XMLWriter.cc
// This file is part of libdap, A C++ implementation of the OPeNDAP Data
// Access Protocol.
// Copyright (c) 2010 OPeNDAP, Inc.
// Author: James Gallagher <jgallagher@opendap.org>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
//
// You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
/*
* XMLWriter.cpp
*
* Created on: Jul 28, 2010
* Author: jimg
*/
#include "config.h"
#include <libxml/encoding.h>
#include <libxml/xmlwriter.h>
#include "XMLWriter.h"
#include "InternalErr.h"
// 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.
const char *ENCODING = "ISO-8859-1";
const int XML_BUF_SIZE = 2000000;
using namespace libdap;
XMLWriter::XMLWriter(const string &pad) {
// LEAK The LIBXML_TEST_VERSION macro leaks 40 bytes according to valgrind
// on centos7. jhrg 6/19/19
// LIBXML_TEST_VERSION;
/* Create a new XML buffer, to which the XML document will be
* written */
try {
if (!(d_doc_buf = xmlBufferCreateSize(XML_BUF_SIZE)))
throw InternalErr(__FILE__, __LINE__, "Error allocating the xml buffer");
xmlBufferSetAllocationScheme(d_doc_buf, XML_BUFFER_ALLOC_DOUBLEIT);
/* Create a new XmlWriter for memory, with no compression.
* Remark: there is no compression for this kind of xmlTextWriter */
if (!(d_writer = xmlNewTextWriterMemory(d_doc_buf, 0)))
throw InternalErr(__FILE__, __LINE__, "Error allocating memory for xml writer");
if (xmlTextWriterSetIndent(d_writer, pad.length()) < 0)
throw InternalErr(__FILE__, __LINE__, "Error starting indentation for response document ");
if (xmlTextWriterSetIndentString(d_writer, (const xmlChar*)pad.c_str()) < 0)
throw InternalErr(__FILE__, __LINE__, "Error setting indentation for response document ");
d_started = true;
d_ended = false;
/* Start the document with the xml default for the version,
* encoding ISO 8859-1 and the default for the standalone
* declaration. MY_ENCODING defined at top of this file*/
if (xmlTextWriterStartDocument(d_writer, NULL, ENCODING, NULL) < 0)
throw InternalErr(__FILE__, __LINE__, "Error starting xml response document");
}
catch (InternalErr &e) {
m_cleanup();
throw;
}
}
XMLWriter::~XMLWriter() {
m_cleanup();
}
void XMLWriter::m_cleanup() {
// make sure the buffer and writer are all cleaned up
if (d_writer) {
xmlFreeTextWriter(d_writer); // This frees both d_writer and d_doc_buf
d_writer = 0;
// d_doc_buf = 0;
}
// We could be here because of an exception and d_writer might be zero
if (d_doc_buf) {
xmlBufferFree(d_doc_buf);
d_doc_buf = 0;
}
d_started = false;
d_ended = false;
}
const char *XMLWriter::get_doc() {
if (d_writer && d_started) {
if (xmlTextWriterEndDocument(d_writer) < 0)
throw InternalErr(__FILE__, __LINE__, "Error ending the document");
d_ended = true;
// must call this before getting the buffer content. Odd, but appears to be true.
// jhrg
xmlFreeTextWriter(d_writer);
d_writer = 0;
}
if (!d_doc_buf->content)
throw InternalErr(__FILE__, __LINE__, "Error retrieving response document as string");
return (const char *)d_doc_buf->content;
}
unsigned int XMLWriter::get_doc_size() {
if (d_writer && d_started) {
if (xmlTextWriterEndDocument(d_writer) < 0)
throw InternalErr(__FILE__, __LINE__, "Error ending the document");
d_ended = true;
// must call this before getting the buffer content. Odd, but appears to be true.
// jhrg
xmlFreeTextWriter(d_writer);
d_writer = 0;
}
if (!d_doc_buf->content)
throw InternalErr(__FILE__, __LINE__, "Error retrieving response document as string");
// how much of the buffer is in use?
return d_doc_buf->use;
}
libdap::InternalErr
A class for software fault reporting.
Definition InternalErr.h:65
libdap
top level DAP object to house generic methods
Definition AlarmHandler.h:36