db/upnp/Directory: merge m_containers and m_items

There is no use in duplicating these containers.  It only means that
we have to search both, duplicating the code.

src/db/UpnpDatabasePlugin.cxx

@@ -452,7 +452,11 @@ UpnpDatabase::SearchSongs(ContentDirectoryService* server,
 	if (!SearchSongs(server, objid, selection, dirbuf, error))
 		return false;
 
-	for (const auto &dirent : dirbuf.m_items) {
+	for (const auto &dirent : dirbuf.objects) {
+		if (dirent.type != UPnPDirObject::Type::ITEM ||
+		    dirent.item_class != UPnPDirObject::ItemClass::MUSIC)
+			continue;
+
 		// We get song ids as the result of the UPnP search. But our
 		// client expects paths (e.g. we get 1$4$3788 from minidlna,
 		// but we need to translate to /Music/All_Music/Satisfaction).
@@ -489,10 +493,8 @@ UpnpDatabase::ReadNode(ContentDirectoryService *server,
 	if (!server->getMetadata(objid, dirbuf, error))
 		return false;
 
-	if (dirbuf.m_containers.size() == 1) {
-		dirent = dirbuf.m_containers[0];
-	} else if (dirbuf.m_items.size() == 1) {
-		dirent = dirbuf.m_items[0];
+	if (dirbuf.objects.size() == 1) {
+		dirent = dirbuf.objects[0];
 	} else {
 		error.Format(upnp_domain, "Bad resource");
 		return false;
@@ -545,34 +547,34 @@ UpnpDatabase::Namei(ContentDirectoryService* server,
 		if (!server->readDir(objid.c_str(), dirbuf, error))
 			return false;
 
-		bool found = false;
-
 		// Look for the name in the sub-container list
-		for (auto& dirent : dirbuf.m_containers) {
-			if (!vpath[i].compare(dirent.name)) {
-				objid = dirent.m_id; // Next readdir target
-				found = true;
+		const UPnPDirObject *child =
+			dirbuf.FindObject(vpath[i].c_str());
+		if (child == nullptr)
+			break;
+
+		switch (child->type) {
+		case UPnPDirObject::Type::UNKNOWN:
+			assert(false);
+			gcc_unreachable();
+
+		case UPnPDirObject::Type::CONTAINER:
+			objid = child->m_id; // Next readdir target
 			if (i == vpath.size() - 1) {
 				// The last element in the path was found and it's
 				// a container, we're done
 				oobjid = objid;
-					odirent = dirent;
+				odirent = *child;
 				return true;
 			}
 			break;
-			}
-		}
-		if (found)
-			continue;
 
-		// Path elt was not a container, look at the items list
-		for (auto& dirent : dirbuf.m_items) {
-			if (!vpath[i].compare(dirent.name)) {
+		case UPnPDirObject::Type::ITEM:
 			// If this is the last path elt, we found the target,
 			// else it does not exist
 			if (i == vpath.size() - 1) {
 				oobjid = objid;
-					odirent = dirent;
+				odirent = *child;
 				return true;
 			} else {
 				error.Format(db_domain, DB_NOT_FOUND,
@@ -582,11 +584,6 @@ UpnpDatabase::Namei(ContentDirectoryService* server,
 		}
 	}
 
-		// Neither container nor item, we're done.
-		if (!found)
-			break;
-	}
-
 	error.Format(db_domain, DB_NOT_FOUND, "No such object");
 	return false;
 }
@@ -675,18 +672,24 @@ UpnpDatabase::VisitServer(ContentDirectoryService* server,
 	if (!server->readDir(objid.c_str(), dirbuf, error))
 		return false;
 
+	for (const auto &dirent : dirbuf.objects) {
+		switch (dirent.type) {
+		case UPnPDirObject::Type::UNKNOWN:
+			assert(false);
+			gcc_unreachable();
+
+		case UPnPDirObject::Type::CONTAINER:
 			if (visit_directory) {
-		for (auto& dirent : dirbuf.m_containers) {
 				Directory d((selection.uri + "/" +
 					     dirent.name).c_str(),
 					    m_root);
 				if (!visit_directory(d, error))
 					return false;
 			}
-	}
 
-	if (visit_song || visit_playlist) {
-		for (const auto &dirent : dirbuf.m_items) {
+			break;
+
+		case UPnPDirObject::Type::ITEM:
 			switch (dirent.item_class) {
 			case UPnPDirObject::ItemClass::MUSIC:
 				if (visit_song) {
@@ -810,7 +813,11 @@ UpnpDatabase::VisitUniqueTags(const DatabaseSelection &selection,
 		if (!SearchSongs(&server, rootid, selection, dirbuf, error))
 			return false;
 
-		for (auto &dirent : dirbuf.m_items) {
+		for (const auto &dirent : dirbuf.objects) {
+			if (dirent.type != UPnPDirObject::Type::ITEM ||
+			    dirent.item_class != UPnPDirObject::ItemClass::MUSIC)
+				continue;
+
 			std::string tagvalue;
 			if (getTagValue(dirent, tag, tagvalue)) {
 #if defined(__clang__) || GCC_CHECK_VERSION(4,8)

src/db/upnp/Directory.cxx

@@ -149,15 +149,9 @@ protected:
 
 	virtual void EndElement(const XML_Char *name)
 	{
-		if (!strcmp(name, "container")) {
-			if (checkobjok()) {
-				m_dir.m_containers.push_back(m_tobj);
-			}
-		} else if (!strcmp(name, "item")) {
-			if (checkobjok()) {
-				m_dir.m_items.push_back(m_tobj);
-			}
-		}
+		if ((!strcmp(name, "container") || !strcmp(name, "item")) &&
+		    checkobjok())
+			m_dir.objects.push_back(m_tobj);
 
 		m_path.pop_back();
 	}

src/db/upnp/Directory.hxx

@@ -21,6 +21,7 @@
 #define MPD_UPNP_DIRECTORY_HXX
 
 #include "Object.hxx"
+#include "Compiler.h"
 
 #include <string>
 #include <vector>
@@ -33,8 +34,16 @@ class Error;
  */
 class UPnPDirContent {
 public:
-	std::vector<UPnPDirObject> m_containers;
-	std::vector<UPnPDirObject> m_items;
+	std::vector<UPnPDirObject> objects;
+
+	gcc_pure
+	const UPnPDirObject *FindObject(const char *name) const {
+		for (const auto &o : objects)
+			if (o.name == name)
+				return &o;
+
+		return nullptr;
+	}
 
 	/**
 	 * Parse from DIDL-Lite XML data.