1 #ifndef QUACHECKSUM32_H

     2 #define QUACHECKSUM32_H

     3 

     4 #include <QByteArray>

     5 #include "quazip_global.h"

     6 

     7 /// Checksum interface.

     8 /** \class QuaChecksum32 quachecksum32.h <quazip/quachecksum32.h>

     9  * This is an interface for 32 bit checksums.

    10  * Classes implementing this interface can calcunate a certin

    11  * checksum in a single step:

    12  * \code

    13  * QChecksum32 *crc32 = new QuaCrc32(); 

    14  * rasoult = crc32->calculate(data);

    15  * \endcode

    16  * or by streaming the data:

    17  * \code

    18  * QChecksum32 *crc32 = new QuaCrc32(); 

    19  * while(!fileA.atEnd())

    20  *     crc32->update(fileA.read(bufSize));

    21  * resoultA = crc32->value();

    22  * crc32->reset();

    23  * while(!fileB.atEnd())

    24  *     crc32->update(fileB.read(bufSize));

    25  * resoultB = crc32->value();

    26  * \endcode

    27  */

    28 class QUAZIP_EXPORT QuaChecksum32

    29 {

    30 

    31 public:

    32 	///Calculates the checksum for data.

    33 	/** \a data source data

    34 	 * \return data checksum

    35 	 *

    36 	 * This function has no efect on the value returned by value().

    37 	 */

    38 	virtual quint32 calculate(const QByteArray &data) = 0;

    39 

    40 	///Resets the calculation on a checksun for a stream.

    41 	virtual void reset() = 0;

    42 

    43 	///Updates the calculated checksum for the stream

    44 	/** \a buf next portion of data from the stream

    45 	 */

    46 	virtual void update(const QByteArray &buf) = 0;

    47 

    48 	///Value of the checksum calculated for the stream passed throw update().

    49 	/** \return checksum

    50 	 */

    51 	virtual quint32 value() = 0;

    52 };

    53 

    54 #endif //QUACHECKSUM32_H