BufferManagerWrite.java revision 608:7e06bf1dcb09 
1/*
2 * Copyright (c) 2000, 2003, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package com.sun.corba.se.impl.encoding;
27
28import com.sun.corba.se.spi.logging.CORBALogDomains;
29
30import com.sun.corba.se.spi.orb.ORB;
31
32import com.sun.corba.se.impl.encoding.ByteBufferWithInfo;
33
34import com.sun.corba.se.impl.logging.ORBUtilSystemException;
35
36/**
37 * Defines the contract between the BufferManager and
38 * CDR stream on the writing side.  The CDR stream
39 * calls back to the BufferManagerWrite when it needs
40 * more room in the output buffer to continue.  The
41 * BufferManager can then grow the output buffer or
42 * use some kind of fragmentation technique.
43 */
44public abstract class BufferManagerWrite
45{
46    protected ORB orb ;
47    protected ORBUtilSystemException wrapper ;
48
49    BufferManagerWrite( ORB orb )
50    {
51        this.orb = orb ;
52        this.wrapper = ORBUtilSystemException.get( orb,
53            CORBALogDomains.RPC_ENCODING ) ;
54    }
55
56    /**
57     * Has the stream sent out any fragments so far?
58     */
59    public abstract boolean sentFragment();
60
61    /**
62     * Has the entire message been sent?  (Has
63     * sendMessage been called?)
64     */
65    public boolean sentFullMessage() {
66        return sentFullMessage;
67    }
68
69    /**
70     * Returns the correct buffer size for this type of
71     * buffer manager as set in the ORB.
72     */
73    public abstract int getBufferSize();
74
75    /*
76     * Called from CDROutputStream.grow.
77     *
78     * bbwi.buf contains a byte array which needs to grow by bbwi.needed bytes.
79     *
80     * This can be handled in several ways:
81     *
82     * 1. Resize the bbwi.buf like the current implementation of
83     *    CDROutputStream.grow.
84     *
85     * 2. Collect the buffer for a later send:
86     *    this.bufQ.put(bbwi);
87     *    return new ByteBufferWithInfo(bbwi.length);
88     *
89     * 3. Send buffer as fragment:
90     *    Backpatch fragment size field in bbwi.buf.
91     *    Set more fragments bit in bbwi.buf.
92     *    this.connection.send(bbwi);
93     *    return reinitialized bbwi.buf with fragment header
94     *
95     * All cases should adjust the returned bbwi.* appropriately.
96     *
97     * Should set the bbwi.fragmented flag to true only in cases 2 and 3.
98     */
99
100    public abstract void overflow (ByteBufferWithInfo bbwi);
101
102    /**
103     * Called after Stub._invoke (i.e., before complete message has been sent).
104     *
105     * IIOPOutputStream.writeTo called from IIOPOutputStream.invoke
106     *
107     * Case: overflow was never called (bbwi.buf contains complete message).
108     *       Backpatch size field.
109     *       If growing or collecting:
110     *          this.bufQ.put(bbwi).
111     *          this.bufQ.iterate // However, see comment in getBufferQ
112     *             this.connection.send(fragment)
113     *       If streaming:
114     *          this.connection.send(bbwi).
115     *
116     * Case: overflow was called N times (bbwi.buf contains last buffer).
117     *       If growing or collecting:
118     *          this.bufQ.put(bbwi).
119     *          backpatch size field in first buffer.
120     *          this.bufQ.iterate // However, see comment in getBufferQ
121     *             this.connection.send(fragment)
122     *       If streaming:
123     *          backpatch fragment size field in bbwi.buf.
124     *          Set no more fragments bit.
125     *          this.connection.send(bbwi).
126     */
127
128    public abstract void sendMessage ();
129
130    /**
131     * A reference to the connection level stream will be required when
132     * sending fragments.
133     */
134    public void setOutputObject(Object outputObject) {
135        this.outputObject = outputObject;
136    }
137
138    /**
139     * Close the BufferManagerWrite and do any outstanding cleanup.
140     */
141     abstract public void close();
142
143
144    // XREVISIT - Currently a java.lang.Object during
145    // the rip-int-generic transition.  Should eventually
146    // become a GIOPOutputObject.
147    protected Object outputObject;
148
149    protected boolean sentFullMessage = false;
150}
151