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engines/bagel/spacebar/boflib/vhash_table.h

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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/>.
+ *
+ */
+
+#ifndef BAGEL_BOFLIB_VHASH_TABLE_H
+#define BAGEL_BOFLIB_VHASH_TABLE_H
+
+#include "bagel/spacebar/boflib/list.h"
+
+namespace Bagel {
+namespace SpaceBar {
+
+template<class T, int S>
+class CBofVHashTable {
+public:
+	CBofVHashTable(unsigned(*hashFun)(const T &));
+	virtual ~CBofVHashTable();
+	bool contains(const T &val);
+	void insert(const T &val);
+
+private:
+	// Default constructor is not allowed.  A declaration is provided,
+	// but an implementation is not.  A link error will result if an
+	// attempt is made to use this constructor.  The location which
+	// is attempting to reference the default constructor should be changed
+	// so that it calls the class constructor which takes a pointer to a
+	// function and a table size.
+	CBofVHashTable();
+
+	// Member which holds the hash table itself.
+	CBofList<T *> _xHashTable[S];
+
+	// Member which holds a pointer to the table's hashing
+	// function.
+	unsigned(*_pHashFunction)(const T &);
+
+	// Member which holds the count of buckets in the hash table.
+	int _nHashTableSize;
+
+	// Boolean which affords a light-weight test of whether the hash
+	// table is empty.
+	//
+	bool _bisEmpty;
+};
+
+// CBofVHashTable::CBofVHashTable - class constructor.
+//
+template<class T, int S>
+CBofVHashTable<T, S>::CBofVHashTable(unsigned(*hashFun)(const T &)) : _nHashTableSize(S),
+	_pHashFunction(hashFun), _bisEmpty(true) {
+}
+
+// CBofVHashTable::~CBofVHashTable - class destructor.
+template<class T, int S>
+CBofVHashTable<T, S>::~CBofVHashTable() {
+	for (int x = 0; x < _nHashTableSize; x++) {
+		CBofList<T *> *pHashBucket = &_xHashTable[x];
+		int nListEntries = pHashBucket->getActualCount();
+
+		for (int i = 0; i < nListEntries; i++) {
+			T *pListItem = pHashBucket->getNodeItem(i);
+			delete pListItem;
+			pHashBucket->setNodeItem(i, (T *)nullptr);
+		}
+	}
+}
+
+// CBofVHashTable<T, S>::insert - add a value to the hash table.
+template<class T, int S>
+void CBofVHashTable<T, S>::insert(const T &val) {
+	T *pNodeValue = new T(val);
+	CBofListNode<T *> *pNode = new CBofListNode<T *>(pNodeValue);
+	assert(pNode != nullptr);
+
+	int nHashBucketIndex = ((*_pHashFunction)(val)) % _nHashTableSize;
+	assert(nHashBucketIndex < _nHashTableSize);
+
+	CBofList<T *> *pHashBucket = &_xHashTable[nHashBucketIndex];
+	assert(pHashBucket != nullptr);
+	pHashBucket->addToTail(pNode);
+}
+
+// CBofVHashTable<T, S>contains - predicate to test whether a value is stored in the hash table.
+template<class T, int S>
+bool CBofVHashTable<T, S>::contains(const T &val) {
+	bool returnValue = false;
+	int nHashBucketIndex = ((*_pHashFunction)(val)) % _nHashTableSize;
+	assert(nHashBucketIndex < _nHashTableSize);
+
+	CBofVHashTable<T, S> *const fakeThis = (CBofVHashTable<T, S> *const)this;
+	CBofList<T *> *pHashBucket = &(fakeThis->_xHashTable[nHashBucketIndex]);
+	assert(pHashBucket != nullptr);
+	int nItemsInBucket = pHashBucket->getCount();
+	for (int i = 0; i < nItemsInBucket; i++) {
+		T *TableEntry = pHashBucket->getNodeItem(i);
+		if (TableEntry->compareNoCase((const char *)val) == 0) {
+			returnValue = true;
+			break;
+		}
+	}
+	return returnValue;
+}
+
+} // namespace SpaceBar
+} // namespace Bagel
+
+#endif