# gevent

# Source code for gevent._socketcommon

    # Copyright (c) 2009-2014 Denis Bilenko and gevent contributors. See LICENSE for details.
    from __future__ import absolute_import

    # standard functions and classes that this module re-implements in a gevent-aware way:
    _implements = [
        'create_connection',
        'socket',
        'SocketType',
        'fromfd',
        'socketpair',
    ]

    __dns__ = [
        'getaddrinfo',
        'gethostbyname',
        'gethostbyname_ex',
        'gethostbyaddr',
        'getnameinfo',
        'getfqdn',
    ]

    _implements += __dns__

    # non-standard functions that this module provides:
    __extensions__ = [
        'cancel_wait',
        'wait_read',
        'wait_write',
        'wait_readwrite',
    ]

    # standard functions and classes that this module re-imports
    __imports__ = [
        'error',
        'gaierror',
        'herror',
        'htonl',
        'htons',
        'ntohl',
        'ntohs',
        'inet_aton',
        'inet_ntoa',
        'inet_pton',
        'inet_ntop',
        'timeout',
        'gethostname',
        'getprotobyname',
        'getservbyname',
        'getservbyport',
        'getdefaulttimeout',
        'setdefaulttimeout',
        # Windows:
        'errorTab',
    ]

    __py3_imports__ = [
        # Python 3
        'AddressFamily',
        'SocketKind',
        'CMSG_LEN',
        'CMSG_SPACE',
        'dup',
        'if_indextoname',
        'if_nameindex',
        'if_nametoindex',
        'sethostname',
    ]

    __imports__.extend(__py3_imports__)

    import time
    import sys
    from gevent._hub_local import get_hub_noargs as get_hub
    from gevent._compat import string_types, integer_types, PY3
    from gevent._util import copy_globals

    is_windows = sys.platform == 'win32'
    is_macos = sys.platform == 'darwin'

    # pylint:disable=no-name-in-module,unused-import
    if is_windows:
        # no such thing as WSAEPERM or error code 10001 according to winsock.h or MSDN
        from errno import WSAEINVAL as EINVAL
        from errno import WSAEWOULDBLOCK as EWOULDBLOCK
        from errno import WSAEINPROGRESS as EINPROGRESS
        from errno import WSAEALREADY as EALREADY
        from errno import WSAEISCONN as EISCONN
        from gevent.win32util import formatError as strerror
        EAGAIN = EWOULDBLOCK
    else:
        from errno import EINVAL
        from errno import EWOULDBLOCK
        from errno import EINPROGRESS
        from errno import EALREADY
        from errno import EAGAIN
        from errno import EISCONN
        from os import strerror

    try:
        from errno import EBADF
    except ImportError:
        EBADF = 9

    # macOS can return EPROTOTYPE when writing to a socket that is shutting
    # Down. Retrying the write should return the expected EPIPE error.
    # Downstream classes (like pywsgi) know how to handle/ignore EPIPE.
    # This set is used by socket.send() to decide whether the write should
    # be retried. The default is to retry only on EWOULDBLOCK. Here we add
    # EPROTOTYPE on macOS to handle this platform-specific race condition.
    GSENDAGAIN = (EWOULDBLOCK,)
    if is_macos:
        from errno import EPROTOTYPE
        GSENDAGAIN += (EPROTOTYPE,)

    import _socket
    _realsocket = _socket.socket
    import socket as __socket__

    _name = _value = None
    __imports__ = copy_globals(__socket__, globals(),
                               only_names=__imports__,
                               ignore_missing_names=True)

    for _name in __socket__.__all__:
        _value = getattr(__socket__, _name)
        if isinstance(_value, (integer_types, string_types)):
            globals()[_name] = _value
            __imports__.append(_name)

    del _name, _value

    _timeout_error = timeout # pylint: disable=undefined-variable

    from gevent import _hub_primitives
    _hub_primitives.set_default_timeout_error(_timeout_error)

    wait = _hub_primitives.wait_on_watcher
    wait_read = _hub_primitives.wait_read
    wait_write = _hub_primitives.wait_write
    wait_readwrite = _hub_primitives.wait_readwrite

    #: The exception raised by default on a call to :func:`cancel_wait`
    class cancel_wait_ex(error): # pylint: disable=undefined-variable
        def __init__(self):
            super(cancel_wait_ex, self).__init__(
                EBADF,
                'File descriptor was closed in another greenlet')

    def cancel_wait(watcher, error=cancel_wait_ex):
        """See :meth:`gevent.hub.Hub.cancel_wait`"""
        get_hub().cancel_wait(watcher, error)

    def gethostbyname(hostname):
        """
        gethostbyname(host) -> address

        Return the IP address (a string of the form '255.255.255.255') for a host.

        .. seealso:: :doc:`/dns`
        """
        return get_hub().resolver.gethostbyname(hostname)

    def gethostbyname_ex(hostname):
        """
        gethostbyname_ex(host) -> (name, aliaslist, addresslist)

        Return the true host name, a list of aliases, and a list of IP addresses,
        for a host.  The host argument is a string giving a host name or IP number.
        Resolve host and port into list of address info entries.

        .. seealso:: :doc:`/dns`
        """
        return get_hub().resolver.gethostbyname_ex(hostname)

    def getaddrinfo(host, port, family=0, socktype=0, proto=0, flags=0):
        """
        Resolve host and port into list of address info entries.

        Translate the host/port argument into a sequence of 5-tuples that contain
        all the necessary arguments for creating a socket connected to that service.
        host is a domain name, a string representation of an IPv4/v6 address or
        None. port is a string service name such as 'http', a numeric port number or
        None. By passing None as the value of host and port, you can pass NULL to
        the underlying C API.

        The family, type and proto arguments can be optionally specified in order to
        narrow the list of addresses returned. Passing zero as a value for each of
        these arguments selects the full range of results.

        .. seealso:: :doc:`/dns`
        """
        return get_hub().resolver.getaddrinfo(host, port, family, socktype, proto, flags)

    if PY3:
        # The name of the socktype param changed to type in Python 3.
        # See https://github.com/gevent/gevent/issues/960
        # Using inspect here to directly detect the condition is painful because we have to
        # wrap it with a try/except TypeError because not all Python 2
        # versions can get the args of a builtin; we also have to use a with to suppress
        # the deprecation warning.
        d = getaddrinfo.__doc__

        def getaddrinfo(host, port, family=0, type=0, proto=0, flags=0):
            # pylint:disable=function-redefined, undefined-variable
            # Also, on Python 3, we need to translate into the special enums.
            # Our lower-level resolvers, including the thread and blocking, which use _socket,
            # function simply with integers.
            addrlist = get_hub().resolver.getaddrinfo(host, port, family, type, proto, flags)
            result = [
                (_intenum_converter(af, AddressFamily),
                 _intenum_converter(socktype, SocketKind),
                 proto, canonname, sa)
                for af, socktype, proto, canonname, sa
                in addrlist
            ]
            return result

        getaddrinfo.__doc__ = d
        del d

        def _intenum_converter(value, enum_klass):
            try:
                return enum_klass(value)
            except ValueError: # pragma: no cover
                return value

    def gethostbyaddr(ip_address):
        """
        gethostbyaddr(ip_address) -> (name, aliaslist, addresslist)

        Return the true host name, a list of aliases, and a list of IP addresses,
        for a host.  The host argument is a string giving a host name or IP number.

        .. seealso:: :doc:`/dns`
        """
        return get_hub().resolver.gethostbyaddr(ip_address)

    def getnameinfo(sockaddr, flags):
        """
        getnameinfo(sockaddr, flags) -> (host, port)

        Get host and port for a sockaddr.

        .. seealso:: :doc:`/dns`
        """
        return get_hub().resolver.getnameinfo(sockaddr, flags)

    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.
        """
        # pylint: disable=undefined-variable
        name = name.strip()
        if not name or name == '0.0.0.0':
            name = gethostname()
        try:
            hostname, aliases, _ = gethostbyaddr(name)
        except error:
            pass
        else:
            aliases.insert(0, hostname)
            for name in aliases: # EWW! pylint:disable=redefined-argument-from-local
                if isinstance(name, bytes):
                    if b'.' in name:
                        break
                elif '.' in name:
                    break
            else:
                name = hostname
        return name

    def __send_chunk(socket, data_memory, flags, timeleft, end, timeout=_timeout_error):
        """
        Send the complete contents of ``data_memory`` before returning.
        This is the core loop around :meth:`send`.

        :param timeleft: Either ``None`` if there is no timeout involved,
           or a float indicating the timeout to use.
        :param end: Either ``None`` if there is no timeout involved, or
           a float giving the absolute end time.
        :return: An updated value for ``timeleft`` (or None)
        :raises timeout: If ``timeleft`` was given and elapsed while
           sending this chunk.
        """
        data_sent = 0
        len_data_memory = len(data_memory)
        started_timer = 0
        while data_sent < len_data_memory:
            chunk = data_memory[data_sent:]
            if timeleft is None:
                data_sent += socket.send(chunk, flags)
            elif started_timer and timeleft <= 0:
                # Check before sending to guarantee a check
                # happens even if each chunk successfully sends its data
                # (especially important for SSL sockets since they have large
                # buffers). But only do this if we've actually tried to
                # send something once to avoid spurious timeouts on non-blocking
                # sockets.
                raise timeout('timed out')
            else:
                started_timer = 1
                data_sent += socket.send(chunk, flags, timeout=timeleft)
                timeleft = end - time.time()

        return timeleft

    def _sendall(socket, data_memory, flags,
                 SOL_SOCKET=__socket__.SOL_SOCKET,  # pylint:disable=no-member
                 SO_SNDBUF=__socket__.SO_SNDBUF):  # pylint:disable=no-member
        """
        Send the *data_memory* (which should be a memoryview)
        using the gevent *socket*, performing well on PyPy.
        """

        # On PyPy up through 5.10.0, both PyPy2 and PyPy3, subviews
        # (slices) of a memoryview() object copy the underlying bytes the
        # first time the builtin socket.send() method is called. On a
        # non-blocking socket (that thus calls socket.send() many times)
        # with a large input, this results in many repeated copies of an
        # ever smaller string, depending on the networking buffering. For
        # example, if each send() can process 1MB of a 50MB input, and we
        # naively pass the entire remaining subview each time, we'd copy
        # 49MB, 48MB, 47MB, etc, thus completely killing performance. To
        # workaround this problem, we work in reasonable, fixed-size
        # chunks. This results in a 10x improvement to bench_sendall.py,
        # while having no measurable impact on CPython (since it doesn't
        # copy at all the only extra overhead is a few python function
        # calls, which is negligible for large inputs).

        # On one macOS machine, PyPy3 5.10.1 produced ~ 67.53 MB/s before this change,
        # and ~ 616.01 MB/s after.

        # See https://bitbucket.org/pypy/pypy/issues/2091/non-blocking-socketsend-slow-gevent

        # Too small of a chunk (the socket's buf size is usually too
        # small) results in reduced perf due to *too many* calls to send and too many
        # small copies. With a buffer of 143K (the default on my system), for
        # example, bench_sendall.py yields ~264MB/s, while using 1MB yields
        # ~653MB/s (matching CPython). 1MB is arbitrary and might be better
        # chosen, say, to match a page size?

        len_data_memory = len(data_memory)
        if not len_data_memory:
            # Don't try to send empty data at all, no point, and breaks ssl
            # See issue 719
            return 0

        chunk_size = max(socket.getsockopt(SOL_SOCKET, SO_SNDBUF), 1024 * 1024)

        data_sent = 0
        end = None
        timeleft = None
        if socket.timeout is not None:
            timeleft = socket.timeout
            end = time.time() + timeleft

        while data_sent < len_data_memory:
            chunk_end = min(data_sent + chunk_size, len_data_memory)
            chunk = data_memory[data_sent:chunk_end]

            timeleft = __send_chunk(socket, chunk, flags, timeleft, end)
            data_sent += len(chunk) # Guaranteed it sent the whole thing

    # pylint:disable=no-member
    _RESOLVABLE_FAMILIES = (__socket__.AF_INET,)
    if __socket__.has_ipv6:
        _RESOLVABLE_FAMILIES += (__socket__.AF_INET6,)

    def _resolve_addr(sock, address):
        # Internal method: resolve the AF_INET[6] address using
        # getaddrinfo.
        if sock.family not in _RESOLVABLE_FAMILIES or not isinstance(address, tuple):
            return address
        # address is (host, port) (ipv4) or (host, port, flowinfo, scopeid) (ipv6).

        # We don't pass the port to getaddrinfo because the C
        # socket module doesn't either (on some systems its
        # illegal to do that without also passing socket type and
        # protocol). Instead we join the port back at the end.
        # See https://github.com/gevent/gevent/issues/1252
        host, port = address[:2]
        r = getaddrinfo(host, None, sock.family)
        address = r[0][-1]
        if len(address) == 2:
            address = (address[0], port)
        else:
            address = (address[0], port, address[2], address[3])
        return address