1
2 // This file is part of libdap, A C++ implementation of the OPeNDAP Data
3 // Access Protocol.
4
5 // Copyright (c) 2010 OPeNDAP, Inc.
6 // Author: James Gallagher <jgallagher@opendap.org>
7 //
8 // This library is free software; you can redistribute it and/or
9 // modify it under the terms of the GNU Lesser General Public
10 // License as published by the Free Software Foundation; either
11 // version 2.1 of the License, or (at your option) any later version.
12 //
13 // This library is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 // Lesser General Public License for more details.
17 //
18 // You should have received a copy of the GNU Lesser General Public
19 // License along with this library; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 //
22 // You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
23
24 /*
25 * XMLWriter.cpp
26 *
27 * Created on: Jul 28, 2010
28 * Author: jimg
29 */
30
31 #include "config.h"
32
33 #include <libxml/encoding.h>
34 #include <libxml/xmlwriter.h>
35
36 #include "XMLWriter.h"
37 #include "InternalErr.h"
38
39 // TODO - Bite the bullet and make the encoding UTF-8 as required by dap4. This will break a lot of tests but the baselines could be amended using a bash script and sed.
40 const char *ENCODING = "ISO-8859-1";
41 const int XML_BUF_SIZE = 2000000;
42
43 using namespace libdap;
44
XMLWriter(const string & pad)45 XMLWriter::XMLWriter(const string &pad) {
46 // LEAK The LIBXML_TEST_VERSION macro leaks 40 bytes according to valgrind
47 // on centos7. jhrg 6/19/19
48 // LIBXML_TEST_VERSION;
49
50 /* Create a new XML buffer, to which the XML document will be
51 * written */
52 try {
53 if (!(d_doc_buf = xmlBufferCreateSize(XML_BUF_SIZE)))
54 throw InternalErr(__FILE__, __LINE__, "Error allocating the xml buffer");
55
56 xmlBufferSetAllocationScheme(d_doc_buf, XML_BUFFER_ALLOC_DOUBLEIT);
57
58 /* Create a new XmlWriter for memory, with no compression.
59 * Remark: there is no compression for this kind of xmlTextWriter */
60 if (!(d_writer = xmlNewTextWriterMemory(d_doc_buf, 0)))
61 throw InternalErr(__FILE__, __LINE__, "Error allocating memory for xml writer");
62
63 if (xmlTextWriterSetIndent(d_writer, pad.length()) < 0)
64 throw InternalErr(__FILE__, __LINE__, "Error starting indentation for response document ");
65
66 if (xmlTextWriterSetIndentString(d_writer, (const xmlChar*)pad.c_str()) < 0)
67 throw InternalErr(__FILE__, __LINE__, "Error setting indentation for response document ");
68
69 d_started = true;
70 d_ended = false;
71
72 /* Start the document with the xml default for the version,
73 * encoding ISO 8859-1 and the default for the standalone
74 * declaration. MY_ENCODING defined at top of this file*/
75 if (xmlTextWriterStartDocument(d_writer, NULL, ENCODING, NULL) < 0)
76 throw InternalErr(__FILE__, __LINE__, "Error starting xml response document");
77 }
78 catch (InternalErr &e) {
79 m_cleanup();
80 throw;
81 }
82
83 }
84
~XMLWriter()85 XMLWriter::~XMLWriter() {
86 m_cleanup();
87 }
88
m_cleanup()89 void XMLWriter::m_cleanup() {
90 // make sure the buffer and writer are all cleaned up
91 if (d_writer) {
92 xmlFreeTextWriter(d_writer); // This frees both d_writer and d_doc_buf
93 d_writer = 0;
94 // d_doc_buf = 0;
95 }
96
97 // We could be here because of an exception and d_writer might be zero
98 if (d_doc_buf) {
99 xmlBufferFree(d_doc_buf);
100 d_doc_buf = 0;
101 }
102
103 d_started = false;
104 d_ended = false;
105 }
106
get_doc()107 const char *XMLWriter::get_doc() {
108 if (d_writer && d_started) {
109 if (xmlTextWriterEndDocument(d_writer) < 0)
110 throw InternalErr(__FILE__, __LINE__, "Error ending the document");
111
112 d_ended = true;
113
114 // must call this before getting the buffer content. Odd, but appears to be true.
115 // jhrg
116 xmlFreeTextWriter(d_writer);
117 d_writer = 0;
118 }
119
120 if (!d_doc_buf->content)
121 throw InternalErr(__FILE__, __LINE__, "Error retrieving response document as string");
122
123 return (const char *)d_doc_buf->content;
124 }
125
get_doc_size()126 unsigned int XMLWriter::get_doc_size() {
127 if (d_writer && d_started) {
128 if (xmlTextWriterEndDocument(d_writer) < 0)
129 throw InternalErr(__FILE__, __LINE__, "Error ending the document");
130
131 d_ended = true;
132
133 // must call this before getting the buffer content. Odd, but appears to be true.
134 // jhrg
135 xmlFreeTextWriter(d_writer);
136 d_writer = 0;
137 }
138
139 if (!d_doc_buf->content)
140 throw InternalErr(__FILE__, __LINE__, "Error retrieving response document as string");
141
142 // how much of the buffer is in use?
143 return d_doc_buf->use;
144 }
145