@Override
  public Set<Object> loadAllKeys(Set<Object> keysToExclude) throws CacheLoaderException {
    Cassandra.Client cassandraClient = null;
    try {
      cassandraClient = dataSource.getConnection();
      Set<Object> s = new HashSet<Object>();
      SlicePredicate slicePredicate = new SlicePredicate();
      slicePredicate.setSlice_range(
          new SliceRange(
              ByteBuffer.wrap(entryColumnPath.getColumn()),
              ByteBufferUtil.EMPTY_BYTE_BUFFER,
              false,
              1));
      String startKey = "";
      boolean complete = false;
      // Get the keys in SLICE_SIZE blocks
      while (!complete) {
        KeyRange keyRange = new KeyRange(SLICE_SIZE);
        keyRange.setStart_token(startKey);
        keyRange.setEnd_token("");
        List<KeySlice> keySlices =
            cassandraClient.get_range_slices(
                entryColumnParent, slicePredicate, keyRange, readConsistencyLevel);
        if (keySlices.size() < SLICE_SIZE) {
          complete = true;
        } else {
          startKey = new String(keySlices.get(keySlices.size() - 1).getKey(), UTF8Charset);
        }

        for (KeySlice keySlice : keySlices) {
          if (keySlice.getColumnsSize() > 0) {
            Object key = unhashKey(keySlice.getKey());
            if (key != null && (keysToExclude == null || !keysToExclude.contains(key))) s.add(key);
          }
        }
      }
      return s;
    } catch (Exception e) {
      throw new CacheLoaderException(e);
    } finally {
      dataSource.releaseConnection(cassandraClient);
    }
  }
  @Override
  public void clear() throws CacheLoaderException {
    Cassandra.Client cassandraClient = null;
    try {
      cassandraClient = dataSource.getConnection();
      SlicePredicate slicePredicate = new SlicePredicate();
      slicePredicate.setSlice_range(
          new SliceRange(
              ByteBuffer.wrap(entryColumnPath.getColumn()),
              ByteBufferUtil.EMPTY_BYTE_BUFFER,
              false,
              1));
      String startKey = "";
      boolean complete = false;
      // Get the keys in SLICE_SIZE blocks
      while (!complete) {
        KeyRange keyRange = new KeyRange(SLICE_SIZE);
        keyRange.setStart_token(startKey);
        keyRange.setEnd_token("");
        List<KeySlice> keySlices =
            cassandraClient.get_range_slices(
                entryColumnParent, slicePredicate, keyRange, readConsistencyLevel);
        if (keySlices.size() < SLICE_SIZE) {
          complete = true;
        } else {
          startKey = new String(keySlices.get(keySlices.size() - 1).getKey(), UTF8Charset);
        }
        Map<ByteBuffer, Map<String, List<Mutation>>> mutationMap =
            new HashMap<ByteBuffer, Map<String, List<Mutation>>>();

        for (KeySlice keySlice : keySlices) {
          remove0(ByteBuffer.wrap(keySlice.getKey()), mutationMap);
        }
        cassandraClient.batch_mutate(mutationMap, ConsistencyLevel.ALL);
      }
    } catch (Exception e) {
      throw new CacheLoaderException(e);
    } finally {
      dataSource.releaseConnection(cassandraClient);
    }
  }
  @Override
  public Set<InternalCacheEntry> load(int numEntries) throws CacheLoaderException {
    Cassandra.Client cassandraClient = null;
    try {
      cassandraClient = dataSource.getConnection();
      Set<InternalCacheEntry> s = new HashSet<InternalCacheEntry>();
      SlicePredicate slicePredicate = new SlicePredicate();
      slicePredicate.setSlice_range(
          new SliceRange(
              ByteBuffer.wrap(entryColumnPath.getColumn()),
              ByteBufferUtil.EMPTY_BYTE_BUFFER,
              false,
              1));
      String startKey = "";

      // Get the keys in SLICE_SIZE blocks
      int sliceSize = Math.min(SLICE_SIZE, numEntries);
      for (boolean complete = false; !complete; ) {
        KeyRange keyRange = new KeyRange(sliceSize);
        keyRange.setStart_token(startKey);
        keyRange.setEnd_token("");
        List<KeySlice> keySlices =
            cassandraClient.get_range_slices(
                entryColumnParent, slicePredicate, keyRange, readConsistencyLevel);

        // Cycle through all the keys
        for (KeySlice keySlice : keySlices) {
          Object key = unhashKey(keySlice.getKey());
          if (key == null) // Skip invalid keys
          continue;
          List<ColumnOrSuperColumn> columns = keySlice.getColumns();
          if (columns.size() > 0) {
            if (log.isDebugEnabled()) {
              log.debugf("Loading %s", key);
            }
            byte[] value = columns.get(0).getColumn().getValue();
            InternalCacheEntry ice = unmarshall(value, key);
            s.add(ice);
          } else if (log.isDebugEnabled()) {
            log.debugf("Skipping empty key %s", key);
          }
        }
        if (keySlices.size() < sliceSize) {
          // Cassandra has returned less keys than what we asked for.
          // Assume we have finished
          complete = true;
        } else {
          // Cassandra has returned exactly the amount of keys we
          // asked for. If we haven't reached the required quota yet,
          // assume we need to cycle again starting from
          // the last returned key (excluded)
          sliceSize = Math.min(SLICE_SIZE, numEntries - s.size());
          if (sliceSize == 0) {
            complete = true;
          } else {
            startKey = new String(keySlices.get(keySlices.size() - 1).getKey(), UTF8Charset);
          }
        }
      }
      return s;
    } catch (Exception e) {
      throw new CacheLoaderException(e);
    } finally {
      dataSource.releaseConnection(cassandraClient);
    }
  }