Initial commit

engines/bagel/boflib/queue.cpp

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "bagel/boflib/queue.h"
+#include "bagel/boflib/stdinc.h"
+
+namespace Bagel {
+
+CQueue::CQueue() {
+}
+
+CQueue::~CQueue() {
+	// Can't destruct if we don't exist
+	assert(isValidObject(this));
+
+	while (removeItem() != nullptr) {
+	}
+
+	// remove() must set _pQueueList to nullptr when it removes the last item
+	assert(_pQueueList == nullptr);
+}
+
+void CQueue::addItem(void *pObject) {
+	// Make sure this object exists
+	assert(isValidObject(this));
+
+	CLList *pNewItem = new CLList(pObject);
+	if (_pQueueList != nullptr) {
+		_pQueueList->addToTail(pNewItem);
+	} else {
+		_pQueueList = pNewItem;
+	}
+
+	assert(pNewItem->getHead() == _pQueueList);
+}
+
+void *CQueue::removeItem() {
+	// Make sure this object exists
+	assert(isValidObject(this));
+
+	// Assume empty list
+	void *pObject = nullptr;
+
+	CLList *pList = _pQueueList;
+	if (pList != nullptr) {
+		pObject = pList->getData();
+
+		_pQueueList = pList->getNext();
+		delete pList;
+	}
+
+	return pObject;
+}
+
+void CQueue::deleteItem(void *pItem) {
+	// Make sure this object exists
+	assert(isValidObject(this));
+	assert(pItem != nullptr);
+
+	CLList *pList = _pQueueList;
+	while (pList != nullptr) {
+		CLList *pNext = pList->getNext();
+
+		if (pItem == pList->getData()) {
+			// If this is the 1st item in the Queue, then move head
+			if (pList == _pQueueList)
+				_pQueueList = _pQueueList->getNext();
+
+			delete pList;
+			break;
+		}
+
+		pList = pNext;
+	}
+}
+
+void *CQueue::getQItem() {
+	assert(isValidObject(this));
+
+	void *pItem = nullptr;
+	if (_pQueueList != nullptr) {
+		pItem = _pQueueList->getData();
+	}
+
+	return pItem;
+}
+
+void CQueue::flush() {
+	assert(isValidObject(this));
+
+	while (removeItem() != nullptr) {
+	}
+}
+
+} // namespace Bagel