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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 class BufferRecycler
{
public final static int DEFAULT_WRITE_CONCAT_BUFFER_LEN = 2000;
public enum ByteBufferType {
READ_IO_BUFFER(4000)
/**
* Buffer used for temporarily storing encoded content; used
* for example by UTF-8 encoding writer
*/
,WRITE_ENCODING_BUFFER(4000)
/**
* Buffer used for temporarily concatenating output; used for
* example when requesting output as byte array.
*/
,WRITE_CONCAT_BUFFER(2000)
;
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
,NAME_COPY_BUFFER(200) // Temporary buffer for getting name characters
;
private final int size;
CharBufferType(int size) { this.size = size; }
}
final protected byte[][] _byteBuffers = new byte[ByteBufferType.values().length][];
final protected char[][] _charBuffers = new char[CharBufferType.values().length][];
public BufferRecycler() { }
public final byte[] allocByteBuffer(ByteBufferType type)
{
int ix = type.ordinal();
byte[] buffer = _byteBuffers[ix];
if (buffer == null) {
buffer = balloc(type.size);
} else {
_byteBuffers[ix] = null;
}
return buffer;
}
public final void releaseByteBuffer(ByteBufferType type, byte[] buffer)
{
_byteBuffers[type.ordinal()] = buffer;
}
public final char[] allocCharBuffer(CharBufferType type)
{
return allocCharBuffer(type, 0);
}
public final char[] allocCharBuffer(CharBufferType type, int minSize)
{
if (type.size > minSize) {
minSize = type.size;
}
int ix = type.ordinal();
char[] buffer = _charBuffers[ix];
if (buffer == null || buffer.length < minSize) {
buffer = calloc(minSize);
} else {
_charBuffers[ix] = null;
}
return buffer;
}
public final void releaseCharBuffer(CharBufferType type, char[] buffer)
{
_charBuffers[type.ordinal()] = buffer;
}
/*
/**********************************************************
/* Actual allocations separated for easier debugging/profiling
/**********************************************************
*/
private final byte[] balloc(int size)
{
return new byte[size];
}
private final char[] calloc(int size)
{
return new char[size];
}
}