--- /dev/null
+/** **************************************************************************
+ * simplexml.c
+ *
+ * Copyright 2008 Bryan Ischo <bryan@ischo.com>
+ *
+ * This file is part of libs3.
+ *
+ * libs3 is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3 of the License.
+ *
+ * In addition, as a special exception, the copyright holders give
+ * permission to link the code of this library and its programs with the
+ * OpenSSL library, and distribute linked combinations including the two.
+ *
+ * libs3 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 General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License version 3
+ * along with libs3, in a file named COPYING. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ ************************************************************************** **/
+
+#include <libxml/parser.h>
+#include <string.h>
+#include "simplexml.h"
+
+// Use libxml2 for parsing XML. XML is severely overused in modern
+// computing. It is useful for only a very small subset of tasks, but
+// software developers who don't know better and are afraid to go against the
+// grain use it for everything, and in most cases, it is completely
+// inappropriate. Usually, the document structure is severely under-specified
+// as well, as is the case with S3. We do our best by just caring about the
+// most important aspects of the S3 "XML document" responses: the elements and
+// their values. The SAX API (just about the lamest API ever devised and
+// proof that XML sucks - well, the real proof is how crappy all of the XML
+// parsing libraries are, including libxml2 - but I digress) is used here
+// because we don't need much from the parser and SAX is fast and low memory.
+//
+// Note that for simplicity we assume all ASCII here. No attempts are made to
+// detect non-ASCII sequences in utf-8 and convert them into ASCII in any way.
+// S3 appears to only use ASCII anyway.
+
+
+static xmlEntityPtr saxGetEntity(void *user_data, const xmlChar *name)
+{
+ (void) user_data;
+
+ return xmlGetPredefinedEntity(name);
+}
+
+
+static void saxStartElement(void *user_data, const xmlChar *nameUtf8,
+ const xmlChar **attr)
+{
+ (void) attr;
+
+ SimpleXml *simpleXml = (SimpleXml *) user_data;
+
+ if (simpleXml->status != S3StatusOK) {
+ return;
+ }
+
+ // Assume that name has no non-ASCII in it
+ char *name = (char *) nameUtf8;
+
+ // Append the element to the element path
+ int len = strlen(name);
+
+ if ((simpleXml->elementPathLen + len + 1) >=
+ (int) sizeof(simpleXml->elementPath)) {
+ // Cannot handle this element, stop!
+ simpleXml->status = S3StatusXmlParseFailure;
+ return;
+ }
+
+ if (simpleXml->elementPathLen) {
+ simpleXml->elementPath[simpleXml->elementPathLen++] = '/';
+ }
+ strcpy(&(simpleXml->elementPath[simpleXml->elementPathLen]), name);
+ simpleXml->elementPathLen += len;
+}
+
+
+static void saxEndElement(void *user_data, const xmlChar *name)
+{
+ (void) name;
+
+ SimpleXml *simpleXml = (SimpleXml *) user_data;
+
+ if (simpleXml->status != S3StatusOK) {
+ return;
+ }
+
+ // Call back with 0 data
+ simpleXml->status = (*(simpleXml->callback))
+ (simpleXml->elementPath, 0, 0, simpleXml->callbackData);
+
+ while ((simpleXml->elementPathLen > 0) &&
+ (simpleXml->elementPath[simpleXml->elementPathLen] != '/')) {
+ simpleXml->elementPathLen--;
+ }
+
+ simpleXml->elementPath[simpleXml->elementPathLen] = 0;
+}
+
+
+static void saxCharacters(void *user_data, const xmlChar *ch, int len)
+{
+ SimpleXml *simpleXml = (SimpleXml *) user_data;
+
+ if (simpleXml->status != S3StatusOK) {
+ return;
+ }
+
+ simpleXml->status = (*(simpleXml->callback))
+ (simpleXml->elementPath, (char *) ch, len, simpleXml->callbackData);
+}
+
+
+static void saxError(void *user_data, const char *msg, ...)
+{
+ (void) msg;
+
+ SimpleXml *simpleXml = (SimpleXml *) user_data;
+
+ if (simpleXml->status != S3StatusOK) {
+ return;
+ }
+
+ simpleXml->status = S3StatusXmlParseFailure;
+}
+
+
+static struct _xmlSAXHandler saxHandlerG =
+{
+ 0, // internalSubsetSAXFunc
+ 0, // isStandaloneSAXFunc
+ 0, // hasInternalSubsetSAXFunc
+ 0, // hasExternalSubsetSAXFunc
+ 0, // resolveEntitySAXFunc
+ &saxGetEntity, // getEntitySAXFunc
+ 0, // entityDeclSAXFunc
+ 0, // notationDeclSAXFunc
+ 0, // attributeDeclSAXFunc
+ 0, // elementDeclSAXFunc
+ 0, // unparsedEntityDeclSAXFunc
+ 0, // setDocumentLocatorSAXFunc
+ 0, // startDocumentSAXFunc
+ 0, // endDocumentSAXFunc
+ &saxStartElement, // startElementSAXFunc
+ &saxEndElement, // endElementSAXFunc
+ 0, // referenceSAXFunc
+ &saxCharacters, // charactersSAXFunc
+ 0, // ignorableWhitespaceSAXFunc
+ 0, // processingInstructionSAXFunc
+ 0, // commentSAXFunc
+ 0, // warningSAXFunc
+ &saxError, // errorSAXFunc
+ &saxError, // fatalErrorSAXFunc
+ 0, // getParameterEntitySAXFunc
+ &saxCharacters, // cdataBlockSAXFunc
+ 0, // externalSubsetSAXFunc
+ 0, // initialized
+ 0, // _private
+ 0, // startElementNsSAX2Func
+ 0, // endElementNsSAX2Func
+ 0 // xmlStructuredErrorFunc serror;
+};
+
+void simplexml_initialize(SimpleXml *simpleXml,
+ SimpleXmlCallback *callback, void *callbackData)
+{
+ simpleXml->callback = callback;
+ simpleXml->callbackData = callbackData;
+ simpleXml->elementPathLen = 0;
+ simpleXml->status = S3StatusOK;
+ simpleXml->xmlParser = 0;
+}
+
+
+void simplexml_deinitialize(SimpleXml *simpleXml)
+{
+ if (simpleXml->xmlParser) {
+ xmlFreeParserCtxt(simpleXml->xmlParser);
+ }
+}
+
+
+S3Status simplexml_add(SimpleXml *simpleXml, const char *data, int dataLen)
+{
+ if (!simpleXml->xmlParser &&
+ (!(simpleXml->xmlParser = xmlCreatePushParserCtxt
+ (&saxHandlerG, simpleXml, 0, 0, 0)))) {
+ return S3StatusInternalError;
+ }
+
+ if (xmlParseChunk((xmlParserCtxtPtr) simpleXml->xmlParser,
+ data, dataLen, 0)) {
+ return S3StatusXmlParseFailure;
+ }
+
+ return simpleXml->status;
+}
projects / bluesky.git / blobdiff