You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
1364 lines
48 KiB
1364 lines
48 KiB
# -*- coding: utf-8 -*-
|
|
"""
|
|
werkzeug.wsgi
|
|
~~~~~~~~~~~~~
|
|
|
|
This module implements WSGI related helpers.
|
|
|
|
:copyright: (c) 2014 by the Werkzeug Team, see AUTHORS for more details.
|
|
:license: BSD, see LICENSE for more details.
|
|
"""
|
|
import io
|
|
try:
|
|
import httplib
|
|
except ImportError:
|
|
from http import client as httplib
|
|
import mimetypes
|
|
import os
|
|
import posixpath
|
|
import re
|
|
import socket
|
|
from datetime import datetime
|
|
from functools import partial, update_wrapper
|
|
from itertools import chain
|
|
from time import mktime, time
|
|
from zlib import adler32
|
|
|
|
from werkzeug._compat import BytesIO, PY2, implements_iterator, iteritems, \
|
|
make_literal_wrapper, string_types, text_type, to_bytes, to_unicode, \
|
|
try_coerce_native, wsgi_get_bytes
|
|
from werkzeug._internal import _empty_stream, _encode_idna
|
|
from werkzeug.filesystem import get_filesystem_encoding
|
|
from werkzeug.http import http_date, is_resource_modified, \
|
|
is_hop_by_hop_header
|
|
from werkzeug.urls import uri_to_iri, url_join, url_parse, url_quote
|
|
from werkzeug.datastructures import EnvironHeaders
|
|
|
|
|
|
def responder(f):
|
|
"""Marks a function as responder. Decorate a function with it and it
|
|
will automatically call the return value as WSGI application.
|
|
|
|
Example::
|
|
|
|
@responder
|
|
def application(environ, start_response):
|
|
return Response('Hello World!')
|
|
"""
|
|
return update_wrapper(lambda *a: f(*a)(*a[-2:]), f)
|
|
|
|
|
|
def get_current_url(environ, root_only=False, strip_querystring=False,
|
|
host_only=False, trusted_hosts=None):
|
|
"""A handy helper function that recreates the full URL as IRI for the
|
|
current request or parts of it. Here's an example:
|
|
|
|
>>> from werkzeug.test import create_environ
|
|
>>> env = create_environ("/?param=foo", "http://localhost/script")
|
|
>>> get_current_url(env)
|
|
'http://localhost/script/?param=foo'
|
|
>>> get_current_url(env, root_only=True)
|
|
'http://localhost/script/'
|
|
>>> get_current_url(env, host_only=True)
|
|
'http://localhost/'
|
|
>>> get_current_url(env, strip_querystring=True)
|
|
'http://localhost/script/'
|
|
|
|
This optionally it verifies that the host is in a list of trusted hosts.
|
|
If the host is not in there it will raise a
|
|
:exc:`~werkzeug.exceptions.SecurityError`.
|
|
|
|
Note that the string returned might contain unicode characters as the
|
|
representation is an IRI not an URI. If you need an ASCII only
|
|
representation you can use the :func:`~werkzeug.urls.iri_to_uri`
|
|
function:
|
|
|
|
>>> from werkzeug.urls import iri_to_uri
|
|
>>> iri_to_uri(get_current_url(env))
|
|
'http://localhost/script/?param=foo'
|
|
|
|
:param environ: the WSGI environment to get the current URL from.
|
|
:param root_only: set `True` if you only want the root URL.
|
|
:param strip_querystring: set to `True` if you don't want the querystring.
|
|
:param host_only: set to `True` if the host URL should be returned.
|
|
:param trusted_hosts: a list of trusted hosts, see :func:`host_is_trusted`
|
|
for more information.
|
|
"""
|
|
tmp = [environ['wsgi.url_scheme'], '://', get_host(environ, trusted_hosts)]
|
|
cat = tmp.append
|
|
if host_only:
|
|
return uri_to_iri(''.join(tmp) + '/')
|
|
cat(url_quote(wsgi_get_bytes(environ.get('SCRIPT_NAME', ''))).rstrip('/'))
|
|
cat('/')
|
|
if not root_only:
|
|
cat(url_quote(wsgi_get_bytes(environ.get('PATH_INFO', '')).lstrip(b'/')))
|
|
if not strip_querystring:
|
|
qs = get_query_string(environ)
|
|
if qs:
|
|
cat('?' + qs)
|
|
return uri_to_iri(''.join(tmp))
|
|
|
|
|
|
def host_is_trusted(hostname, trusted_list):
|
|
"""Checks if a host is trusted against a list. This also takes care
|
|
of port normalization.
|
|
|
|
.. versionadded:: 0.9
|
|
|
|
:param hostname: the hostname to check
|
|
:param trusted_list: a list of hostnames to check against. If a
|
|
hostname starts with a dot it will match against
|
|
all subdomains as well.
|
|
"""
|
|
if not hostname:
|
|
return False
|
|
|
|
if isinstance(trusted_list, string_types):
|
|
trusted_list = [trusted_list]
|
|
|
|
def _normalize(hostname):
|
|
if ':' in hostname:
|
|
hostname = hostname.rsplit(':', 1)[0]
|
|
return _encode_idna(hostname)
|
|
|
|
try:
|
|
hostname = _normalize(hostname)
|
|
except UnicodeError:
|
|
return False
|
|
for ref in trusted_list:
|
|
if ref.startswith('.'):
|
|
ref = ref[1:]
|
|
suffix_match = True
|
|
else:
|
|
suffix_match = False
|
|
try:
|
|
ref = _normalize(ref)
|
|
except UnicodeError:
|
|
return False
|
|
if ref == hostname:
|
|
return True
|
|
if suffix_match and hostname.endswith(b'.' + ref):
|
|
return True
|
|
return False
|
|
|
|
|
|
def get_host(environ, trusted_hosts=None):
|
|
"""Return the real host for the given WSGI environment. This first checks
|
|
the `X-Forwarded-Host` header, then the normal `Host` header, and finally
|
|
the `SERVER_NAME` environment variable (using the first one it finds).
|
|
|
|
Optionally it verifies that the host is in a list of trusted hosts.
|
|
If the host is not in there it will raise a
|
|
:exc:`~werkzeug.exceptions.SecurityError`.
|
|
|
|
:param environ: the WSGI environment to get the host of.
|
|
:param trusted_hosts: a list of trusted hosts, see :func:`host_is_trusted`
|
|
for more information.
|
|
"""
|
|
if 'HTTP_X_FORWARDED_HOST' in environ:
|
|
rv = environ['HTTP_X_FORWARDED_HOST'].split(',', 1)[0].strip()
|
|
elif 'HTTP_HOST' in environ:
|
|
rv = environ['HTTP_HOST']
|
|
else:
|
|
rv = environ['SERVER_NAME']
|
|
if (environ['wsgi.url_scheme'], environ['SERVER_PORT']) not \
|
|
in (('https', '443'), ('http', '80')):
|
|
rv += ':' + environ['SERVER_PORT']
|
|
if trusted_hosts is not None:
|
|
if not host_is_trusted(rv, trusted_hosts):
|
|
from werkzeug.exceptions import SecurityError
|
|
raise SecurityError('Host "%s" is not trusted' % rv)
|
|
return rv
|
|
|
|
|
|
def get_content_length(environ):
|
|
"""Returns the content length from the WSGI environment as
|
|
integer. If it's not available or chunked transfer encoding is used,
|
|
``None`` is returned.
|
|
|
|
.. versionadded:: 0.9
|
|
|
|
:param environ: the WSGI environ to fetch the content length from.
|
|
"""
|
|
if environ.get('HTTP_TRANSFER_ENCODING', '') == 'chunked':
|
|
return None
|
|
|
|
content_length = environ.get('CONTENT_LENGTH')
|
|
if content_length is not None:
|
|
try:
|
|
return max(0, int(content_length))
|
|
except (ValueError, TypeError):
|
|
pass
|
|
|
|
|
|
def get_input_stream(environ, safe_fallback=True):
|
|
"""Returns the input stream from the WSGI environment and wraps it
|
|
in the most sensible way possible. The stream returned is not the
|
|
raw WSGI stream in most cases but one that is safe to read from
|
|
without taking into account the content length.
|
|
|
|
If content length is not set, the stream will be empty for safety reasons.
|
|
If the WSGI server supports chunked or infinite streams, it should set
|
|
the ``wsgi.input_terminated`` value in the WSGI environ to indicate that.
|
|
|
|
.. versionadded:: 0.9
|
|
|
|
:param environ: the WSGI environ to fetch the stream from.
|
|
:param safe_fallback: use an empty stream as a safe fallback when the
|
|
content length is not set. Disabling this allows infinite streams,
|
|
which can be a denial-of-service risk.
|
|
"""
|
|
stream = environ['wsgi.input']
|
|
content_length = get_content_length(environ)
|
|
|
|
# A wsgi extension that tells us if the input is terminated. In
|
|
# that case we return the stream unchanged as we know we can safely
|
|
# read it until the end.
|
|
if environ.get('wsgi.input_terminated'):
|
|
return stream
|
|
|
|
# If the request doesn't specify a content length, returning the stream is
|
|
# potentially dangerous because it could be infinite, malicious or not. If
|
|
# safe_fallback is true, return an empty stream instead for safety.
|
|
if content_length is None:
|
|
return safe_fallback and _empty_stream or stream
|
|
|
|
# Otherwise limit the stream to the content length
|
|
return LimitedStream(stream, content_length)
|
|
|
|
|
|
def get_query_string(environ):
|
|
"""Returns the `QUERY_STRING` from the WSGI environment. This also takes
|
|
care about the WSGI decoding dance on Python 3 environments as a
|
|
native string. The string returned will be restricted to ASCII
|
|
characters.
|
|
|
|
.. versionadded:: 0.9
|
|
|
|
:param environ: the WSGI environment object to get the query string from.
|
|
"""
|
|
qs = wsgi_get_bytes(environ.get('QUERY_STRING', ''))
|
|
# QUERY_STRING really should be ascii safe but some browsers
|
|
# will send us some unicode stuff (I am looking at you IE).
|
|
# In that case we want to urllib quote it badly.
|
|
return try_coerce_native(url_quote(qs, safe=':&%=+$!*\'(),'))
|
|
|
|
|
|
def get_path_info(environ, charset='utf-8', errors='replace'):
|
|
"""Returns the `PATH_INFO` from the WSGI environment and properly
|
|
decodes it. This also takes care about the WSGI decoding dance
|
|
on Python 3 environments. if the `charset` is set to `None` a
|
|
bytestring is returned.
|
|
|
|
.. versionadded:: 0.9
|
|
|
|
:param environ: the WSGI environment object to get the path from.
|
|
:param charset: the charset for the path info, or `None` if no
|
|
decoding should be performed.
|
|
:param errors: the decoding error handling.
|
|
"""
|
|
path = wsgi_get_bytes(environ.get('PATH_INFO', ''))
|
|
return to_unicode(path, charset, errors, allow_none_charset=True)
|
|
|
|
|
|
def get_script_name(environ, charset='utf-8', errors='replace'):
|
|
"""Returns the `SCRIPT_NAME` from the WSGI environment and properly
|
|
decodes it. This also takes care about the WSGI decoding dance
|
|
on Python 3 environments. if the `charset` is set to `None` a
|
|
bytestring is returned.
|
|
|
|
.. versionadded:: 0.9
|
|
|
|
:param environ: the WSGI environment object to get the path from.
|
|
:param charset: the charset for the path, or `None` if no
|
|
decoding should be performed.
|
|
:param errors: the decoding error handling.
|
|
"""
|
|
path = wsgi_get_bytes(environ.get('SCRIPT_NAME', ''))
|
|
return to_unicode(path, charset, errors, allow_none_charset=True)
|
|
|
|
|
|
def pop_path_info(environ, charset='utf-8', errors='replace'):
|
|
"""Removes and returns the next segment of `PATH_INFO`, pushing it onto
|
|
`SCRIPT_NAME`. Returns `None` if there is nothing left on `PATH_INFO`.
|
|
|
|
If the `charset` is set to `None` a bytestring is returned.
|
|
|
|
If there are empty segments (``'/foo//bar``) these are ignored but
|
|
properly pushed to the `SCRIPT_NAME`:
|
|
|
|
>>> env = {'SCRIPT_NAME': '/foo', 'PATH_INFO': '/a/b'}
|
|
>>> pop_path_info(env)
|
|
'a'
|
|
>>> env['SCRIPT_NAME']
|
|
'/foo/a'
|
|
>>> pop_path_info(env)
|
|
'b'
|
|
>>> env['SCRIPT_NAME']
|
|
'/foo/a/b'
|
|
|
|
.. versionadded:: 0.5
|
|
|
|
.. versionchanged:: 0.9
|
|
The path is now decoded and a charset and encoding
|
|
parameter can be provided.
|
|
|
|
:param environ: the WSGI environment that is modified.
|
|
"""
|
|
path = environ.get('PATH_INFO')
|
|
if not path:
|
|
return None
|
|
|
|
script_name = environ.get('SCRIPT_NAME', '')
|
|
|
|
# shift multiple leading slashes over
|
|
old_path = path
|
|
path = path.lstrip('/')
|
|
if path != old_path:
|
|
script_name += '/' * (len(old_path) - len(path))
|
|
|
|
if '/' not in path:
|
|
environ['PATH_INFO'] = ''
|
|
environ['SCRIPT_NAME'] = script_name + path
|
|
rv = wsgi_get_bytes(path)
|
|
else:
|
|
segment, path = path.split('/', 1)
|
|
environ['PATH_INFO'] = '/' + path
|
|
environ['SCRIPT_NAME'] = script_name + segment
|
|
rv = wsgi_get_bytes(segment)
|
|
|
|
return to_unicode(rv, charset, errors, allow_none_charset=True)
|
|
|
|
|
|
def peek_path_info(environ, charset='utf-8', errors='replace'):
|
|
"""Returns the next segment on the `PATH_INFO` or `None` if there
|
|
is none. Works like :func:`pop_path_info` without modifying the
|
|
environment:
|
|
|
|
>>> env = {'SCRIPT_NAME': '/foo', 'PATH_INFO': '/a/b'}
|
|
>>> peek_path_info(env)
|
|
'a'
|
|
>>> peek_path_info(env)
|
|
'a'
|
|
|
|
If the `charset` is set to `None` a bytestring is returned.
|
|
|
|
.. versionadded:: 0.5
|
|
|
|
.. versionchanged:: 0.9
|
|
The path is now decoded and a charset and encoding
|
|
parameter can be provided.
|
|
|
|
:param environ: the WSGI environment that is checked.
|
|
"""
|
|
segments = environ.get('PATH_INFO', '').lstrip('/').split('/', 1)
|
|
if segments:
|
|
return to_unicode(wsgi_get_bytes(segments[0]),
|
|
charset, errors, allow_none_charset=True)
|
|
|
|
|
|
def extract_path_info(environ_or_baseurl, path_or_url, charset='utf-8',
|
|
errors='replace', collapse_http_schemes=True):
|
|
"""Extracts the path info from the given URL (or WSGI environment) and
|
|
path. The path info returned is a unicode string, not a bytestring
|
|
suitable for a WSGI environment. The URLs might also be IRIs.
|
|
|
|
If the path info could not be determined, `None` is returned.
|
|
|
|
Some examples:
|
|
|
|
>>> extract_path_info('http://example.com/app', '/app/hello')
|
|
u'/hello'
|
|
>>> extract_path_info('http://example.com/app',
|
|
... 'https://example.com/app/hello')
|
|
u'/hello'
|
|
>>> extract_path_info('http://example.com/app',
|
|
... 'https://example.com/app/hello',
|
|
... collapse_http_schemes=False) is None
|
|
True
|
|
|
|
Instead of providing a base URL you can also pass a WSGI environment.
|
|
|
|
.. versionadded:: 0.6
|
|
|
|
:param environ_or_baseurl: a WSGI environment dict, a base URL or
|
|
base IRI. This is the root of the
|
|
application.
|
|
:param path_or_url: an absolute path from the server root, a
|
|
relative path (in which case it's the path info)
|
|
or a full URL. Also accepts IRIs and unicode
|
|
parameters.
|
|
:param charset: the charset for byte data in URLs
|
|
:param errors: the error handling on decode
|
|
:param collapse_http_schemes: if set to `False` the algorithm does
|
|
not assume that http and https on the
|
|
same server point to the same
|
|
resource.
|
|
"""
|
|
def _normalize_netloc(scheme, netloc):
|
|
parts = netloc.split(u'@', 1)[-1].split(u':', 1)
|
|
if len(parts) == 2:
|
|
netloc, port = parts
|
|
if (scheme == u'http' and port == u'80') or \
|
|
(scheme == u'https' and port == u'443'):
|
|
port = None
|
|
else:
|
|
netloc = parts[0]
|
|
port = None
|
|
if port is not None:
|
|
netloc += u':' + port
|
|
return netloc
|
|
|
|
# make sure whatever we are working on is a IRI and parse it
|
|
path = uri_to_iri(path_or_url, charset, errors)
|
|
if isinstance(environ_or_baseurl, dict):
|
|
environ_or_baseurl = get_current_url(environ_or_baseurl,
|
|
root_only=True)
|
|
base_iri = uri_to_iri(environ_or_baseurl, charset, errors)
|
|
base_scheme, base_netloc, base_path = url_parse(base_iri)[:3]
|
|
cur_scheme, cur_netloc, cur_path, = \
|
|
url_parse(url_join(base_iri, path))[:3]
|
|
|
|
# normalize the network location
|
|
base_netloc = _normalize_netloc(base_scheme, base_netloc)
|
|
cur_netloc = _normalize_netloc(cur_scheme, cur_netloc)
|
|
|
|
# is that IRI even on a known HTTP scheme?
|
|
if collapse_http_schemes:
|
|
for scheme in base_scheme, cur_scheme:
|
|
if scheme not in (u'http', u'https'):
|
|
return None
|
|
else:
|
|
if not (base_scheme in (u'http', u'https') and
|
|
base_scheme == cur_scheme):
|
|
return None
|
|
|
|
# are the netlocs compatible?
|
|
if base_netloc != cur_netloc:
|
|
return None
|
|
|
|
# are we below the application path?
|
|
base_path = base_path.rstrip(u'/')
|
|
if not cur_path.startswith(base_path):
|
|
return None
|
|
|
|
return u'/' + cur_path[len(base_path):].lstrip(u'/')
|
|
|
|
|
|
class ProxyMiddleware(object):
|
|
"""This middleware routes some requests to the provided WSGI app and
|
|
proxies some requests to an external server. This is not something that
|
|
can generally be done on the WSGI layer and some HTTP requests will not
|
|
tunnel through correctly (for instance websocket requests cannot be
|
|
proxied through WSGI). As a result this is only really useful for some
|
|
basic requests that can be forwarded.
|
|
|
|
Example configuration::
|
|
|
|
app = ProxyMiddleware(app, {
|
|
'/static/': {
|
|
'target': 'http://127.0.0.1:5001/',
|
|
}
|
|
})
|
|
|
|
For each host options can be specified. The following options are
|
|
supported:
|
|
|
|
``target``:
|
|
the target URL to dispatch to
|
|
``remove_prefix``:
|
|
if set to `True` the prefix is chopped off the URL before
|
|
dispatching it to the server.
|
|
``host``:
|
|
When set to ``'<auto>'`` which is the default the host header is
|
|
automatically rewritten to the URL of the target. If set to `None`
|
|
then the host header is unmodified from the client request. Any
|
|
other value overwrites the host header with that value.
|
|
``headers``:
|
|
An optional dictionary of headers that should be sent with the
|
|
request to the target host.
|
|
``ssl_context``:
|
|
In case this is an HTTPS target host then an SSL context can be
|
|
provided here (:class:`ssl.SSLContext`). This can be used for instance
|
|
to disable SSL verification.
|
|
|
|
In this case everything below ``'/static/'`` is proxied to the server on
|
|
port 5001. The host header is automatically rewritten and so are request
|
|
URLs (eg: the leading `/static/` prefix here gets chopped off).
|
|
|
|
.. versionadded:: 0.14
|
|
"""
|
|
|
|
def __init__(self, app, targets, chunk_size=2 << 13, timeout=10):
|
|
def _set_defaults(opts):
|
|
opts.setdefault('remove_prefix', False)
|
|
opts.setdefault('host', '<auto>')
|
|
opts.setdefault('headers', {})
|
|
opts.setdefault('ssl_context', None)
|
|
return opts
|
|
self.app = app
|
|
self.targets = dict(('/%s/' % k.strip('/'), _set_defaults(v))
|
|
for k, v in iteritems(targets))
|
|
self.chunk_size = chunk_size
|
|
self.timeout = timeout
|
|
|
|
def proxy_to(self, opts, path, prefix):
|
|
target = url_parse(opts['target'])
|
|
|
|
def application(environ, start_response):
|
|
headers = list(EnvironHeaders(environ).items())
|
|
headers[:] = [(k, v) for k, v in headers
|
|
if not is_hop_by_hop_header(k) and
|
|
k.lower() not in ('content-length', 'host')]
|
|
headers.append(('Connection', 'close'))
|
|
if opts['host'] == '<auto>':
|
|
headers.append(('Host', target.ascii_host))
|
|
elif opts['host'] is None:
|
|
headers.append(('Host', environ['HTTP_HOST']))
|
|
else:
|
|
headers.append(('Host', opts['host']))
|
|
headers.extend(opts['headers'].items())
|
|
|
|
remote_path = path
|
|
if opts['remove_prefix']:
|
|
remote_path = '%s/%s' % (
|
|
target.path.rstrip('/'),
|
|
remote_path[len(prefix):].lstrip('/')
|
|
)
|
|
|
|
content_length = environ.get('CONTENT_LENGTH')
|
|
chunked = False
|
|
if content_length not in ('', None):
|
|
headers.append(('Content-Length', content_length))
|
|
elif content_length is not None:
|
|
headers.append(('Transfer-Encoding', 'chunked'))
|
|
chunked = True
|
|
|
|
try:
|
|
if target.scheme == 'http':
|
|
con = httplib.HTTPConnection(
|
|
target.ascii_host, target.port or 80,
|
|
timeout=self.timeout)
|
|
elif target.scheme == 'https':
|
|
con = httplib.HTTPSConnection(
|
|
target.ascii_host, target.port or 443,
|
|
timeout=self.timeout,
|
|
context=opts['ssl_context'])
|
|
con.connect()
|
|
con.putrequest(environ['REQUEST_METHOD'], url_quote(remote_path),
|
|
skip_host=True)
|
|
|
|
for k, v in headers:
|
|
if k.lower() == 'connection':
|
|
v = 'close'
|
|
con.putheader(k, v)
|
|
con.endheaders()
|
|
|
|
stream = get_input_stream(environ)
|
|
while 1:
|
|
data = stream.read(self.chunk_size)
|
|
if not data:
|
|
break
|
|
if chunked:
|
|
con.send(b'%x\r\n%s\r\n' % (len(data), data))
|
|
else:
|
|
con.send(data)
|
|
|
|
resp = con.getresponse()
|
|
except socket.error:
|
|
from werkzeug.exceptions import BadGateway
|
|
return BadGateway()(environ, start_response)
|
|
|
|
start_response('%d %s' % (resp.status, resp.reason),
|
|
[(k.title(), v) for k, v in resp.getheaders()
|
|
if not is_hop_by_hop_header(k)])
|
|
|
|
def read():
|
|
while 1:
|
|
try:
|
|
data = resp.read(self.chunk_size)
|
|
except socket.error:
|
|
break
|
|
if not data:
|
|
break
|
|
yield data
|
|
return read()
|
|
return application
|
|
|
|
def __call__(self, environ, start_response):
|
|
path = environ['PATH_INFO']
|
|
app = self.app
|
|
for prefix, opts in iteritems(self.targets):
|
|
if path.startswith(prefix):
|
|
app = self.proxy_to(opts, path, prefix)
|
|
break
|
|
return app(environ, start_response)
|
|
|
|
|
|
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, {
|
|
'/shared': os.path.join(os.path.dirname(__file__), 'shared')
|
|
})
|
|
|
|
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, {
|
|
'/shared': ('myapplication', 'shared_files')
|
|
})
|
|
|
|
This will then serve the ``shared_files`` 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 = iteritems(exports)
|
|
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)
|
|
|
|
|
|
class DispatcherMiddleware(object):
|
|
|
|
"""Allows one to mount middlewares or applications in a WSGI application.
|
|
This is useful if you want to combine multiple WSGI applications::
|
|
|
|
app = DispatcherMiddleware(app, {
|
|
'/app2': app2,
|
|
'/app3': app3
|
|
})
|
|
"""
|
|
|
|
def __init__(self, app, mounts=None):
|
|
self.app = app
|
|
self.mounts = mounts or {}
|
|
|
|
def __call__(self, environ, start_response):
|
|
script = environ.get('PATH_INFO', '')
|
|
path_info = ''
|
|
while '/' in script:
|
|
if script in self.mounts:
|
|
app = self.mounts[script]
|
|
break
|
|
script, last_item = script.rsplit('/', 1)
|
|
path_info = '/%s%s' % (last_item, path_info)
|
|
else:
|
|
app = self.mounts.get(script, self.app)
|
|
original_script_name = environ.get('SCRIPT_NAME', '')
|
|
environ['SCRIPT_NAME'] = original_script_name + script
|
|
environ['PATH_INFO'] = path_info
|
|
return app(environ, start_response)
|
|
|
|
|
|
@implements_iterator
|
|
class ClosingIterator(object):
|
|
|
|
"""The WSGI specification requires that all middlewares and gateways
|
|
respect the `close` callback of an iterator. Because it is useful to add
|
|
another close action to a returned iterator and adding a custom iterator
|
|
is a boring task this class can be used for that::
|
|
|
|
return ClosingIterator(app(environ, start_response), [cleanup_session,
|
|
cleanup_locals])
|
|
|
|
If there is just one close function it can be passed instead of the list.
|
|
|
|
A closing iterator is not needed if the application uses response objects
|
|
and finishes the processing if the response is started::
|
|
|
|
try:
|
|
return response(environ, start_response)
|
|
finally:
|
|
cleanup_session()
|
|
cleanup_locals()
|
|
"""
|
|
|
|
def __init__(self, iterable, callbacks=None):
|
|
iterator = iter(iterable)
|
|
self._next = partial(next, iterator)
|
|
if callbacks is None:
|
|
callbacks = []
|
|
elif callable(callbacks):
|
|
callbacks = [callbacks]
|
|
else:
|
|
callbacks = list(callbacks)
|
|
iterable_close = getattr(iterator, 'close', None)
|
|
if iterable_close:
|
|
callbacks.insert(0, iterable_close)
|
|
self._callbacks = callbacks
|
|
|
|
def __iter__(self):
|
|
return self
|
|
|
|
def __next__(self):
|
|
return self._next()
|
|
|
|
def close(self):
|
|
for callback in self._callbacks:
|
|
callback()
|
|
|
|
|
|
def wrap_file(environ, file, buffer_size=8192):
|
|
"""Wraps a file. This uses the WSGI server's file wrapper if available
|
|
or otherwise the generic :class:`FileWrapper`.
|
|
|
|
.. versionadded:: 0.5
|
|
|
|
If the file wrapper from the WSGI server is used it's important to not
|
|
iterate over it from inside the application but to pass it through
|
|
unchanged. If you want to pass out a file wrapper inside a response
|
|
object you have to set :attr:`~BaseResponse.direct_passthrough` to `True`.
|
|
|
|
More information about file wrappers are available in :pep:`333`.
|
|
|
|
:param file: a :class:`file`-like object with a :meth:`~file.read` method.
|
|
:param buffer_size: number of bytes for one iteration.
|
|
"""
|
|
return environ.get('wsgi.file_wrapper', FileWrapper)(file, buffer_size)
|
|
|
|
|
|
@implements_iterator
|
|
class FileWrapper(object):
|
|
|
|
"""This class can be used to convert a :class:`file`-like object into
|
|
an iterable. It yields `buffer_size` blocks until the file is fully
|
|
read.
|
|
|
|
You should not use this class directly but rather use the
|
|
:func:`wrap_file` function that uses the WSGI server's file wrapper
|
|
support if it's available.
|
|
|
|
.. versionadded:: 0.5
|
|
|
|
If you're using this object together with a :class:`BaseResponse` you have
|
|
to use the `direct_passthrough` mode.
|
|
|
|
:param file: a :class:`file`-like object with a :meth:`~file.read` method.
|
|
:param buffer_size: number of bytes for one iteration.
|
|
"""
|
|
|
|
def __init__(self, file, buffer_size=8192):
|
|
self.file = file
|
|
self.buffer_size = buffer_size
|
|
|
|
def close(self):
|
|
if hasattr(self.file, 'close'):
|
|
self.file.close()
|
|
|
|
def seekable(self):
|
|
if hasattr(self.file, 'seekable'):
|
|
return self.file.seekable()
|
|
if hasattr(self.file, 'seek'):
|
|
return True
|
|
return False
|
|
|
|
def seek(self, *args):
|
|
if hasattr(self.file, 'seek'):
|
|
self.file.seek(*args)
|
|
|
|
def tell(self):
|
|
if hasattr(self.file, 'tell'):
|
|
return self.file.tell()
|
|
return None
|
|
|
|
def __iter__(self):
|
|
return self
|
|
|
|
def __next__(self):
|
|
data = self.file.read(self.buffer_size)
|
|
if data:
|
|
return data
|
|
raise StopIteration()
|
|
|
|
|
|
@implements_iterator
|
|
class _RangeWrapper(object):
|
|
# private for now, but should we make it public in the future ?
|
|
|
|
"""This class can be used to convert an iterable object into
|
|
an iterable that will only yield a piece of the underlying content.
|
|
It yields blocks until the underlying stream range is fully read.
|
|
The yielded blocks will have a size that can't exceed the original
|
|
iterator defined block size, but that can be smaller.
|
|
|
|
If you're using this object together with a :class:`BaseResponse` you have
|
|
to use the `direct_passthrough` mode.
|
|
|
|
:param iterable: an iterable object with a :meth:`__next__` method.
|
|
:param start_byte: byte from which read will start.
|
|
:param byte_range: how many bytes to read.
|
|
"""
|
|
|
|
def __init__(self, iterable, start_byte=0, byte_range=None):
|
|
self.iterable = iter(iterable)
|
|
self.byte_range = byte_range
|
|
self.start_byte = start_byte
|
|
self.end_byte = None
|
|
if byte_range is not None:
|
|
self.end_byte = self.start_byte + self.byte_range
|
|
self.read_length = 0
|
|
self.seekable = hasattr(iterable, 'seekable') and iterable.seekable()
|
|
self.end_reached = False
|
|
|
|
def __iter__(self):
|
|
return self
|
|
|
|
def _next_chunk(self):
|
|
try:
|
|
chunk = next(self.iterable)
|
|
self.read_length += len(chunk)
|
|
return chunk
|
|
except StopIteration:
|
|
self.end_reached = True
|
|
raise
|
|
|
|
def _first_iteration(self):
|
|
chunk = None
|
|
if self.seekable:
|
|
self.iterable.seek(self.start_byte)
|
|
self.read_length = self.iterable.tell()
|
|
contextual_read_length = self.read_length
|
|
else:
|
|
while self.read_length <= self.start_byte:
|
|
chunk = self._next_chunk()
|
|
if chunk is not None:
|
|
chunk = chunk[self.start_byte - self.read_length:]
|
|
contextual_read_length = self.start_byte
|
|
return chunk, contextual_read_length
|
|
|
|
def _next(self):
|
|
if self.end_reached:
|
|
raise StopIteration()
|
|
chunk = None
|
|
contextual_read_length = self.read_length
|
|
if self.read_length == 0:
|
|
chunk, contextual_read_length = self._first_iteration()
|
|
if chunk is None:
|
|
chunk = self._next_chunk()
|
|
if self.end_byte is not None and self.read_length >= self.end_byte:
|
|
self.end_reached = True
|
|
return chunk[:self.end_byte - contextual_read_length]
|
|
return chunk
|
|
|
|
def __next__(self):
|
|
chunk = self._next()
|
|
if chunk:
|
|
return chunk
|
|
self.end_reached = True
|
|
raise StopIteration()
|
|
|
|
def close(self):
|
|
if hasattr(self.iterable, 'close'):
|
|
self.iterable.close()
|
|
|
|
|
|
def _make_chunk_iter(stream, limit, buffer_size):
|
|
"""Helper for the line and chunk iter functions."""
|
|
if isinstance(stream, (bytes, bytearray, text_type)):
|
|
raise TypeError('Passed a string or byte object instead of '
|
|
'true iterator or stream.')
|
|
if not hasattr(stream, 'read'):
|
|
for item in stream:
|
|
if item:
|
|
yield item
|
|
return
|
|
if not isinstance(stream, LimitedStream) and limit is not None:
|
|
stream = LimitedStream(stream, limit)
|
|
_read = stream.read
|
|
while 1:
|
|
item = _read(buffer_size)
|
|
if not item:
|
|
break
|
|
yield item
|
|
|
|
|
|
def make_line_iter(stream, limit=None, buffer_size=10 * 1024,
|
|
cap_at_buffer=False):
|
|
"""Safely iterates line-based over an input stream. If the input stream
|
|
is not a :class:`LimitedStream` the `limit` parameter is mandatory.
|
|
|
|
This uses the stream's :meth:`~file.read` method internally as opposite
|
|
to the :meth:`~file.readline` method that is unsafe and can only be used
|
|
in violation of the WSGI specification. The same problem applies to the
|
|
`__iter__` function of the input stream which calls :meth:`~file.readline`
|
|
without arguments.
|
|
|
|
If you need line-by-line processing it's strongly recommended to iterate
|
|
over the input stream using this helper function.
|
|
|
|
.. versionchanged:: 0.8
|
|
This function now ensures that the limit was reached.
|
|
|
|
.. versionadded:: 0.9
|
|
added support for iterators as input stream.
|
|
|
|
.. versionadded:: 0.11.10
|
|
added support for the `cap_at_buffer` parameter.
|
|
|
|
:param stream: the stream or iterate to iterate over.
|
|
:param limit: the limit in bytes for the stream. (Usually
|
|
content length. Not necessary if the `stream`
|
|
is a :class:`LimitedStream`.
|
|
:param buffer_size: The optional buffer size.
|
|
:param cap_at_buffer: if this is set chunks are split if they are longer
|
|
than the buffer size. Internally this is implemented
|
|
that the buffer size might be exhausted by a factor
|
|
of two however.
|
|
"""
|
|
_iter = _make_chunk_iter(stream, limit, buffer_size)
|
|
|
|
first_item = next(_iter, '')
|
|
if not first_item:
|
|
return
|
|
|
|
s = make_literal_wrapper(first_item)
|
|
empty = s('')
|
|
cr = s('\r')
|
|
lf = s('\n')
|
|
crlf = s('\r\n')
|
|
|
|
_iter = chain((first_item,), _iter)
|
|
|
|
def _iter_basic_lines():
|
|
_join = empty.join
|
|
buffer = []
|
|
while 1:
|
|
new_data = next(_iter, '')
|
|
if not new_data:
|
|
break
|
|
new_buf = []
|
|
buf_size = 0
|
|
for item in chain(buffer, new_data.splitlines(True)):
|
|
new_buf.append(item)
|
|
buf_size += len(item)
|
|
if item and item[-1:] in crlf:
|
|
yield _join(new_buf)
|
|
new_buf = []
|
|
elif cap_at_buffer and buf_size >= buffer_size:
|
|
rv = _join(new_buf)
|
|
while len(rv) >= buffer_size:
|
|
yield rv[:buffer_size]
|
|
rv = rv[buffer_size:]
|
|
new_buf = [rv]
|
|
buffer = new_buf
|
|
if buffer:
|
|
yield _join(buffer)
|
|
|
|
# This hackery is necessary to merge 'foo\r' and '\n' into one item
|
|
# of 'foo\r\n' if we were unlucky and we hit a chunk boundary.
|
|
previous = empty
|
|
for item in _iter_basic_lines():
|
|
if item == lf and previous[-1:] == cr:
|
|
previous += item
|
|
item = empty
|
|
if previous:
|
|
yield previous
|
|
previous = item
|
|
if previous:
|
|
yield previous
|
|
|
|
|
|
def make_chunk_iter(stream, separator, limit=None, buffer_size=10 * 1024,
|
|
cap_at_buffer=False):
|
|
"""Works like :func:`make_line_iter` but accepts a separator
|
|
which divides chunks. If you want newline based processing
|
|
you should use :func:`make_line_iter` instead as it
|
|
supports arbitrary newline markers.
|
|
|
|
.. versionadded:: 0.8
|
|
|
|
.. versionadded:: 0.9
|
|
added support for iterators as input stream.
|
|
|
|
.. versionadded:: 0.11.10
|
|
added support for the `cap_at_buffer` parameter.
|
|
|
|
:param stream: the stream or iterate to iterate over.
|
|
:param separator: the separator that divides chunks.
|
|
:param limit: the limit in bytes for the stream. (Usually
|
|
content length. Not necessary if the `stream`
|
|
is otherwise already limited).
|
|
:param buffer_size: The optional buffer size.
|
|
:param cap_at_buffer: if this is set chunks are split if they are longer
|
|
than the buffer size. Internally this is implemented
|
|
that the buffer size might be exhausted by a factor
|
|
of two however.
|
|
"""
|
|
_iter = _make_chunk_iter(stream, limit, buffer_size)
|
|
|
|
first_item = next(_iter, '')
|
|
if not first_item:
|
|
return
|
|
|
|
_iter = chain((first_item,), _iter)
|
|
if isinstance(first_item, text_type):
|
|
separator = to_unicode(separator)
|
|
_split = re.compile(r'(%s)' % re.escape(separator)).split
|
|
_join = u''.join
|
|
else:
|
|
separator = to_bytes(separator)
|
|
_split = re.compile(b'(' + re.escape(separator) + b')').split
|
|
_join = b''.join
|
|
|
|
buffer = []
|
|
while 1:
|
|
new_data = next(_iter, '')
|
|
if not new_data:
|
|
break
|
|
chunks = _split(new_data)
|
|
new_buf = []
|
|
buf_size = 0
|
|
for item in chain(buffer, chunks):
|
|
if item == separator:
|
|
yield _join(new_buf)
|
|
new_buf = []
|
|
buf_size = 0
|
|
else:
|
|
buf_size += len(item)
|
|
new_buf.append(item)
|
|
|
|
if cap_at_buffer and buf_size >= buffer_size:
|
|
rv = _join(new_buf)
|
|
while len(rv) >= buffer_size:
|
|
yield rv[:buffer_size]
|
|
rv = rv[buffer_size:]
|
|
new_buf = [rv]
|
|
buf_size = len(rv)
|
|
|
|
buffer = new_buf
|
|
if buffer:
|
|
yield _join(buffer)
|
|
|
|
|
|
@implements_iterator
|
|
class LimitedStream(io.IOBase):
|
|
|
|
"""Wraps a stream so that it doesn't read more than n bytes. If the
|
|
stream is exhausted and the caller tries to get more bytes from it
|
|
:func:`on_exhausted` is called which by default returns an empty
|
|
string. The return value of that function is forwarded
|
|
to the reader function. So if it returns an empty string
|
|
:meth:`read` will return an empty string as well.
|
|
|
|
The limit however must never be higher than what the stream can
|
|
output. Otherwise :meth:`readlines` will try to read past the
|
|
limit.
|
|
|
|
.. admonition:: Note on WSGI compliance
|
|
|
|
calls to :meth:`readline` and :meth:`readlines` are not
|
|
WSGI compliant because it passes a size argument to the
|
|
readline methods. Unfortunately the WSGI PEP is not safely
|
|
implementable without a size argument to :meth:`readline`
|
|
because there is no EOF marker in the stream. As a result
|
|
of that the use of :meth:`readline` is discouraged.
|
|
|
|
For the same reason iterating over the :class:`LimitedStream`
|
|
is not portable. It internally calls :meth:`readline`.
|
|
|
|
We strongly suggest using :meth:`read` only or using the
|
|
:func:`make_line_iter` which safely iterates line-based
|
|
over a WSGI input stream.
|
|
|
|
:param stream: the stream to wrap.
|
|
:param limit: the limit for the stream, must not be longer than
|
|
what the string can provide if the stream does not
|
|
end with `EOF` (like `wsgi.input`)
|
|
"""
|
|
|
|
def __init__(self, stream, limit):
|
|
self._read = stream.read
|
|
self._readline = stream.readline
|
|
self._pos = 0
|
|
self.limit = limit
|
|
|
|
def __iter__(self):
|
|
return self
|
|
|
|
@property
|
|
def is_exhausted(self):
|
|
"""If the stream is exhausted this attribute is `True`."""
|
|
return self._pos >= self.limit
|
|
|
|
def on_exhausted(self):
|
|
"""This is called when the stream tries to read past the limit.
|
|
The return value of this function is returned from the reading
|
|
function.
|
|
"""
|
|
# Read null bytes from the stream so that we get the
|
|
# correct end of stream marker.
|
|
return self._read(0)
|
|
|
|
def on_disconnect(self):
|
|
"""What should happen if a disconnect is detected? The return
|
|
value of this function is returned from read functions in case
|
|
the client went away. By default a
|
|
:exc:`~werkzeug.exceptions.ClientDisconnected` exception is raised.
|
|
"""
|
|
from werkzeug.exceptions import ClientDisconnected
|
|
raise ClientDisconnected()
|
|
|
|
def exhaust(self, chunk_size=1024 * 64):
|
|
"""Exhaust the stream. This consumes all the data left until the
|
|
limit is reached.
|
|
|
|
:param chunk_size: the size for a chunk. It will read the chunk
|
|
until the stream is exhausted and throw away
|
|
the results.
|
|
"""
|
|
to_read = self.limit - self._pos
|
|
chunk = chunk_size
|
|
while to_read > 0:
|
|
chunk = min(to_read, chunk)
|
|
self.read(chunk)
|
|
to_read -= chunk
|
|
|
|
def read(self, size=None):
|
|
"""Read `size` bytes or if size is not provided everything is read.
|
|
|
|
:param size: the number of bytes read.
|
|
"""
|
|
if self._pos >= self.limit:
|
|
return self.on_exhausted()
|
|
if size is None or size == -1: # -1 is for consistence with file
|
|
size = self.limit
|
|
to_read = min(self.limit - self._pos, size)
|
|
try:
|
|
read = self._read(to_read)
|
|
except (IOError, ValueError):
|
|
return self.on_disconnect()
|
|
if to_read and len(read) != to_read:
|
|
return self.on_disconnect()
|
|
self._pos += len(read)
|
|
return read
|
|
|
|
def readline(self, size=None):
|
|
"""Reads one line from the stream."""
|
|
if self._pos >= self.limit:
|
|
return self.on_exhausted()
|
|
if size is None:
|
|
size = self.limit - self._pos
|
|
else:
|
|
size = min(size, self.limit - self._pos)
|
|
try:
|
|
line = self._readline(size)
|
|
except (ValueError, IOError):
|
|
return self.on_disconnect()
|
|
if size and not line:
|
|
return self.on_disconnect()
|
|
self._pos += len(line)
|
|
return line
|
|
|
|
def readlines(self, size=None):
|
|
"""Reads a file into a list of strings. It calls :meth:`readline`
|
|
until the file is read to the end. It does support the optional
|
|
`size` argument if the underlaying stream supports it for
|
|
`readline`.
|
|
"""
|
|
last_pos = self._pos
|
|
result = []
|
|
if size is not None:
|
|
end = min(self.limit, last_pos + size)
|
|
else:
|
|
end = self.limit
|
|
while 1:
|
|
if size is not None:
|
|
size -= last_pos - self._pos
|
|
if self._pos >= end:
|
|
break
|
|
result.append(self.readline(size))
|
|
if size is not None:
|
|
last_pos = self._pos
|
|
return result
|
|
|
|
def tell(self):
|
|
"""Returns the position of the stream.
|
|
|
|
.. versionadded:: 0.9
|
|
"""
|
|
return self._pos
|
|
|
|
def __next__(self):
|
|
line = self.readline()
|
|
if not line:
|
|
raise StopIteration()
|
|
return line
|
|
|
|
def readable(self):
|
|
return True
|
|
|