public DefaultSnapshotDataTarget(
final File file,
final int hostId,
final String clusterName,
final String databaseName,
final String tableName,
final int numPartitions,
final boolean isReplicated,
final List<Integer> partitionIds,
final VoltTable schemaTable,
final long txnId,
final long timestamp,
int version[])
throws IOException {
String hostname = CoreUtils.getHostnameOrAddress();
m_file = file;
m_tableName = tableName;
m_fos = new FileOutputStream(file);
m_channel = m_fos.getChannel();
m_needsFinalClose = !isReplicated;
final FastSerializer fs = new FastSerializer();
fs.writeInt(0); // CRC
fs.writeInt(0); // Header length placeholder
fs.writeByte(
1); // Indicate the snapshot was not completed, set to true for the CRC calculation, false
// later
for (int ii = 0; ii < 4; ii++) {
fs.writeInt(version[ii]); // version
}
JSONStringer stringer = new JSONStringer();
byte jsonBytes[] = null;
try {
stringer.object();
stringer.key("txnId").value(txnId);
stringer.key("hostId").value(hostId);
stringer.key("hostname").value(hostname);
stringer.key("clusterName").value(clusterName);
stringer.key("databaseName").value(databaseName);
stringer.key("tableName").value(tableName.toUpperCase());
stringer.key("isReplicated").value(isReplicated);
stringer.key("isCompressed").value(true);
stringer.key("checksumType").value("CRC32C");
stringer.key("timestamp").value(timestamp);
/*
* The timestamp string is for human consumption, automated stuff should use
* the actual timestamp
*/
stringer.key("timestampString").value(SnapshotUtil.formatHumanReadableDate(timestamp));
if (!isReplicated) {
stringer.key("partitionIds").array();
for (int partitionId : partitionIds) {
stringer.value(partitionId);
}
stringer.endArray();
stringer.key("numPartitions").value(numPartitions);
}
stringer.endObject();
String jsonString = stringer.toString();
JSONObject jsonObj = new JSONObject(jsonString);
jsonString = jsonObj.toString(4);
jsonBytes = jsonString.getBytes("UTF-8");
} catch (Exception e) {
throw new IOException(e);
}
fs.writeInt(jsonBytes.length);
fs.write(jsonBytes);
final BBContainer container = fs.getBBContainer();
container.b.position(4);
container.b.putInt(container.b.remaining() - 4);
container.b.position(0);
final byte schemaBytes[] = PrivateVoltTableFactory.getSchemaBytes(schemaTable);
final PureJavaCrc32 crc = new PureJavaCrc32();
ByteBuffer aggregateBuffer = ByteBuffer.allocate(container.b.remaining() + schemaBytes.length);
aggregateBuffer.put(container.b);
aggregateBuffer.put(schemaBytes);
aggregateBuffer.flip();
crc.update(aggregateBuffer.array(), 4, aggregateBuffer.capacity() - 4);
final int crcValue = (int) crc.getValue();
aggregateBuffer.putInt(crcValue).position(8);
aggregateBuffer.put((byte) 0).position(0); // Haven't actually finished writing file
if (m_simulateFullDiskWritingHeader) {
m_writeException = new IOException("Disk full");
m_writeFailed = true;
m_fos.close();
throw m_writeException;
}
/*
* Be completely sure the write succeeded. If it didn't
* the disk is probably full or the path is bunk etc.
*/
m_acceptOneWrite = true;
ListenableFuture<?> writeFuture =
write(Callables.returning((BBContainer) DBBPool.wrapBB(aggregateBuffer)), false);
try {
writeFuture.get();
} catch (InterruptedException e) {
m_fos.close();
throw new java.io.InterruptedIOException();
} catch (ExecutionException e) {
m_fos.close();
throw m_writeException;
}
if (m_writeFailed) {
m_fos.close();
throw m_writeException;
}
ScheduledFuture<?> syncTask = null;
syncTask =
m_syncService.scheduleAtFixedRate(
new Runnable() {
@Override
public void run() {
// Only sync for at least 4 megabyte of data, enough to amortize the cost of seeking
// on ye olden platters. Since we are appending to a file it's actually 2 seeks.
while (m_bytesWrittenSinceLastSync.get() > (1024 * 1024 * 4)) {
final int bytesSinceLastSync = m_bytesWrittenSinceLastSync.getAndSet(0);
try {
m_channel.force(false);
} catch (IOException e) {
if (!(e instanceof java.nio.channels.AsynchronousCloseException)) {
SNAP_LOG.error("Error syncing snapshot", e);
} else {
SNAP_LOG.debug(
"Asynchronous close syncing snasphot data, presumably graceful", e);
}
}
m_bytesAllowedBeforeSync.release(bytesSinceLastSync);
}
}
},
SNAPSHOT_SYNC_FREQUENCY,
SNAPSHOT_SYNC_FREQUENCY,
TimeUnit.MILLISECONDS);
m_syncTask = syncTask;
}
