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 * The Universal Permissive License (UPL), Version 1.0
 *
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 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
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 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
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 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
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 * The above copyright notice and either this complete permission notice or at a
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package com.oracle.truffle.js.runtime.array;

abstract class ByteArrayAccess {

    @SuppressWarnings("static-method")
    public final int getInt8(byte[] buffer, int byteIndex) {
        return buffer[byteIndex];
    }

    public final int getUint8(byte[] buffer, int byteIndex) {
        return getInt8(buffer, byteIndex) & 0xff;
    }

    public abstract int getInt16(byte[] buffer, int byteIndex);

    public final int getUint16(byte[] buffer, int byteIndex) {
        return getInt16(buffer, byteIndex) & 0xffff;
    }

    public abstract int getInt32(byte[] buffer, int byteIndex);

    public final long getUint32(byte[] buffer, int byteIndex) {
        return getInt32(buffer, byteIndex) & 0xffffffffL;
    }

    public abstract float getFloat(byte[] buffer, int byteIndex);

    public abstract double getDouble(byte[] buffer, int byteIndex);

    public abstract long getInt64(byte[] buffer, int byteIndex);

    @SuppressWarnings("static-method")
    public final void putInt8(byte[] buffer, int byteIndex, int value) {
        buffer[byteIndex] = (byte) value;
    }

    public abstract void putInt16(byte[] buffer, int byteIndex, int value);

    public abstract void putInt32(byte[] buffer, int byteIndex, int value);

    public abstract void putFloat(byte[] buffer, int byteIndex, float value);

    public abstract void putDouble(byte[] buffer, int byteIndex, double value);

    public abstract void putInt64(byte[] buffer, int byteIndex, long value);

    static final ByteArrayAccess littleEndian() {
        return ByteArraySupport.littleEndian();
    }

    static final ByteArrayAccess bigEndian() {
        return ByteArraySupport.bigEndian();
    }

    static final ByteArrayAccess nativeOrder() {
        return ByteArraySupport.nativeOrder();
    }

    static final ByteArrayAccess forOrder(boolean littleEndian) {
        return littleEndian ? littleEndian() : bigEndian();
    }
}

abstract class BytewiseByteArrayAccess extends ByteArrayAccess {
    private static int makeInt16(byte b0, byte b1) {
        return (b1 << 8) | (b0 & 0xff);
    }

    private static int makeInt32(byte b0, byte b1, byte b2, byte b3) {
        return (((b3) << 24) | ((b2 & 0xff) << 16) | ((b1 & 0xff) << 8) | ((b0 & 0xff)));
    }

    private static long makeInt64(byte b0, byte b1, byte b2, byte b3, byte b4, byte b5, byte b6, byte b7) {
        return ((((long) b7) << 56) | (((long) b6 & 0xff) << 48) | (((long) b5 & 0xff) << 40) | (((long) b4 & 0xff) << 32) | (((long) b3 & 0xff) << 24) | (((long) b2 & 0xff) << 16) |
                        (((long) b1 & 0xff) << 8) | (((long) b0 & 0xff)));
    }

    @Override
    public final int getInt16(byte[] buffer, int byteIndex) {
        return makeInt16(buffer[byteIndex + b(0, 2)], buffer[byteIndex + b(1, 2)]);
    }

    @Override
    public final int getInt32(byte[] buffer, int byteIndex) {
        return makeInt32(buffer[byteIndex + b(0, 4)], buffer[byteIndex + b(1, 4)], buffer[byteIndex + b(2, 4)], buffer[byteIndex + b(3, 4)]);
    }

    @Override
    public final float getFloat(byte[] buffer, int byteIndex) {
        return Float.intBitsToFloat(getInt32(buffer, byteIndex));
    }

    @Override
    public final double getDouble(byte[] buffer, int byteIndex) {
        return Double.longBitsToDouble(makeInt64(buffer[byteIndex + b(0, 8)], buffer[byteIndex + b(1, 8)], buffer[byteIndex + b(2, 8)], buffer[byteIndex + b(3, 8)], buffer[byteIndex + b(4, 8)],
                        buffer[byteIndex + b(5, 8)], buffer[byteIndex + b(6, 8)], buffer[byteIndex + b(7, 8)]));
    }

    @Override
    public long getInt64(byte[] buffer, int byteIndex) {
        return makeInt64(buffer[byteIndex + b(0, 8)], buffer[byteIndex + b(1, 8)], buffer[byteIndex + b(2, 8)], buffer[byteIndex + b(3, 8)], buffer[byteIndex + b(4, 8)],
                        buffer[byteIndex + b(5, 8)], buffer[byteIndex + b(6, 8)], buffer[byteIndex + b(7, 8)]);
    }

    @Override
    public final void putInt16(byte[] buffer, int byteIndex, int value) {
        buffer[byteIndex + b(0, 2)] = (byte) (value);
        buffer[byteIndex + b(1, 2)] = (byte) (value >> 8);
    }

    @Override
    public final void putInt32(byte[] buffer, int byteIndex, int value) {
        buffer[byteIndex + b(0, 4)] = (byte) (value);
        buffer[byteIndex + b(1, 4)] = (byte) (value >> 8);
        buffer[byteIndex + b(2, 4)] = (byte) (value >> 16);
        buffer[byteIndex + b(3, 4)] = (byte) (value >> 24);
    }

    @Override
    public final void putInt64(byte[] buffer, int byteIndex, long value) {
        buffer[byteIndex + b(0, 8)] = (byte) (value);
        buffer[byteIndex + b(1, 8)] = (byte) (value >> 8);
        buffer[byteIndex + b(2, 8)] = (byte) (value >> 16);
        buffer[byteIndex + b(3, 8)] = (byte) (value >> 24);
        buffer[byteIndex + b(4, 8)] = (byte) (value >> 32);
        buffer[byteIndex + b(5, 8)] = (byte) (value >> 40);
        buffer[byteIndex + b(6, 8)] = (byte) (value >> 48);
        buffer[byteIndex + b(7, 8)] = (byte) (value >> 56);
    }

    @Override
    public final void putFloat(byte[] buffer, int byteIndex, float value) {
        putInt32(buffer, byteIndex, Float.floatToRawIntBits(value));
    }

    @Override
    public final void putDouble(byte[] buffer, int byteIndex, double value) {
        putInt64(buffer, byteIndex, Double.doubleToRawLongBits(value));
    }

    
Byte order.
Params:
bytePos – byte position in little endian byte order
size – size of type in bytes/**
     * Byte order.
     *
     * @param bytePos byte position in little endian byte order
     * @param size size of type in bytes
     */
    protected abstract int b(int bytePos, int size);
}

final class LittleEndianByteArrayAccess extends BytewiseByteArrayAccess {
    static final ByteArrayAccess INSTANCE = new LittleEndianByteArrayAccess();

    @Override
    protected int b(int bytePos, int size) {
        return bytePos;
    }
}

final class BigEndianByteArrayAccess extends BytewiseByteArrayAccess {
    static final ByteArrayAccess INSTANCE = new BigEndianByteArrayAccess();

    @Override
    protected int b(int bytePos, int size) {
        return size - 1 - bytePos;
    }
}