/** *Copyright [2009-2010] [dennis zhuang(killme2008@gmail.com)] *Licensed under the Apache License, Version 2.0 (the "License"); *you may not use this file except in compliance with the License. *You may obtain a copy of the License at * http://www.apache.org/licenses/LICENSE-2.0 *Unless required by applicable law or agreed to in writing, *software distributed under the License is distributed on an "AS IS" BASIS, *WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, *either express or implied. See the License for the specific language governing permissions and limitations under the License */ /** *Copyright [2009-2010] [dennis zhuang(killme2008@gmail.com)] *Licensed under the Apache License, Version 2.0 (the "License"); *you may not use this file except in compliance with the License. *You may obtain a copy of the License at * http://www.apache.org/licenses/LICENSE-2.0 *Unless required by applicable law or agreed to in writing, *software distributed under the License is distributed on an "AS IS" BASIS, *WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, *either express or implied. See the License for the specific language governing permissions and limitations under the License */ package com.google.code.hs4j.network.core.impl; import java.net.ServerSocket; import java.net.Socket; import com.google.code.hs4j.network.core.SocketOption; /** * Standard socket options * * @author dennis * */ public class StandardSocketOption { /** * Keep connection alive. * * <p> * The value of this socket option is a {@code Boolean} that represents * whether the option is enabled or disabled. When the {@code SO_KEEPALIVE} * option is enabled the operating system may use a <em>keep-alive</em> * mechanism to periodically probe the other end of a connection when the * connection is otherwise idle. The exact semantics of the keep alive * mechanism is system dependent and therefore unspecified. * * <p> * The initial value of this socket option is {@code FALSE}. The socket * option may be enabled or disabled at any time. * * @see <a href="http://www.ietf.org/rfc/rfc1122.txt">RFC 1122 * * Requirements for Internet Hosts -- Communication Layers< /a> * @see Socket#setKeepAlive */ public static final SocketOption<Boolean> SO_KEEPALIVE = new SocketOption<Boolean>( "SO_KEEPALIVE", Boolean.class); /** * The size of the socket send buffer. * * <p> * The value of this socket option is an {@code Integer} that is the size of * the socket send buffer in bytes. The socket send buffer is an output * buffer used by the networking implementation. It may need to be increased * for high-volume connections. The value of the socket option is a * <em>hint</em> to the implementation to size the buffer and the actual * size may differ. The socket option can be queried to retrieve the actual * size. * * <p> * For datagram-oriented sockets, the size of the send buffer may limit the * size of the datagrams that may be sent by the socket. Whether datagrams * larger than the buffer size are sent or discarded is system dependent. * * <p> * The initial/default size of the socket send buffer and the range of * allowable values is system dependent although a negative size is not * allowed. An attempt to set the socket send buffer to larger than its * maximum size causes it to be set to its maximum size. * * <p> * An implementation allows this socket option to be set before the socket * is bound or connected. Whether an implementation allows the socket send * buffer to be changed after the socket is bound is system dependent. * * @see Socket#setSendBufferSize */ public static final SocketOption<Integer> SO_SNDBUF = new SocketOption<Integer>( "SO_SNDBUF", Integer.class); /** * The size of the socket receive buffer. * * <p> * The value of this socket option is an {@code Integer} that is the size of * the socket receive buffer in bytes. The socket receive buffer is an input * buffer used by the networking implementation. It may need to be increased * for high-volume connections or decreased to limit the possible backlog of * incoming data. The value of the socket option is a <em>hint</em> to the * implementation to size the buffer and the actual size may differ. * * <p> * For datagram-oriented sockets, the size of the receive buffer may limit * the size of the datagrams that can be received. Whether datagrams larger * than the buffer size can be received is system dependent. Increasing the * socket receive buffer may be important for cases where datagrams arrive * in bursts faster than they can be processed. * * <p> * In the case of stream-oriented sockets and the TCP/IP protocol, the size * of the socket receive buffer may be used when advertising the size of the * TCP receive window to the remote peer. * * <p> * The initial/default size of the socket receive buffer and the range of * allowable values is system dependent although a negative size is not * allowed. An attempt to set the socket receive buffer to larger than its * maximum size causes it to be set to its maximum size. * * <p> * An implementation allows this socket option to be set before the socket * is bound or connected. Whether an implementation allows the socket * receive buffer to be changed after the socket is bound is system * dependent. * * @see <a href="http://www.ietf.org/rfc/rfc1323.txt">RFC 1323: TCP * * Extensions for High Performance< /a> * @see Socket#setReceiveBufferSize * @see ServerSocket#setReceiveBufferSize */ public static final SocketOption<Integer> SO_RCVBUF = new SocketOption<Integer>( "SO_RCVBUF", Integer.class); /** * Re-use address. * * <p> * The value of this socket option is a {@code Boolean} that represents * whether the option is enabled or disabled. The exact semantics of this * socket option are socket type and system dependent. * * <p> * In the case of stream-oriented sockets, this socket option will usually * determine whether the socket can be bound to a socket address when a * previous connection involving that socket address is in the * <em>TIME_WAIT</em> state. On implementations where the semantics differ, * and the socket option is not required to be enabled in order to bind the * socket when a previous connection is in this state, then the * implementation may choose to ignore this option. * * <p> * For datagram-oriented sockets the socket option is used to allow multiple * programs bind to the same address. This option should be enabled when the * socket is to be used for Internet Protocol (IP) multicasting. * * <p> * An implementation allows this socket option to be set before the socket * is bound or connected. Changing the value of this socket option after the * socket is bound has no effect. The default value of this socket option is * system dependent. * * @see <a href="http://www.ietf.org/rfc/rfc793.txt">RFC 793: * * Transmission Control Protocol< /a> * @see ServerSocket#setReuseAddress */ public static final SocketOption<Boolean> SO_REUSEADDR = new SocketOption<Boolean>( "SO_REUSEADDR", Boolean.class); /** * Linger on close if data is present. * * <p> * The value of this socket option is an {@code Integer} that controls the * action taken when unsent data is queued on the socket and a method to * close the socket is invoked. If the value of the socket option is zero or * greater, then it represents a timeout value, in seconds, known as the * <em>linger interval</em>. The linger interval is the timeout for the * {@code close} method to block while the operating system attempts to * transmit the unsent data or it decides that it is unable to transmit the * data. If the value of the socket option is less than zero then the option * is disabled. In that case the {@code close} method does not wait until * unsent data is transmitted; if possible the operating system will * transmit any unsent data before the connection is closed. * * <p> * This socket option is intended for use with sockets that are configured * in {@link java.nio.channels.SelectableChannel#isBlocking() blocking} mode * only. The behavior of the {@code close} method when this option is * enabled on a non-blocking socket is not defined. * * <p> * The initial value of this socket option is a negative value, meaning that * the option is disabled. The option may be enabled, or the linger interval * changed, at any time. The maximum value of the linger interval is system * dependent. Setting the linger interval to a value that is greater than * its maximum value causes the linger interval to be set to its maximum * value. * * @see Socket#setSoLinger */ public static final SocketOption<Integer> SO_LINGER = new SocketOption<Integer>( "SO_LINGER", Integer.class); /** * Disable the Nagle algorithm. * * <p> * The value of this socket option is a {@code Boolean} that represents * whether the option is enabled or disabled. The socket option is specific * to stream-oriented sockets using the TCP/IP protocol. TCP/IP uses an * algorithm known as <em>The Nagle Algorithm</em> to coalesce short * segments and improve network efficiency. * * <p> * The default value of this socket option is {@code FALSE}. The socket * option should only be enabled in cases where it is known that the * coalescing impacts performance. The socket option may be enabled at any * time. In other words, the Nagle Algorithm can be disabled. Once the * option is enabled, it is system dependent whether it can be subsequently * disabled. If it cannot, then invoking the {@code setOption} method to * disable the option has no effect. * * @see <a href="http://www.ietf.org/rfc/rfc1122.txt">RFC 1122: * * Requirements for Internet Hosts -- Communication Layers< /a> * @see Socket#setTcpNoDelay */ public static final SocketOption<Boolean> TCP_NODELAY = new SocketOption<Boolean>( "TCP_NODELAY", Boolean.class); }