@Override
public synchronized void open() throws IOException {
try {
_bytesDB.open();
_index.open();
} catch (IOException ioe) {
_index.close();
_bytesDB.close();
throw ioe;
}
}
@Override
public synchronized boolean delete(byte[] key) throws Exception {
if (key == null) return false;
// Lookup index meta
byte[] metaBytes = _index.lookup(key);
if (metaBytes == null) return false;
IndexMeta meta = IndexMeta.parse(metaBytes);
if (meta == null) return false;
// Delete from bytes DB
_bytesDB.set(meta.getDataAddr(), null, System.currentTimeMillis());
// Update index
_index.update(key, null);
_updateCnt++;
if (_updateCnt >= _batchSize) {
_updateCnt = 0;
persist();
}
return true;
}
@Override
public byte[] get(byte[] key) {
if (key == null) return null;
byte[] metaBytes = _index.lookup(key);
if (metaBytes == null) return null;
IndexMeta meta = IndexMeta.parse(metaBytes);
if (meta == null) return null;
return _bytesDB.get(meta.getDataAddr());
}
@Override
public synchronized boolean put(byte[] key, byte[] value) throws Exception {
if (value == null) return delete(key);
if (key == null) return false;
// Lookup index meta
IndexMeta meta = null;
byte[] metaBytes = _index.lookup(key);
if (metaBytes != null) {
meta = IndexMeta.parse(metaBytes);
}
// Update index if needed
if (meta == null) {
// Add to bytes DB
int index = _bytesDB.add(value, System.currentTimeMillis());
metaBytes = IndexMeta.build(index);
// Update hashIndex
_index.update(key, metaBytes);
} else {
// Update bytes DB
int index = meta.getDataAddr();
_bytesDB.set(index, value, System.currentTimeMillis());
// No need to update hashIndex
}
_updateCnt++;
if (_updateCnt >= _batchSize) {
_updateCnt = 0;
persist();
}
return true;
}
@Override
public synchronized void sync() throws IOException {
_bytesDB.sync();
_index.sync();
}
@Override
public synchronized void persist() throws IOException {
_bytesDB.persist();
_index.persist();
}
@Override
public synchronized void clear() throws IOException {
_bytesDB.clear();
_index.clear();
}