readstream.h

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/* xoreos - A reimplementation of BioWare's Aurora engine
 *
 * xoreos is the legal property of its developers, whose names
 * can be found in the AUTHORS file distributed with this source
 * distribution.
 *
 * xoreos 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.
 *
 * xoreos 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 xoreos. If not, see <http://www.gnu.org/licenses/>.
 */

/* Based on ScummVM (<http://scummvm.org>) code, which is released
 * under the terms of version 2 or later of the GNU General Public
 * License.
 *
 * The original copyright note in ScummVM reads as follows:
 *
 * 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 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 COMMON_READSTREAM_H
#define COMMON_READSTREAM_H

#include "src/common/types.h"
#include "src/common/endianness.h"
#include "src/common/disposableptr.h"
#include "src/common/util.h"
#include "src/common/error.h"

namespace Common {

class MemoryReadStream;

class ReadStream {
public:
    static const uint32 kEOF = 0xFFFFFFFF;

    static const size_t kSizeInvalid     = SIZE_MAX;
    static const size_t kPositionInvalid = SIZE_MAX;

    ReadStream();
    virtual ~ReadStream();

    virtual bool eos() const = 0;

    virtual size_t read(void *dataPtr, size_t dataSize) = 0;

    // --- The following methods should generally not be overloaded ---

    byte readByte() {
        byte b;
        if (read(&b, 1) != 1)
            throw Exception(kReadError);

        return b;
    }

    FORCEINLINE int8 readSByte() {
        return (int8)readByte();
    }

    uint32 readChar() {
        byte b;
        try {
            b = readByte();
        } catch (...) {
            return kEOF;
        }

        return b;
    }

    uint16 readUint16LE() {
        uint16 val;
        if (read(&val, 2) != 2)
            throw Exception(kReadError);

        return FROM_LE_16(val);
    }

    uint32 readUint32LE() {
        uint32 val;
        if (read(&val, 4) != 4)
            throw Exception(kReadError);

        return FROM_LE_32(val);
    }

    uint64 readUint64LE() {
        uint64 val;
        if (read(&val, 8) != 8)
            throw Exception(kReadError);

        return FROM_LE_64(val);
    }

    uint16 readUint16BE() {
        uint16 val;
        if (read(&val, 2) != 2)
            throw Exception(kReadError);

        return FROM_BE_16(val);
    }

    uint32 readUint32BE() {
        uint32 val;
        if (read(&val, 4) != 4)
            throw Exception(kReadError);

        return FROM_BE_32(val);
    }

    uint64 readUint64BE() {
        uint64 val;
        if (read(&val, 8) != 8)
            throw Exception(kReadError);

        return FROM_BE_64(val);
    }

    FORCEINLINE int16 readSint16LE() {
        return (int16)readUint16LE();
    }

    FORCEINLINE int32 readSint32LE() {
        return (int32)readUint32LE();
    }

    FORCEINLINE int64 readSint64LE() {
        return (int64)readUint64LE();
    }

    FORCEINLINE int16 readSint16BE() {
        return (int16)readUint16BE();
    }

    FORCEINLINE int32 readSint32BE() {
        return (int32)readUint32BE();
    }

    FORCEINLINE int64 readSint64BE() {
        return (int64)readUint64BE();
    }

    FORCEINLINE float readIEEEFloatLE() {
        return convertIEEEFloat(readUint32LE());
    }

    FORCEINLINE float readIEEEFloatBE() {
        return convertIEEEFloat(readUint32BE());
    }

    FORCEINLINE double readIEEEDoubleLE() {
        return convertIEEEDouble(readUint64LE());
    }

    FORCEINLINE double readIEEEDoubleBE() {
        return convertIEEEDouble(readUint64BE());
    }

    MemoryReadStream *readStream(size_t dataSize);
};


class SeekableReadStream : virtual public ReadStream {
public:
    enum Origin {
        kOriginBegin   = 0, 
        kOriginCurrent = 1, 
        kOriginEnd     = 2, 
        kOriginMAX          
    };

    SeekableReadStream();
    ~SeekableReadStream();

    virtual size_t pos() const = 0;

    virtual size_t size() const = 0;

    virtual size_t seek(ptrdiff_t offset, Origin whence = kOriginBegin) = 0;

    virtual size_t skip(ptrdiff_t offset) {
        return seek(offset, kOriginCurrent);
    }

    static size_t evalSeek(ptrdiff_t offset, Origin whence, size_t pos, size_t begin, size_t size);
};


class SubReadStream : virtual public ReadStream {
public:
    SubReadStream(ReadStream *parentStream, size_t end, bool disposeParentStream = false);
    ~SubReadStream();

    bool eos() const;

    size_t read(void *dataPtr, size_t dataSize);

protected:
    DisposablePtr<ReadStream> _parentStream;

    size_t _pos;
    size_t _end;

    bool _eos;
};


class SeekableSubReadStream : public SubReadStream, public SeekableReadStream {
public:
    SeekableSubReadStream(SeekableReadStream *parentStream, size_t begin, size_t end,
                          bool disposeParentStream = false);
    ~SeekableSubReadStream();

    size_t pos() const;
    size_t size() const;

    size_t seek(ptrdiff_t offset, Origin whence = kOriginBegin);

protected:
    SeekableReadStream *_parentStream;

    size_t _begin;
};


class SeekableSubReadStreamEndian : public SeekableSubReadStream {
private:
    const bool _bigEndian;

public:
    SeekableSubReadStreamEndian(SeekableReadStream *parentStream, size_t begin, size_t end,
                                bool bigEndian = false, bool disposeParentStream = false);
    ~SeekableSubReadStreamEndian();

    uint16 readUint16() {
        return _bigEndian ? readUint16BE() : readUint16LE();
    }

    uint32 readUint32() {
        return _bigEndian ? readUint32BE() : readUint32LE();
    }

    uint64 readUint64() {
        return _bigEndian ? readUint64BE() : readUint64LE();
    }

    int16 readSint16() {
        return _bigEndian ? readSint16BE() : readSint16LE();
    }

    int32 readSint32() {
        return _bigEndian ? readSint32BE() : readSint32LE();
    }

    int64 readSint64() {
        return _bigEndian ? readSint64BE() : readSint64LE();
    }

    float readIEEEFloat() {
        return _bigEndian ? readIEEEFloatBE() : readIEEEFloatLE();
    }

    double readIEEEDouble() {
        return _bigEndian ? readIEEEDoubleBE() : readIEEEDoubleLE();
    }
};

} // End of namespace Common

#endif // COMMON_READSTREAM_H