Add future 0.18.2

lib/future/backports/socket.py

@@ -0,0 +1,454 @@
+# Wrapper module for _socket, providing some additional facilities
+# implemented in Python.
+
+"""\
+This module provides socket operations and some related functions.
+On Unix, it supports IP (Internet Protocol) and Unix domain sockets.
+On other systems, it only supports IP. Functions specific for a
+socket are available as methods of the socket object.
+
+Functions:
+
+socket() -- create a new socket object
+socketpair() -- create a pair of new socket objects [*]
+fromfd() -- create a socket object from an open file descriptor [*]
+fromshare() -- create a socket object from data received from socket.share() [*]
+gethostname() -- return the current hostname
+gethostbyname() -- map a hostname to its IP number
+gethostbyaddr() -- map an IP number or hostname to DNS info
+getservbyname() -- map a service name and a protocol name to a port number
+getprotobyname() -- map a protocol name (e.g. 'tcp') to a number
+ntohs(), ntohl() -- convert 16, 32 bit int from network to host byte order
+htons(), htonl() -- convert 16, 32 bit int from host to network byte order
+inet_aton() -- convert IP addr string (123.45.67.89) to 32-bit packed format
+inet_ntoa() -- convert 32-bit packed format IP to string (123.45.67.89)
+socket.getdefaulttimeout() -- get the default timeout value
+socket.setdefaulttimeout() -- set the default timeout value
+create_connection() -- connects to an address, with an optional timeout and
+                       optional source address.
+
+ [*] not available on all platforms!
+
+Special objects:
+
+SocketType -- type object for socket objects
+error -- exception raised for I/O errors
+has_ipv6 -- boolean value indicating if IPv6 is supported
+
+Integer constants:
+
+AF_INET, AF_UNIX -- socket domains (first argument to socket() call)
+SOCK_STREAM, SOCK_DGRAM, SOCK_RAW -- socket types (second argument)
+
+Many other constants may be defined; these may be used in calls to
+the setsockopt() and getsockopt() methods.
+"""
+
+from __future__ import unicode_literals
+from __future__ import print_function
+from __future__ import division
+from __future__ import absolute_import
+from future.builtins import super
+
+import _socket
+from _socket import *
+
+import os, sys, io
+
+try:
+    import errno
+except ImportError:
+    errno = None
+EBADF = getattr(errno, 'EBADF', 9)
+EAGAIN = getattr(errno, 'EAGAIN', 11)
+EWOULDBLOCK = getattr(errno, 'EWOULDBLOCK', 11)
+
+__all__ = ["getfqdn", "create_connection"]
+__all__.extend(os._get_exports_list(_socket))
+
+
+_realsocket = socket
+
+# WSA error codes
+if sys.platform.lower().startswith("win"):
+    errorTab = {}
+    errorTab[10004] = "The operation was interrupted."
+    errorTab[10009] = "A bad file handle was passed."
+    errorTab[10013] = "Permission denied."
+    errorTab[10014] = "A fault occurred on the network??" # WSAEFAULT
+    errorTab[10022] = "An invalid operation was attempted."
+    errorTab[10035] = "The socket operation would block"
+    errorTab[10036] = "A blocking operation is already in progress."
+    errorTab[10048] = "The network address is in use."
+    errorTab[10054] = "The connection has been reset."
+    errorTab[10058] = "The network has been shut down."
+    errorTab[10060] = "The operation timed out."
+    errorTab[10061] = "Connection refused."
+    errorTab[10063] = "The name is too long."
+    errorTab[10064] = "The host is down."
+    errorTab[10065] = "The host is unreachable."
+    __all__.append("errorTab")
+
+
+class socket(_socket.socket):
+
+    """A subclass of _socket.socket adding the makefile() method."""
+
+    __slots__ = ["__weakref__", "_io_refs", "_closed"]
+
+    def __init__(self, family=AF_INET, type=SOCK_STREAM, proto=0, fileno=None):
+        if fileno is None:
+            _socket.socket.__init__(self, family, type, proto)
+        else:
+            _socket.socket.__init__(self, family, type, proto, fileno)
+        self._io_refs = 0
+        self._closed = False
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        if not self._closed:
+            self.close()
+
+    def __repr__(self):
+        """Wrap __repr__() to reveal the real class name."""
+        s = _socket.socket.__repr__(self)
+        if s.startswith("<socket object"):
+            s = "<%s.%s%s%s" % (self.__class__.__module__,
+                                self.__class__.__name__,
+                                getattr(self, '_closed', False) and " [closed] " or "",
+                                s[7:])
+        return s
+
+    def __getstate__(self):
+        raise TypeError("Cannot serialize socket object")
+
+    def dup(self):
+        """dup() -> socket object
+
+        Return a new socket object connected to the same system resource.
+        """
+        fd = dup(self.fileno())
+        sock = self.__class__(self.family, self.type, self.proto, fileno=fd)
+        sock.settimeout(self.gettimeout())
+        return sock
+
+    def accept(self):
+        """accept() -> (socket object, address info)
+
+        Wait for an incoming connection.  Return a new socket
+        representing the connection, and the address of the client.
+        For IP sockets, the address info is a pair (hostaddr, port).
+        """
+        fd, addr = self._accept()
+        sock = socket(self.family, self.type, self.proto, fileno=fd)
+        # Issue #7995: if no default timeout is set and the listening
+        # socket had a (non-zero) timeout, force the new socket in blocking
+        # mode to override platform-specific socket flags inheritance.
+        if getdefaulttimeout() is None and self.gettimeout():
+            sock.setblocking(True)
+        return sock, addr
+
+    def makefile(self, mode="r", buffering=None, **_3to2kwargs):
+        """makefile(...) -> an I/O stream connected to the socket
+
+        The arguments are as for io.open() after the filename,
+        except the only mode characters supported are 'r', 'w' and 'b'.
+        The semantics are similar too.  (XXX refactor to share code?)
+        """
+        if 'newline' in _3to2kwargs: newline = _3to2kwargs['newline']; del _3to2kwargs['newline']
+        else: newline = None
+        if 'errors' in _3to2kwargs: errors = _3to2kwargs['errors']; del _3to2kwargs['errors']
+        else: errors = None
+        if 'encoding' in _3to2kwargs: encoding = _3to2kwargs['encoding']; del _3to2kwargs['encoding']
+        else: encoding = None
+        for c in mode:
+            if c not in ("r", "w", "b"):
+                raise ValueError("invalid mode %r (only r, w, b allowed)")
+        writing = "w" in mode
+        reading = "r" in mode or not writing
+        assert reading or writing
+        binary = "b" in mode
+        rawmode = ""
+        if reading:
+            rawmode += "r"
+        if writing:
+            rawmode += "w"
+        raw = SocketIO(self, rawmode)
+        self._io_refs += 1
+        if buffering is None:
+            buffering = -1
+        if buffering < 0:
+            buffering = io.DEFAULT_BUFFER_SIZE
+        if buffering == 0:
+            if not binary:
+                raise ValueError("unbuffered streams must be binary")
+            return raw
+        if reading and writing:
+            buffer = io.BufferedRWPair(raw, raw, buffering)
+        elif reading:
+            buffer = io.BufferedReader(raw, buffering)
+        else:
+            assert writing
+            buffer = io.BufferedWriter(raw, buffering)
+        if binary:
+            return buffer
+        text = io.TextIOWrapper(buffer, encoding, errors, newline)
+        text.mode = mode
+        return text
+
+    def _decref_socketios(self):
+        if self._io_refs > 0:
+            self._io_refs -= 1
+        if self._closed:
+            self.close()
+
+    def _real_close(self, _ss=_socket.socket):
+        # This function should not reference any globals. See issue #808164.
+        _ss.close(self)
+
+    def close(self):
+        # This function should not reference any globals. See issue #808164.
+        self._closed = True
+        if self._io_refs <= 0:
+            self._real_close()
+
+    def detach(self):
+        """detach() -> file descriptor
+
+        Close the socket object without closing the underlying file descriptor.
+        The object cannot be used after this call, but the file descriptor
+        can be reused for other purposes.  The file descriptor is returned.
+        """
+        self._closed = True
+        return super().detach()
+
+def fromfd(fd, family, type, proto=0):
+    """ fromfd(fd, family, type[, proto]) -> socket object
+
+    Create a socket object from a duplicate of the given file
+    descriptor.  The remaining arguments are the same as for socket().
+    """
+    nfd = dup(fd)
+    return socket(family, type, proto, nfd)
+
+if hasattr(_socket.socket, "share"):
+    def fromshare(info):
+        """ fromshare(info) -> socket object
+
+        Create a socket object from a the bytes object returned by
+        socket.share(pid).
+        """
+        return socket(0, 0, 0, info)
+
+if hasattr(_socket, "socketpair"):
+
+    def socketpair(family=None, type=SOCK_STREAM, proto=0):
+        """socketpair([family[, type[, proto]]]) -> (socket object, socket object)
+
+        Create a pair of socket objects from the sockets returned by the platform
+        socketpair() function.
+        The arguments are the same as for socket() except the default family is
+        AF_UNIX if defined on the platform; otherwise, the default is AF_INET.
+        """
+        if family is None:
+            try:
+                family = AF_UNIX
+            except NameError:
+                family = AF_INET
+        a, b = _socket.socketpair(family, type, proto)
+        a = socket(family, type, proto, a.detach())
+        b = socket(family, type, proto, b.detach())
+        return a, b
+
+
+_blocking_errnos = set([EAGAIN, EWOULDBLOCK])
+
+class SocketIO(io.RawIOBase):
+
+    """Raw I/O implementation for stream sockets.
+
+    This class supports the makefile() method on sockets.  It provides
+    the raw I/O interface on top of a socket object.
+    """
+
+    # One might wonder why not let FileIO do the job instead.  There are two
+    # main reasons why FileIO is not adapted:
+    # - it wouldn't work under Windows (where you can't used read() and
+    #   write() on a socket handle)
+    # - it wouldn't work with socket timeouts (FileIO would ignore the
+    #   timeout and consider the socket non-blocking)
+
+    # XXX More docs
+
+    def __init__(self, sock, mode):
+        if mode not in ("r", "w", "rw", "rb", "wb", "rwb"):
+            raise ValueError("invalid mode: %r" % mode)
+        io.RawIOBase.__init__(self)
+        self._sock = sock
+        if "b" not in mode:
+            mode += "b"
+        self._mode = mode
+        self._reading = "r" in mode
+        self._writing = "w" in mode
+        self._timeout_occurred = False
+
+    def readinto(self, b):
+        """Read up to len(b) bytes into the writable buffer *b* and return
+        the number of bytes read.  If the socket is non-blocking and no bytes
+        are available, None is returned.
+
+        If *b* is non-empty, a 0 return value indicates that the connection
+        was shutdown at the other end.
+        """
+        self._checkClosed()
+        self._checkReadable()
+        if self._timeout_occurred:
+            raise IOError("cannot read from timed out object")
+        while True:
+            try:
+                return self._sock.recv_into(b)
+            except timeout:
+                self._timeout_occurred = True
+                raise
+            # except InterruptedError:
+            #     continue
+            except error as e:
+                if e.args[0] in _blocking_errnos:
+                    return None
+                raise
+
+    def write(self, b):
+        """Write the given bytes or bytearray object *b* to the socket
+        and return the number of bytes written.  This can be less than
+        len(b) if not all data could be written.  If the socket is
+        non-blocking and no bytes could be written None is returned.
+        """
+        self._checkClosed()
+        self._checkWritable()
+        try:
+            return self._sock.send(b)
+        except error as e:
+            # XXX what about EINTR?
+            if e.args[0] in _blocking_errnos:
+                return None
+            raise
+
+    def readable(self):
+        """True if the SocketIO is open for reading.
+        """
+        if self.closed:
+            raise ValueError("I/O operation on closed socket.")
+        return self._reading
+
+    def writable(self):
+        """True if the SocketIO is open for writing.
+        """
+        if self.closed:
+            raise ValueError("I/O operation on closed socket.")
+        return self._writing
+
+    def seekable(self):
+        """True if the SocketIO is open for seeking.
+        """
+        if self.closed:
+            raise ValueError("I/O operation on closed socket.")
+        return super().seekable()
+
+    def fileno(self):
+        """Return the file descriptor of the underlying socket.
+        """
+        self._checkClosed()
+        return self._sock.fileno()
+
+    @property
+    def name(self):
+        if not self.closed:
+            return self.fileno()
+        else:
+            return -1
+
+    @property
+    def mode(self):
+        return self._mode
+
+    def close(self):
+        """Close the SocketIO object.  This doesn't close the underlying
+        socket, except if all references to it have disappeared.
+        """
+        if self.closed:
+            return
+        io.RawIOBase.close(self)
+        self._sock._decref_socketios()
+        self._sock = None
+
+
+def getfqdn(name=''):
+    """Get fully qualified domain name from name.
+
+    An empty argument is interpreted as meaning the local host.
+
+    First the hostname returned by gethostbyaddr() is checked, then
+    possibly existing aliases. In case no FQDN is available, hostname
+    from gethostname() is returned.
+    """
+    name = name.strip()
+    if not name or name == '0.0.0.0':
+        name = gethostname()
+    try:
+        hostname, aliases, ipaddrs = gethostbyaddr(name)
+    except error:
+        pass
+    else:
+        aliases.insert(0, hostname)
+        for name in aliases:
+            if '.' in name:
+                break
+        else:
+            name = hostname
+    return name
+
+
+# Re-use the same sentinel as in the Python stdlib socket module:
+from socket import _GLOBAL_DEFAULT_TIMEOUT
+# Was: _GLOBAL_DEFAULT_TIMEOUT = object()
+
+
+def create_connection(address, timeout=_GLOBAL_DEFAULT_TIMEOUT,
+                      source_address=None):
+    """Connect to *address* and return the socket object.
+
+    Convenience function.  Connect to *address* (a 2-tuple ``(host,
+    port)``) and return the socket object.  Passing the optional
+    *timeout* parameter will set the timeout on the socket instance
+    before attempting to connect.  If no *timeout* is supplied, the
+    global default timeout setting returned by :func:`getdefaulttimeout`
+    is used.  If *source_address* is set it must be a tuple of (host, port)
+    for the socket to bind as a source address before making the connection.
+    An host of '' or port 0 tells the OS to use the default.
+    """
+
+    host, port = address
+    err = None
+    for res in getaddrinfo(host, port, 0, SOCK_STREAM):
+        af, socktype, proto, canonname, sa = res
+        sock = None
+        try:
+            sock = socket(af, socktype, proto)
+            if timeout is not _GLOBAL_DEFAULT_TIMEOUT:
+                sock.settimeout(timeout)
+            if source_address:
+                sock.bind(source_address)
+            sock.connect(sa)
+            return sock
+
+        except error as _:
+            err = _
+            if sock is not None:
+                sock.close()
+
+    if err is not None:
+        raise err
+    else:
+        raise error("getaddrinfo returns an empty list")