/**
* {@inheritDoc}
*
* @throws NullPointerException if any of the arguments are null
*/
@Override
public boolean replace(
@NotNull final K key, @NotNull final V oldValue, @NotNull final V newValue) {
if (key == null) throw new NullPointerException("'key' can not be null");
if (oldValue == null) throw new NullPointerException("'oldValue' can not be null");
if (newValue == null) throw new NullPointerException("'newValue' can not be null");
return oldValue.equals(replaceIfValueIs(key, oldValue, newValue));
}
/**
* implementation for map.replace(Key,Value) and map.replace(Key,Old,New)
*
* @param keyBytes the key of the entry to be replaced
* @param expectedValue the expected value to replaced
* @param newValue the new value that will only be set if the existing value in the map equals
* the {@param expectedValue} or {@param expectedValue} is null
* @param hash2 a hash code relating to the {@keyBytes} ( not the natural hash of {@keyBytes} )
* @return null if the value was not replaced, else the value that is replaced is returned
*/
V replace(
final DirectBytes keyBytes, final V expectedValue, final V newValue, final int hash2) {
lock();
try {
hashLookup.startSearch(hash2);
while (true) {
final int pos = hashLookup.nextPos();
if (pos < 0) {
return null;
} else {
final long offset = entriesOffset + pos * entrySize;
tmpBytes.storePositionAndSize(bytes, offset, entrySize);
if (!keyEquals(keyBytes, tmpBytes)) continue;
final long keyLength = keyBytes.remaining();
tmpBytes.skip(keyLength);
long valuePosition = tmpBytes.position();
tmpBytes.readStopBit();
final long alignPosition = align(tmpBytes.position());
tmpBytes.position(alignPosition);
final V valueRead = readObjectUsing(null, offset + keyLength);
if (valueRead == null) return null;
if (expectedValue == null || expectedValue.equals(valueRead)) {
tmpBytes.position(valuePosition);
appendInstance(keyBytes, newValue);
}
return valueRead;
}
}
} finally {
unlock();
}
}
/**
* implementation for map.remove(Key,Value)
*
* @param keyBytes the key of the entry to remove
* @param expectedValue the entry will only be removed if the {@param existingValue} equals null
* or the {@param existingValue} equals that of the entry.value
* @param hash2 a hash code relating to the {@keyBytes} ( not the natural hash of {@keyBytes} )
* @return
*/
V remove(final DirectBytes keyBytes, final V expectedValue, int hash2) {
lock();
try {
hash2 = hashLookup.startSearch(hash2);
while (true) {
final int pos = hashLookup.nextPos();
if (pos < 0) {
return null;
} else {
final long offset = entriesOffset + pos * entrySize;
tmpBytes.storePositionAndSize(bytes, offset, entrySize);
if (!keyEquals(keyBytes, tmpBytes)) continue;
final long keyLength =
align(keyBytes.remaining() + tmpBytes.position()); // includes the stop bit length.
tmpBytes.position(keyLength);
V valueRemoved =
expectedValue == null && removeReturnsNull
? null
: readObjectUsing(null, offset + keyLength);
if (expectedValue != null && !expectedValue.equals(valueRemoved)) return null;
hashLookup.remove(hash2, pos);
decrementSize();
freeList.clear(pos);
if (pos < nextSet) nextSet = pos;
return valueRemoved;
}
}
} finally {
unlock();
}
}
