void _pickInitial() throws MongoException {
if (_curAddress != null) return;
// we need to just get a server to query for ismaster
_pickCurrent();
try {
_logger.info("current address beginning of _pickInitial: " + _curAddress);
DBObject im = isMasterCmd();
if (_isMaster(im)) return;
synchronized (_allHosts) {
Collections.shuffle(_allHosts);
for (ServerAddress a : _allHosts) {
if (_curAddress == a) continue;
_logger.info("remote [" + _curAddress + "] -> [" + a + "]");
_set(a);
im = isMasterCmd();
if (_isMaster(im)) return;
_logger.severe("switched to: " + a + " but isn't master");
}
throw new MongoException("can't find master");
}
} catch (Exception e) {
_logger.log(Level.SEVERE, "can't pick initial master, using random one", e);
}
}
public DBTCPConnector(Mongo m, ServerAddress addr) throws MongoException {
_mongo = m;
_portHolder = new DBPortPool.Holder(m._options);
_checkAddress(addr);
_createLogger.info(addr.toString());
if (addr.isPaired()) {
_allHosts = new ArrayList<ServerAddress>(addr.explode());
_createLogger.info("switch to paired mode : " + _allHosts + " -> " + _curAddress);
} else {
_set(addr);
_allHosts = null;
}
}
public DBTCPConnector(Mongo m, List<ServerAddress> all) throws MongoException {
_mongo = m;
_portHolder = new DBPortPool.Holder(m._options);
_checkAddress(all);
_allHosts = new ArrayList<ServerAddress>(all); // make a copy so it can't be modified
_createLogger.info(all + " -> " + _curAddress);
}
/**
* Creates and initializes an SPV block store. Will create the given file if it's missing. This
* operation will block on disk.
*/
public SPVBlockStore(NetworkParameters params, File file) throws BlockStoreException {
checkNotNull(file);
this.params = checkNotNull(params);
try {
this.numHeaders = DEFAULT_NUM_HEADERS;
boolean exists = file.exists();
// Set up the backing file.
randomAccessFile = new RandomAccessFile(file, "rw");
long fileSize = getFileSize();
if (!exists) {
log.info("Creating new SPV block chain file " + file);
randomAccessFile.setLength(fileSize);
} else if (randomAccessFile.length() != fileSize) {
throw new BlockStoreException(
"File size on disk does not match expected size: "
+ randomAccessFile.length()
+ " vs "
+ fileSize);
}
FileChannel channel = randomAccessFile.getChannel();
fileLock = channel.tryLock();
if (fileLock == null)
throw new BlockStoreException("Store file is already locked by another process");
// Map it into memory read/write. The kernel will take care of flushing writes to disk at the
// most
// efficient times, which may mean that until the map is deallocated the data on disk is
// randomly
// inconsistent. However the only process accessing it is us, via this mapping, so our own
// view will
// always be correct. Once we establish the mmap the underlying file and channel can go away.
// Note that
// the details of mmapping vary between platforms.
buffer = channel.map(FileChannel.MapMode.READ_WRITE, 0, fileSize);
// Check or initialize the header bytes to ensure we don't try to open some random file.
byte[] header;
if (exists) {
header = new byte[4];
buffer.get(header);
if (!new String(header, "US-ASCII").equals(HEADER_MAGIC))
throw new BlockStoreException("Header bytes do not equal " + HEADER_MAGIC);
} else {
initNewStore(params);
}
} catch (Exception e) {
try {
if (randomAccessFile != null) randomAccessFile.close();
} catch (IOException e2) {
throw new BlockStoreException(e2);
}
throw new BlockStoreException(e);
}
}
@Override
public void close() throws BlockStoreException {
try {
buffer.force();
if (System.getProperty("os.name").toLowerCase().contains("win")) {
log.info("Windows mmap hack: Forcing buffer cleaning");
WindowsMMapHack.forceRelease(buffer);
}
buffer = null; // Allow it to be GCd and the underlying file mapping to go away.
randomAccessFile.close();
} catch (IOException e) {
throw new BlockStoreException(e);
}
}
private void _pickCurrent() throws MongoException {
if (_allHosts == null)
throw new MongoException(
"got master/slave issue but not in master/slave mode on the client side");
synchronized (_allHosts) {
Collections.shuffle(_allHosts);
for (int i = 0; i < _allHosts.size(); i++) {
ServerAddress a = _allHosts.get(i);
if (a == _curAddress) continue;
if (_curAddress != null) {
_logger.info("switching from [" + _curAddress + "] to [" + a + "]");
}
_set(a);
return;
}
}
throw new MongoException("couldn't find a new host to swtich too");
}