Memory.java

package elw.dp.mips;

import gnu.trove.TIntArrayList;
import gnu.trove.TIntByteHashMap;
import gnu.trove.TIntIntHashMap;

import java.util.Arrays;

public class Memory {
    private TIntByteHashMap contentMap = new TIntByteHashMap();

    private TIntArrayList readAdresses = new TIntArrayList();
    private TIntArrayList writeAdresses = new TIntArrayList();

    public int getWord(int address) {
        readAdresses.add(address);

        return getWordInternal(address);
    }

    public int getWordInternal(final int address) {
        final byte byte0 = getByteInternal(address);
        final byte byte1 = getByteInternal(address + 1);
        final byte byte2 = getByteInternal(address + 2);
        final byte byte3 = getByteInternal(address + 3);

        return (byte0 << 24) | ((byte1 << 16) & 0xFF0000) | ((byte2 << 8) & 0xFF00) | ((int) byte3 & 0xFF);
    }

    public int setWord(int address, int newWord) {
        writeAdresses.add(address);
        writeAdresses.add(address + 1);
        writeAdresses.add(address + 2);
        writeAdresses.add(address + 3);

        return setWordInternal(address, newWord);
    }

    private int setWordInternal(int address, int newWord) {
        final int oldWord = getWordInternal(address);

        setByteInternal(address, (byte) (newWord >> 24));
        setByteInternal(address + 1, (byte) (newWord >> 16 & 0xFF));
        setByteInternal(address + 2, (byte) (newWord >> 8 & 0xFF));
        setByteInternal(address + 3, (byte) (newWord & 0xFF));

        return oldWord;
    }

    public byte getByteInternal(final int address) {
        return contentMap.get(address);
    }

    private byte setByteInternal(int address, byte value) {
        return contentMap.put(address, value);
    }

    public byte getByte(int address) {
        readAdresses.add(address);

        return getByteInternal(address);
    }

    public byte setByte(int address, byte newByte) {
        writeAdresses.add(address);

        return setByteInternal(address, newByte);
    }

    public TIntArrayList getReadAdresses() {
        return readAdresses;
    }

    public TIntArrayList getWriteAdresses() {
        return writeAdresses;
    }

    public void resetAccess() {
        readAdresses.clear();
        writeAdresses.clear();
    }

    public int getSize() {
        return contentMap.size();
    }

    public int getAddressAt(int index) {
        //  LATER optimize this
        final int[] keys = contentMap.keys();
        Arrays.sort(keys);

        return keys[index];
    }

    public void setData(final TIntIntHashMap newData) {
        resetAccess();

        contentMap.clear();
        final int[] addresses = newData.keys();
        for (final int addr : addresses) {
            setWord(addr, newData.get(addr));
        }
    }

    public boolean hasWord(final int address) {
        return hasByte(address) && hasByte(address + 1) && hasByte(address + 2) && hasByte(address + 3);
    }

    private boolean hasByte(final int address) {
        return contentMap.containsKey(address);
    }
}