Java Code Examples for org.iq80.leveldb.DBIterator#next()
The following examples show how to use
org.iq80.leveldb.DBIterator#next() .
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Example 1
| Source File: LevelDBUtilTest.java From julongchain with Apache License 2.0 | 6 votes |
|
@Test
public void getAll() {
try {
// LevelDB db = LevelDBUtil.getDB("/var/julongchain/stateLeveldb");
LevelDB db =
LevelDBUtil.getDB(
"/var/julongchain/production/node/chains/chains/myGroup");
// byte[] bytes = LevelDBUtil.get(db, "aaa".getBytes(), false);
// System.out.println(new String(bytes));
DBIterator iterator = LevelDBUtil.getIterator(db);
while(iterator.hasNext()){
Map.Entry<byte[], byte[]> next = iterator.next();
System.out.println("key:[" + new String(next.getKey()) + "] value:[" + new String(next.getValue()) + "]");
}
} catch (LevelDBException e) {
e.printStackTrace();
}
}
Example 2
| Source File: SelectLevelDBData.java From gsc-core with GNU Lesser General Public License v3.0 | 6 votes |
|
public static void data(String dataName) {
Options options = new Options();
//options.createIfMissing(true);
DB db = null;
try {
System.out.println("Path: " + path + dataName);
db = factory.open(new File(path + dataName), options);
logger.info("---------------------------------------------");
System.out.println();
DBIterator iterator = db.iterator();
iterator.seekToFirst();
int count = 0;
while (iterator.hasNext()) {
count++;
switch (dataName) {
case "properties":
properties(iterator.peekNext().getKey(), iterator.peekNext().getValue());
break;
case "peers":
peers(iterator.peekNext().getKey(), iterator.peekNext().getValue());
break;
case "nodes":
peers(iterator.peekNext().getKey(), iterator.peekNext().getValue());
break;
default:
break;
}
iterator.next();
}
iterator.close();
System.out.println(dataName + " Num: " + count);
System.out.println();
logger.info("---------------------------------------------");
db.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Example 3
| Source File: LevelDbUtil.java From mcg-helper with Apache License 2.0 | 6 votes |
|
public static void print() throws IOException {
//iterator，遍历，顺序读
//读取当前snapshot，快照，读取期间数据的变更，不会反应出来
Snapshot snapshot = db.getSnapshot();
//读选项
ReadOptions readOptions = new ReadOptions();
readOptions.fillCache(false);//遍历中swap出来的数据，不应该保存在memtable中。
readOptions.snapshot(snapshot);//默认snapshot为当前。
DBIterator iterator = db.iterator(readOptions);
while (iterator.hasNext()) {
Map.Entry<byte[],byte[]> item = iterator.next();
String key = new String(item.getKey(), Constants.CHARSET);
String value = new String(item.getValue(), Constants.CHARSET);
logger.debug("key:{}，value:{}", key, value);
}
iterator.close();
}
Example 4
| Source File: DatabaseImpl.java From ethereumj with MIT License | 5 votes |
|
public DatabaseImpl(String name) {
// Initialize Database
this.name = name;
Options options = new Options();
options.createIfMissing(true);
options.compressionType(CompressionType.NONE);
try {
logger.debug("Opening database");
File dbLocation = new File(System.getProperty("user.dir") + "/" +
SystemProperties.CONFIG.databaseDir() + "/");
File fileLocation = new File(dbLocation, name);
if(SystemProperties.CONFIG.databaseReset()) {
destroyDB(fileLocation);
}
logger.debug("Initializing new or existing database: '{}'", name);
db = factory.open(fileLocation, options);
// logger.debug("Showing database stats");
// String stats = DATABASE.getProperty("leveldb.stats");
// logger.debug(stats);
if (logger.isTraceEnabled()){
logger.trace("Dump for: {}", fileLocation.toString());
DBIterator iter = db.iterator();
while(iter.hasNext()){
byte[] key = iter.peekNext().getKey();
byte[] value = iter.peekNext().getValue();
logger.trace("key={}, value={}", Hex.toHexString(key), Hex.toHexString(value));
iter.next();
}
}
} catch (IOException ioe) {
logger.error(ioe.getMessage(), ioe);
throw new RuntimeException("Can't initialize database");
}
}
Example 5
| Source File: EzLevelDbTable.java From ezdb with Apache License 2.0 | 5 votes |
|
private TableIterator<H, R, V> reverseSeekToLast(H hashKey, R fromRangeKey,
R toRangeKey, final byte[] keyBytesFrom, byte[] keyBytesTo,
final DBIterator iterator,
Function<CheckKeysRequest, Boolean> checkKeys) {
iterator.seek(keyBytesFrom);
Entry<byte[], byte[]> last = null;
while (iterator.hasNext()
&& checkKeys.apply(new CheckKeysRequest(hashKey, fromRangeKey,
toRangeKey, keyBytesFrom, keyBytesTo, iterator
.peekNext()))) {
last = iterator.next();
}
// if there is no last one, there is nothing at all in the table
if (last == null) {
return new TableIterator<H, R, V>() {
@Override
public boolean hasNext() {
return false;
}
@Override
public TableRow<H, R, V> next() {
throw new NoSuchElementException();
}
@Override
public void remove() {
throw new NoSuchElementException();
}
@Override
public void close() {
}
};
}
// since last has been found, seek again for that one
iterator.seek(last.getKey());
return null;
}
Example 6
| Source File: LevelDbStore.java From dubbox with Apache License 2.0 | 4 votes |
|
public static void main(String[] args) throws Exception {
Kryo kryo = new Kryo();
kryo.setReferences(false);
kryo.setRegistrationRequired(false);
kryo.setInstantiatorStrategy(new DefaultInstantiatorStrategy(new StdInstantiatorStrategy()));
// kryo.register(Transaction.class);
// kryo.register(Xid.class);
// kryo.register(TransactionType.class);
// kryo.register(TransactionStatus.class);
// kryo.register(Participant.class);
// Output output = new Output(new ByteArrayOutputStream());//new Output(new FileOutputStream("file.bin"));
//
// DefaultTransaction defaultTransaction = new DefaultTransaction();
// defaultTransaction.setXid(new DefaultXid("1", "2", "3"));
//
// kryo.writeObject(output, defaultTransaction);
// output.flush();
// output.close();
Options options = new Options();
options.createIfMissing(true);
options.cacheSize(100 * 1048576); // 100MB cache
options.logger(new org.iq80.leveldb.Logger() {
public void log(String message) {
TransactionLog.REPOSITORY.info(message);
}
});
DB db = Iq80DBFactory.factory.open(new File("txtreedb"), options);
// String stats = db.getProperty("leveldb.stats");
// System.out.println(stats);
DBIterator iterator = null;
try {
iterator = db.iterator();
for(iterator.seekToFirst(); iterator.hasNext(); iterator.next()) {
String key = Iq80DBFactory.asString(iterator.peekNext().getKey());
Transaction value = (Transaction) SerializationUtil.deserialize(iterator.peekNext().getValue());
System.out.println(key+" = "+value);
}
} finally {
if (iterator != null) {
iterator.close();
}
}
// String transactionId = "f282205a-e794-4bda-83a2-bb28b8839cad";
// Input input = new Input(db.get(Iq80DBFactory.bytes(transactionId)));
// Transaction transaction = (Transaction) kryo.readClassAndObject(input);
// System.out.println(transaction);
}
Example 7
| Source File: StandaloneStoreClient.java From warp10-platform with Apache License 2.0 | 4 votes |
|
@Override
public long delete(WriteToken token, Metadata metadata, long start, long end) throws IOException {
//
// Regen classId/labelsId
//
// 128BITS
metadata.setLabelsId(GTSHelper.labelsId(this.keystore.getKey(KeyStore.SIPHASH_LABELS), metadata.getLabels()));
metadata.setClassId(GTSHelper.classId(this.keystore.getKey(KeyStore.SIPHASH_CLASS), metadata.getName()));
//
// Retrieve an iterator
//
DBIterator iterator = this.db.iterator();
//
// Seek the most recent key
//
// 128BITS
byte[] bend = new byte[Constants.HBASE_RAW_DATA_KEY_PREFIX.length + 8 + 8 + 8];
ByteBuffer bb = ByteBuffer.wrap(bend).order(ByteOrder.BIG_ENDIAN);
bb.put(Constants.HBASE_RAW_DATA_KEY_PREFIX);
bb.putLong(metadata.getClassId());
bb.putLong(metadata.getLabelsId());
bb.putLong(Long.MAX_VALUE - end);
iterator.seek(bend);
byte[] bstart = new byte[bend.length];
bb = ByteBuffer.wrap(bstart).order(ByteOrder.BIG_ENDIAN);
bb.put(Constants.HBASE_RAW_DATA_KEY_PREFIX);
bb.putLong(metadata.getClassId());
bb.putLong(metadata.getLabelsId());
bb.putLong(Long.MAX_VALUE - start);
//
// Scan the iterator, deleting keys if they are between start and end
//
long count = 0L;
WriteBatch batch = this.db.createWriteBatch();
int batchsize = 0;
WriteOptions options = new WriteOptions().sync(1.0 == syncrate);
while (iterator.hasNext()) {
Entry<byte[],byte[]> entry = iterator.next();
if (Bytes.compareTo(entry.getKey(), bend) >= 0 && Bytes.compareTo(entry.getKey(), bstart) <= 0) {
batch.delete(entry.getKey());
batchsize++;
if (MAX_DELETE_BATCHSIZE <= batchsize) {
if (syncwrites) {
options = new WriteOptions().sync(Math.random() < syncrate);
}
this.db.write(batch, options);
batch.close();
batch = this.db.createWriteBatch();
batchsize = 0;
}
//this.db.delete(entry.getKey());
count++;
} else {
break;
}
}
if (batchsize > 0) {
if (syncwrites) {
options = new WriteOptions().sync(Math.random() < syncrate);
}
this.db.write(batch, options);
}
iterator.close();
batch.close();
return count;
}
Example 8
| Source File: EzLevelDbTable.java From ezdb with Apache License 2.0 | 4 votes |
|
@Override
public TableIterator<H, R, V> range(H hashKey) {
final DBIterator iterator = db.iterator();
final byte[] keyBytesFrom = Util.combine(hashKeySerde, rangeKeySerde,
hashKey, null);
iterator.seek(keyBytesFrom);
return new AutoClosingTableIterator<H, R, V>(
new TableIterator<H, R, V>() {
@Override
public boolean hasNext() {
return iterator.hasNext()
&& Util.compareKeys(hashKeyComparator, null,
keyBytesFrom, iterator.peekNext()
.getKey()) == 0;
}
@Override
public TableRow<H, R, V> next() {
if(hasNext()) {
return new RawTableRow<H, R, V>(iterator.next(),
hashKeySerde, rangeKeySerde, valueSerde);
}else {
throw new NoSuchElementException();
}
}
@Override
public void remove() {
iterator.remove();
}
@Override
public void close() {
try {
iterator.close();
} catch (Exception e) {
throw new DbException(e);
}
}
});
}
Example 9
| Source File: EzLevelDbTable.java From ezdb with Apache License 2.0 | 4 votes |
|
@Override
public TableIterator<H, R, V> range(H hashKey, R fromRangeKey) {
if (fromRangeKey == null) {
return range(hashKey);
}
final DBIterator iterator = db.iterator();
final byte[] keyBytesFrom = Util.combine(hashKeySerde, rangeKeySerde,
hashKey, fromRangeKey);
iterator.seek(keyBytesFrom);
return new AutoClosingTableIterator<H, R, V>(
new TableIterator<H, R, V>() {
@Override
public boolean hasNext() {
return iterator.hasNext()
&& Util.compareKeys(hashKeyComparator, null,
keyBytesFrom, iterator.peekNext()
.getKey()) == 0;
}
@Override
public TableRow<H, R, V> next() {
if(hasNext()) {
return new RawTableRow<H, R, V>(iterator.next(),
hashKeySerde, rangeKeySerde, valueSerde);
}else {
throw new NoSuchElementException();
}
}
@Override
public void remove() {
iterator.remove();
}
@Override
public void close() {
try {
iterator.close();
} catch (Exception e) {
throw new DbException(e);
}
}
});
}
Example 10
| Source File: EzLevelDbTable.java From ezdb with Apache License 2.0 | 4 votes |
|
@Override
public TableIterator<H, R, V> range(H hashKey, R fromRangeKey, R toRangeKey) {
if (toRangeKey == null) {
return range(hashKey, fromRangeKey);
}
final DBIterator iterator = db.iterator();
final byte[] keyBytesFrom = Util.combine(hashKeySerde, rangeKeySerde,
hashKey, fromRangeKey);
final byte[] keyBytesTo = Util.combine(hashKeySerde, rangeKeySerde,
hashKey, toRangeKey);
iterator.seek(keyBytesFrom);
return new AutoClosingTableIterator<H, R, V>(
new TableIterator<H, R, V>() {
@Override
public boolean hasNext() {
return iterator.hasNext()
&& Util.compareKeys(hashKeyComparator,
rangeKeyComparator, keyBytesTo,
iterator.peekNext().getKey()) >= 0;
}
@Override
public TableRow<H, R, V> next() {
if(hasNext()) {
return new RawTableRow<H, R, V>(iterator.next(),
hashKeySerde, rangeKeySerde, valueSerde);
}else {
throw new NoSuchElementException();
}
}
@Override
public void remove() {
iterator.remove();
}
@Override
public void close() {
try {
iterator.close();
} catch (Exception e) {
throw new DbException(e);
}
}
});
}
