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Java > Open Source Codes > com > sun > corba > se > impl > encoding > CDRInputStream_1_2


1 /*
2  * @(#)CDRInputStream_1_2.java 1.14 04/03/01
3  *
4  * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
5  * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6  */
7 package com.sun.corba.se.impl.encoding;
8
9 import com.sun.corba.se.spi.ior.iiop.GIOPVersion;
10 import com.sun.corba.se.impl.orbutil.ORBConstants;
11
12 public class CDRInputStream_1_2 extends CDRInputStream_1_1
13 {
14     // Indicates whether the header is padded. In GIOP 1.2 and above,
15 // the body must be aligned on an 8-octet boundary, and so the header is
16 // padded appropriately. However, if there is no body to a request or reply
17 // message, there is no header padding, in the unfragmented case.
18 protected boolean headerPadding;
19     
20     // used to remember headerPadding flag when mark() and restore() are used.
21 protected boolean restoreHeaderPadding;
22
23     // Called by RequestMessage_1_2 or ReplyMessage_1_2 classes only.
24 void setHeaderPadding(boolean headerPadding) {
25         this.headerPadding = headerPadding;
26     }
27
28     // the mark and reset methods have been overridden to remember the
29 // headerPadding flag.
30
31     public void mark(int readlimit) {
32         super.mark(readlimit);
33         restoreHeaderPadding = headerPadding;
34     }
35
36     public void reset() {
37         super.reset();
38         headerPadding = restoreHeaderPadding;
39         restoreHeaderPadding = false;
40     }
41
42     // Template method
43 // This method has been overriden to ensure that the duplicated stream
44 // inherits the headerPadding flag, in case of GIOP 1.2 and above, streams.
45 public CDRInputStreamBase dup() {
46         CDRInputStreamBase result = super.dup();
47         ((CDRInputStream_1_2)result).headerPadding = this.headerPadding;
48         return result;
49     }
50     
51     protected void alignAndCheck(int align, int n) {
52
53         // headerPadding bit is set by read method of the RequestMessage_1_2
54 // or ReplyMessage_1_2 classes. When set, the very first body read
55 // operation (from the stub code) would trigger an alignAndCheck
56 // method call, that would in turn skip the header padding that was
57 // inserted during the earlier write operation by the sender. The
58 // padding ensures that the body is aligned on an 8-octet boundary,
59 // for GIOP versions 1.2 and beyond.
60 if (headerPadding == true) {
61             headerPadding = false;
62             alignOnBoundary(ORBConstants.GIOP_12_MSG_BODY_ALIGNMENT);
63         }
64       
65         checkBlockLength(align, n);
66
67         // WARNING: Must compute real alignment after calling
68 // checkBlockLength since it may move the position
69
70         // In GIOP 1.2, a fragment may end with some alignment
71 // padding (which leads to all fragments ending perfectly
72 // on evenly divisible 8 byte boundaries). A new fragment
73 // never requires alignment with the header since it ends
74 // on an 8 byte boundary.
75
76         int alignIncr = computeAlignment(bbwi.position(),align);
77         bbwi.position(bbwi.position() + alignIncr);
78
79         if (bbwi.position() + n > bbwi.buflen) {
80             grow(1, n);
81         }
82     }
83
84     public GIOPVersion getGIOPVersion() {
85         return GIOPVersion.V1_2;
86     }
87         
88     public char read_wchar() {
89         // In GIOP 1.2, a wchar is encoded as an unsigned octet length
90 // followed by the octets of the converted wchar.
91 int numBytes = read_octet();
92
93         char[] result = getConvertedChars(numBytes, getWCharConverter());
94
95         // Did the provided bytes convert to more than one
96 // character? This may come up as more unicode values are
97 // assigned, and a single 16 bit Java char isn't enough.
98 // Better to use strings for i18n purposes.
99 if (getWCharConverter().getNumChars() > 1)
100         throw wrapper.btcResultMoreThanOneChar() ;
101
102         return result[0];
103     }
104
105     public String JavaDoc read_wstring() {
106         // In GIOP 1.2, wstrings are not terminated by a null. The
107 // length is the number of octets in the converted format.
108 // A zero length string is represented with the 4 byte length
109 // value of 0.
110
111         int len = read_long();
112
113         //
114 // IMPORTANT: Do not replace 'new String("")' with "", it may result
115 // in a Serialization bug (See serialization.zerolengthstring) and
116 // bug id: 4728756 for details
117 if (len == 0)
118             return new String JavaDoc("");
119
120         checkForNegativeLength(len);
121
122         return new String JavaDoc(getConvertedChars(len, getWCharConverter()),
123                           0,
124                           getWCharConverter().getNumChars());
125     }
126 }
127
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