Examples with DBIterator org.iq80.leveldb.DBIterator used on opensource projects

Example 6 with DBIterator

use of org.iq80.leveldb.DBIterator in project cdap by caskdata.

the class LevelDBTableCore method deleteRows.

public void deleteRows(byte[] prefix) throws IOException {
    Preconditions.checkNotNull(prefix, "prefix must not be null");
    DB db = getDB();
    WriteBatch batch = db.createWriteBatch();
    try (DBIterator iterator = db.iterator()) {
        iterator.seek(createStartKey(prefix));
        while (iterator.hasNext()) {
            Map.Entry<byte[], byte[]> entry = iterator.next();
            if (!Bytes.startsWith(KeyValue.fromKey(entry.getKey()).getRow(), prefix)) {
                // iterator is past prefix
                break;
            }
            batch.delete(entry.getKey());
        }
        db.write(batch);
    }
}

Example 7 with DBIterator

use of org.iq80.leveldb.DBIterator in project cdap by caskdata.

the class LevelDBTableCore method deleteRange.

public void deleteRange(byte[] startRow, byte[] stopRow, @Nullable FuzzyRowFilter filter, @Nullable byte[][] columns) throws IOException {
    if (columns != null) {
        if (columns.length == 0) {
            return;
        }
        columns = Arrays.copyOf(columns, columns.length);
        Arrays.sort(columns, Bytes.BYTES_COMPARATOR);
    }
    DB db = getDB();
    DBIterator iterator = db.iterator();
    seekToStart(iterator, startRow);
    byte[] endKey = stopRow == null ? null : createEndKey(stopRow);
    DBIterator deleteIterator = db.iterator();
    seekToStart(deleteIterator, startRow);
    // todo make configurable
    final int deletesPerRound = 1024;
    try (Scanner scanner = new LevelDBScanner(iterator, endKey, filter, columns, null)) {
        Row rowValues;
        WriteBatch batch = db.createWriteBatch();
        int deletesInBatch = 0;
        // go through all matching cells and delete them in batches.
        while ((rowValues = scanner.next()) != null) {
            byte[] row = rowValues.getRow();
            for (byte[] column : rowValues.getColumns().keySet()) {
                addToDeleteBatch(batch, deleteIterator, row, column);
                deletesInBatch++;
                // perform the deletes when we have built up a batch.
                if (deletesInBatch >= deletesPerRound) {
                    // delete all the entries that were found
                    db.write(batch, getWriteOptions());
                    batch = db.createWriteBatch();
                    deletesInBatch = 0;
                }
            }
        }
        // perform any outstanding deletes
        if (deletesInBatch > 0) {
            db.write(batch, getWriteOptions());
        }
    } finally {
        deleteIterator.close();
    }
}

Example 8 with DBIterator

use of org.iq80.leveldb.DBIterator in project camel by apache.

the class LevelDBAggregationRepository method getKeys.

public Set<String> getKeys() {
    final Set<String> keys = new LinkedHashSet<String>();
    // interval task could potentially be running while we are shutting down so check for that
    if (!isRunAllowed()) {
        return null;
    }
    DBIterator it = levelDBFile.getDb().iterator();
    String keyBuffer;
    try {
        String prefix = repositoryName + '\0';
        for (it.seek(keyBuilder(repositoryName, "")); it.hasNext(); it.next()) {
            if (!isRunAllowed()) {
                break;
            }
            keyBuffer = asString(it.peekNext().getKey());
            if (!keyBuffer.startsWith(prefix)) {
                break;
            }
            String key = keyBuffer.substring(prefix.length());
            LOG.trace("getKey [{}]", key);
            keys.add(key);
        }
    } finally {
        // Make sure you close the iterator to avoid resource leaks.
        IOHelper.close(it);
    }
    return Collections.unmodifiableSet(keys);
}

Example 9 with DBIterator

use of org.iq80.leveldb.DBIterator in project camel by apache.

the class LevelDBAggregationRepository method scan.

public Set<String> scan(CamelContext camelContext) {
    final Set<String> answer = new LinkedHashSet<String>();
    if (!isRunAllowed()) {
        return null;
    }
    DBIterator it = levelDBFile.getDb().iterator();
    String keyBuffer;
    try {
        String prefix = getRepositoryNameCompleted() + '\0';
        for (it.seek(keyBuilder(getRepositoryNameCompleted(), "")); it.hasNext(); it.next()) {
            keyBuffer = asString(it.peekNext().getKey());
            if (!keyBuffer.startsWith(prefix)) {
                break;
            }
            String exchangeId = keyBuffer.substring(prefix.length());
            LOG.trace("Scan exchangeId [{}]", exchangeId);
            answer.add(exchangeId);
        }
    } finally {
        // Make sure you close the iterator to avoid resource leaks.
        IOHelper.close(it);
    }
    if (answer.size() == 0) {
        LOG.trace("Scanned and found no exchange to recover.");
    } else {
        if (LOG.isDebugEnabled()) {
            LOG.debug("Scanned and found {} exchange(s) to recover (note some of them may already be in progress).", answer.size());
        }
    }
    return answer;
}

Example 10 with DBIterator

use of org.iq80.leveldb.DBIterator in project hadoop by apache.

the class RollingLevelDBTimelineStore method getDomain.

@Override
public TimelineDomain getDomain(String domainId) throws IOException {
    DBIterator iterator = null;
    try {
        byte[] prefix = KeyBuilder.newInstance().add(domainId).getBytesForLookup();
        iterator = domaindb.iterator();
        iterator.seek(prefix);
        return getTimelineDomain(iterator, domainId, prefix);
    } finally {
        IOUtils.cleanup(LOG, iterator);
    }
}