Examples with PagesListSetNextRecord org.apache.ignite.internal.pagemem.wal.record.delta.PagesListSetNextRecord used on opensource projects

Example 6 with PagesListSetNextRecord

use of org.apache.ignite.internal.pagemem.wal.record.delta.PagesListSetNextRecord in project ignite by apache.

the class PagesList method fairMerge.

/**
 * Link previous and next to each other.
 * @param prevId Previous Previous page ID.
 * @param pageId Page ID.
 * @param nextId Next page ID.
 * @param nextPage Next page absolute pointer.
 * @param nextAddr Next page address.
 * @param statHolder Statistics holder to track IO operations.
 * @throws IgniteCheckedException If failed.
 */
private void fairMerge(final long prevId, long pageId, long nextId, long nextPage, long nextAddr, IoStatisticsHolder statHolder) throws IgniteCheckedException {
    long prevPage = acquirePage(prevId, statHolder);
    try {
        // No check, we keep a reference.
        final long prevAddr = writeLock(prevId, prevPage);
        assert prevAddr != 0L;
        try {
            PagesListNodeIO prevIO = PagesListNodeIO.VERSIONS.forPage(prevAddr);
            PagesListNodeIO nextIO = PagesListNodeIO.VERSIONS.forPage(nextAddr);
            // These references must be updated at the same time in write locks.
            assert prevIO.getNextId(prevAddr) == pageId;
            assert nextIO.getPreviousId(nextAddr) == pageId;
            prevIO.setNextId(prevAddr, nextId);
            if (needWalDeltaRecord(prevId, prevPage, null))
                wal.log(new PagesListSetNextRecord(grpId, prevId, nextId));
            nextIO.setPreviousId(nextAddr, prevId);
            if (needWalDeltaRecord(nextId, nextPage, null))
                wal.log(new PagesListSetPreviousRecord(grpId, nextId, prevId));
        } finally {
            writeUnlock(prevId, prevPage, prevAddr, true);
        }
    } finally {
        releasePage(prevId, prevPage);
    }
}

Example 7 with PagesListSetNextRecord

use of org.apache.ignite.internal.pagemem.wal.record.delta.PagesListSetNextRecord in project ignite by apache.

the class PagesList method handlePageFull.

/**
     * @param pageId Page ID.
     * @param page Page pointer.
     * @param pageAddr Page address.
     * @param io IO.
     * @param dataId Data page ID.
     * @param data Data page pointer.
     * @param dataAddr Data page address.
     * @param bucket Bucket index.
     * @throws IgniteCheckedException If failed.
     * */
private void handlePageFull(final long pageId, final long page, final long pageAddr, PagesListNodeIO io, final long dataId, final long data, final long dataAddr, int bucket) throws IgniteCheckedException {
    DataPageIO dataIO = DataPageIO.VERSIONS.forPage(dataAddr);
    // Attempt to add page failed: the node page is full.
    if (isReuseBucket(bucket)) {
        // We can put only empty data pages to reuse bucket.
        assert dataIO.isEmpty(dataAddr);
        // Change page type to index and add it as next node page to this list.
        long newDataId = PageIdUtils.changeType(dataId, FLAG_IDX);
        setupNextPage(io, pageId, pageAddr, newDataId, dataAddr);
        if (needWalDeltaRecord(pageId, page, null))
            wal.log(new PagesListSetNextRecord(cacheId, pageId, newDataId));
        if (needWalDeltaRecord(dataId, data, null))
            wal.log(new PagesListInitNewPageRecord(cacheId, dataId, io.getType(), io.getVersion(), newDataId, pageId, 0L));
        // In reuse bucket the page itself can be used as a free page.
        bucketsSize[bucket].incrementAndGet();
        updateTail(bucket, pageId, newDataId);
    } else {
        // Just allocate a new node page and add our data page there.
        final long nextId = allocatePage(null);
        final long nextPage = acquirePage(nextId);
        try {
            // Newly allocated page.
            long nextPageAddr = writeLock(nextId, nextPage);
            assert nextPageAddr != 0L;
            // Here we should never write full page, because it is known to be new.
            Boolean nextWalPlc = FALSE;
            try {
                setupNextPage(io, pageId, pageAddr, nextId, nextPageAddr);
                if (needWalDeltaRecord(pageId, page, null))
                    wal.log(new PagesListSetNextRecord(cacheId, pageId, nextId));
                int idx = io.addPage(nextPageAddr, dataId, pageSize());
                if (needWalDeltaRecord(nextId, nextPage, nextWalPlc))
                    wal.log(new PagesListInitNewPageRecord(cacheId, nextId, io.getType(), io.getVersion(), nextId, pageId, dataId));
                assert idx != -1;
                dataIO.setFreeListPageId(dataAddr, nextId);
                if (needWalDeltaRecord(dataId, data, null))
                    wal.log(new DataPageSetFreeListPageRecord(cacheId, dataId, nextId));
                bucketsSize[bucket].incrementAndGet();
                updateTail(bucket, pageId, nextId);
            } finally {
                writeUnlock(nextId, nextPage, nextPageAddr, nextWalPlc, true);
            }
        } finally {
            releasePage(nextId, nextPage);
        }
    }
}

Example 8 with PagesListSetNextRecord

use of org.apache.ignite.internal.pagemem.wal.record.delta.PagesListSetNextRecord in project ignite by apache.

the class PagesList method fairMerge.

/**
     * Link previous and next to each other.
     * @param prevId Previous Previous page ID.
     * @param pageId Page ID.
     * @param nextId Next page ID.
     * @param nextPage Next page absolute pointer.
     * @param nextAddr Next page address.
     * @throws IgniteCheckedException If failed.
     */
private void fairMerge(final long prevId, long pageId, long nextId, long nextPage, long nextAddr) throws IgniteCheckedException {
    long prevPage = acquirePage(prevId);
    try {
        // No check, we keep a reference.
        final long prevAddr = writeLock(prevId, prevPage);
        assert prevAddr != 0L;
        try {
            PagesListNodeIO prevIO = PagesListNodeIO.VERSIONS.forPage(prevAddr);
            PagesListNodeIO nextIO = PagesListNodeIO.VERSIONS.forPage(nextAddr);
            // These references must be updated at the same time in write locks.
            assert prevIO.getNextId(prevAddr) == pageId;
            assert nextIO.getPreviousId(nextAddr) == pageId;
            prevIO.setNextId(prevAddr, nextId);
            if (needWalDeltaRecord(prevId, prevPage, null))
                wal.log(new PagesListSetNextRecord(cacheId, prevId, nextId));
            nextIO.setPreviousId(nextAddr, prevId);
            if (needWalDeltaRecord(nextId, nextPage, null))
                wal.log(new PagesListSetPreviousRecord(cacheId, nextId, prevId));
        } finally {
            writeUnlock(prevId, prevPage, prevAddr, true);
        }
    } finally {
        releasePage(prevId, prevPage);
    }
}

Example 9 with PagesListSetNextRecord

use of org.apache.ignite.internal.pagemem.wal.record.delta.PagesListSetNextRecord in project ignite by apache.

the class RecordDataV1Serializer method readRecord.

/**
 * {@inheritDoc}
 */
@Override
public WALRecord readRecord(WALRecord.RecordType type, ByteBufferBackedDataInput in) throws IOException, IgniteCheckedException {
    WALRecord res;
    switch(type) {
        case PAGE_RECORD:
            byte[] arr = new byte[pageSize];
            int cacheId = in.readInt();
            long pageId = in.readLong();
            in.readFully(arr);
            res = new PageSnapshot(new FullPageId(pageId, cacheId), arr);
            break;
        case CHECKPOINT_RECORD:
            long msb = in.readLong();
            long lsb = in.readLong();
            boolean hasPtr = in.readByte() != 0;
            int idx = hasPtr ? in.readInt() : 0;
            int off = hasPtr ? in.readInt() : 0;
            int len = hasPtr ? in.readInt() : 0;
            Map<Integer, CacheState> states = readPartitionStates(in);
            boolean end = in.readByte() != 0;
            FileWALPointer walPtr = hasPtr ? new FileWALPointer(idx, off, len) : null;
            CheckpointRecord cpRec = new CheckpointRecord(new UUID(msb, lsb), walPtr, end);
            cpRec.cacheGroupStates(states);
            res = cpRec;
            break;
        case META_PAGE_INIT:
            cacheId = in.readInt();
            pageId = in.readLong();
            int ioType = in.readUnsignedShort();
            int ioVer = in.readUnsignedShort();
            long treeRoot = in.readLong();
            long reuseListRoot = in.readLong();
            res = new MetaPageInitRecord(cacheId, pageId, ioType, ioVer, treeRoot, reuseListRoot);
            break;
        case PARTITION_META_PAGE_UPDATE_COUNTERS:
            cacheId = in.readInt();
            pageId = in.readLong();
            long updCntr = in.readLong();
            long rmvId = in.readLong();
            int partSize = in.readInt();
            long countersPageId = in.readLong();
            byte state = in.readByte();
            int allocatedIdxCandidate = in.readInt();
            res = new MetaPageUpdatePartitionDataRecord(cacheId, pageId, updCntr, rmvId, partSize, countersPageId, state, allocatedIdxCandidate);
            break;
        case MEMORY_RECOVERY:
            long ts = in.readLong();
            res = new MemoryRecoveryRecord(ts);
            break;
        case PARTITION_DESTROY:
            cacheId = in.readInt();
            int partId = in.readInt();
            res = new PartitionDestroyRecord(cacheId, partId);
            break;
        case DATA_RECORD:
            int entryCnt = in.readInt();
            List<DataEntry> entries = new ArrayList<>(entryCnt);
            for (int i = 0; i < entryCnt; i++) entries.add(readDataEntry(in));
            res = new DataRecord(entries, 0L);
            break;
        case METASTORE_DATA_RECORD:
            int strLen = in.readInt();
            byte[] strBytes = new byte[strLen];
            in.readFully(strBytes);
            String key = new String(strBytes);
            int valLen = in.readInt();
            assert valLen >= 0;
            byte[] val;
            if (valLen > 0) {
                val = new byte[valLen];
                in.readFully(val);
            } else
                val = null;
            return new MetastoreDataRecord(key, val);
        case HEADER_RECORD:
            long magic = in.readLong();
            if (magic != HeaderRecord.REGULAR_MAGIC && magic != HeaderRecord.COMPACTED_MAGIC)
                throw new EOFException("Magic is corrupted [actual=" + U.hexLong(magic) + ']');
            int ver = in.readInt();
            res = new HeaderRecord(ver);
            break;
        case DATA_PAGE_INSERT_RECORD:
            {
                cacheId = in.readInt();
                pageId = in.readLong();
                int size = in.readUnsignedShort();
                in.ensure(size);
                byte[] payload = new byte[size];
                in.readFully(payload);
                res = new DataPageInsertRecord(cacheId, pageId, payload);
                break;
            }
        case DATA_PAGE_UPDATE_RECORD:
            {
                cacheId = in.readInt();
                pageId = in.readLong();
                int itemId = in.readInt();
                int size = in.readUnsignedShort();
                in.ensure(size);
                byte[] payload = new byte[size];
                in.readFully(payload);
                res = new DataPageUpdateRecord(cacheId, pageId, itemId, payload);
                break;
            }
        case DATA_PAGE_INSERT_FRAGMENT_RECORD:
            {
                cacheId = in.readInt();
                pageId = in.readLong();
                final long lastLink = in.readLong();
                final int payloadSize = in.readInt();
                final byte[] payload = new byte[payloadSize];
                in.readFully(payload);
                res = new DataPageInsertFragmentRecord(cacheId, pageId, payload, lastLink);
                break;
            }
        case DATA_PAGE_REMOVE_RECORD:
            cacheId = in.readInt();
            pageId = in.readLong();
            int itemId = in.readUnsignedByte();
            res = new DataPageRemoveRecord(cacheId, pageId, itemId);
            break;
        case DATA_PAGE_SET_FREE_LIST_PAGE:
            cacheId = in.readInt();
            pageId = in.readLong();
            long freeListPage = in.readLong();
            res = new DataPageSetFreeListPageRecord(cacheId, pageId, freeListPage);
            break;
        case INIT_NEW_PAGE_RECORD:
            cacheId = in.readInt();
            pageId = in.readLong();
            ioType = in.readUnsignedShort();
            ioVer = in.readUnsignedShort();
            long virtualPageId = in.readLong();
            res = new InitNewPageRecord(cacheId, pageId, ioType, ioVer, virtualPageId);
            break;
        case BTREE_META_PAGE_INIT_ROOT:
            cacheId = in.readInt();
            pageId = in.readLong();
            long rootId = in.readLong();
            res = new MetaPageInitRootRecord(cacheId, pageId, rootId);
            break;
        case BTREE_META_PAGE_INIT_ROOT2:
            cacheId = in.readInt();
            pageId = in.readLong();
            long rootId2 = in.readLong();
            int inlineSize = in.readShort();
            res = new MetaPageInitRootInlineRecord(cacheId, pageId, rootId2, inlineSize);
            break;
        case BTREE_META_PAGE_ADD_ROOT:
            cacheId = in.readInt();
            pageId = in.readLong();
            rootId = in.readLong();
            res = new MetaPageAddRootRecord(cacheId, pageId, rootId);
            break;
        case BTREE_META_PAGE_CUT_ROOT:
            cacheId = in.readInt();
            pageId = in.readLong();
            res = new MetaPageCutRootRecord(cacheId, pageId);
            break;
        case BTREE_INIT_NEW_ROOT:
            cacheId = in.readInt();
            pageId = in.readLong();
            rootId = in.readLong();
            ioType = in.readUnsignedShort();
            ioVer = in.readUnsignedShort();
            long leftId = in.readLong();
            long rightId = in.readLong();
            BPlusIO<?> io = BPlusIO.getBPlusIO(ioType, ioVer);
            byte[] rowBytes = new byte[io.getItemSize()];
            in.readFully(rowBytes);
            res = new NewRootInitRecord<>(cacheId, pageId, rootId, (BPlusInnerIO<?>) io, leftId, rowBytes, rightId);
            break;
        case BTREE_PAGE_RECYCLE:
            cacheId = in.readInt();
            pageId = in.readLong();
            long newPageId = in.readLong();
            res = new RecycleRecord(cacheId, pageId, newPageId);
            break;
        case BTREE_PAGE_INSERT:
            cacheId = in.readInt();
            pageId = in.readLong();
            ioType = in.readUnsignedShort();
            ioVer = in.readUnsignedShort();
            int itemIdx = in.readUnsignedShort();
            rightId = in.readLong();
            io = BPlusIO.getBPlusIO(ioType, ioVer);
            rowBytes = new byte[io.getItemSize()];
            in.readFully(rowBytes);
            res = new InsertRecord<>(cacheId, pageId, io, itemIdx, rowBytes, rightId);
            break;
        case BTREE_FIX_LEFTMOST_CHILD:
            cacheId = in.readInt();
            pageId = in.readLong();
            rightId = in.readLong();
            res = new FixLeftmostChildRecord(cacheId, pageId, rightId);
            break;
        case BTREE_FIX_COUNT:
            cacheId = in.readInt();
            pageId = in.readLong();
            int cnt = in.readUnsignedShort();
            res = new FixCountRecord(cacheId, pageId, cnt);
            break;
        case BTREE_PAGE_REPLACE:
            cacheId = in.readInt();
            pageId = in.readLong();
            ioType = in.readUnsignedShort();
            ioVer = in.readUnsignedShort();
            itemIdx = in.readUnsignedShort();
            io = BPlusIO.getBPlusIO(ioType, ioVer);
            rowBytes = new byte[io.getItemSize()];
            in.readFully(rowBytes);
            res = new ReplaceRecord<>(cacheId, pageId, io, rowBytes, itemIdx);
            break;
        case BTREE_PAGE_REMOVE:
            cacheId = in.readInt();
            pageId = in.readLong();
            itemIdx = in.readUnsignedShort();
            cnt = in.readUnsignedShort();
            res = new RemoveRecord(cacheId, pageId, itemIdx, cnt);
            break;
        case BTREE_PAGE_INNER_REPLACE:
            cacheId = in.readInt();
            pageId = in.readLong();
            int dstIdx = in.readUnsignedShort();
            long srcPageId = in.readLong();
            int srcIdx = in.readUnsignedShort();
            rmvId = in.readLong();
            res = new InnerReplaceRecord<>(cacheId, pageId, dstIdx, srcPageId, srcIdx, rmvId);
            break;
        case BTREE_FORWARD_PAGE_SPLIT:
            cacheId = in.readInt();
            pageId = in.readLong();
            long fwdId = in.readLong();
            ioType = in.readUnsignedShort();
            ioVer = in.readUnsignedShort();
            srcPageId = in.readLong();
            int mid = in.readUnsignedShort();
            cnt = in.readUnsignedShort();
            res = new SplitForwardPageRecord(cacheId, pageId, fwdId, ioType, ioVer, srcPageId, mid, cnt);
            break;
        case BTREE_EXISTING_PAGE_SPLIT:
            cacheId = in.readInt();
            pageId = in.readLong();
            mid = in.readUnsignedShort();
            fwdId = in.readLong();
            res = new SplitExistingPageRecord(cacheId, pageId, mid, fwdId);
            break;
        case BTREE_PAGE_MERGE:
            cacheId = in.readInt();
            pageId = in.readLong();
            long prntId = in.readLong();
            int prntIdx = in.readUnsignedShort();
            rightId = in.readLong();
            boolean emptyBranch = in.readBoolean();
            res = new MergeRecord<>(cacheId, pageId, prntId, prntIdx, rightId, emptyBranch);
            break;
        case BTREE_FIX_REMOVE_ID:
            cacheId = in.readInt();
            pageId = in.readLong();
            rmvId = in.readLong();
            res = new FixRemoveId(cacheId, pageId, rmvId);
            break;
        case PAGES_LIST_SET_NEXT:
            cacheId = in.readInt();
            pageId = in.readLong();
            long nextPageId = in.readLong();
            res = new PagesListSetNextRecord(cacheId, pageId, nextPageId);
            break;
        case PAGES_LIST_SET_PREVIOUS:
            cacheId = in.readInt();
            pageId = in.readLong();
            long prevPageId = in.readLong();
            res = new PagesListSetPreviousRecord(cacheId, pageId, prevPageId);
            break;
        case PAGES_LIST_INIT_NEW_PAGE:
            cacheId = in.readInt();
            pageId = in.readLong();
            ioType = in.readInt();
            ioVer = in.readInt();
            newPageId = in.readLong();
            prevPageId = in.readLong();
            long addDataPageId = in.readLong();
            res = new PagesListInitNewPageRecord(cacheId, pageId, ioType, ioVer, newPageId, prevPageId, addDataPageId);
            break;
        case PAGES_LIST_ADD_PAGE:
            cacheId = in.readInt();
            pageId = in.readLong();
            long dataPageId = in.readLong();
            res = new PagesListAddPageRecord(cacheId, pageId, dataPageId);
            break;
        case PAGES_LIST_REMOVE_PAGE:
            cacheId = in.readInt();
            pageId = in.readLong();
            long rmvdPageId = in.readLong();
            res = new PagesListRemovePageRecord(cacheId, pageId, rmvdPageId);
            break;
        case TRACKING_PAGE_DELTA:
            cacheId = in.readInt();
            pageId = in.readLong();
            long pageIdToMark = in.readLong();
            long nextSnapshotId0 = in.readLong();
            long lastSuccessfulSnapshotId0 = in.readLong();
            res = new TrackingPageDeltaRecord(cacheId, pageId, pageIdToMark, nextSnapshotId0, lastSuccessfulSnapshotId0);
            break;
        case META_PAGE_UPDATE_NEXT_SNAPSHOT_ID:
            cacheId = in.readInt();
            pageId = in.readLong();
            long nextSnapshotId = in.readLong();
            res = new MetaPageUpdateNextSnapshotId(cacheId, pageId, nextSnapshotId);
            break;
        case META_PAGE_UPDATE_LAST_SUCCESSFUL_FULL_SNAPSHOT_ID:
            cacheId = in.readInt();
            pageId = in.readLong();
            long lastSuccessfulFullSnapshotId = in.readLong();
            res = new MetaPageUpdateLastSuccessfulFullSnapshotId(cacheId, pageId, lastSuccessfulFullSnapshotId);
            break;
        case META_PAGE_UPDATE_LAST_SUCCESSFUL_SNAPSHOT_ID:
            cacheId = in.readInt();
            pageId = in.readLong();
            long lastSuccessfulSnapshotId = in.readLong();
            long lastSuccessfulSnapshotTag = in.readLong();
            res = new MetaPageUpdateLastSuccessfulSnapshotId(cacheId, pageId, lastSuccessfulSnapshotId, lastSuccessfulSnapshotTag);
            break;
        case META_PAGE_UPDATE_LAST_ALLOCATED_INDEX:
            cacheId = in.readInt();
            pageId = in.readLong();
            int lastAllocatedIdx = in.readInt();
            res = new MetaPageUpdateLastAllocatedIndex(cacheId, pageId, lastAllocatedIdx);
            break;
        case PART_META_UPDATE_STATE:
            cacheId = in.readInt();
            partId = in.readInt();
            state = in.readByte();
            long updateCntr = in.readLong();
            GridDhtPartitionState partState = GridDhtPartitionState.fromOrdinal(state);
            res = new PartitionMetaStateRecord(cacheId, partId, partState, updateCntr);
            break;
        case PAGE_LIST_META_RESET_COUNT_RECORD:
            cacheId = in.readInt();
            pageId = in.readLong();
            res = new PageListMetaResetCountRecord(cacheId, pageId);
            break;
        case SWITCH_SEGMENT_RECORD:
            throw new EOFException("END OF SEGMENT");
        case TX_RECORD:
            res = txRecordSerializer.read(in);
            break;
        default:
            throw new UnsupportedOperationException("Type: " + type);
    }
    return res;
}

Example 10 with PagesListSetNextRecord

use of org.apache.ignite.internal.pagemem.wal.record.delta.PagesListSetNextRecord in project ignite by apache.

the class PagesList method putReuseBag.

/**
 * @param pageId Page ID.
 * @param page Page pointer.
 * @param pageAddr Page address.
 * @param io IO.
 * @param bag Reuse bag.
 * @param bucket Bucket.
 * @return {@code true} If succeeded.
 * @throws IgniteCheckedException if failed.
 */
@SuppressWarnings("ForLoopReplaceableByForEach")
private boolean putReuseBag(final long pageId, final long page, final long pageAddr, PagesListNodeIO io, ReuseBag bag, int bucket) throws IgniteCheckedException {
    assert bag != null : "bag is null";
    assert !bag.isEmpty() : "bag is empty";
    if (io.getNextId(pageAddr) != 0L)
        // Splitted.
        return false;
    long nextId;
    long prevId = pageId;
    long prevPage = page;
    long prevAddr = pageAddr;
    Boolean walPlc = null;
    // TODO may be unlock right away and do not keep all these pages locked?
    GridLongList locked = null;
    try {
        while ((nextId = bag.pollFreePage()) != 0L) {
            int idx = io.addPage(prevAddr, nextId, pageSize());
            if (idx == -1) {
                // Attempt to add page failed: the node page is full.
                final long nextPage = acquirePage(nextId);
                try {
                    // Page from reuse bag can't be concurrently recycled.
                    long nextPageAddr = writeLock(nextId, nextPage);
                    assert nextPageAddr != 0L;
                    if (locked == null)
                        locked = new GridLongList(6);
                    locked.add(nextId);
                    locked.add(nextPage);
                    locked.add(nextPageAddr);
                    setupNextPage(io, prevId, prevAddr, nextId, nextPageAddr);
                    if (needWalDeltaRecord(prevId, prevPage, walPlc))
                        wal.log(new PagesListSetNextRecord(grpId, prevId, nextId));
                    // Here we should never write full page, because it is known to be new.
                    if (needWalDeltaRecord(nextId, nextPage, FALSE))
                        wal.log(new PagesListInitNewPageRecord(grpId, nextId, io.getType(), io.getVersion(), nextId, prevId, 0L));
                    // In reuse bucket the page itself can be used as a free page.
                    if (isReuseBucket(bucket))
                        incrementBucketSize(bucket);
                    // Switch to this new page, which is now a part of our list
                    // to add the rest of the bag to the new page.
                    prevAddr = nextPageAddr;
                    prevId = nextId;
                    prevPage = nextPage;
                    // Starting from tis point all wal records are written for reused pages from the bag.
                    // This mean that we use delta records only.
                    walPlc = FALSE;
                } finally {
                    releasePage(nextId, nextPage);
                }
            } else {
                // TODO: use single WAL record for bag?
                if (needWalDeltaRecord(prevId, prevPage, walPlc))
                    wal.log(new PagesListAddPageRecord(grpId, prevId, nextId));
                incrementBucketSize(bucket);
            }
        }
    } finally {
        if (locked != null) {
            // We have to update our bucket with the new tail.
            updateTail(bucket, pageId, prevId);
            // Release write.
            for (int i = 0; i < locked.size(); i += 3) writeUnlock(locked.get(i), locked.get(i + 1), locked.get(i + 2), FALSE, true);
        }
    }
    return true;
}