src.java.org.codehaus.jackson.util.BufferRecycler Maven / Gradle / Ivy
package org.codehaus.jackson.util;
/**
* This is a small utility class, whose main functionality is to allow
* simple reuse of raw byte/char buffers. It is usually used through
* ThreadLocal member of the owning class pointing to
* instance of this class through a SoftReference. The
* end result is a low-overhead GC-cleanable recycling: hopefully
* ideal for use by stream readers.
*/
public final class BufferRecycler
{
public enum ByteBufferType {
READ_IO_BUFFER(4000)
,WRITE_IO_BUFFER(4000);
private final int size;
ByteBufferType(int size) { this.size = size; }
}
public enum CharBufferType {
TOKEN_BUFFER(2000) // Tokenizable input
,CONCAT_BUFFER(2000) // concatenated output
,TEXT_BUFFER(200) // Text content from input
,BOOTSTRAP_BUFFER(200) // Temporary buffer for merged reader
;
private final int size;
CharBufferType(int size) { this.size = size; }
}
final protected byte[][] mByteBuffers = new byte[ByteBufferType.values().length][];
final protected char[][] mCharBuffers = new char[CharBufferType.values().length][];
public BufferRecycler() { }
public byte[] allocByteBuffer(ByteBufferType type)
{
int ix = type.ordinal();
byte[] buffer = mByteBuffers[ix];
if (buffer == null) {
buffer = balloc(type.size);
} else {
mByteBuffers[ix] = null;
}
return buffer;
}
public void releaseByteBuffer(ByteBufferType type, byte[] buffer)
{
mByteBuffers[type.ordinal()] = buffer;
}
public char[] allocCharBuffer(CharBufferType type)
{
return allocCharBuffer(type, 0);
}
public char[] allocCharBuffer(CharBufferType type, int minSize)
{
minSize = (minSize >= type.size) ? minSize : type.size;
int ix = type.ordinal();
char[] buffer = mCharBuffers[ix];
if (buffer == null || buffer.length < minSize) {
buffer = calloc(minSize);
} else {
mCharBuffers[ix] = null;
}
return buffer;
}
public void releaseCharBuffer(CharBufferType type, char[] buffer)
{
mCharBuffers[type.ordinal()] = buffer;
}
/*
//////////////////////////////////////////////////////////////
// Actual allocations separated for easier debugging/profiling
//////////////////////////////////////////////////////////////
*/
private byte[] balloc(int size)
{
return new byte[size];
}
private char[] calloc(int size)
{
return new char[size];
}
}