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Fork of Esoteric Software's Kryo built by Nathan Sweet that replaces Minlog with slf4j as the logging facade. This contains the shaded reflectasm jar to prevent conflicts with other versions of asm.
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/* Copyright (c) 2008, Nathan Sweet
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following
 * conditions are met:
 * 
 * - Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
 * disclaimer in the documentation and/or other materials provided with the distribution.
 * - Neither the name of Esoteric Software nor the names of its contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */

package com.esotericsoftware.kryo.io;

import java.io.IOException;
import java.io.InputStream;

import com.esotericsoftware.kryo.KryoException;
import com.esotericsoftware.kryo.util.UnsafeUtil;

import static com.esotericsoftware.kryo.util.UnsafeUtil.*;

/** An optimized InputStream that reads data from a byte array and optionally fills the byte array from another InputStream as
 * needed. Utility methods are provided for efficiently writing primitive types, arrays of primitive types and strings. It uses
 * @link{sun.misc.Unsafe} to achieve a very good performance.
 * 
 * 
 * Important notes:

 * 
Bulk operations, e.g. on arrays of primitive types, are always using native byte order.
 * Fixed-size char, int, long, short, float and double elements are always read using native byte order.
 * Best performance is achieved if no variable length encoding for integers is used.
 * Serialized representation used as input for this class should always be produced using @link{UnsafeOutput}
 * 
 * @author Roman Levenstein  */
public final class UnsafeInput extends Input {

	private boolean varIntsEnabled = false;

	/** Creates an uninitialized Input. {@link #setBuffer(byte[], int, int)} must be called before the Input is used. */
	public UnsafeInput () {
	}

	/** Creates a new Input for reading from a byte array.
	 * @param bufferSize The initial and maximum size of the buffer. An exception is thrown if this size is exceeded. */
	public UnsafeInput (int bufferSize) {
		super(bufferSize);
	}

	/** Creates a new Input for reading from a byte array.
	 * @see #setBuffer(byte[]) */
	public UnsafeInput (byte[] buffer) {
		super(buffer);
	}

	/** Creates a new Input for reading from a byte array.
	 * @see #setBuffer(byte[], int, int) */
	public UnsafeInput (byte[] buffer, int offset, int count) {
		super(buffer, offset, count);
	}

	/** Creates a new Input for reading from an InputStream. A buffer size of 4096 is used. */
	public UnsafeInput (InputStream inputStream) {
		super(inputStream);
	}

	/** Creates a new Input for reading from an InputStream. */
	public UnsafeInput (InputStream inputStream, int bufferSize) {
		super(inputStream, bufferSize);
	}

	// int

	/** Reads a 4 byte int. */
	public int readInt () throws KryoException {
		require(4);
		int result = unsafe().getInt(buffer, byteArrayBaseOffset + position);
		position += 4;
		return result;
	}

	// float

	/** Reads a 4 byte float. */
	public float readFloat () throws KryoException {
		require(4);
		float result = unsafe().getFloat(buffer, byteArrayBaseOffset + position);
		position += 4;
		return result;
	}

	// short

	/** Reads a 2 byte short. */
	public short readShort () throws KryoException {
		require(2);
		short result = unsafe().getShort(buffer, byteArrayBaseOffset + position);
		position += 2;
		return result;
	}

	// long

	/** Reads an 8 byte long. */
	public long readLong () throws KryoException {
		require(8);
		long result = unsafe().getLong(buffer, byteArrayBaseOffset + position);
		position += 8;
		return result;
	}

	// double

	/** Writes an 8 byte double. */
	public double readDouble () throws KryoException {
		require(8);
		double result = unsafe().getDouble(buffer, byteArrayBaseOffset + position);
		position += 8;
		return result;
	}
	
	// char
	
	public char readChar () throws KryoException {
		require(2);
		char result = unsafe().getChar(buffer, byteArrayBaseOffset + position);
		position += 2;
		return result;
	}


	public int readInt (boolean optimizePositive) throws KryoException {
		if (!varIntsEnabled)
			return readInt();
		else
			return super.readInt(optimizePositive);
	}

	public long readLong (boolean optimizePositive) throws KryoException {
		if (!varIntsEnabled)
			return readLong();
		else
			return super.readLong(optimizePositive);
	}

	// Methods implementing bulk operations on arrays of primitive types

	/** {@inheritDoc} */
	final public int[] readInts (int length, boolean optimizePositive) throws KryoException {
		if (!varIntsEnabled) {
			int bytesToCopy = length << 2;
			int[] array = new int[length];
			readBytes(array, intArrayBaseOffset, 0, bytesToCopy);
			return array;
		} else
			return super.readInts(length, optimizePositive);
	}

	/** {@inheritDoc} */
	final public long[] readLongs (int length, boolean optimizePositive) throws KryoException {
		if (!varIntsEnabled) {
			int bytesToCopy = length << 3;
			long[] array = new long[length];
			readBytes(array, longArrayBaseOffset, 0, bytesToCopy);
			return array;
		} else
			return super.readLongs(length, optimizePositive);
	}

	/** {@inheritDoc} */
	final public int[] readInts (int length) throws KryoException {
		int bytesToCopy = length << 2;
		int[] array = new int[length];
		readBytes(array, intArrayBaseOffset, 0, bytesToCopy);
		return array;
	}

	/** {@inheritDoc} */
	final public long[] readLongs (int length) throws KryoException {
		int bytesToCopy = length << 3;
		long[] array = new long[length];
		readBytes(array, longArrayBaseOffset, 0, bytesToCopy);
		return array;
	}

	/** {@inheritDoc} */
	final public float[] readFloats (int length) throws KryoException {
		int bytesToCopy = length << 2;
		float[] array = new float[length];
		readBytes(array, floatArrayBaseOffset, 0, bytesToCopy);
		return array;
	}

	/** {@inheritDoc} */
	final public short[] readShorts (int length) throws KryoException {
		int bytesToCopy = length << 1;
		short[] array = new short[length];
		readBytes(array, shortArrayBaseOffset, 0, bytesToCopy);
		return array;
	}

	/** {@inheritDoc} */
	final public char[] readChars (int length) throws KryoException {
		int bytesToCopy = length << 1;
		char[] array = new char[length];
		readBytes(array, charArrayBaseOffset, 0, bytesToCopy);
		return array;
	}

	/** {@inheritDoc} */
	final public double[] readDoubles (int length) throws KryoException {
		int bytesToCopy = length << 3;
		double[] array = new double[length];
		readBytes(array, doubleArrayBaseOffset, 0, bytesToCopy);
		return array;
	}

	final public void readBytes (Object dstObj, long offset, long count) throws KryoException {
		// Unsafe supports efficient bulk reading into arrays of primitives only because
		// of JVM limitations due to GC
		if (dstObj.getClass().isArray())
			readBytes(dstObj, 0, offset, (int)count);
		else {
			throw new KryoException("Only bulk reads of arrays is supported");
		}
	}

	final private void readBytes (Object dstArray, long dstArrayTypeOffset, long offset, int count) throws KryoException {
		int copyCount = Math.min(limit - position, count);
		while (true) {
			unsafe().copyMemory(buffer, byteArrayBaseOffset + position, dstArray, dstArrayTypeOffset + offset, copyCount);
			position += copyCount;
			count -= copyCount;
			if (count == 0) break;
			offset += copyCount;
			copyCount = Math.min(count, capacity);
			require(copyCount);
		}
	}

	/*** Return current setting for variable length encoding of integers
	 * @return current setting for variable length encoding of integers */
	public boolean getVarIntsEnabled () {
		return varIntsEnabled;
	}

	/*** Controls if a variable length encoding for integer types should be used when serializers suggest it.
	 * 
	 * @param varIntsEnabled */
	public void setVarIntsEnabled (boolean varIntsEnabled) {
		this.varIntsEnabled = varIntsEnabled;
	}
}