--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/net/StandardSocketOption.java Sun Aug 31 18:39:01 2008 +0100
@@ -0,0 +1,352 @@
+/*
+ * Copyright 2007-2008 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.net;
+
+/**
+ * Defines the <em>standard</em> socket options.
+ *
+ * <p> The {@link SocketOption#name name} of each socket option defined by this
+ * class is its field name.
+ *
+ * <p> In this release, the socket options defined here are used by {@link
+ * java.nio.channels.NetworkChannel network} channels in the {@link
+ * java.nio.channels channels} package.
+ *
+ * @since 1.7
+ */
+
+public final class StandardSocketOption {
+ private StandardSocketOption() { }
+
+ // -- SOL_SOCKET --
+
+ /**
+ * Allow transmission of broadcast datagrams.
+ *
+ * <p> The value of this socket option is a {@code Boolean} that represents
+ * whether the option is enabled or disabled. The option is specific to
+ * datagram-oriented sockets sending to {@link java.net.Inet4Address IPv4}
+ * broadcast addresses. When the socket option is enabled then the socket
+ * can be used to send <em>broadcast datagrams</em>.
+ *
+ * <p> The initial value of this socket option is {@code FALSE}. The socket
+ * option may be enabled or disabled at any time. Some operating systems may
+ * require that the Java virtual machine be started with implementation
+ * specific privileges to enable this option or send broadcast datagrams.
+ *
+ * @see <a href="http://www.ietf.org/rfc/rfc919.txt">RFC 929:
+ * Broadcasting Internet Datagrams</a>
+ */
+ public static final SocketOption<Boolean> SO_BROADCAST =
+ new StdSocketOption<Boolean>("SO_BROADCAST", Boolean.class);
+
+ /**
+ * 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>
+ */
+ public static final SocketOption<Boolean> SO_KEEPALIVE =
+ new StdSocketOption<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.
+ */
+ public static final SocketOption<Integer> SO_SNDBUF =
+ new StdSocketOption<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>
+ */
+ public static final SocketOption<Integer> SO_RCVBUF =
+ new StdSocketOption<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>
+ */
+ public static final SocketOption<Boolean> SO_REUSEADDR =
+ new StdSocketOption<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.
+ */
+ public static final SocketOption<Integer> SO_LINGER =
+ new StdSocketOption<Integer>("SO_LINGER", Integer.class);
+
+
+ // -- IPPROTO_IP --
+
+ /**
+ * The Type of Service (ToS) octet in the Internet Protocol (IP) header.
+ *
+ * <p> The value of this socket option is an {@code Integer}, the least
+ * significant 8 bits of which represents the value of the ToS octet in IP
+ * packets sent by sockets to an {@link StandardProtocolFamily#INET IPv4}
+ * socket. The interpretation of the ToS octet is network specific and
+ * is not defined by this class. Further information on the ToS octet can be
+ * found in <a href="http://www.ietf.org/rfc/rfc1349.txt">RFC 1349</a>
+ * and <a href="http://www.ietf.org/rfc/rfc2474.txt">RFC 2474</a>. The
+ * value of the socket option is a <em>hint</em>. An implementation may
+ * ignore the value, or ignore specific values.
+ *
+ * <p> The initial/default value of the TOS field in the ToS octet is
+ * implementation specific but will typically be {@code 0}. For
+ * datagram-oriented sockets the option may be configured at any time after
+ * the socket has been bound. The new value of the octet is used when sending
+ * subsequent datagrams. It is system dependent whether this option can be
+ * queried or changed prior to binding the socket.
+ *
+ * <p> The behavior of this socket option on a stream-oriented socket, or an
+ * {@link StandardProtocolFamily#INET6 IPv6} socket, is not defined in this
+ * release.
+ */
+ public static final SocketOption<Integer> IP_TOS =
+ new StdSocketOption<Integer>("IP_TOS", Integer.class);
+
+ /**
+ * The network interface for Internet Protocol (IP) multicast datagrams.
+ *
+ * <p> The value of this socket option is a {@link NetworkInterface} that
+ * represents the outgoing interface for multicast datagrams sent by the
+ * datagram-oriented socket. For {@link StandardProtocolFamily#INET6 IPv6}
+ * sockets then it is system dependent whether setting this option also
+ * sets the outgoing interface for multlicast datagrams sent to IPv4
+ * addresses.
+ *
+ * <p> The initial/default value of this socket option may be {@code null}
+ * to indicate that outgoing interface will be selected by the operating
+ * system, typically based on the network routing tables. An implementation
+ * allows this socket option to be set after the socket is bound. Whether
+ * the socket option can be queried or changed prior to binding the socket
+ * is system dependent.
+ *
+ * @see java.nio.channels.MulticastChannel
+ */
+ public static final SocketOption<NetworkInterface> IP_MULTICAST_IF =
+ new StdSocketOption<NetworkInterface>("IP_MULTICAST_IF", NetworkInterface.class);
+
+ /**
+ * The <em>time-to-live</em> for Internet Protocol (IP) multicast datagrams.
+ *
+ * <p> The value of this socket option is an {@code Integer} in the range
+ * <tt>0 <= value <= 255</tt>. It is used to control
+ * the scope of multicast datagrams sent by the datagram-oriented socket.
+ * In the case of an {@link StandardProtocolFamily#INET IPv4} socket
+ * the option is the time-to-live (TTL) on multicast datagrams sent by the
+ * socket. Datagrams with a TTL of zero are not transmitted on the network
+ * but may be delivered locally. In the case of an {@link
+ * StandardProtocolFamily#INET6 IPv6} socket the option is the
+ * <em>hop limit</em> which is number of <em>hops</em> that the datagram can
+ * pass through before expiring on the network. For IPv6 sockets it is
+ * system dependent whether the option also sets the <em>time-to-live</em>
+ * on multicast datagrams sent to IPv4 addresses.
+ *
+ * <p> The initial/default value of the time-to-live setting is typically
+ * {@code 1}. An implementation allows this socket option to be set after
+ * the socket is bound. Whether the socket option can be queried or changed
+ * prior to binding the socket is system dependent.
+ *
+ * @see java.nio.channels.MulticastChannel
+ */
+ public static final SocketOption<Integer> IP_MULTICAST_TTL =
+ new StdSocketOption<Integer>("IP_MULTICAST_TTL", Integer.class);
+
+ /**
+ * Loopback for Internet Protocol (IP) multicast datagrams.
+ *
+ * <p> The value of this socket option is a {@code Boolean} that controls
+ * the <em>loopback</em> of multicast datagrams. The value of the socket
+ * option represents if the option is enabled or disabled.
+ *
+ * <p> The exact semantics of this socket options are system dependent.
+ * In particular, it is system dependent whether the loopback applies to
+ * multicast datagrams sent from the socket or received by the socket.
+ * For {@link StandardProtocolFamily#INET6 IPv6} sockets then it is
+ * system dependent whether the option also applies to multicast datagrams
+ * sent to IPv4 addresses.
+ *
+ * <p> The initial/default value of this socket option is {@code TRUE}. An
+ * implementation allows this socket option to be set after the socket is
+ * bound. Whether the socket option can be queried or changed prior to
+ * binding the socket is system dependent.
+ *
+ * @see java.nio.channels.MulticastChannel
+ */
+ public static final SocketOption<Boolean> IP_MULTICAST_LOOP =
+ new StdSocketOption<Boolean>("IP_MULTICAST_LOOP", Boolean.class);
+
+
+ // -- IPPROTO_TCP --
+
+ /**
+ * 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. In that case, 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>
+ */
+ public static final SocketOption<Boolean> TCP_NODELAY =
+ new StdSocketOption<Boolean>("TCP_NODELAY", Boolean.class);
+
+
+ private static class StdSocketOption<T> implements SocketOption<T> {
+ private final String name;
+ private final Class<T> type;
+ StdSocketOption(String name, Class<T> type) {
+ this.name = name;
+ this.type = type;
+ }
+ @Override public String name() { return name; }
+ @Override public Class<T> type() { return type; }
+ @Override public String toString() { return name; }
+ }
+}