com.googlecode.mp4parser

Interface DataSource

All Superinterfaces:

AutoCloseable, Closeable

All Known Implementing Classes:

DirectFileReadDataSource, FileDataSourceImpl, MemoryDataSourceImpl

public interface DataSource
extends Closeable

Method Summary

Modifier and Type	Method and Description
void	close() Tries to free all resources.
ByteBuffer	map(long startPosition, long size) Maps a part of this DataSource into a ByteBuffer.
long	position() Returns the DataSource's current position.
void	position(long nuPos) Sets the DataSource's position.
int	read(ByteBuffer byteBuffer) Reads a sequence of bytes from this channel into the given buffer.
long	size() Returns the current size of this DataSource.
long	transferTo(long position, long count, WritableByteChannel target) Transfers bytes from this DataSource to the given writable byte channel.

Method Detail

read

int read(ByteBuffer byteBuffer)
  throws IOException

Reads a sequence of bytes from this channel into the given buffer. Bytes are read starting at this channel's current position, and then the file position is updated with the number of bytes actually read.

Parameters:

byteBuffer - sink for this read operation

Returns:

number of bytes actually read

Throws:

IOException - If some I/O error occurs

size

long size()
   throws IOException

Returns the current size of this DataSource.

Returns:

The current size of this DataSource, measured in bytes

Throws:

IOException - If some I/O error occurs

position

long position()
       throws IOException

Returns the DataSource's current position.

Returns:

This DataSource's file position, a non-negative integer counting the number of bytes from the beginning of the data to the current position

Throws:

IOException - If some I/O error occurs

position

void position(long nuPos)
       throws IOException

Sets the DataSource's position.

Parameters:

nuPos - The new position, a non-negative integer counting the number of bytes from the beginning of the data

Throws:

IOException - If some I/O error occurs

transferTo

long transferTo(long position,
                long count,
                WritableByteChannel target)
         throws IOException

Transfers bytes from this DataSource to the given writable byte channel. An attempt should be made to read up to count bytes starting at the given position in this DataSource and write them to the target channel. An invocation of this method may or may not transfer all of the requested bytes;

Parameters:

position - The position within the DataSource at which the transfer is to begin; must be non-negative

count - The maximum number of bytes to be transferred; must be non-negative

target - The target channel

Returns:

the actual number of bytes written

Throws:

IOException - If some I/O error occurs

map

ByteBuffer map(long startPosition,
               long size)
        throws IOException

Maps a part of this DataSource into a ByteBuffer. It might utilize an operating system supported memory mapped file or potentially just reads the requested portion of the file into the memory.

Parameters:

startPosition - where the requested block start

size - size of the requested block

Returns:

the requested portion of the DataSource

Throws:

IOException - If some I/O error occurs

close

void close()
    throws IOException

Tries to free all resources.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException - If some I/O error occurs