yields (module_loader, name, ispkg) for all modules recursively + on path, or, if path is None, all accessible modules. + + 'path' should be either None or a list of paths to look for + modules in. + + 'prefix' is a string to output on the front of every module name + on output. + + Note that this function must import all *packages* (NOT all + modules!) on the given path, in order to access the __path__ + attribute to find submodules. + + 'onerror' is a function which gets called with one argument (the + name of the package which was being imported) if any exception + occurs while trying to import a package. If no onerror function is + supplied, ImportErrors are caught and ignored, while all other + exceptions are propagated, terminating the search. + + Examples: + + # list all modules python can access + walk_packages() + + # list all submodules of ctypes + walk_packages(ctypes.__path__, ctypes.__name__+'.') + """ + + def seen(p, m={}): + if p in m: + return True + m[p] = True + + for importer, name, ispkg in iter_modules(path, prefix): + yield importer, name, ispkg + + if ispkg: + try: + __import__(name) + except ImportError: + if onerror is not None: + onerror(name) + except Exception: + if onerror is not None: + onerror(name) + else: + raise + else: + path = getattr(sys.modules[name], '__path__', None) or [] + + # don't traverse path items we've seen before + path = [p for p in path if not seen(p)] + + for item in walk_packages(path, name+'.', onerror): + yield item + + +def iter_modules(path=None, prefix=''): + """Yields (module_loader, name, ispkg) for all submodules on path, + or, if path is None, all top-level modules on sys.path. + + 'path' should be either None or a list of paths to look for + modules in. + + 'prefix' is a string to output on the front of every module name + on output. + """ + + if path is None: + importers = iter_importers() + else: + importers = map(get_importer, path) + + yielded = {} + for i in importers: + for name, ispkg in iter_importer_modules(i, prefix): + if name not in yielded: + yielded[name] = 1 + yield i, name, ispkg + + +#@simplegeneric +def iter_importer_modules(importer, prefix=''): + if not hasattr(importer, 'iter_modules'): + return [] + return importer.iter_modules(prefix) + +iter_importer_modules = simplegeneric(iter_importer_modules) + + +class ImpImporter: + """PEP 302 Importer that wraps Python's "classic" import algorithm + + ImpImporter(dirname) produces a PEP 302 importer that searches that + directory. ImpImporter(None) produces a PEP 302 importer that searches + the current sys.path, plus any modules that are frozen or built-in. + + Note that ImpImporter does not currently support being used by placement + on sys.meta_path. + """ + + def __init__(self, path=None): + self.path = path + + def find_module(self, fullname, path=None): + # Note: we ignore 'path' argument since it is only used via meta_path + subname = fullname.split(".")[-1] + if subname != fullname and self.path is None: + return None + if self.path is None: + path = None + else: + path = [os.path.realpath(self.path)] + try: + file, filename, etc = imp.find_module(subname, path) + except ImportError: + return None + return ImpLoader(fullname, file, filename, etc) + + def iter_modules(self, prefix=''): + if self.path is None or not os.path.isdir(self.path): + return + + yielded = {} + import inspect + try: + filenames = os.listdir(self.path) + except OSError: + # ignore unreadable directories like import does + filenames = [] + filenames.sort() # handle packages before same-named modules + + for fn in filenames: + modname = inspect.getmodulename(fn) + if modname=='__init__' or modname in yielded: + continue + + path = os.path.join(self.path, fn) + ispkg = False + + if not modname and os.path.isdir(path) and '.' not in fn: + modname = fn + try: + dircontents = os.listdir(path) + except OSError: + # ignore unreadable directories like import does + dircontents = [] + for fn in dircontents: + subname = inspect.getmodulename(fn) + if subname=='__init__': + ispkg = True + break + else: + continue # not a package + + if modname and '.' not in modname: + yielded[modname] = 1 + yield prefix + modname, ispkg + + +class ImpLoader: + """PEP 302 Loader that wraps Python's "classic" import algorithm + """ + code = source = None + + def __init__(self, fullname, file, filename, etc): + self.file = file + self.filename = filename + self.fullname = fullname + self.etc = etc + + def load_module(self, fullname): + self._reopen() + try: + mod = imp.load_module(fullname, self.file, self.filename, self.etc) + finally: + if self.file: + self.file.close() + # Note: we don't set __loader__ because we want the module to look + # normal; i.e. this is just a wrapper for standard import machinery + return mod + + def get_data(self, pathname): + return open(pathname, "rb").read() + + def _reopen(self): + if self.file and self.file.closed: + mod_type = self.etc[2] + if mod_type==imp.PY_SOURCE: + self.file = open(self.filename, 'rU') + elif mod_type in (imp.PY_COMPILED, imp.C_EXTENSION): + self.file = open(self.filename, 'rb') + + def _fix_name(self, fullname): + if fullname is None: + fullname = self.fullname + elif fullname != self.fullname: + raise ImportError("Loader for module %s cannot handle " + "module %s" % (self.fullname, fullname)) + return fullname + + def is_package(self, fullname): + fullname = self._fix_name(fullname) + return self.etc[2]==imp.PKG_DIRECTORY + + def get_code(self, fullname=None): + fullname = self._fix_name(fullname) + if self.code is None: + mod_type = self.etc[2] + if mod_type==imp.PY_SOURCE: + source = self.get_source(fullname) + self.code = compile(source, self.filename, 'exec') + elif mod_type==imp.PY_COMPILED: + self._reopen() + try: + self.code = read_code(self.file) + finally: + self.file.close() + elif mod_type==imp.PKG_DIRECTORY: + self.code = self._get_delegate().get_code() + return self.code + + def get_source(self, fullname=None): + fullname = self._fix_name(fullname) + if self.source is None: + mod_type = self.etc[2] + if mod_type==imp.PY_SOURCE: + self._reopen() + try: + self.source = self.file.read() + finally: + self.file.close() + elif mod_type==imp.PY_COMPILED: + if os.path.exists(self.filename[:-1]): + f = open(self.filename[:-1], 'rU') + self.source = f.read() + f.close() + elif mod_type==imp.PKG_DIRECTORY: + self.source = self._get_delegate().get_source() + return self.source + + + def _get_delegate(self): + return ImpImporter(self.filename).find_module('__init__') + + def get_filename(self, fullname=None): + fullname = self._fix_name(fullname) + mod_type = self.etc[2] + if self.etc[2]==imp.PKG_DIRECTORY: + return self._get_delegate().get_filename() + elif self.etc[2] in (imp.PY_SOURCE, imp.PY_COMPILED, imp.C_EXTENSION): + return self.filename + return None + + +try: + import zipimport + from zipimport import zipimporter + + def iter_zipimport_modules(importer, prefix=''): + dirlist = zipimport._zip_directory_cache[importer.archive].keys() + dirlist.sort() + _prefix = importer.prefix + plen = len(_prefix) + yielded = {} + import inspect + for fn in dirlist: + if not fn.startswith(_prefix): + continue + + fn = fn[plen:].split(os.sep) + + if len(fn)==2 and fn[1].startswith('__init__.py'): + if fn[0] not in yielded: + yielded[fn[0]] = 1 + yield fn[0], True + + if len(fn)!=1: + continue + + modname = inspect.getmodulename(fn[0]) + if modname=='__init__': + continue + + if modname and '.' not in modname and modname not in yielded: + yielded[modname] = 1 + yield prefix + modname, False + + iter_importer_modules.register(zipimporter, iter_zipimport_modules) + +except ImportError: + pass + + +def get_importer(path_item): + """Retrieve a PEP 302 importer for the given path item + + The returned importer is cached in sys.path_importer_cache + if it was newly created by a path hook. + + If there is no importer, a wrapper around the basic import + machinery is returned. This wrapper is never inserted into + the importer cache (None is inserted instead). + + The cache (or part of it) can be cleared manually if a + rescan of sys.path_hooks is necessary. + """ + try: + importer = sys.path_importer_cache[path_item] + except KeyError: + for path_hook in sys.path_hooks: + try: + importer = path_hook(path_item) + break + except ImportError: + pass + else: + importer = None + sys.path_importer_cache.setdefault(path_item, importer) + + if importer is None: + try: + importer = ImpImporter(path_item) + except ImportError: + importer = None + return importer + + +def iter_importers(fullname=""): + """Yield PEP 302 importers for the given module name + + If fullname contains a '.', the importers will be for the package + containing fullname, otherwise they will be importers for sys.meta_path, + sys.path, and Python's "classic" import machinery, in that order. If + the named module is in a package, that package is imported as a side + effect of invoking this function. + + Non PEP 302 mechanisms (e.g. the Windows registry) used by the + standard import machinery to find files in alternative locations + are partially supported, but are searched AFTER sys.path. Normally, + these locations are searched BEFORE sys.path, preventing sys.path + entries from shadowing them. + + For this to cause a visible difference in behaviour, there must + be a module or package name that is accessible via both sys.path + and one of the non PEP 302 file system mechanisms. In this case, + the emulation will find the former version, while the builtin + import mechanism will find the latter. + + Items of the following types can be affected by this discrepancy: + imp.C_EXTENSION, imp.PY_SOURCE, imp.PY_COMPILED, imp.PKG_DIRECTORY + """ + if fullname.startswith('.'): + raise ImportError("Relative module names not supported") + if '.' in fullname: + # Get the containing package's __path__ + pkg = '.'.join(fullname.split('.')[:-1]) + if pkg not in sys.modules: + __import__(pkg) + path = getattr(sys.modules[pkg], '__path__', None) or [] + else: + for importer in sys.meta_path: + yield importer + path = sys.path + for item in path: + yield get_importer(item) + if '.' not in fullname: + yield ImpImporter() + +def get_loader(module_or_name): + """Get a PEP 302 "loader" object for module_or_name + + If the module or package is accessible via the normal import + mechanism, a wrapper around the relevant part of that machinery + is returned. Returns None if the module cannot be found or imported. + If the named module is not already imported, its containing package + (if any) is imported, in order to establish the package __path__. + + This function uses iter_importers(), and is thus subject to the same + limitations regarding platform-specific special import locations such + as the Windows registry. + """ + if module_or_name in sys.modules: + module_or_name = sys.modules[module_or_name] + if isinstance(module_or_name, ModuleType): + module = module_or_name + loader = getattr(module, '__loader__', None) + if loader is not None: + return loader + fullname = module.__name__ + else: + fullname = module_or_name + return find_loader(fullname) + +def find_loader(fullname): + """Find a PEP 302 "loader" object for fullname + + If fullname contains dots, path must be the containing package's __path__. + Returns None if the module cannot be found or imported. This function uses + iter_importers(), and is thus subject to the same limitations regarding + platform-specific special import locations such as the Windows registry. + """ + for importer in iter_importers(fullname): + loader = importer.find_module(fullname) + if loader is not None: + return loader + + return None + + +def extend_path(path, name): + """Extend a package's path. + + Intended use is to place the following code in a package's __init__.py: + + from pkgutil import extend_path + __path__ = extend_path(__path__, __name__) + + This will add to the package's __path__ all subdirectories of + directories on sys.path named after the package. This is useful + if one wants to distribute different parts of a single logical + package as multiple directories. + + It also looks for *.pkg files beginning where * matches the name + argument. This feature is similar to *.pth files (see site.py), + except that it doesn't special-case lines starting with 'import'. + A *.pkg file is trusted at face value: apart from checking for + duplicates, all entries found in a *.pkg file are added to the + path, regardless of whether they are exist the filesystem. (This + is a feature.) + + If the input path is not a list (as is the case for frozen + packages) it is returned unchanged. The input path is not + modified; an extended copy is returned. Items are only appended + to the copy at the end. + + It is assumed that sys.path is a sequence. Items of sys.path that + are not (unicode or 8-bit) strings referring to existing + directories are ignored. Unicode items of sys.path that cause + errors when used as filenames may cause this function to raise an + exception (in line with os.path.isdir() behavior). + """ + + if not isinstance(path, list): + # This could happen e.g. when this is called from inside a + # frozen package. Return the path unchanged in that case. + return path + + pname = os.path.join(*name.split('.')) # Reconstitute as relative path + # Just in case os.extsep != '.' + sname = os.extsep.join(name.split('.')) + sname_pkg = sname + os.extsep + "pkg" + init_py = "__init__" + os.extsep + "py" + + path = path[:] # Start with a copy of the existing path + + for dir in sys.path: + if not isinstance(dir, basestring) or not os.path.isdir(dir): + continue + subdir = os.path.join(dir, pname) + # XXX This may still add duplicate entries to path on + # case-insensitive filesystems + initfile = os.path.join(subdir, init_py) + if subdir not in path and os.path.isfile(initfile): + path.append(subdir) + # XXX Is this the right thing for subpackages like zope.app? + # It looks for a file named "zope.app.pkg" + pkgfile = os.path.join(dir, sname_pkg) + if os.path.isfile(pkgfile): + try: + f = open(pkgfile) + except IOError, msg: + sys.stderr.write("Can't open %s: %s\n" % + (pkgfile, msg)) + else: + for line in f: + line = line.rstrip('\n') + if not line or line.startswith('#'): + continue + path.append(line) # Don't check for existence! + f.close() + + return path + +def get_data(package, resource): + """Get a resource from a package. + + This is a wrapper round the PEP 302 loader get_data API. The package + argument should be the name of a package, in standard module format + (foo.bar). The resource argument should be in the form of a relative + filename, using '/' as the path separator. The parent directory name '..' + is not allowed, and nor is a rooted name (starting with a '/'). + + The function returns a binary string, which is the contents of the + specified resource. + + For packages located in the filesystem, which have already been imported, + this is the rough equivalent of + + d = os.path.dirname(sys.modules[package].__file__) + data = open(os.path.join(d, resource), 'rb').read() + + If the package cannot be located or loaded, or it uses a PEP 302 loader + which does not support get_data(), then None is returned. + """ + + loader = get_loader(package) + if loader is None or not hasattr(loader, 'get_data'): + return None + mod = sys.modules.get(package) or loader.load_module(package) + if mod is None or not hasattr(mod, '__file__'): + return None + + # Modify the resource name to be compatible with the loader.get_data + # signature - an os.path format "filename" starting with the dirname of + # the package's __file__ + parts = resource.split('/') + parts.insert(0, os.path.dirname(mod.__file__)) + resource_name = os.path.join(*parts) + return loader.get_data(resource_name) diff --git a/econtext/core.py b/econtext/core.py index 92c8ea20..b4689887 100644 --- a/econtext/core.py +++ b/econtext/core.py @@ -154,7 +154,12 @@ class Importer(object): """ def __init__(self, context): self._context = context - self._present = {'econtext': ['econtext.utils', 'econtext.master']} + self._present = {'econtext': [ + 'econtext.compat', + 'econtext.compat.pkgutil', + 'econtext.master', + 'econtext.utils', + ]} self.tls = threading.local() def __repr__(self): @@ -193,13 +198,13 @@ class Importer(object): if ret is None: raise ImportError('Master does not have %r' % (fullname,)) - is_pkg, present, path, data = ret + pkg_present, path, data = ret mod = sys.modules.setdefault(fullname, imp.new_module(fullname)) mod.__loader__ = self - if is_pkg: + if pkg_present is not None: # it's a package. mod.__path__ = [] mod.__package__ = fullname - self._present[fullname] = present + self._present[fullname] = pkg_present else: mod.__package__ = fullname.rpartition('.')[0] code = compile(zlib.decompress(data), 'master:' + path, 'exec') diff --git a/econtext/master.py b/econtext/master.py index e749e4b7..8f2c75da 100644 --- a/econtext/master.py +++ b/econtext/master.py @@ -17,6 +17,11 @@ import textwrap import types import zlib +if not hasattr(pkgutil, 'find_loader'): + # find_loader() was new in >=2.5, but the modern pkgutil.py syntax has + # been kept intentionally 2.3 compatible so we can reuse it. + from econtext.compat import pkgutil + import econtext.core @@ -38,10 +43,10 @@ def minimize_source(source): return source.replace(' ', '\t') -def get_child_modules(module, prefix): +def get_child_modules(path, fullname): """Return the canonical names of all submodules of a package `module`.""" - it = pkgutil.iter_modules(module.__path__, prefix) - return [name for _, name, _ in it] + it = pkgutil.iter_modules([os.path.dirname(path)]) + return ['%s.%s' % (fullname, name) for _, name, _ in it] def create_child(*args): @@ -103,31 +108,43 @@ class ModuleResponder(object): self._context.add_handle_cb(self.get_module, handle=econtext.core.GET_MODULE) + def __repr__(self): + return 'ModuleResponder(%r)' % (self._context,) + def get_module(self, data): if data == econtext.core._DEAD: return reply_to, fullname = data - LOG.debug('get_module(%r, %r)', reply_to, fullname) + LOG.debug('%r.get_module(%r, %r)', self, reply_to, fullname) try: - module = __import__(fullname, {}, {}, ['']) - is_pkg = getattr(module, '__path__', None) is not None - path = inspect.getsourcefile(module) - try: - source = inspect.getsource(module) - except IOError: - if not is_pkg: - raise - source = '\n' + loader = pkgutil.find_loader(fullname) + LOG.debug('pkgutil.find_loader(%r) -> %r', fullname, loader) + if loader is None: + raise ImportError('pkgutil provides no loader for %r' % + (fullname,)) + + path = loader.get_filename(fullname) + LOG.debug('%r.get_filename(%r) -> %r', loader, fullname, path) + + # Handle __main__ specially. + if path is None and fullname in sys.modules: + path = sys.modules[fullname].__file__.rstrip('co') + source = inspect.getsource(sys.modules[fullname]) + is_pkg = hasattr(sys.modules[fullname], '__path__') + else: + source = loader.get_source(fullname) + is_pkg = loader.is_package(fullname) if is_pkg: - prefix = module.__name__ + '.' - present = get_child_modules(module, prefix) + pkg_present = get_child_modules(path, fullname) + LOG.debug('get_child_modules(%r, %r) -> %r', + path, fullname, pkg_present) else: - present = None + pkg_present = None compressed = zlib.compress(minimize_source(source)) - reply = (is_pkg, present, path, compressed) + reply = (pkg_present, path, compressed) self._context.enqueue(reply_to, reply) except Exception: LOG.debug('While importing %r', fullname, exc_info=True)