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* DataHandlerCallback.h
* DataHandlerCallback.h - file I/O for libebml.
* Copyright (c) 2006 David Conrad
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* Lesser General Public License for more details.
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#include <QuickTime/QuickTime.h>
#include <ebml/IOCallback.h>
#include <stdexcept>
#include <cerrno>
#include <sys/param.h>
using namespace std;
using namespace libebml;
#define READ_SIZE 32*1024
class DataHBuffer {
uint8_t *buffer;
size_t allocatedSize;
uint64_t fileOffset;
size_t dataSize;
// this clears the buffer
void Realloc(size_t bufferSize);
DataHBuffer(size_t bufferSize = READ_SIZE);
bool ContainsOffset(uint64_t offset);
// this returns a pointer to a buffer at least as big as size, and saves
// the given offset and size of data that will be stored
uint8_t * GetBuffer(uint64_t offset, size_t size);
// this copies as much data from the buffer as possible from the given file offset,
// returning the number of bytes actually copied.
size_t Read(uint64_t offset, size_t size, uint8_t *store);
// QuickTime Data Handler callback for libmatroska
class DataHandlerCallback:public IOCallback
ComponentInstance dataHandler;
uint64 mCurrentPosition;
bool closeHandler;
bool supportsWideOffsets;
open_mode aMode;
UInt64 filesize;
DataHBuffer dataBuffer;
void Initialize(const open_mode aMode);
DataHandlerCallback(ComponentInstance dataHandler, const open_mode aMode);
DataHandlerCallback(Handle dataRef, OSType dataRefType, const open_mode aMode);
virtual ~DataHandlerCallback() throw();
virtual uint32 read(void *Buffer, size_t Size);
// Seek to the specified position. The mode can have either SEEK_SET, SEEK_CUR
// or SEEK_END. The callback should return true(1) if the seek operation succeeded
// or false (0), when the seek fails.
virtual void setFilePointer(int64 Offset, seek_mode Mode=seek_beginning);
// This callback just works like its read pendant. It returns the number of bytes written.
virtual size_t write(const void *Buffer, size_t Size);
// Although the position is always positive, the return value of this callback is signed to
// easily allow negative values for returning errors. When an error occurs, the implementor
// should return -1 and the file pointer otherwise.
// If an error occurs, an exception should be thrown.
virtual uint64 getFilePointer();
// The close callback flushes the file buffers to disk and closes the file. When using the stdio
// library, this is equivalent to calling fclose. When the close is not successful, an exception
// should be thrown.
virtual void close();
SInt64 getFileSize();
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