Merge flask framework and other stuff from master

1 files changed, 260 insertions, 0 deletions

diff --git a/python/werkzeug/middleware/shared_data.py b/python/werkzeug/middleware/shared_data.py
new file mode 100644
index 0000000..a902281
--- /dev/null
+++ b/python/werkzeug/middleware/shared_data.py
@@ -0,0 +1,260 @@
+"""
+Serve Shared Static Files
+=========================
+
+.. autoclass:: SharedDataMiddleware
+    :members: is_allowed
+
+:copyright: 2007 Pallets
+:license: BSD-3-Clause
+"""
+import mimetypes
+import os
+import posixpath
+from datetime import datetime
+from io import BytesIO
+from time import mktime
+from time import time
+from zlib import adler32
+
+from .._compat import PY2
+from .._compat import string_types
+from ..filesystem import get_filesystem_encoding
+from ..http import http_date
+from ..http import is_resource_modified
+from ..wsgi import get_path_info
+from ..wsgi import wrap_file
+
+
+class SharedDataMiddleware(object):
+
+    """A WSGI middleware that provides static content for development
+    environments or simple server setups. Usage is quite simple::
+
+        import os
+        from werkzeug.wsgi import SharedDataMiddleware
+
+        app = SharedDataMiddleware(app, {
+            '/static': os.path.join(os.path.dirname(__file__), 'static')
+        })
+
+    The contents of the folder ``./shared`` will now be available on
+    ``http://example.com/shared/``.  This is pretty useful during development
+    because a standalone media server is not required.  One can also mount
+    files on the root folder and still continue to use the application because
+    the shared data middleware forwards all unhandled requests to the
+    application, even if the requests are below one of the shared folders.
+
+    If `pkg_resources` is available you can also tell the middleware to serve
+    files from package data::
+
+        app = SharedDataMiddleware(app, {
+            '/static': ('myapplication', 'static')
+        })
+
+    This will then serve the ``static`` folder in the `myapplication`
+    Python package.
+
+    The optional `disallow` parameter can be a list of :func:`~fnmatch.fnmatch`
+    rules for files that are not accessible from the web.  If `cache` is set to
+    `False` no caching headers are sent.
+
+    Currently the middleware does not support non ASCII filenames.  If the
+    encoding on the file system happens to be the encoding of the URI it may
+    work but this could also be by accident.  We strongly suggest using ASCII
+    only file names for static files.
+
+    The middleware will guess the mimetype using the Python `mimetype`
+    module.  If it's unable to figure out the charset it will fall back
+    to `fallback_mimetype`.
+
+    .. versionchanged:: 0.5
+       The cache timeout is configurable now.
+
+    .. versionadded:: 0.6
+       The `fallback_mimetype` parameter was added.
+
+    :param app: the application to wrap.  If you don't want to wrap an
+                application you can pass it :exc:`NotFound`.
+    :param exports: a list or dict of exported files and folders.
+    :param disallow: a list of :func:`~fnmatch.fnmatch` rules.
+    :param fallback_mimetype: the fallback mimetype for unknown files.
+    :param cache: enable or disable caching headers.
+    :param cache_timeout: the cache timeout in seconds for the headers.
+    """
+
+    def __init__(
+        self,
+        app,
+        exports,
+        disallow=None,
+        cache=True,
+        cache_timeout=60 * 60 * 12,
+        fallback_mimetype="text/plain",
+    ):
+        self.app = app
+        self.exports = []
+        self.cache = cache
+        self.cache_timeout = cache_timeout
+
+        if hasattr(exports, "items"):
+            exports = exports.items()
+
+        for key, value in exports:
+            if isinstance(value, tuple):
+                loader = self.get_package_loader(*value)
+            elif isinstance(value, string_types):
+                if os.path.isfile(value):
+                    loader = self.get_file_loader(value)
+                else:
+                    loader = self.get_directory_loader(value)
+            else:
+                raise TypeError("unknown def %r" % value)
+
+            self.exports.append((key, loader))
+
+        if disallow is not None:
+            from fnmatch import fnmatch
+
+            self.is_allowed = lambda x: not fnmatch(x, disallow)
+
+        self.fallback_mimetype = fallback_mimetype
+
+    def is_allowed(self, filename):
+        """Subclasses can override this method to disallow the access to
+        certain files.  However by providing `disallow` in the constructor
+        this method is overwritten.
+        """
+        return True
+
+    def _opener(self, filename):
+        return lambda: (
+            open(filename, "rb"),
+            datetime.utcfromtimestamp(os.path.getmtime(filename)),
+            int(os.path.getsize(filename)),
+        )
+
+    def get_file_loader(self, filename):
+        return lambda x: (os.path.basename(filename), self._opener(filename))
+
+    def get_package_loader(self, package, package_path):
+        from pkg_resources import DefaultProvider, ResourceManager, get_provider
+
+        loadtime = datetime.utcnow()
+        provider = get_provider(package)
+        manager = ResourceManager()
+        filesystem_bound = isinstance(provider, DefaultProvider)
+
+        def loader(path):
+            if path is None:
+                return None, None
+
+            path = posixpath.join(package_path, path)
+
+            if not provider.has_resource(path):
+                return None, None
+
+            basename = posixpath.basename(path)
+
+            if filesystem_bound:
+                return (
+                    basename,
+                    self._opener(provider.get_resource_filename(manager, path)),
+                )
+
+            s = provider.get_resource_string(manager, path)
+            return basename, lambda: (BytesIO(s), loadtime, len(s))
+
+        return loader
+
+    def get_directory_loader(self, directory):
+        def loader(path):
+            if path is not None:
+                path = os.path.join(directory, path)
+            else:
+                path = directory
+
+            if os.path.isfile(path):
+                return os.path.basename(path), self._opener(path)
+
+            return None, None
+
+        return loader
+
+    def generate_etag(self, mtime, file_size, real_filename):
+        if not isinstance(real_filename, bytes):
+            real_filename = real_filename.encode(get_filesystem_encoding())
+
+        return "wzsdm-%d-%s-%s" % (
+            mktime(mtime.timetuple()),
+            file_size,
+            adler32(real_filename) & 0xFFFFFFFF,
+        )
+
+    def __call__(self, environ, start_response):
+        cleaned_path = get_path_info(environ)
+
+        if PY2:
+            cleaned_path = cleaned_path.encode(get_filesystem_encoding())
+
+        # sanitize the path for non unix systems
+        cleaned_path = cleaned_path.strip("/")
+
+        for sep in os.sep, os.altsep:
+            if sep and sep != "/":
+                cleaned_path = cleaned_path.replace(sep, "/")
+
+        path = "/" + "/".join(x for x in cleaned_path.split("/") if x and x != "..")
+        file_loader = None
+
+        for search_path, loader in self.exports:
+            if search_path == path:
+                real_filename, file_loader = loader(None)
+
+                if file_loader is not None:
+                    break
+
+            if not search_path.endswith("/"):
+                search_path += "/"
+
+            if path.startswith(search_path):
+                real_filename, file_loader = loader(path[len(search_path) :])
+
+                if file_loader is not None:
+                    break
+
+        if file_loader is None or not self.is_allowed(real_filename):
+            return self.app(environ, start_response)
+
+        guessed_type = mimetypes.guess_type(real_filename)
+        mime_type = guessed_type[0] or self.fallback_mimetype
+        f, mtime, file_size = file_loader()
+
+        headers = [("Date", http_date())]
+
+        if self.cache:
+            timeout = self.cache_timeout
+            etag = self.generate_etag(mtime, file_size, real_filename)
+            headers += [
+                ("Etag", '"%s"' % etag),
+                ("Cache-Control", "max-age=%d, public" % timeout),
+            ]
+
+            if not is_resource_modified(environ, etag, last_modified=mtime):
+                f.close()
+                start_response("304 Not Modified", headers)
+                return []
+
+            headers.append(("Expires", http_date(time() + timeout)))
+        else:
+            headers.append(("Cache-Control", "public"))
+
+        headers.extend(
+            (
+                ("Content-Type", mime_type),
+                ("Content-Length", str(file_size)),
+                ("Last-Modified", http_date(mtime)),
+            )
+        )
+        start_response("200 OK", headers)
+        return wrap_file(environ, f)