org.glassfish.grizzly
Interface Buffer<K>

All Superinterfaces:

Comparable<Buffer<K>>

All Known Implementing Classes:

ByteBufferWrapper, DefaultMemoryManager.TrimAwareWrapper, SlabByteBufferWrapper

public interface Buffer<K>
extends Comparable<Buffer<K>>

JDK ByteBuffer was taken as base for Grizzly Buffer interface, but Buffer has several extensions: it's possible to prepend some data to a Buffer and release Buffer, when it's not required any more.

Author:

Alexey Stashok

Method Summary

Buffer<K>	asReadOnlyBuffer() Creates a new, read-only byte buffer that shares this buffer's content.
int	capacity() Returns this buffer's capacity.
Buffer<K>	clear() Clears this buffer.
Buffer<K>	compact() Compacts this buffer (optional operation).
String	contentAsString(Charset charset) Returns Buffer content as String
void	dispose() Notify the allocator that the space for this Buffer is no longer needed.
Buffer<K>	duplicate() Creates a new byte buffer that shares this buffer's content.
Buffer<K>	flip() Flips this buffer.
byte	get() Relative get method.
Buffer<K>	get(byte[] dst) Relative bulk get method.
Buffer<K>	get(byte[] dst, int offset, int length) Relative bulk get method.
byte	get(int index) Absolute get method.
char	getChar() Relative get method for reading a char value.
char	getChar(int index) Absolute get method for reading a char value.
double	getDouble() Relative get method for reading a double value.
double	getDouble(int index) Absolute get method for reading a double value.
float	getFloat() Relative get method for reading a float value.
float	getFloat(int index) Absolute get method for reading a float value.
int	getInt() Relative get method for reading an int value.
int	getInt(int index) Absolute get method for reading an int value.
long	getLong() Relative get method for reading a long value.
long	getLong(int index) Absolute get method for reading a long value.
short	getShort() Relative get method for reading a short value.
short	getShort(int index) Absolute get method for reading a short value.
boolean	hasRemaining() Tells whether there are any elements between the current position and the limit.
boolean	isReadOnly() Tells whether or not this buffer is read-only.
int	limit() Returns this buffer's limit.
Buffer<K>	limit(int newLimit) Sets this buffer's limit.
Buffer<K>	mark() Sets this buffer's mark at its position.
ByteOrder	order() Retrieves this buffer's byte order.
Buffer<K>	order(ByteOrder bo) Modifies this buffer's byte order.
int	position() Returns this buffer's position.
Buffer<K>	position(int newPosition) Sets this buffer's position.
K	prepend(K header) Prepend data from header.position() to header.limit() to the current buffer.
Buffer<K>	put(Buffer src) Relative bulk put method (optional operation).
Buffer<K>	put(byte b) Relative put method (optional operation).
Buffer<K>	put(byte[] src) Relative bulk put method (optional operation).
Buffer<K>	put(byte[] src, int offset, int length) Relative bulk put method (optional operation).
Buffer<K>	put(int index, byte b) Absolute put method (optional operation).
Buffer<K>	putChar(char value) Relative put method for writing a char value (optional operation).
Buffer<K>	putChar(int index, char value) Absolute put method for writing a char value (optional operation).
Buffer<K>	putDouble(double value) Relative put method for writing a double value (optional operation).
Buffer<K>	putDouble(int index, double value) Absolute put method for writing a double value (optional operation).
Buffer<K>	putFloat(float value) Relative put method for writing a float value (optional operation).
Buffer<K>	putFloat(int index, float value) Absolute put method for writing a float value (optional operation).
Buffer<K>	putInt(int value) Relative put method for writing an int value (optional operation).
Buffer<K>	putInt(int index, int value) Absolute put method for writing an int value (optional operation).
Buffer<K>	putLong(int index, long value) Absolute put method for writing a long value (optional operation).
Buffer<K>	putLong(long value) Relative put method for writing a long value (optional operation).
Buffer<K>	putShort(int index, short value) Absolute put method for writing a short value (optional operation).
Buffer<K>	putShort(short value) Relative put method for writing a short value (optional operation).
int	remaining() Returns the number of elements between the current position and the limit.
Buffer<K>	reset() Resets this buffer's position to the previously-marked position.
Buffer<K>	rewind() Rewinds this buffer.
Buffer<K>	slice() Creates a new byte buffer whose content is a shared subsequence of this buffer's content.
void	trim() Trim the buffer by reducing capacity to position, if possible.
K	underlying() Return the JDK underlying buffer

Methods inherited from interface java.lang.Comparable

compareTo

Method Detail

prepend

K prepend(K header)

Prepend data from header.position() to header.limit() to the current buffer. This will change the value returned by buffer()!

Throws:

IllegalArgumentException - if header.limit() - header.position() is greater than headerSize.

trim

void trim()

Trim the buffer by reducing capacity to position, if possible. May return without changing capacity. Also resets the position to 0, like reset().

dispose

void dispose()

Notify the allocator that the space for this Buffer is no longer needed. All calls to methods on a Buffer will fail after a call to dispose().

underlying

K underlying()

Return the JDK underlying buffer

Returns:

the JDK underlying buffer

capacity

int capacity()

Returns this buffer's capacity.

Returns:

The capacity of this buffer

position

int position()

Returns this buffer's position.

Returns:

The position of this buffer

position

Buffer<K> position(int newPosition)

Sets this buffer's position. If the mark is defined and larger than the new position then it is discarded.

Parameters:

newPosition - The new position value; must be non-negative and no larger than the current limit

Returns:

This buffer

Throws:

IllegalArgumentException - If the preconditions on newPosition do not hold

limit

int limit()

Returns this buffer's limit.

Returns:

The limit of this buffer

limit

Buffer<K> limit(int newLimit)

Sets this buffer's limit. If the position is larger than the new limit then it is set to the new limit. If the mark is defined and larger than the new limit then it is discarded.

Parameters:

newLimit - The new limit value; must be non-negative and no larger than this buffer's capacity

Returns:

This buffer

Throws:

IllegalArgumentException - If the preconditions on newLimit do not hold

mark

Buffer<K> mark()

Sets this buffer's mark at its position.

Returns:

This buffer

reset

Buffer<K> reset()

Resets this buffer's position to the previously-marked position.

Invoking this method neither changes nor discards the mark's value.

Returns:

This buffer

Throws:

InvalidMarkException - If the mark has not been set

clear

Buffer<K> clear()

Clears this buffer. The position is set to zero, the limit is set to the capacity, and the mark is discarded.

Invoke this method before using a sequence of channel-read or put operations to fill this buffer. For example:

 buf.clear();     // Prepare buffer for reading
 in.read(buf);    // Read data

This method does not actually erase the data in the buffer, but it is named as if it did because it will most often be used in situations in which that might as well be the case.

Returns:

This buffer

flip

Buffer<K> flip()

Flips this buffer. The limit is set to the current position and then the position is set to zero. If the mark is defined then it is discarded.

After a sequence of channel-read or put operations, invoke this method to prepare for a sequence of channel-write or relative get operations. For example:

 buf.put(magic);    // Prepend header
 in.read(buf);      // Read data into rest of buffer
 buf.flip();        // Flip buffer
 out.write(buf);    // Write header + data to channel

This method is often used in conjunction with the compact method when transferring data from one place to another.

Returns:

This buffer

rewind

Buffer<K> rewind()

Rewinds this buffer. The position is set to zero and the mark is discarded.

Invoke this method before a sequence of channel-write or get operations, assuming that the limit has already been set appropriately. For example:

 out.write(buf);    // Write remaining data
 buf.rewind();      // Rewind buffer
 buf.get(array);    // Copy data into array

Returns:

This buffer

remaining

int remaining()

Returns the number of elements between the current position and the limit.

Returns:

The number of elements remaining in this buffer

hasRemaining

boolean hasRemaining()

Tells whether there are any elements between the current position and the limit.

Returns:

true if, and only if, there is at least one element remaining in this buffer

isReadOnly

boolean isReadOnly()

Tells whether or not this buffer is read-only.

Returns:

true if, and only if, this buffer is read-only

slice

Buffer<K> slice()

Creates a new byte buffer whose content is a shared subsequence of this buffer's content.

The content of the new buffer will start at this buffer's current position. Changes to this buffer's content will be visible in the new buffer, and vice versa; the two buffers' position, limit, and mark values will be independent.

The new buffer's position will be zero, its capacity and its limit will be the number of bytes remaining in this buffer, and its mark will be undefined. The new buffer will be direct if, and only if, this buffer is direct, and it will be read-only if, and only if, this buffer is read-only.

Returns:

The new byte buffer

duplicate

Buffer<K> duplicate()

Creates a new byte buffer that shares this buffer's content.

The content of the new buffer will be that of this buffer. Changes to this buffer's content will be visible in the new buffer, and vice versa; the two buffers' position, limit, and mark values will be independent.

The new buffer's capacity, limit, position, and mark values will be identical to those of this buffer. The new buffer will be direct if, and only if, this buffer is direct, and it will be read-only if, and only if, this buffer is read-only.

Returns:

The new byte buffer

asReadOnlyBuffer

Buffer<K> asReadOnlyBuffer()

Creates a new, read-only byte buffer that shares this buffer's content.

The content of the new buffer will be that of this buffer. Changes to this buffer's content will be visible in the new buffer; the new buffer itself, however, will be read-only and will not allow the shared content to be modified. The two buffers' position, limit, and mark values will be independent.

The new buffer's capacity, limit, position, and mark values will be identical to those of this buffer.

If this buffer is itself read-only then this method behaves in exactly the same way as the duplicate method.

Returns:

The new, read-only byte buffer

get

byte get()

Relative get method. Reads the byte at this buffer's current position, and then increments the position.

Returns:

The byte at the buffer's current position

Throws:

BufferUnderflowException - If the buffer's current position is not smaller than its limit

put

Buffer<K> put(byte b)

Relative put method (optional operation).

Writes the given byte into this buffer at the current position, and then increments the position.

Parameters:

b - The byte to be written

Returns:

This buffer

Throws:

BufferOverflowException - If this buffer's current position is not smaller than its limit

ReadOnlyBufferException - If this buffer is read-only

get

byte get(int index)

Absolute get method. Reads the byte at the given index.

Parameters:

index - The index from which the byte will be read

Returns:

The byte at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit

put

Buffer<K> put(int index,
              byte b)

Absolute put method (optional operation).

Writes the given byte into this buffer at the given index.

Parameters:

index - The index at which the byte will be written

b - The byte value to be written

Returns:

This buffer

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit

ReadOnlyBufferException - If this buffer is read-only

get

Buffer<K> get(byte[] dst,
              int offset,
              int length)

Relative bulk get method.

This method transfers bytes from this buffer into the given destination array. If there are fewer bytes remaining in the buffer than are required to satisfy the request, that is, if length > remaining(), then no bytes are transferred and a BufferUnderflowException is thrown.

Otherwise, this method copies length bytes from this buffer into the given array, starting at the current position of this buffer and at the given offset in the array. The position of this buffer is then incremented by length.

In other words, an invocation of this method of the form src.get(dst, off, len) has exactly the same effect as the loop

     for (int i = off; i < off + len; i++)
         dst[i] = src.get(); 

except that it first checks that there are sufficient bytes in this buffer and it is potentially much more efficient.

Parameters:

dst - The array into which bytes are to be written

offset - The offset within the array of the first byte to be written; must be non-negative and no larger than dst.length

length - The maximum number of bytes to be written to the given array; must be non-negative and no larger than dst.length - offset

Returns:

This buffer

Throws:

BufferUnderflowException - If there are fewer than length bytes remaining in this buffer

IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold

get

Buffer<K> get(byte[] dst)

Relative bulk get method.

This method transfers bytes from this buffer into the given destination array. An invocation of this method of the form src.get(a) behaves in exactly the same way as the invocation

     src.get(a, 0, a.length) 

Returns:

This buffer

Throws:

BufferUnderflowException - If there are fewer than length bytes remaining in this buffer

put

Buffer<K> put(Buffer src)

Relative bulk put method (optional operation).

This method transfers the bytes remaining in the given source buffer into this buffer. If there are more bytes remaining in the source buffer than in this buffer, that is, if src.remaining() > remaining(), then no bytes are transferred and a BufferOverflowException is thrown.

Otherwise, this method copies n = src.remaining() bytes from the given buffer into this buffer, starting at each buffer's current position. The positions of both buffers are then incremented by n.

In other words, an invocation of this method of the form dst.put(src) has exactly the same effect as the loop

     while (src.hasRemaining())
         dst.put(src.get()); 

except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient.

Parameters:

src - The source buffer from which bytes are to be read; must not be this buffer

Returns:

This buffer

Throws:

BufferOverflowException - If there is insufficient space in this buffer for the remaining bytes in the source buffer

IllegalArgumentException - If the source buffer is this buffer

ReadOnlyBufferException - If this buffer is read-only

put

Buffer<K> put(byte[] src,
              int offset,
              int length)

Relative bulk put method (optional operation).

This method transfers bytes into this buffer from the given source array. If there are more bytes to be copied from the array than remain in this buffer, that is, if length > remaining(), then no bytes are transferred and a BufferOverflowException is thrown.

Otherwise, this method copies length bytes from the given array into this buffer, starting at the given offset in the array and at the current position of this buffer. The position of this buffer is then incremented by length.

In other words, an invocation of this method of the form dst.put(src, off, len) has exactly the same effect as the loop

     for (int i = off; i < off + len; i++)
         dst.put(a[i]); 

except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient.

Parameters:

src - The array from which bytes are to be read

offset - The offset within the array of the first byte to be read; must be non-negative and no larger than array.length

length - The number of bytes to be read from the given array; must be non-negative and no larger than array.length - offset

Returns:

This buffer

Throws:

BufferOverflowException - If there is insufficient space in this buffer

IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold

ReadOnlyBufferException - If this buffer is read-only

put

Buffer<K> put(byte[] src)

Relative bulk put method (optional operation).

This method transfers the entire content of the given source byte array into this buffer. An invocation of this method of the form dst.put(a) behaves in exactly the same way as the invocation

     dst.put(a, 0, a.length) 

Returns:

This buffer

Throws:

BufferOverflowException - If there is insufficient space in this buffer

ReadOnlyBufferException - If this buffer is read-only

compact

Buffer<K> compact()

Compacts this buffer (optional operation).

The bytes between the buffer's current position and its limit, if any, are copied to the beginning of the buffer. That is, the byte at index p = position() is copied to index zero, the byte at index p + 1 is copied to index one, and so forth until the byte at index limit() - 1 is copied to index n = limit() - 1 - p. The buffer's position is then set to n+1 and its limit is set to its capacity. The mark, if defined, is discarded.

The buffer's position is set to the number of bytes copied, rather than to zero, so that an invocation of this method can be followed immediately by an invocation of another relative put method.

Invoke this method after writing data from a buffer in case the write was incomplete. The following loop, for example, copies bytes from one channel to another via the buffer buf:

 buf.clear();          // Prepare buffer for use
 for (;;) {
     if (in.read(buf) < 0 && !buf.hasRemaining())
         break;        // No more bytes to transfer
     buf.flip();
     out.write(buf);
     buf.compact();    // In case of partial write
 }

Returns:

This buffer

Throws:

ReadOnlyBufferException - If this buffer is read-only

order

ByteOrder order()

Retrieves this buffer's byte order.

The byte order is used when reading or writing multibyte values, and when creating buffers that are views of this byte buffer. The order of a newly-created byte buffer is always BIG_ENDIAN.

Returns:

This buffer's byte order

order

Buffer<K> order(ByteOrder bo)

Modifies this buffer's byte order.

Parameters:

bo - The new byte order, either BIG_ENDIAN or LITTLE_ENDIAN

Returns:

This buffer

getChar

char getChar()

Relative get method for reading a char value.

Reads the next two bytes at this buffer's current position, composing them into a char value according to the current byte order, and then increments the position by two.

Returns:

The char value at the buffer's current position

Throws:

BufferUnderflowException - If there are fewer than two bytes remaining in this buffer

putChar

Buffer<K> putChar(char value)

Relative put method for writing a char value (optional operation).

Writes two bytes containing the given char value, in the current byte order, into this buffer at the current position, and then increments the position by two.

Parameters:

value - The char value to be written

Returns:

This buffer

Throws:

BufferOverflowException - If there are fewer than two bytes remaining in this buffer

ReadOnlyBufferException - If this buffer is read-only

getChar

char getChar(int index)

Absolute get method for reading a char value.

Reads two bytes at the given index, composing them into a char value according to the current byte order.

Parameters:

index - The index from which the bytes will be read

Returns:

The char value at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus one

putChar

Buffer<K> putChar(int index,
                  char value)

Absolute put method for writing a char value (optional operation).

Writes two bytes containing the given char value, in the current byte order, into this buffer at the given index.

Parameters:

index - The index at which the bytes will be written

value - The char value to be written

Returns:

This buffer

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus one

ReadOnlyBufferException - If this buffer is read-only

getShort

short getShort()

Relative get method for reading a short value.

Reads the next two bytes at this buffer's current position, composing them into a short value according to the current byte order, and then increments the position by two.

Returns:

The short value at the buffer's current position

Throws:

BufferUnderflowException - If there are fewer than two bytes remaining in this buffer

putShort

Buffer<K> putShort(short value)

Relative put method for writing a short value (optional operation).

Writes two bytes containing the given short value, in the current byte order, into this buffer at the current position, and then increments the position by two.

Parameters:

value - The short value to be written

Returns:

This buffer

Throws:

BufferOverflowException - If there are fewer than two bytes remaining in this buffer

ReadOnlyBufferException - If this buffer is read-only

getShort

short getShort(int index)

Absolute get method for reading a short value.

Reads two bytes at the given index, composing them into a short value according to the current byte order.

Parameters:

index - The index from which the bytes will be read

Returns:

The short value at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus one

putShort

Buffer<K> putShort(int index,
                   short value)

Absolute put method for writing a short value (optional operation).

Writes two bytes containing the given short value, in the current byte order, into this buffer at the given index.

Parameters:

index - The index at which the bytes will be written

value - The short value to be written

Returns:

This buffer

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus one

ReadOnlyBufferException - If this buffer is read-only

getInt

int getInt()

Relative get method for reading an int value.

Reads the next four bytes at this buffer's current position, composing them into an int value according to the current byte order, and then increments the position by four.

Returns:

The int value at the buffer's current position

Throws:

BufferUnderflowException - If there are fewer than four bytes remaining in this buffer

putInt

Buffer<K> putInt(int value)

Relative put method for writing an int value (optional operation).

Writes four bytes containing the given int value, in the current byte order, into this buffer at the current position, and then increments the position by four.

Parameters:

value - The int value to be written

Returns:

This buffer

Throws:

BufferOverflowException - If there are fewer than four bytes remaining in this buffer

ReadOnlyBufferException - If this buffer is read-only

getInt

int getInt(int index)

Absolute get method for reading an int value.

Reads four bytes at the given index, composing them into a int value according to the current byte order.

Parameters:

index - The index from which the bytes will be read

Returns:

The int value at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus three

putInt

Buffer<K> putInt(int index,
                 int value)

Absolute put method for writing an int value (optional operation).

Writes four bytes containing the given int value, in the current byte order, into this buffer at the given index.

Parameters:

index - The index at which the bytes will be written

value - The int value to be written

Returns:

This buffer

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus three

ReadOnlyBufferException - If this buffer is read-only

getLong

long getLong()

Relative get method for reading a long value.

Reads the next eight bytes at this buffer's current position, composing them into a long value according to the current byte order, and then increments the position by eight.

Returns:

The long value at the buffer's current position

Throws:

BufferUnderflowException - If there are fewer than eight bytes remaining in this buffer

putLong

Buffer<K> putLong(long value)

Relative put method for writing a long value (optional operation).

Writes eight bytes containing the given long value, in the current byte order, into this buffer at the current position, and then increments the position by eight.

Parameters:

value - The long value to be written

Returns:

This buffer

Throws:

BufferOverflowException - If there are fewer than eight bytes remaining in this buffer

ReadOnlyBufferException - If this buffer is read-only

getLong

long getLong(int index)

Absolute get method for reading a long value.

Reads eight bytes at the given index, composing them into a long value according to the current byte order.

Parameters:

index - The index from which the bytes will be read

Returns:

The long value at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus seven

putLong

Buffer<K> putLong(int index,
                  long value)

Absolute put method for writing a long value (optional operation).

Writes eight bytes containing the given long value, in the current byte order, into this buffer at the given index.

Parameters:

index - The index at which the bytes will be written

value - The long value to be written

Returns:

This buffer

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus seven

ReadOnlyBufferException - If this buffer is read-only

getFloat

float getFloat()

Relative get method for reading a float value.

Reads the next four bytes at this buffer's current position, composing them into a float value according to the current byte order, and then increments the position by four.

Returns:

The float value at the buffer's current position

Throws:

BufferUnderflowException - If there are fewer than four bytes remaining in this buffer

putFloat

Buffer<K> putFloat(float value)

Relative put method for writing a float value (optional operation).

Writes four bytes containing the given float value, in the current byte order, into this buffer at the current position, and then increments the position by four.

Parameters:

value - The float value to be written

Returns:

This buffer

Throws:

BufferOverflowException - If there are fewer than four bytes remaining in this buffer

ReadOnlyBufferException - If this buffer is read-only

getFloat

float getFloat(int index)

Absolute get method for reading a float value.

Reads four bytes at the given index, composing them into a float value according to the current byte order.

Parameters:

index - The index from which the bytes will be read

Returns:

The float value at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus three

putFloat

Buffer<K> putFloat(int index,
                   float value)

Absolute put method for writing a float value (optional operation).

Writes four bytes containing the given float value, in the current byte order, into this buffer at the given index.

Parameters:

index - The index at which the bytes will be written

value - The float value to be written

Returns:

This buffer

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus three

ReadOnlyBufferException - If this buffer is read-only

getDouble

double getDouble()

Relative get method for reading a double value.

Reads the next eight bytes at this buffer's current position, composing them into a double value according to the current byte order, and then increments the position by eight.

Returns:

The double value at the buffer's current position

Throws:

BufferUnderflowException - If there are fewer than eight bytes remaining in this buffer

putDouble

Buffer<K> putDouble(double value)

Relative put method for writing a double value (optional operation).

Writes eight bytes containing the given double value, in the current byte order, into this buffer at the current position, and then increments the position by eight.

Parameters:

value - The double value to be written

Returns:

This buffer

Throws:

BufferOverflowException - If there are fewer than eight bytes remaining in this buffer

ReadOnlyBufferException - If this buffer is read-only

getDouble

double getDouble(int index)

Absolute get method for reading a double value.

Reads eight bytes at the given index, composing them into a double value according to the current byte order.

Parameters:

index - The index from which the bytes will be read

Returns:

The double value at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus seven

putDouble

Buffer<K> putDouble(int index,
                    double value)

Absolute put method for writing a double value (optional operation).

Writes eight bytes containing the given double value, in the current byte order, into this buffer at the given index.

Parameters:

index - The index at which the bytes will be written

value - The double value to be written

Returns:

This buffer

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus seven

ReadOnlyBufferException - If this buffer is read-only

contentAsString

String contentAsString(Charset charset)

Returns Buffer content as String

Parameters:

charset - the Charset, which will be use for byte[] -> String transformation.

Returns:

String representation of this Buffer content.