1 /* Constructed.java -- Constructed type. 2 Copyright (C) 2006 Free Software Foundation, Inc. 3 4 This file is a part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2 of the License, or (at 9 your option) any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; if not, write to the Free Software 18 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 19 USA 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 39 package gnu.javax.net.ssl.provider; 40 41 /** 42 * The base interface to SSL constructed types. 43 * 44 * <p><b>Contract for ByteBuffer-based constructed types:</b> 45 * 46 * <p>Most implementations of this interface supported by this library 47 * take a "view" of an underlying ByteBuffer. The general contract of 48 * such classes is that they <em>will not</em> modify the position or 49 * limit of the buffer when doing read operations. That is, the position 50 * of the underlying buffer <em>should</em> remain at 0 throughout the 51 * lifetime of the object, and the limit should be either set to the 52 * capacity of the buffer, or to the size of the object (in most cases, 53 * the length of the protocol object is determined by the contents of 54 * the object, so the limit isn't useful in such cases. Of course, if the 55 * limit is set to something other than the object's length, it must be 56 * larger than the object length). 57 * 58 * <p>Setter methods (usually in a class that implements the {@link Builder} 59 * interface) may modify the limit, but the general contract remains that 60 * the position remain at zero, and that the limit be at least as large as 61 * the object length. 62 * 63 * <p>Thus, very often the code will use <em>absolute</em> getters and setters 64 * for primitive types, or it will use the {@link java.nio.ByteBuffer#duplicate()} 65 * method, and sometimes the {@link java.nio.ByteBuffer#slice()} method, and 66 * will change the position or limit of the duplicate buffer. 67 */ 68 public interface Constructed 69 { 70 /** 71 * Returns the total length, in bytes, of this structure. 72 * 73 * @return The length of this structure. 74 */ length()75 int length(); 76 77 /** 78 * Returns a printable representation of this structure, with the 79 * given prefix prepended to each line. 80 * 81 * @param prefix The prefix to prepend to each line of the 82 * output. This value may be <code>null</code>. 83 * @return A printable representation of this structure. 84 */ toString(String prefix)85 String toString(String prefix); 86 } 87