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engines/gob/dbase.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/>.
+ *
+ *
+ * This file is dual-licensed.
+ * In addition to the GPLv3 license mentioned above, this code is also
+ * licensed under LGPL 2.1. See LICENSES/COPYING.LGPL file for the
+ * full text of the license.
+ *
+ */
+
+#ifndef GOB_DBASE_H
+#define GOB_DBASE_H
+
+#include "common/system.h"
+#include "common/util.h"
+#include "common/str.h"
+#include "common/stream.h"
+#include "common/array.h"
+
+namespace Gob {
+
+/**
+ * A class for reading Multiple Index (.mdx) files for dBase.
+ * Currently, we only read the key definitions, not the actual index data.
+ *
+ */
+class dbaseMultipeIndex {
+
+public:
+	dbaseMultipeIndex();
+	~dbaseMultipeIndex() {}
+
+	bool load(Common::SeekableReadStream &stream);
+	void clear();
+
+	class FieldReference {
+	public:
+		FieldReference() : _fieldName(""), _maxLength(0) {}
+		FieldReference(const Common::String &fieldName, size_t maxLength) : _fieldName(fieldName), _maxLength(maxLength) {}
+
+		const Common::String &getFieldName() const { return _fieldName; }
+		size_t getMaxLength() const { return _maxLength; }
+
+	private:
+		Common::String _fieldName;
+		size_t _maxLength;
+	};
+
+	static Common::Array<FieldReference> parseKeyDefinition(const Common::String &keyDefinition);
+
+	const Common::Array<FieldReference>* getTagKeyDefinition(Common::String tagName) const;
+
+private:
+	byte _version;
+	TimeDate _creationDate;
+	Common::String _dataFilename;
+	uint16 _nbrOfTagsInUse;
+	TimeDate _lastUpdate;
+
+	static const uint16 INDEX_PAGE_SIZE = 512;
+	Common::HashMap<Common::String, Common::Array<FieldReference>> _tagKeyDefinitions;
+};
+
+/**
+ * A class for reading dBase files.
+ *
+ * Only dBase III files supported for now, and only field type
+ * string is actually useful.
+ */
+class dBase {
+public:
+	enum Type {
+		kTypeString = 0x43, // 'C'
+		kTypeDate   = 0x44, // 'D'
+		kTypeBool   = 0x4C, // 'L'
+		kTypeMemo   = 0x4D, // 'M'
+		kTypeNumber = 0x4E  // 'N'
+	};
+
+	/** A field description. */
+	struct Field {
+		Common::String name; ///< Name of the field.
+
+		Type  type;     ///< Type of the field.
+		uint8 size;     ///< Size of raw field data in bytes.
+		uint8 decimals; ///< Number of decimals the field holds.
+	};
+
+	/** A record. */
+	struct Record {
+		bool deleted; ///< Has this record been deleted?
+		Common::Array<const byte *> fields; ///< Raw field data.
+	};
+
+	struct FieldPattern {
+		size_t fieldIndex;
+		size_t maxLength;
+		Common::String pattern;
+	};
+
+	dBase();
+	~dBase();
+
+	bool load(Common::SeekableReadStream &stream);
+	bool loadMemo(Common::SeekableReadStream &stream);
+	bool loadMultipleIndex(Common::SeekableReadStream &stream);
+	void clear();
+
+	byte getVersion() const;
+	bool hasMemo() const;
+
+	/** Return the date the database was last updated. */
+	TimeDate getLastUpdate() const;
+
+	const Common::Array<Field>  &getFields()  const;
+	const Common::Array<Record> &getRecords() const;
+
+	/** Extract a string out of raw field data. */
+	Common::String getString(const Record &record, int field) const;
+
+	void setQuery(const Common::String &query);
+	void setCurrentIndex(const Common::String &tagName);
+	void findFirstMatchingRecord();
+	void findNextMatchingRecord();
+	bool hasMatchingRecord();
+	Common::String getFieldOfMatchingRecord(Common::String fieldName);
+
+private:
+	byte _version;
+	byte _versionMajor;
+	bool _hasMemo;
+
+	TimeDate _lastUpdate;
+
+	Common::Array<Field>  _fields;
+	Common::Array<Record> _records;
+
+	int _currentRecordIndex;
+	Common::Array<FieldPattern> _currentFieldFilter;
+
+	byte *_recordData;
+
+	Common::Array<Common::String> _memoData;
+
+	Common::String _currentIndexTag;
+	bool _hasMultipleIndex;
+	dbaseMultipeIndex _multipleIndex;
+
+	static const uint16 MEMO_BLOCK_SIZE = 512;
+
+	static inline uint32 stringLength(const byte *data, uint32 max);
+	static inline Common::String readString(Common::SeekableReadStream &stream, int n);
+};
+
+} // End of namespace Gob
+
+#endif // GOB_DBASE_H