| 1 | package com.rox.mem; | |
| 2 | ||
| 3 | import static com.rox.ByteUtil.BYTE_MASK; | |
| 4 | ||
| 5 | public class RAM implements Memory { | |
| 6 | private final int[] memory; | |
| 7 | /** What this RAM is called in error messages, e.g. {@code PRG-RAM}. */ | |
| 8 | private final String name; | |
| 9 | ||
| 10 | public RAM(final int size) { | |
| 11 | this(size, "RAM"); | |
| 12 | } | |
| 13 | ||
| 14 | public RAM(final int size, final String name) { | |
| 15 |
1
1. <init> : negated conditional → KILLED |
if (Integer.bitCount(size) != 1) { |
| 16 | throw new IllegalArgumentException( | |
| 17 | name + " size must be power of two"); | |
| 18 | } | |
| 19 | this.memory = new int[size]; | |
| 20 | this.name = name; | |
| 21 | } | |
| 22 | ||
| 23 | @Override | |
| 24 | public int read(final int address) { | |
| 25 |
4
1. read : Replaced bitwise AND with OR → KILLED 2. read : replaced int return with 0 for com/rox/mem/RAM::read → KILLED 3. read : Replaced integer subtraction with addition → KILLED 4. read : Replaced bitwise AND with OR → KILLED |
return memory[address & (memory.length - 1)] & BYTE_MASK; |
| 26 | } | |
| 27 | ||
| 28 | @Override | |
| 29 | public void write(final int address, final int value) { | |
| 30 |
3
1. write : Replaced bitwise AND with OR → KILLED 2. write : Replaced integer subtraction with addition → KILLED 3. write : Replaced bitwise AND with OR → KILLED |
memory[address & (memory.length - 1)] = value & BYTE_MASK; |
| 31 | } | |
| 32 | ||
| 33 | /** A copy of every byte, for a save state. */ | |
| 34 | public int[] snapshot() { | |
| 35 |
1
1. snapshot : replaced return value with null for com/rox/mem/RAM::snapshot → KILLED |
return memory.clone(); |
| 36 | } | |
| 37 | ||
| 38 | /** | |
| 39 | * Checks {@code contents} could be {@link #restore}d, without changing anything. | |
| 40 | * | |
| 41 | * @throws IllegalArgumentException if {@code contents} isn't exactly this RAM's size | |
| 42 | */ | |
| 43 | public void checkRestorable(final int[] contents) { | |
| 44 |
1
1. checkRestorable : negated conditional → KILLED |
if (contents.length != memory.length) { |
| 45 | throw new IllegalArgumentException( | |
| 46 | "Expected " + memory.length + " bytes of " + name + ", got " + contents.length); | |
| 47 | } | |
| 48 | } | |
| 49 | ||
| 50 | /** | |
| 51 | * Overwrites every byte with {@code contents} (copied, not kept) - the counterpart of {@link #snapshot()}. | |
| 52 | * | |
| 53 | * @throws IllegalArgumentException if {@code contents} isn't exactly this RAM's size | |
| 54 | */ | |
| 55 | public void restore(final int[] contents) { | |
| 56 |
1
1. restore : removed call to com/rox/mem/RAM::checkRestorable → KILLED |
checkRestorable(contents); |
| 57 |
2
1. restore : negated conditional → KILLED 2. restore : changed conditional boundary → KILLED |
for (int i = 0; i < memory.length; i++) { |
| 58 |
1
1. restore : Replaced bitwise AND with OR → KILLED |
memory[i] = contents[i] & BYTE_MASK; |
| 59 | } | |
| 60 | } | |
| 61 | } | |
Mutations | ||
| 15 |
1.1 |
|
| 25 |
1.1 2.2 3.3 4.4 |
|
| 30 |
1.1 2.2 3.3 |
|
| 35 |
1.1 |
|
| 44 |
1.1 |
|
| 56 |
1.1 |
|
| 57 |
1.1 2.2 |
|
| 58 |
1.1 |