lib/upnp: use std::unique_ptr

Makefile.am

@@ -244,6 +244,7 @@ UPNP_SOURCES = \
 	src/lib/upnp/ixmlwrap.cxx src/lib/upnp/ixmlwrap.hxx \
 	src/lib/upnp/Callback.hxx \
 	src/lib/upnp/Util.cxx src/lib/upnp/Util.hxx \
+	src/lib/upnp/UniqueIxml.hxx \
 	src/lib/upnp/WorkQueue.hxx \
 	src/lib/upnp/Action.hxx
 

src/lib/upnp/ContentDirectoryService.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "ContentDirectoryService.hxx"
+#include "UniqueIxml.hxx"
 #include "Domain.hxx"
 #include "Device.hxx"
 #include "ixmlwrap.hxx"
@@ -56,20 +57,18 @@ ContentDirectoryService::getSearchCapabilities(UpnpClient_Handle hdl,
 {
 	assert(result.empty());
 
-	IXML_Document *request =
-		UpnpMakeAction("GetSearchCapabilities", m_serviceType.c_str(),
-			       0,
-			       nullptr, nullptr);
-	if (request == 0) {
+	UniqueIxmlDocument request(UpnpMakeAction("GetSearchCapabilities", m_serviceType.c_str(),
+						  0,
+						  nullptr, nullptr));
+	if (!request) {
 		error.Set(upnp_domain, "UpnpMakeAction() failed");
 		return false;
 	}
 
-	IXML_Document *response;
+	IXML_Document *_response;
 	auto code = UpnpSendAction(hdl, m_actionURL.c_str(),
 				   m_serviceType.c_str(),
-				   0 /*devUDN*/, request, &response);
-	ixmlDocument_free(request);
+				   0 /*devUDN*/, request.get(), &_response);
 	if (code != UPNP_E_SUCCESS) {
 		error.Format(upnp_domain, code,
 			     "UpnpSendAction() failed: %s",
@@ -77,18 +76,17 @@ ContentDirectoryService::getSearchCapabilities(UpnpClient_Handle hdl,
 		return false;
 	}
 
-	const char *s = ixmlwrap::getFirstElementValue(response, "SearchCaps");
-	if (s == nullptr || *s == 0) {
-		ixmlDocument_free(response);
-		return true;
-	}
+	UniqueIxmlDocument response(_response);
+
+	const char *s = ixmlwrap::getFirstElementValue(response.get(),
+						       "SearchCaps");
+	if (s == nullptr || *s == 0)
+		return true;
 
-	bool success = true;
 	if (!csvToStrings(s, result)) {
 		error.Set(upnp_domain, "Bad response");
-		success = false;
+		return false;
 	}
 
-	ixmlDocument_free(response);
-	return success;
+	return true;
 }

src/lib/upnp/UniqueIxml.hxx

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2003-2016 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_UPNP_UNIQUE_XML_HXX
+#define MPD_UPNP_UNIQUE_XML_HXX
+
+#include <upnp/ixml.h>
+
+#include <memory>
+
+struct UpnpIxmlDeleter {
+	void operator()(IXML_Document *doc) {
+		ixmlDocument_free(doc);
+	}
+
+	void operator()(IXML_NodeList *nl) {
+		ixmlNodeList_free(nl);
+	}
+};
+
+typedef std::unique_ptr<IXML_Document, UpnpIxmlDeleter> UniqueIxmlDocument;
+typedef std::unique_ptr<IXML_NodeList, UpnpIxmlDeleter> UniqueIxmlNodeList;
+
+#endif

src/lib/upnp/ixmlwrap.cxx

@@ -16,29 +16,26 @@
  */
 
 #include "ixmlwrap.hxx"
+#include "UniqueIxml.hxx"
 
 namespace ixmlwrap {
 
 const char *
 getFirstElementValue(IXML_Document *doc, const char *name)
 {
-	const char *ret = nullptr;
-	IXML_NodeList *nodes =
-		ixmlDocument_getElementsByTagName(doc, name);
+	UniqueIxmlNodeList nodes(ixmlDocument_getElementsByTagName(doc, name));
+	if (!nodes)
+		return nullptr;
 
-	if (nodes) {
-		IXML_Node *first = ixmlNodeList_item(nodes, 0);
-		if (first) {
-			IXML_Node *dnode = ixmlNode_getFirstChild(first);
-			if (dnode) {
-				ret = ixmlNode_getNodeValue(dnode);
-			}
-		}
+	IXML_Node *first = ixmlNodeList_item(nodes.get(), 0);
+	if (!first)
+		return nullptr;
 
-		ixmlNodeList_free(nodes);
-	}
+	IXML_Node *dnode = ixmlNode_getFirstChild(first);
+	if (!dnode)
+		return nullptr;
 
-	return ret;
+	return ixmlNode_getNodeValue(dnode);
 }
 
 }