org.lmdbjava

Class DirectBufferProxy

java.lang.Object

org.lmdbjava.BufferProxy<org.agrona.DirectBuffer>

org.lmdbjava.DirectBufferProxy

public final class DirectBufferProxy
extends BufferProxy<org.agrona.DirectBuffer>

A buffer proxy backed by Agrona's DirectBuffer.

This class requires UnsafeAccess and Agrona must be in the classpath.

Field Summary

Fields

Modifier and Type	Field and Description
static BufferProxy<org.agrona.DirectBuffer>	PROXY_DB The MutableDirectBuffer proxy.

Fields inherited from class org.lmdbjava.BufferProxy

MDB_VAL_STRUCT_SIZE, STRUCT_FIELD_OFFSET_DATA, STRUCT_FIELD_OFFSET_SIZE

Constructor Summary

Constructors

Constructor and Description
DirectBufferProxy()

Method Summary

Modifier and Type	Method and Description
protected org.agrona.DirectBuffer	allocate() Allocate a new buffer suitable for passing to BufferProxy.out(java.lang.Object, jnr.ffi.Pointer, long).
protected int	compare(org.agrona.DirectBuffer o1, org.agrona.DirectBuffer o2) Compare the two buffers.
static int	compareBuff(org.agrona.DirectBuffer o1, org.agrona.DirectBuffer o2) Lexicographically compare two buffers.
protected void	deallocate(org.agrona.DirectBuffer buff) Deallocate a buffer that was previously provided by BufferProxy.allocate().
protected byte[]	getBytes(org.agrona.DirectBuffer buffer) Obtain a copy of the bytes contained within the passed buffer.
protected void	in(org.agrona.DirectBuffer buffer, int size, jnr.ffi.Pointer ptr, long ptrAddr) Called when the MDB_val should be set to reflect the passed buffer.
protected void	in(org.agrona.DirectBuffer buffer, jnr.ffi.Pointer ptr, long ptrAddr) Called when the MDB_val should be set to reflect the passed buffer.
protected org.agrona.DirectBuffer	out(org.agrona.DirectBuffer buffer, jnr.ffi.Pointer ptr, long ptrAddr) Called when the MDB_val may have changed and the passed buffer should be modified to reflect the new MDB_val.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

PROXY_DB

public static final BufferProxy<org.agrona.DirectBuffer> PROXY_DB

The MutableDirectBuffer proxy. Guaranteed to never be null, although a class initialization exception will occur if an attempt is made to access this field when unsafe or Agrona is unavailable.

Constructor Detail

DirectBufferProxy

public DirectBufferProxy()

Method Detail

compareBuff

public static int compareBuff(org.agrona.DirectBuffer o1,
                              org.agrona.DirectBuffer o2)

Lexicographically compare two buffers.

Parameters:

o1 - left operand (required)

o2 - right operand (required)

Returns:

as specified by Comparable interface

allocate

protected org.agrona.DirectBuffer allocate()

Description copied from class: BufferProxy

Allocate a new buffer suitable for passing to BufferProxy.out(java.lang.Object, jnr.ffi.Pointer, long).

Specified by:

allocate in class BufferProxy<org.agrona.DirectBuffer>

Returns:

a buffer for passing to the out method

compare

protected int compare(org.agrona.DirectBuffer o1,
                      org.agrona.DirectBuffer o2)

Description copied from class: BufferProxy

Compare the two buffers.

Implemented as a protected method to discourage use of the buffer proxy in collections etc (given by design it wraps a temporary value only).

Specified by:

compare in class BufferProxy<org.agrona.DirectBuffer>

Parameters:

o1 - left operand

o2 - right operand

Returns:

as per Comparable

deallocate

protected void deallocate(org.agrona.DirectBuffer buff)

Description copied from class: BufferProxy

Deallocate a buffer that was previously provided by BufferProxy.allocate().

Specified by:

deallocate in class BufferProxy<org.agrona.DirectBuffer>

Parameters:

buff - the buffer to deallocate (required)

getBytes

protected byte[] getBytes(org.agrona.DirectBuffer buffer)

Description copied from class: BufferProxy

Obtain a copy of the bytes contained within the passed buffer.

Specified by:

getBytes in class BufferProxy<org.agrona.DirectBuffer>

Parameters:

buffer - a non-null buffer created by this proxy instance

Returns:

a copy of the bytes this buffer is currently representing

in

protected void in(org.agrona.DirectBuffer buffer,
                  jnr.ffi.Pointer ptr,
                  long ptrAddr)

Description copied from class: BufferProxy

Called when the MDB_val should be set to reflect the passed buffer. This buffer will have been created by end users, not BufferProxy.allocate().

Specified by:

in in class BufferProxy<org.agrona.DirectBuffer>

Parameters:

buffer - the buffer to write to MDB_val

ptr - the pointer to the MDB_val

ptrAddr - the address of the MDB_val pointer

in

protected void in(org.agrona.DirectBuffer buffer,
                  int size,
                  jnr.ffi.Pointer ptr,
                  long ptrAddr)

Description copied from class: BufferProxy

Called when the MDB_val should be set to reflect the passed buffer.

Specified by:

in in class BufferProxy<org.agrona.DirectBuffer>

Parameters:

buffer - the buffer to write to MDB_val

size - the buffer size to write to MDB_val

ptr - the pointer to the MDB_val

ptrAddr - the address of the MDB_val pointer

out

protected org.agrona.DirectBuffer out(org.agrona.DirectBuffer buffer,
                                      jnr.ffi.Pointer ptr,
                                      long ptrAddr)

Description copied from class: BufferProxy

Called when the MDB_val may have changed and the passed buffer should be modified to reflect the new MDB_val.

Specified by:

out in class BufferProxy<org.agrona.DirectBuffer>

Parameters:

buffer - the buffer to write to MDB_val

ptr - the pointer to the MDB_val

ptrAddr - the address of the MDB_val pointer

Returns:

the buffer for MDB_val