protected long indexHeaderChecksum() {
long ret = 0;
for (long offset = 0; offset < IO_USER_START; offset += 8) {
if (offset == IO_INDEX_SUM) continue;
long indexVal = index.getLong(offset);
ret += indexVal + DataIO.longHash(indexVal + offset);
}
return ret;
}
@Test
public void commitChecksum() {
WriteAheadLog wal = new WriteAheadLog(null);
wal.open(WriteAheadLog.NOREPLAY);
wal.startNextFile();
wal.walPutLong(111L, 1000);
wal.commit();
long offset1 = wal.fileOffset - 5;
int checksum1 = DataIO.longHash(wal.curVol.hash(16, offset1 - 16, 111L));
assertEquals(checksum1, wal.curVol.getInt(offset1 + 1));
wal.walPutLong(111L, 1000);
wal.commit();
long offset2 = wal.fileOffset - 5;
int checksum2 =
checksum1 + DataIO.longHash(wal.curVol.hash(offset1 + 5, offset2 - offset1 - 5, 111L));
assertEquals(checksum2, wal.curVol.getInt(offset2 + 1));
}
/**
* @return the previous value associated with the specified key, or <tt>null</tt> if there was no
* mapping for the key
* @throws NullPointerException if the specified key or value is null
*/
public V replace(long key, V value) {
if (value == null) throw new NullPointerException();
final int hash = DataIO.longHash(key ^ hashSalt);
return segmentFor(hash).replace(key, hash, value);
}
/** @throws NullPointerException if any of the arguments are null */
public boolean replace(long key, V oldValue, V newValue) {
if (oldValue == null || newValue == null) throw new NullPointerException();
final int hash = DataIO.longHash(key ^ hashSalt);
return segmentFor(hash).replace(key, hash, oldValue, newValue);
}
/** @throws NullPointerException if the specified key is null */
public boolean remove(long key, Object value) {
final int hash = DataIO.longHash(key ^ hashSalt);
return value != null && segmentFor(hash).remove(key, hash, value) != null;
}
/**
* Removes the key (and its corresponding value) from this map. This method does nothing if the
* key is not in the map.
*
* @param key the key that needs to be removed
* @return the previous value associated with <tt>key</tt>, or <tt>null</tt> if there was no
* mapping for <tt>key</tt>
* @throws NullPointerException if the specified key is null
*/
@Override
public V remove(long key) {
final int hash = DataIO.longHash(key ^ hashSalt);
return segmentFor(hash).remove(key, hash, null);
}
/**
* @return the previous value associated with the specified key, or <tt>null</tt> if there was no
* mapping for the key
* @throws NullPointerException if the specified key or value is null
*/
public V putIfAbsent(long key, V value) {
if (value == null) throw new NullPointerException();
final int hash = DataIO.longHash(key ^ hashSalt);
return segmentFor(hash).put(key, hash, value, true);
}
/**
* Tests if the specified object is a key in this table.
*
* @param key possible key
* @return <tt>true</tt> if and only if the specified object is a key in this table, as determined
* by the <tt>equals</tt> method; <tt>false</tt> otherwise.
* @throws NullPointerException if the specified key is null
*/
public boolean containsKey(long key) {
final int hash = DataIO.longHash(key ^ hashSalt);
return segmentFor(hash).containsKey(key, hash);
}
/**
* Returns the value to which the specified key is mapped, or {@code null} if this map contains no
* mapping for the key.
*
* <p>More formally, if this map contains a mapping from a key {@code k} to a value {@code keys}
* such that {@code key.equals(k)}, then this method returns {@code keys}; otherwise it returns
* {@code null}. (There can be at most one such mapping.)
*
* @throws NullPointerException if the specified key is null
*/
@Override
public V get(long key) {
final int hash = DataIO.longHash(key ^ hashSalt);
return segmentFor(hash).get(key, hash);
}
