synchronized void save() {
Long lastKey = this.lastSyncKey;
Set<Entry<Long, RedoLogValue>> entrySet =
lastKey == null ? skipListMap.entrySet() : skipListMap.tailMap(lastKey, false).entrySet();
if (!entrySet.isEmpty()) {
WriteBuffer buff = WriteBufferPool.poll();
try {
for (Entry<Long, RedoLogValue> e : entrySet) {
lastKey = e.getKey();
keyType.write(buff, lastKey);
valueType.write(buff, e.getValue());
}
int chunkLength = buff.position();
if (chunkLength > 0) {
buff.limit(chunkLength);
buff.position(0);
fileStorage.writeFully(pos, buff.getBuffer());
pos += chunkLength;
fileStorage.sync();
}
this.lastSyncKey = lastKey;
} finally {
WriteBufferPool.offer(buff);
}
}
}
RedoLogChunk(int id, Map<String, String> config) {
this.id = id;
// 不使用ObjectDataType，因为ObjectDataType需要自动侦测，会有一些开销
this.keyType = new RedoLogKeyType();
this.valueType = new RedoLogValueType();
skipListMap = new ConcurrentSkipListMap<>(new KeyComparator<Long>(keyType));
String chunkFileName = getChunkFileName(config, id);
fileStorage = new FileStorage();
fileStorage.open(chunkFileName, config);
pos = fileStorage.size();
if (pos > 0) read();
}
private void read() {
ByteBuffer buffer = fileStorage.readFully(0, (int) pos);
while (buffer.remaining() > 0) {
Long k = (Long) keyType.read(buffer);
RedoLogValue v = (RedoLogValue) valueType.read(buffer);
skipListMap.put(k, v);
lastSyncKey = k;
}
}
@Override
public String toString() {
return "RedoLogChunk[" + id + ", " + fileStorage.getFileName() + "]";
}
void close() {
save();
fileStorage.close();
}