com.adobe.internal.io

Class ByteArrayByteWriter

java.lang.Object

com.adobe.internal.io.ByteArrayByteWriter

All Implemented Interfaces:

ByteReader, ByteWriter

public final class ByteArrayByteWriter
extends Object
implements ByteWriter

This class implements a ByteWriter in which the data is written into a byte array. The buffer automatically grows as data is written to it. The data can be retrieved by using toByteReader() and toByteArray(). This class uses an array of byte buffers which are ascending powers of two in size. They are added automatically as they are needed. The array starts with TWO buffers of size mMinBufSize, then one each of buffers sized in ascending powers of two until mMaxBufSize is reached. There may then be an arbitrary number of buffers sized mMaxBufSize. Starting with TWO buffers of size mMinBufSize may seem odd, but it has the nice quality of making it easy to compute the buffer array index from ONLY the high order bit of the position address. This class is not threadsafe. It is not safe to pass an instance of this class to multiple threads. It is not safe to pass an instance of this class to multiple users even if in the same thread. It is not safe to give the same byte buffers to multiple instances of this class.

Field Summary

Fields inherited from interface com.adobe.internal.io.ByteReader

EOF

Constructor Summary

Constructors

Constructor and Description
ByteArrayByteWriter() Create a new ByteArrayByteWriter with a default sized backing byte array.
ByteArrayByteWriter(ArrayList bufferArray, int length)
ByteArrayByteWriter(byte[] buffer) Create a new ByteArrayByteReader with the given byte array.
ByteArrayByteWriter(byte[] buffer, int offset, int length) Create a new ByteArrayByteWriter with a backing byte array given.
ByteArrayByteWriter(int size) Create a new ByteArrayByteWriter with a backing byte array of the size given.

Method Summary

Modifier and Type	Method and Description
void	close() Closes this ByteReader and releases any system resources associated with this stream.
void	flush() Flushes this ByteWriter and forces any unwritten buffered output bytes to be written out to the underlying repository.
long	length() Returns the number of total bytes in the repository that are visible through this API.
int	read(long position) Read a single byte from the underlying bytes at the given position.
int	read(long position, byte[] b, int offset, int length) Transfers bytes from the underlying repository into the given destination array.
byte[]	toByteArray() Copy out the backing store to a single byte array.
String	toString()
void	write(long position, byte[] b, int offset, int length) Write an array of bytes at the position given.
void	write(long position, int b) Write the byte given at the position given.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ByteArrayByteWriter

public ByteArrayByteWriter()

Create a new ByteArrayByteWriter with a default sized backing byte array.

ByteArrayByteWriter

public ByteArrayByteWriter(byte[] buffer)

Create a new ByteArrayByteReader with the given byte array. The buffer is not copied.

Parameters:

buffer - the byte array to use.

ByteArrayByteWriter

public ByteArrayByteWriter(int size)

Create a new ByteArrayByteWriter with a backing byte array of the size given.

Parameters:

size - the initial buffer size in bytes.

ByteArrayByteWriter

public ByteArrayByteWriter(byte[] buffer,
                           int offset,
                           int length)

Create a new ByteArrayByteWriter with a backing byte array given.

Parameters:

buffer -

offset -

length -

ByteArrayByteWriter

public ByteArrayByteWriter(ArrayList bufferArray,
                           int length)

Parameters:

bufferArray -

length -

Method Detail

toByteArray

public byte[] toByteArray()

Copy out the backing store to a single byte array. This requires us to allocate a single byte array equal in size to the sum of all the component arrays. Clients are warned that if the total size is very large, they may get an OutOfMemory exception by doing this.

Returns:

the byte array copy.

write

public void write(long position,
                  int b)
           throws IOException

Description copied from interface: ByteWriter

Write the byte given at the position given. If during the write operation the byte to be written is beyond the end of the virtual array visible through this interface then the length of that virtual array becomes the position of the byte written plus one (because of zero based counting). length of virtual array = max(length of virtual array, position of byte written + 1)

Specified by:

write in interface ByteWriter

Parameters:

position - the zero-based offset within the byte array.

b - the byte to write.

Throws:

IOException - if an error occurs during the write operation

See Also:

ByteWriter.write(long, int)

write

public void write(long position,
                  byte[] b,
                  int offset,
                  int length)
           throws IOException

Description copied from interface: ByteWriter

Write an array of bytes at the position given. If during the write operation any of the bytes are to be written beyond the end of the virtual array visible through this interface then the length of that virtual array becomes the position of the byte written plus one (because of zero based counting). for each byte written : length of virtual array = max(length of virtual array, position of byte written + 1)

Specified by:

write in interface ByteWriter

Parameters:

position - the zero-based offset within the byte array.

b - the array of bytes to write from.

offset - the offset within the byte array to start writing from.

length - the number of bytes to write from the byte array.

Throws:

IOException - if an error occurs during the write operation

See Also:

ByteWriter.write(long, byte[], int, int)

length

public long length()
            throws IOException

Description copied from interface: ByteReader

Returns the number of total bytes in the repository that are visible through this API.

Specified by:

length in interface ByteReader

Returns:

the number of bytes in the repository.

Throws:

IOException - if an error occurs while trying to determine the length

See Also:

ByteReader.length()

flush

public void flush()
           throws IOException

Description copied from interface: ByteWriter

Flushes this ByteWriter and forces any unwritten buffered output bytes to be written out to the underlying repository.

Specified by:

flush in interface ByteWriter

Throws:

IOException - if an error occurs while trying to flush the buffer

See Also:

ByteWriter.flush()

close

public void close()
           throws IOException

Description copied from interface: ByteReader

Closes this ByteReader and releases any system resources associated with this stream.

Specified by:

close in interface ByteReader

Throws:

IOException - if an error occurs while trying to close

See Also:

ByteReader.close()

toString

public String toString()

Overrides:

toString in class Object

See Also:

Object.toString()

read

public int read(long position)
         throws IOException

Description copied from interface: ByteReader

Read a single byte from the underlying bytes at the given position.

Specified by:

read in interface ByteReader

Parameters:

position - the position to read the byte from.

Returns:

the byte at the postion or EOF if the position is outside of the legal range.

Throws:

IOException - if an error occurs during the read operation

See Also:

ByteReader.read(long)

read

public int read(long position,
                byte[] b,
                int offset,
                int length)
         throws IOException

Description copied from interface: ByteReader

Transfers bytes from the underlying repository into the given destination array. Copy up to length bytes from the repository starting at the postion given into the given array starting at the given offset.

Specified by:

read in interface ByteReader

Parameters:

position - the position to read the byte from.

b - the array to write the bytes into.

offset - the offset in the array at which the first byte is written.

length - the maximum number of bytes to write into the array.

Returns:

the number of bytes actually written to the array.

Throws:

IOException - if an error occurs during the read operation

See Also:

ByteReader.read(long, byte[], int, int)