/**
   * Waits for renting partitions.
   *
   * @return {@code True} if mapping was changed.
   * @throws IgniteCheckedException If failed.
   */
  private boolean waitForRent() throws IgniteCheckedException {
    boolean changed = false;

    // Synchronously wait for all renting partitions to complete.
    for (Iterator<GridDhtLocalPartition> it = locParts.values().iterator(); it.hasNext(); ) {
      GridDhtLocalPartition p = it.next();

      GridDhtPartitionState state = p.state();

      if (state == RENTING || state == EVICTED) {
        if (log.isDebugEnabled()) log.debug("Waiting for renting partition: " + p);

        // Wait for partition to empty out.
        p.rent(true).get();

        if (log.isDebugEnabled()) log.debug("Finished waiting for renting partition: " + p);

        // Remove evicted partition.
        it.remove();

        changed = true;
      }
    }

    return changed;
  }
  /**
   * @param cancel {@code True} to close with cancellation.
   * @throws GridException If failed.
   */
  @Override
  public void close(boolean cancel) throws GridException {
    if (!closed.compareAndSet(false, true)) return;

    busyLock.block();

    if (log.isDebugEnabled())
      log.debug("Closing data loader [ldr=" + this + ", cancel=" + cancel + ']');

    GridException e = null;

    try {
      // Assuming that no methods are called on this loader after this method is called.
      if (cancel) {
        cancelled = true;

        for (Buffer buf : bufMappings.values()) buf.cancelAll();
      } else doFlush();

      ctx.event().removeLocalEventListener(discoLsnr);

      ctx.io().removeMessageListener(topic);
    } catch (GridException e0) {
      e = e0;
    }

    fut.onDone(null, e);

    if (e != null) throw e;
  }
  /**
   * Flushes every internal buffer if buffer was flushed before passed in threshold.
   *
   * <p>Does not wait for result and does not fail on errors assuming that this method should be
   * called periodically.
   */
  @Override
  public void tryFlush() throws GridInterruptedException {
    if (!busyLock.enterBusy()) return;

    try {
      for (Buffer buf : bufMappings.values()) buf.flush();

      lastFlushTime = U.currentTimeMillis();
    } finally {
      leaveBusy();
    }
  }
  /** {@inheritDoc} */
  @Override
  void onCancelAtStop() {
    super.onCancelAtStop();

    for (GridCacheQueryFutureAdapter fut : futs.values())
      try {
        fut.cancel();
      } catch (IgniteCheckedException e) {
        U.error(log, "Failed to cancel running query future: " + fut, e);
      }

    U.interrupt(threads.values());
  }
  /** {@inheritDoc} */
  @Override
  public void printMemoryStats(int threshold) {
    X.println(
        ">>>  Cache partition topology stats [grid="
            + cctx.gridName()
            + ", cache="
            + cctx.name()
            + ']');

    for (GridDhtLocalPartition part : locParts.values()) {
      int size = part.size();

      if (size >= threshold)
        X.println(">>>   Local partition [part=" + part.id() + ", size=" + size + ']');
    }
  }
  /**
   * Performs flush.
   *
   * @throws GridException If failed.
   */
  private void doFlush() throws GridException {
    lastFlushTime = U.currentTimeMillis();

    List<GridFuture> activeFuts0 = null;

    int doneCnt = 0;

    for (GridFuture<?> f : activeFuts) {
      if (!f.isDone()) {
        if (activeFuts0 == null) activeFuts0 = new ArrayList<>((int) (activeFuts.size() * 1.2));

        activeFuts0.add(f);
      } else {
        f.get();

        doneCnt++;
      }
    }

    if (activeFuts0 == null || activeFuts0.isEmpty()) return;

    while (true) {
      Queue<GridFuture<?>> q = null;

      for (Buffer buf : bufMappings.values()) {
        GridFuture<?> flushFut = buf.flush();

        if (flushFut != null) {
          if (q == null) q = new ArrayDeque<>(bufMappings.size() * 2);

          q.add(flushFut);
        }
      }

      if (q != null) {
        assert !q.isEmpty();

        boolean err = false;

        for (GridFuture fut = q.poll(); fut != null; fut = q.poll()) {
          try {
            fut.get();
          } catch (GridException e) {
            if (log.isDebugEnabled()) log.debug("Failed to flush buffer: " + e);

            err = true;
          }
        }

        if (err)
          // Remaps needed - flush buffers.
          continue;
      }

      doneCnt = 0;

      for (int i = 0; i < activeFuts0.size(); i++) {
        GridFuture f = activeFuts0.get(i);

        if (f == null) doneCnt++;
        else if (f.isDone()) {
          f.get();

          doneCnt++;

          activeFuts0.set(i, null);
        } else break;
      }

      if (doneCnt == activeFuts0.size()) return;
    }
  }
  /** Clears values for this partition. */
  private void clearAll() {
    GridCacheVersion clearVer = cctx.versions().next();

    boolean swap = cctx.isSwapOrOffheapEnabled();

    boolean rec = cctx.events().isRecordable(EVT_CACHE_REBALANCE_OBJECT_UNLOADED);

    Iterator<GridDhtCacheEntry> it = map.values().iterator();

    GridCloseableIterator<Map.Entry<byte[], GridCacheSwapEntry>> swapIt = null;

    if (swap
        && GridQueryProcessor.isEnabled(cctx.config())) { // Indexing needs to unswap cache values.
      Iterator<GridDhtCacheEntry> unswapIt = null;

      try {
        swapIt = cctx.swap().iterator(id);
        unswapIt = unswapIterator(swapIt);
      } catch (Exception e) {
        U.error(log, "Failed to clear swap for evicted partition: " + this, e);
      }

      if (unswapIt != null) it = F.concat(it, unswapIt);
    }

    try {
      while (it.hasNext()) {
        GridDhtCacheEntry cached = it.next();

        try {
          if (cached.clearInternal(clearVer, swap)) {
            map.remove(cached.key(), cached);

            if (!cached.isInternal()) {
              mapPubSize.decrement();

              if (rec)
                cctx.events()
                    .addEvent(
                        cached.partition(),
                        cached.key(),
                        cctx.localNodeId(),
                        (IgniteUuid) null,
                        null,
                        EVT_CACHE_REBALANCE_OBJECT_UNLOADED,
                        null,
                        false,
                        cached.rawGet(),
                        cached.hasValue(),
                        null,
                        null,
                        null);
            }
          }
        } catch (IgniteCheckedException e) {
          U.error(log, "Failed to clear cache entry for evicted partition: " + cached, e);
        }
      }
    } finally {
      U.close(swapIt, log);
    }
  }
 /** @return Entries belonging to partition. */
 public Collection<GridDhtCacheEntry> entries() {
   return map.values();
 }
 /** {@inheritDoc} */
 @Override
 public Collection<GridDhtLocalPartition> currentLocalPartitions() {
   return locParts.values();
 }
 /** {@inheritDoc} */
 @Override
 public List<GridDhtLocalPartition> localPartitions() {
   return new LinkedList<>(locParts.values());
 }
  /**
   * @param updateSeq Update sequence.
   * @return Checks if any of the local partitions need to be evicted.
   */
  private boolean checkEvictions(long updateSeq) {
    assert lock.isWriteLockedByCurrentThread();

    boolean changed = false;

    UUID locId = cctx.nodeId();

    for (GridDhtLocalPartition part : locParts.values()) {
      GridDhtPartitionState state = part.state();

      if (state.active()) {
        int p = part.id();

        List<ClusterNode> affNodes = cctx.affinity().nodes(p, topVer);

        if (!affNodes.contains(cctx.localNode())) {
          Collection<UUID> nodeIds = F.nodeIds(nodes(p, topVer, OWNING));

          // If all affinity nodes are owners, then evict partition from local node.
          if (nodeIds.containsAll(F.nodeIds(affNodes))) {
            part.rent(false);

            updateLocal(part.id(), locId, part.state(), updateSeq);

            changed = true;

            if (log.isDebugEnabled())
              log.debug("Evicted local partition (all affinity nodes are owners): " + part);
          } else {
            int ownerCnt = nodeIds.size();
            int affCnt = affNodes.size();

            if (ownerCnt > affCnt) {
              List<ClusterNode> sorted = new ArrayList<>(cctx.discovery().nodes(nodeIds));

              // Sort by node orders in ascending order.
              Collections.sort(sorted, CU.nodeComparator(true));

              int diff = sorted.size() - affCnt;

              for (int i = 0; i < diff; i++) {
                ClusterNode n = sorted.get(i);

                if (locId.equals(n.id())) {
                  part.rent(false);

                  updateLocal(part.id(), locId, part.state(), updateSeq);

                  changed = true;

                  if (log.isDebugEnabled())
                    log.debug(
                        "Evicted local partition (this node is oldest non-affinity node): " + part);

                  break;
                }
              }
            }
          }
        }
      }
    }

    return changed;
  }