/*
 * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
 *
 * This program is free software: you can use, redistribute, and/or modify
 * it under the terms of the GNU Affero General Public License, version 3
 * or later ("AGPL"), as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "tsdb.h"
#define ASCENDING_TRAVERSE(o)      (o == TSDB_ORDER_ASC)
#define QH_GET_NUM_OF_COLS(handle) ((size_t)(taosArrayGetSize((handle)->pColumns)))

#define GET_FILE_DATA_BLOCK_INFO(_checkInfo, _block)                                      \
  ((SDataBlockInfo){.window = {.skey = (_block)->minKey.ts, .ekey = (_block)->maxKey.ts}, \
                    .numOfCols = (_block)->numOfCols,                                     \
                    .rows = (_block)->numOfRows,                                          \
                    .uid = (_checkInfo)->tableId})

enum {
  TSDB_CACHED_TYPE_NONE = 0,
  TSDB_CACHED_TYPE_LASTROW = 1,
  TSDB_CACHED_TYPE_LAST = 2,
};

typedef struct SQueryFilePos {
  int32_t     fid;
  int32_t     slot;
  int32_t     pos;
  int64_t     lastKey;
  int32_t     rows;
  bool        composedBlock;
  bool        blockCompleted;
  STimeWindow win;
} SQueryFilePos;

typedef struct SDataBlockLoadInfo {
  SDFileSet* fileGroup;
  int32_t    slot;
  uint64_t   uid;
  SArray*    pLoadedCols;
} SDataBlockLoadInfo;

enum {
  CHECKINFO_CHOSEN_MEM = 0,
  CHECKINFO_CHOSEN_IMEM = 1,
  CHECKINFO_CHOSEN_BOTH = 2  // for update=2(merge case)
};

typedef struct STableBlockScanInfo {
  uint64_t     uid;
  TSKEY        lastKey;
  SBlockIdx    blockIdx;
  SArray*      pBlockList;        // block data index list
  // SBlockInfo*  pCompInfo;
//  int32_t      compSize;
//  int32_t      numOfBlocks : 29;  // number of qualified data blocks not the original blocks
  uint8_t      chosen : 2;        // indicate which iterator should move forward
  bool         iterInit;       // whether to initialize the in-memory skip list iterator or not
  STbDataIter  iter;              // mem buffer skip list iterator
  STbDataIter  iiter;             // imem buffer skip list iterator
  bool         memHasVal;
  bool         imemHasVal;
} STableBlockScanInfo;

typedef struct SBlockOrderWrapper {
  int64_t uid;
  SBlock* pBlock;
} SBlockOrderWrapper;

typedef struct SBlockOrderSupporter {
  int32_t           numOfTables;
  SBlockOrderWrapper**  pDataBlockInfo;
  int32_t*          indexPerTable;
  int32_t*          numOfBlocksPerTable;
} SBlockOrderSupporter;

typedef struct SIOCostSummary {
  int64_t           blockLoadTime;
  int64_t           statisInfoLoadTime;
  int64_t           checkForNextTime;
  int64_t           headFileLoad;
  int64_t           headFileLoadTime;
} SIOCostSummary;

typedef struct SBlockLoadSuppInfo {
  SColumnDataAgg*   pstatis;
  SColumnDataAgg**  plist;
  int16_t*          colIdList;   // default load column
  int32_t*          slotIds;     // colId to slotId
} SBlockLoadSuppInfo;

typedef struct SFileSetIter {
  int32_t           numOfFiles;  // number of total files
  int32_t           index;       // current accessed index in the list
  SArray*           pFileList;   // data file list
} SFileSetIter;

typedef struct SFileDataBlockInfo {
  int32_t tbBlockIdx;   // index position in STableBlockScanInfo in order to check whether neighbor block overlaps with it
  int64_t uid;
} SFileDataBlockInfo;

typedef struct SDataBlockIter {
  int32_t      numOfBlocks;
  int32_t      index;
  SArray*      blockList;   // SArray<SFileDataBlockInfo>
} SDataBlockIter;

typedef struct SFileBlockDumpInfo {
  int32_t      totalRows;
  int32_t      rowIndex;
  int64_t      lastKey;
} SFileBlockDumpInfo;

typedef struct SComposedDataBlock {
  bool         composed;
  int32_t      rows;
} SComposedDataBlock;

typedef struct SReaderStatus {
  SQueryFilePos  cur;     // current position
  int32_t        tableListIndex;
  bool           loadFromFile;      // check file stage
  bool           initStartPos;
  SHashObj*      pTableMap;         // SHash<STableBlockScanInfo>
  int32_t        realNumOfRows;

  SFileBlockDumpInfo fBlockDumpInfo;
  SBlockData     fileBlockData;

  SFileSetIter   fileIter;
  SDataBlockIter blockIter;
} SReaderStatus;

struct STsdbReader {
  STsdb*             pTsdb;
  uint64_t           suid;
  int16_t            order;
  STimeWindow        window;  // the primary query time window that applies to all queries
  SSDataBlock*       pResBlock;
  int32_t            capacity;
  SReaderStatus      status;
  char*              idStr;                    // query info handle, for debug purpose
  int32_t            type;  // query type: 1. retrieve all data blocks, 2. retrieve direct prev|next rows
  SBlockLoadSuppInfo suppInfo;
  SArray*            prev;  // previous row which is before than time window
  SArray*            next;  // next row which is after the query time window
  SIOCostSummary     cost;
  STSchema*          pSchema;

  SDataFReader*      pFileReader;
  int64_t            startVersion;
  int64_t            endVersion;
#if 0
  SFileBlockInfo*   pDataBlockInfo;
  SDataCols*         pDataCols;         // in order to hold current file data block
  int32_t            allocSize;         // allocated data block size
  SDataBlockLoadInfo dataBlockLoadInfo; /* record current block load information */
  SLoadCompBlockInfo compBlockLoadInfo; /* record current compblock information in SQueryAttr */
  //  SDFileSet* pFileGroup;
  // SFSIter            fileIter;
  // SReadH             rhelper;
  //  SColumnDataAgg* statis;  // query level statistics, only one table block statistics info exists at any time
  //  SColumnDataAgg** pstatis;// the ptr array list to return to caller
#endif
};

static SFileDataBlockInfo* getCurrentBlockInfo(SDataBlockIter* pBlockIter);
static int tsdbReadRowsFromCache(STableBlockScanInfo* pScanInfo, TSDBKEY maxKey, int32_t capacity, STsdbReader* pReader);
static TSDBROW* getValidRow(STbDataIter* pIter, bool* hasVal, STsdbReader* pReader);
static int32_t doLoadRowsOfIdenticalTsInFileBlock(SBlockData* pData, SFileBlockDumpInfo* pDumpInfo, int64_t ts, SRowMerger *pMerger,
                                           STsdbReader* pReader, STSRow** pRow);

// static void tsdbInitDataBlockLoadInfo(SDataBlockLoadInfo* pBlockLoadInfo) {
//   pBlockLoadInfo->slot = -1;
//   pBlockLoadInfo->uid = 0;
//   pBlockLoadInfo->fileGroup = NULL;
// }

// static void tsdbInitCompBlockLoadInfo(SLoadCompBlockInfo* pCompBlockLoadInfo) {
//   pCompBlockLoadInfo->tid = -1;
//   pCompBlockLoadInfo->fileId = -1;
// }

static int32_t setColumnIdList(STsdbReader* pReader, SSDataBlock* pBlock) {
  size_t numOfCols = taosArrayGetSize(pBlock->pDataBlock);
  pReader->suppInfo.colIdList = taosMemoryCalloc(numOfCols, sizeof(int16_t));
  if (pReader->suppInfo.colIdList == NULL) {
    return TSDB_CODE_OUT_OF_MEMORY;
  }

  for (int32_t i = 0; i < numOfCols; ++i) {
    SColumnInfoData* pCol = taosArrayGet(pBlock->pDataBlock, i);
    pReader->suppInfo.colIdList[i] = pCol->info.colId;
  }

  return TSDB_CODE_SUCCESS;
}

static SHashObj* createDataBlockScanInfo(STsdbReader* pTsdbReader, const uint64_t* idList, int32_t numOfTables) {
   ASSERT(numOfTables >= 1);

   // allocate buffer in order to load data blocks from file
   // todo use simple hash instead
   SHashObj* pTableMap = taosHashInit(numOfTables, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), false, HASH_NO_LOCK);
   if (pTableMap == NULL) {
     return NULL;
   }

   // todo apply the lastkey of table check to avoid to load header file
   for (int32_t j = 0; j < numOfTables; ++j) {
     STableBlockScanInfo info = {.lastKey = 0, .uid = idList[j]};
     if (ASCENDING_TRAVERSE(pTsdbReader->order)) {
       if (info.lastKey == INT64_MIN || info.lastKey < pTsdbReader->window.skey) {
         info.lastKey = pTsdbReader->window.skey;
       }
       
       ASSERT(info.lastKey >= pTsdbReader->window.skey && info.lastKey <= pTsdbReader->window.ekey);
     } else {
       info.lastKey = pTsdbReader->window.skey;
     }

     taosHashPut(pTableMap, &info.uid, sizeof(uint64_t), &info, sizeof(info));
     tsdbDebug("%p check table uid:%" PRId64 " from lastKey:%" PRId64 " %s", pTsdbReader, info.uid, info.lastKey,
               pTsdbReader->idStr);
   }

   return pTableMap;
}

// static void resetCheckInfo(STsdbReader* pTsdbReadHandle) {
//   size_t numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
//   assert(numOfTables >= 1);

//   // todo apply the lastkey of table check to avoid to load header file
//   for (int32_t i = 0; i < numOfTables; ++i) {
//     STableBlockScanInfo* pCheckInfo = (STableBlockScanInfo*)taosArrayGet(pTsdbReadHandle->pTableCheckInfo, i);
//     pCheckInfo->lastKey = pTsdbReadHandle->window.skey;
//     pCheckInfo->iter = tsdbTbDataIterDestroy(pCheckInfo->iter);
//     pCheckInfo->iiter = tsdbTbDataIterDestroy(pCheckInfo->iiter);
//     pCheckInfo->initBuf = false;

//     if (ASCENDING_TRAVERSE(pTsdbReadHandle->order)) {
//       assert(pCheckInfo->lastKey >= pTsdbReadHandle->window.skey);
//     } else {
//       assert(pCheckInfo->lastKey <= pTsdbReadHandle->window.skey);
//     }
//   }
// }

// // only one table, not need to sort again
// static SArray* createCheckInfoFromCheckInfo(STableBlockScanInfo* pCheckInfo, TSKEY skey, SArray** psTable) {
//   SArray* pNew = taosArrayInit(1, sizeof(STableBlockScanInfo));

//   STableBlockScanInfo info = {.lastKey = skey};

//   info.tableId = pCheckInfo->tableId;
//   taosArrayPush(pNew, &info);
//   return pNew;
// }

static bool isEmptyQueryTimeWindow(STsdbReader* pTsdbReader) {
   ASSERT(pTsdbReader != NULL);

   STimeWindow* w = &pTsdbReader->window;
   bool         asc = ASCENDING_TRAVERSE(pTsdbReader->order);

   return ((asc && w->skey > w->ekey) || (!asc && w->ekey > w->skey));
 }

// // Update the query time window according to the data time to live(TTL) information, in order to avoid to return
// // the expired data to client, even it is queried already.
// static int64_t getEarliestValidTimestamp(STsdb* pTsdb) {
//   STsdbKeepCfg* pCfg = &pTsdb->keepCfg;

//   int64_t now = taosGetTimestamp(pCfg->precision);
//   return now - (tsTickPerMin[pCfg->precision] * pCfg->keep2) + 1;  // needs to add one tick
// }

// todo remove this
static void setQueryTimewindow(STsdbReader* pReader, SQueryTableDataCond* pCond, int32_t tWinIdx) {
  // pReader->window = pCond->twindows[tWinIdx];

  // bool    updateTs = false;
  // int64_t startTs = getEarliestValidTimestamp(pReader->pTsdb);
  // if (ASCENDING_TRAVERSE(pReader->order)) {
  //   if (startTs > pReader->window.skey) {
  //     pReader->window.skey = startTs;
  //     pCond->twindows[tWinIdx].skey = startTs;
  //     updateTs = true;
  //   }
  // } else {
  //   if (startTs > pReader->window.ekey) {
  //     pReader->window.ekey = startTs;
  //     pCond->twindows[tWinIdx].ekey = startTs;
  //     updateTs = true;
  //   }
  // }

  // if (updateTs) {
  //   tsdbDebug("%p update the query time window, old:%" PRId64 " - %" PRId64 ", new:%" PRId64 " - %" PRId64 ", %s",
  //             pReader, pCond->twindows[tWinIdx].skey, pCond->twindows[tWinIdx].ekey, pReader->window.skey,
  //             pReader->window.ekey, pReader->idStr);
  // }
}

static void checkResultSize(const SQueryTableDataCond* pCond, STsdbReader* pReader) {
  int32_t rowLen = 0;
  for (int32_t i = 0; i < pCond->numOfCols; ++i) {
    rowLen += pCond->colList[i].bytes;
  }

  // make sure the output SSDataBlock size be less than 2MB.
  int32_t TWOMB = 2 * 1024 * 1024;
  if (pReader->capacity * rowLen > TWOMB) {
    pReader->capacity = TWOMB / rowLen;
  }
}

// init file iterator
static int32_t initFileIterator(SFileSetIter* pIter, const STsdbFSState* pFState) {
  pIter->index = -1;
  pIter->numOfFiles = taosArrayGetSize(pFState->aDFileSet);
  pIter->pFileList = taosArrayDup(pFState->aDFileSet);

  return TSDB_CODE_SUCCESS;
}

static void resetDataBlockIterator(SDataBlockIter* pIter) {
  pIter->numOfBlocks = -1;
}

static bool nextFilesetIterator(SFileSetIter* pIter, int32_t order, STsdbReader* pReader) {
  if (pIter->index >= pIter->numOfFiles) {
    return false;
  }

  pIter->index += 1;
  
  // check file the time range of coverage
  STimeWindow win = {0};
  SDFileSet *pDFile = (SDFileSet *)taosArrayGet(pIter->pFileList, pIter->index);

  int32_t code = tsdbDataFReaderOpen(&pReader->pFileReader, pReader->pTsdb, pDFile);
  if (code != TSDB_CODE_SUCCESS) {
    goto _err;
  }

// tsdbGetFidKeyRange(pCfg->days, pCfg->precision, pTsdbReadHandle->pFileGroup->fid, &win.skey, &win.ekey);

 // current file are not overlapped with query time window, ignore remain files
 if ((ASCENDING_TRAVERSE(order) && win.skey > pReader->window.ekey) ||
     (!ASCENDING_TRAVERSE(order) && win.ekey < pReader->window.ekey)) {
   tsdbDebug("%p remain files are not qualified for qrange:%" PRId64 "-%" PRId64 ", ignore, %s", pReader,
             pReader->window.skey, pReader->window.ekey, pReader->idStr);
   return false;
 }
 
  _err:
  return false;
}

static void initReaderStatus(SReaderStatus* pStatus) {
  pStatus->cur.fid        = INT32_MIN;
  pStatus->cur.win        = TSWINDOW_INITIALIZER;
  pStatus->initStartPos   = false;
  pStatus->tableListIndex = 0;  // current active table index
  pStatus->loadFromFile   = true;
}

static int32_t tsdbReaderCreate(SVnode* pVnode, SQueryTableDataCond* pCond, STsdbReader** ppReader, const char* idstr) {
  int32_t      code = 0;
  STsdbReader* pReader = (STsdbReader*)taosMemoryCalloc(1, sizeof(*pReader));
  if (pReader == NULL) {
    code = TSDB_CODE_OUT_OF_MEMORY;
    goto _end;
  }

  initReaderStatus(&pReader->status);
  pReader->pTsdb       = pVnode->pTsdb;
  pReader->suid        = pCond->suid;
  pReader->order       = pCond->order;
  pReader->capacity    = 4096;
  pReader->idStr       = strdup(idstr);
  pReader->startVersion= pCond->startVersion;
  pReader->endVersion  = pCond->endVersion;

  // todo remove this
  setQueryTimewindow(pReader, pCond, 0);

  if (pCond->numOfCols > 0) {
    checkResultSize(pCond, pReader);

    // allocate buffer in order to load data blocks from file
    pReader->suppInfo.pstatis = taosMemoryCalloc(pCond->numOfCols, sizeof(SColumnDataAgg));
    if (pReader->suppInfo.pstatis == NULL) {
      code = TSDB_CODE_OUT_OF_MEMORY;
      goto _end;
    }

    // todo use new api refactor this
    pReader->pResBlock = taosMemoryCalloc(1, sizeof(SSDataBlock));
    if (pReader->pResBlock == NULL) {
      code = TSDB_CODE_OUT_OF_MEMORY;
      goto _end;
    }

    pReader->pResBlock->pDataBlock = taosArrayInit(pCond->numOfCols, sizeof(SColumnInfoData));
    for (int32_t i = 0; i < pCond->numOfCols; ++i) {
      SColumnInfoData colInfo = {{0}, 0};
      colInfo.info = pCond->colList[i];
      taosArrayPush(pReader->pResBlock->pDataBlock, &colInfo);
    }

    setColumnIdList(pReader, pReader->pResBlock);
    pReader->suppInfo.slotIds = taosMemoryCalloc(pCond->numOfCols, sizeof(int32_t));
    pReader->suppInfo.plist = taosMemoryCalloc(pCond->numOfCols, POINTER_BYTES);
  }

  // todo  refactor
  STsdbFSState* pFState = pReader->pTsdb->fs->cState;
  initFileIterator(&pReader->status.fileIter, pFState);
  resetDataBlockIterator(&pReader->status.blockIter);

  // no data in files, let's try buffer in memory
  if (pReader->status.fileIter.numOfFiles == 0) {
    pReader->status.loadFromFile = false;
  }

  *ppReader = pReader;
  return code;

_end:
  tsdbReaderClose(pReader);
  *ppReader = NULL;
  return code;
}

// static int32_t setCurrentSchema(SVnode* pVnode, STsdbReader* pTsdbReadHandle) {
//   STableBlockScanInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, 0);

//   int32_t sversion = 1;

//   SMetaReader mr = {0};
//   metaReaderInit(&mr, pVnode->pMeta, 0);
//   int32_t code = metaGetTableEntryByUid(&mr, pCheckInfo->tableId);
//   if (code != TSDB_CODE_SUCCESS) {
//     terrno = TSDB_CODE_TDB_INVALID_TABLE_ID;
//     metaReaderClear(&mr);
//     return terrno;
//   }

//   if (mr.me.type == TSDB_CHILD_TABLE) {
//     tb_uid_t suid = mr.me.ctbEntry.suid;
//     code = metaGetTableEntryByUid(&mr, suid);
//     if (code != TSDB_CODE_SUCCESS) {
//       terrno = TSDB_CODE_TDB_INVALID_TABLE_ID;
//       metaReaderClear(&mr);
//       return terrno;
//     }
//     sversion = mr.me.stbEntry.schemaRow.version;
//   } else {
//     ASSERT(mr.me.type == TSDB_NORMAL_TABLE);
//     sversion = mr.me.ntbEntry.schemaRow.version;
//   }

//   metaReaderClear(&mr);
//   pTsdbReadHandle->pSchema = metaGetTbTSchema(pVnode->pMeta, pCheckInfo->tableId, sversion);
//   return TSDB_CODE_SUCCESS;
// }

// void tsdbResetQueryHandleForNewTable(STsdbReader* queryHandle, SQueryTableDataCond* pCond, STableListInfo* tableList,
//                                      int32_t tWinIdx) {
//   STsdbReader* pTsdbReadHandle = queryHandle;

//   pTsdbReadHandle->order = pCond->order;
//   pTsdbReadHandle->window = pCond->twindows[tWinIdx];
//   pTsdbReadHandle->type = TSDB_QUERY_TYPE_ALL;
//   pTsdbReadHandle->cur.fid = -1;
//   pTsdbReadHandle->cur.win = TSWINDOW_INITIALIZER;
//   pTsdbReadHandle->checkFiles = true;
//   pTsdbReadHandle->activeIndex = 0;  // current active table index
//   pTsdbReadHandle->locateStart = false;
//   pTsdbReadHandle->loadExternalRow = pCond->loadExternalRows;

//   if (ASCENDING_TRAVERSE(pCond->order)) {
//     assert(pTsdbReadHandle->window.skey <= pTsdbReadHandle->window.ekey);
//   } else {
//     assert(pTsdbReadHandle->window.skey >= pTsdbReadHandle->window.ekey);
//   }

//   // allocate buffer in order to load data blocks from file
//   memset(pTsdbReadHandle->suppInfo.pstatis, 0, sizeof(SColumnDataAgg));
//   memset(pTsdbReadHandle->suppInfo.plist, 0, POINTER_BYTES);

//   tsdbInitDataBlockLoadInfo(&pTsdbReadHandle->dataBlockLoadInfo);
//   tsdbInitCompBlockLoadInfo(&pTsdbReadHandle->compBlockLoadInfo);

//   SArray* pTable = NULL;
//   //  STsdbMeta* pMeta = tsdbGetMeta(pTsdbReadHandle->pTsdb);

//   //  pTsdbReadHandle->pTableCheckInfo = destroyTableCheckInfo(pTsdbReadHandle->pTableCheckInfo);

//   pTsdbReadHandle->pTableCheckInfo = NULL;  // createDataBlockScanInfo(pTsdbReadHandle, groupList, pMeta,
//                                             // &pTable);
//   if (pTsdbReadHandle->pTableCheckInfo == NULL) {
//     //    tsdbReaderClose(pTsdbReadHandle);
//     terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
//   }

//   //  pTsdbReadHandle->prev = doFreeColumnInfoData(pTsdbReadHandle->prev);
//   //  pTsdbReadHandle->next = doFreeColumnInfoData(pTsdbReadHandle->next);
// }

// SArray* tsdbGetQueriedTableList(STsdbReader** pHandle) {
//   assert(pHandle != NULL);

//   STsdbReader* pTsdbReadHandle = (STsdbReader*)pHandle;

//   size_t  size = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
//   SArray* res = taosArrayInit(size, POINTER_BYTES);
//   return res;
// }

// static bool initTableMemIterator(STsdbReader* pHandle, STableBlockScanInfo* pCheckInfo) {
//   if (pCheckInfo->initBuf) {
//     return true;
//   }

//   pCheckInfo->initBuf = true;
//   int32_t order = pHandle->order;

//   STbData* pMem = NULL;
//   STbData* pIMem = NULL;
//   int8_t   backward = (pHandle->order == TSDB_ORDER_DESC) ? 1 : 0;

//   TSKEY tLastKey = keyToTkey(pCheckInfo->lastKey);
//   if (pHandle->pTsdb->mem != NULL) {
//     tsdbGetTbDataFromMemTable(pHandle->pTsdb->mem, pCheckInfo->suid, pCheckInfo->tableId, &pMem);
//     if (pMem != NULL) {
//       tsdbTbDataIterCreate(pMem, &(TSDBKEY){.version = 0, .ts = tLastKey}, backward, &pCheckInfo->iter);
//     }
//   }

//   if (pHandle->pTsdb->imem != NULL) {
//     tsdbGetTbDataFromMemTable(pHandle->pTsdb->mem, pCheckInfo->suid, pCheckInfo->tableId, &pIMem);
//     if (pIMem != NULL) {
//       tsdbTbDataIterCreate(pIMem, &(TSDBKEY){.version = 0, .ts = tLastKey}, backward, &pCheckInfo->iiter);
//     }
//   }

//   // both iterators are NULL, no data in buffer right now
//   if (pCheckInfo->iter == NULL && pCheckInfo->iiter == NULL) {
//     return false;
//   }

//   bool memEmpty =
//       (pCheckInfo->iter == NULL) || (pCheckInfo->iter != NULL && !tsdbTbDataIterGet(pCheckInfo->iter, NULL));
//   bool imemEmpty =
//       (pCheckInfo->iiter == NULL) || (pCheckInfo->iiter != NULL && !tsdbTbDataIterGet(pCheckInfo->iiter, NULL));
//   if (memEmpty && imemEmpty) {  // buffer is empty
//     return false;
//   }

//   if (!memEmpty) {
//     TSDBROW row;

//     tsdbTbDataIterGet(pCheckInfo->iter, &row);
//     TSKEY key = row.pTSRow->ts;  // first timestamp in buffer
//     tsdbDebug("%p uid:%" PRId64 ", check data in mem from skey:%" PRId64 ", order:%d, ts range in buf:%" PRId64
//               "-%" PRId64 ", lastKey:%" PRId64 ", numOfRows:%" PRId64 ", %s",
//               pHandle, pCheckInfo->tableId, key, order, pMem->minKey.ts, pMem->maxKey.ts, pCheckInfo->lastKey,
//               pMem->sl.size, pHandle->idStr);

//     if (ASCENDING_TRAVERSE(order)) {
//       assert(pCheckInfo->lastKey <= key);
//     } else {
//       assert(pCheckInfo->lastKey >= key);
//     }

//   } else {
//     tsdbDebug("%p uid:%" PRId64 ", no data in mem, %s", pHandle, pCheckInfo->tableId, pHandle->idStr);
//   }

//   if (!imemEmpty) {
//     TSDBROW row;

//     tsdbTbDataIterGet(pCheckInfo->iter, &row);
//     TSKEY key = row.pTSRow->ts;  // first timestamp in buffer
//     tsdbDebug("%p uid:%" PRId64 ", check data in imem from skey:%" PRId64 ", order:%d, ts range in buf:%" PRId64
//               "-%" PRId64 ", lastKey:%" PRId64 ", numOfRows:%" PRId64 ", %s",
//               pHandle, pCheckInfo->tableId, key, order, pIMem->minKey.ts, pIMem->maxKey.ts, pCheckInfo->lastKey,
//               pIMem->sl.size, pHandle->idStr);

//     if (ASCENDING_TRAVERSE(order)) {
//       assert(pCheckInfo->lastKey <= key);
//     } else {
//       assert(pCheckInfo->lastKey >= key);
//     }
//   } else {
//     tsdbDebug("%p uid:%" PRId64 ", no data in imem, %s", pHandle, pCheckInfo->tableId, pHandle->idStr);
//   }

//   return true;
// }

// static void destroyTableMemIterator(STableBlockScanInfo* pCheckInfo) {
//   tsdbTbDataIterDestroy(pCheckInfo->iter);
//   tsdbTbDataIterDestroy(pCheckInfo->iiter);
// }

// static TSKEY extractFirstTraverseKey(STableBlockScanInfo* pCheckInfo, int32_t order, int32_t update, TDRowVerT maxVer) {
//   TSDBROW row = {0};
//   STSRow *rmem = NULL, *rimem = NULL;

//   if (pCheckInfo->iter) {
//     if (tsdbTbDataIterGet(pCheckInfo->iter, &row)) {
//       rmem = row.pTSRow;
//     }
//   }

//   if (pCheckInfo->iiter) {
//     if (tsdbTbDataIterGet(pCheckInfo->iiter, &row)) {
//       rimem = row.pTSRow;
//     }
//   }

//   if (rmem == NULL && rimem == NULL) {
//     return TSKEY_INITIAL_VAL;
//   }

//   if (rmem != NULL && rimem == NULL) {
//     pCheckInfo->chosen = CHECKINFO_CHOSEN_MEM;
//     return TD_ROW_KEY(rmem);
//   }

//   if (rmem == NULL && rimem != NULL) {
//     pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
//     return TD_ROW_KEY(rimem);
//   }

//   TSKEY r1 = TD_ROW_KEY(rmem);
//   TSKEY r2 = TD_ROW_KEY(rimem);

//   if (r1 == r2) {
//     if (TD_SUPPORT_UPDATE(update)) {
//       pCheckInfo->chosen = CHECKINFO_CHOSEN_BOTH;
//     } else {
//       pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
//       tsdbTbDataIterNext(pCheckInfo->iter);
//     }
//     return r1;
//   } else if (r1 < r2 && ASCENDING_TRAVERSE(order)) {
//     pCheckInfo->chosen = CHECKINFO_CHOSEN_MEM;
//     return r1;
//   } else {
//     pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
//     return r2;
//   }
// }

// static STSRow* getSRowInTableMem(STableBlockScanInfo* pCheckInfo, int32_t order, int32_t update, STSRow** extraRow,
//                                  TDRowVerT maxVer) {
//   TSDBROW row;
//   STSRow *rmem = NULL, *rimem = NULL;
//   if (pCheckInfo->iter) {
//     if (tsdbTbDataIterGet(pCheckInfo->iter, &row)) {
//       rmem = row.pTSRow;
//     }
//   }

//   if (pCheckInfo->iiter) {
//     if (tsdbTbDataIterGet(pCheckInfo->iiter, &row)) {
//       rimem = row.pTSRow;
//     }
//   }

//   if (rmem == NULL && rimem == NULL) {
//     return NULL;
//   }

//   if (rmem != NULL && rimem == NULL) {
//     pCheckInfo->chosen = 0;
//     return rmem;
//   }

//   if (rmem == NULL && rimem != NULL) {
//     pCheckInfo->chosen = 1;
//     return rimem;
//   }

//   TSKEY r1 = TD_ROW_KEY(rmem);
//   TSKEY r2 = TD_ROW_KEY(rimem);

//   if (r1 == r2) {
//     if (TD_SUPPORT_UPDATE(update)) {
//       pCheckInfo->chosen = CHECKINFO_CHOSEN_BOTH;
//       *extraRow = rimem;
//       return rmem;
//     } else {
//       tsdbTbDataIterNext(pCheckInfo->iter);
//       pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
//       return rimem;
//     }
//   } else {
//     if (ASCENDING_TRAVERSE(order)) {
//       if (r1 < r2) {
//         pCheckInfo->chosen = CHECKINFO_CHOSEN_MEM;
//         return rmem;
//       } else {
//         pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
//         return rimem;
//       }
//     } else {
//       if (r1 < r2) {
//         pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
//         return rimem;
//       } else {
//         pCheckInfo->chosen = CHECKINFO_CHOSEN_IMEM;
//         return rmem;
//       }
//     }
//   }
// }

// static bool moveToNextRowInMem(STableBlockScanInfo* pCheckInfo) {
//   bool hasNext = false;
//   if (pCheckInfo->chosen == CHECKINFO_CHOSEN_MEM) {
//     if (pCheckInfo->iter != NULL) {
//       hasNext = tsdbTbDataIterNext(pCheckInfo->iter);
//     }

//     if (hasNext) {
//       return hasNext;
//     }

//     if (pCheckInfo->iiter != NULL) {
//       return tsdbTbDataIterGet(pCheckInfo->iiter, NULL);
//     }
//   } else if (pCheckInfo->chosen == CHECKINFO_CHOSEN_IMEM) {
//     if (pCheckInfo->iiter != NULL) {
//       hasNext = tsdbTbDataIterNext(pCheckInfo->iiter);
//     }

//     if (hasNext) {
//       return hasNext;
//     }

//     if (pCheckInfo->iter != NULL) {
//       return tsdbTbDataIterGet(pCheckInfo->iter, NULL);
//     }
//   } else {
//     if (pCheckInfo->iter != NULL) {
//       hasNext = tsdbTbDataIterNext(pCheckInfo->iter);
//     }
//     if (pCheckInfo->iiter != NULL) {
//       hasNext = tsdbTbDataIterNext(pCheckInfo->iiter) || hasNext;
//     }
//   }

//   return hasNext;
// }

// static bool hasMoreDataInCache(STsdbReader* pHandle) {
//   STsdbCfg* pCfg = REPO_CFG(pHandle->pTsdb);
//   size_t    size = taosArrayGetSize(pHandle->pTableCheckInfo);
//   assert(pHandle->activeIndex < size && pHandle->activeIndex >= 0 && size >= 1);
//   pHandle->cur.fid = INT32_MIN;

//   STableBlockScanInfo* pCheckInfo = taosArrayGet(pHandle->pTableCheckInfo, pHandle->activeIndex);
//   if (!pCheckInfo->initBuf) {
//     initTableMemIterator(pHandle, pCheckInfo);
//   }

//   STSRow* row = getSRowInTableMem(pCheckInfo, pHandle->order, pCfg->update, NULL, TD_VER_MAX);
//   if (row == NULL) {
//     return false;
//   }

//   pCheckInfo->lastKey = TD_ROW_KEY(row);  // first timestamp in buffer
//   tsdbDebug("%p uid:%" PRId64 ", check data in buffer from skey:%" PRId64 ", order:%d, %s", pHandle,
//             pCheckInfo->tableId, pCheckInfo->lastKey, pHandle->order, pHandle->idStr);

//   // all data in mem are checked already.
//   if ((pCheckInfo->lastKey > pHandle->window.ekey && ASCENDING_TRAVERSE(pHandle->order)) ||
//       (pCheckInfo->lastKey < pHandle->window.ekey && !ASCENDING_TRAVERSE(pHandle->order))) {
//     return false;
//   }

//   int32_t      step = ASCENDING_TRAVERSE(pHandle->order) ? 1 : -1;
//   STimeWindow* win = &pHandle->cur.win;
//   pHandle->cur.rows = tsdbReadRowsFromCache(pCheckInfo, pHandle->window.ekey, pHandle->outputCapacity, win, pHandle);

//   // update the last key value
//   pCheckInfo->lastKey = win->ekey + step;
//   pHandle->cur.lastKey = win->ekey + step;
//   pHandle->cur.mixBlock = true;

//   if (!ASCENDING_TRAVERSE(pHandle->order)) {
//     TSWAP(win->skey, win->ekey);
//   }

//   return true;
// }

// static int32_t getFileIdFromKey(TSKEY key, int32_t daysPerFile, int32_t precision) {
//   assert(precision >= TSDB_TIME_PRECISION_MICRO || precision <= TSDB_TIME_PRECISION_NANO);
//   if (key == TSKEY_INITIAL_VAL) {
//     return INT32_MIN;
//   }

//   if (key < 0) {
//     key -= (daysPerFile * tsTickPerMin[precision]);
//   }

//   int64_t fid = (int64_t)(key / (daysPerFile * tsTickPerMin[precision]));  // set the starting fileId
//   if (fid < 0L && llabs(fid) > INT32_MAX) {                                // data value overflow for INT32
//     fid = INT32_MIN;
//   }

//   if (fid > 0L && fid > INT32_MAX) {
//     fid = INT32_MAX;
//   }

//   return (int32_t)fid;
// }

// static int32_t binarySearchForBlock(SBlock* pBlock, int32_t numOfBlocks, TSKEY skey, int32_t order) {
//   int32_t firstSlot = 0;
//   int32_t lastSlot = numOfBlocks - 1;

//   int32_t midSlot = firstSlot;

//   while (1) {
//     numOfBlocks = lastSlot - firstSlot + 1;
//     midSlot = (firstSlot + (numOfBlocks >> 1));

//     if (numOfBlocks == 1) break;

//     if (skey > pBlock[midSlot].maxKey.ts) {
//       if (numOfBlocks == 2) break;
//       if ((order == TSDB_ORDER_DESC) && (skey < pBlock[midSlot + 1].minKey.ts)) break;
//       firstSlot = midSlot + 1;
//     } else if (skey < pBlock[midSlot].minKey.ts) {
//       if ((order == TSDB_ORDER_ASC) && (skey > pBlock[midSlot - 1].maxKey.ts)) break;
//       lastSlot = midSlot - 1;
//     } else {
//       break;  // got the slot
//     }
//   }

//   return midSlot;
// }

static int32_t doLoadBlockIndex(STsdbReader* pReader, SDataFReader* pFileReader, SArray* pIndexList) {
  int32_t code = 0;

  SMapData blockIdxMap;
  tMapDataReset(&blockIdxMap);

  code = tsdbReadBlockIdx(pFileReader, &blockIdxMap, NULL);
  if (code != TSDB_CODE_SUCCESS) {
    goto _err;
  }

  if (blockIdxMap.nItem == 0) {
    return TSDB_CODE_SUCCESS;
  }

  SBlockIdx blockIndex = {0};
  for (int32_t i = 0; i < blockIdxMap.nItem; ++i) {
    code = tMapDataGetItemByIdx(&blockIdxMap, i, &blockIndex, tGetBlockIdx);
    if (code != TSDB_CODE_SUCCESS) {
      goto _err;
    }

    if (blockIndex.suid != pReader->suid) {
      continue;
    }

    // this block belongs to a table that is not queried.
    void* p = taosHashGet(pReader->status.pTableMap, &blockIndex.uid, sizeof(uint64_t));
    if (p == NULL) {
      continue;
    }

    if ((ASCENDING_TRAVERSE(pReader->order) &&
         (blockIndex.minKey > pReader->window.ekey || blockIndex.maxKey < pReader->window.skey)) ||
        (!ASCENDING_TRAVERSE(pReader->order) &&
         (blockIndex.minKey > pReader->window.skey || blockIndex.maxKey < pReader->window.ekey))) {
      continue;
    }

    STableBlockScanInfo* pScanInfo = p;
    if (pScanInfo->pBlockList == NULL) {
      pScanInfo->pBlockList = taosArrayInit(16, sizeof(SBlock));
    }

    taosArrayPush(pIndexList, &blockIndex);
  }

  tMapDataClear(&blockIdxMap);
  return TSDB_CODE_SUCCESS;

_err:
  tMapDataClear(&blockIdxMap);
  return code;
}

static int32_t doLoadFileBlock(STsdbReader* pReader, SArray* pIndexList, uint32_t* numOfValidTables) {
  size_t numOfTables = taosArrayGetSize(pIndexList);

  *numOfValidTables = 0;

  for(int32_t i = 0; i < numOfTables; ++i) {
    SBlockIdx* pBlockIdx = taosArrayGet(pIndexList, i);

    SMapData mapData;
    tMapDataReset(&mapData);
    tsdbReadBlock(pReader->pFileReader, pBlockIdx, &mapData, NULL);

    STableBlockScanInfo* pScanInfo = taosHashGet(pReader->status.pTableMap, &pBlockIdx->uid, sizeof(int64_t));
    ASSERT(pScanInfo->pBlockList == NULL || taosArrayGetSize(pScanInfo->pBlockList) == 0);
    for (int32_t j = 0; j < mapData.nItem; ++j) {
      SBlock block = {0};

      int32_t code = tMapDataGetItemByIdx(&mapData, j, &block, tGetBlock);
      if (code != TSDB_CODE_SUCCESS) {
        return code;
      }

      if ((ASCENDING_TRAVERSE(pReader->order) &&
           (block.minKey.ts > pReader->window.ekey || block.maxKey.ts < pReader->window.skey)) ||
          (!ASCENDING_TRAVERSE(pReader->order) &&
           (block.minKey.ts > pReader->window.skey || block.maxKey.ts < pReader->window.ekey))) {
        continue;
      }

      void* p = taosArrayPush(pScanInfo->pBlockList, &block);
      if (p == NULL) {
        return TSDB_CODE_OUT_OF_MEMORY;
      }
    }

    if (pScanInfo->pBlockList != NULL && taosArrayGetSize(pScanInfo->pBlockList) > 0) {
      (*numOfValidTables) += 1;
    }
  }

  return TSDB_CODE_SUCCESS;
}

static int32_t doLoadFileBlockData(STsdbReader* pReader, SDataBlockIter* pBlockIter, STableBlockScanInfo* pBlockScanInfo, SBlockData* pBlockData) {
 int64_t st = taosGetTimestampUs();
 int32_t numOfCols = taosArrayGetSize(pReader->pResBlock->pDataBlock);

  SFileDataBlockInfo* pFBlock = getCurrentBlockInfo(pBlockIter);
  SBlock* pBlock = taosArrayGet(pBlockScanInfo->pBlockList, pFBlock->tbBlockIdx);
  
 uint8_t *pb = NULL, *pb1 = NULL;
 int32_t code = tsdbReadBlockData(pReader->pFileReader, &pBlockScanInfo->blockIdx, pBlock, pBlockData, /*pReader->suppInfo.colIdList, numOfCols, */&pb, &pb1);
 if (code != TSDB_CODE_SUCCESS) {
   goto _error;
 }

/*
 int32_t ret = tsdbLoadBlockDataCols(&(pReader->rhelper), pBlock, pCheckInfo->pCompInfo, colIds,
                                     (int)(QH_GET_NUM_OF_COLS(pReader)), true);
 if (ret != TSDB_CODE_SUCCESS) {
   int32_t c = terrno;
   assert(c != TSDB_CODE_SUCCESS);
   goto _error;
 }

 SDataBlockLoadInfo* pBlockLoadInfo = &pReader->dataBlockLoadInfo;

 pBlockLoadInfo->fileGroup = pReader->pFileGroup;
 pBlockLoadInfo->slot = pReader->cur.slot;
 pBlockLoadInfo->uid = pCheckInfo->tableId;

 SDataCols* pCols = pReader->rhelper.pDCols[0];
 assert(pCols->numOfRows != 0 && pCols->numOfRows <= pBlock->numOfRows);

 pBlock->numOfRows = pCols->numOfRows;
*/

 int64_t elapsedTime = (taosGetTimestampUs() - st);
 pReader->cost.blockLoadTime += elapsedTime;

 tsdbDebug("%p load file block into buffer, global index:%d, table index:%d, brange:%" PRId64 "-%" PRId64
           ", rows:%d, minVer:%" PRId64 ", maxVer:%" PRId64 ", elapsed time:%" PRId64 " us, %s",
           pReader, pBlockIter->index, pFBlock->tbBlockIdx, pBlock->minKey.ts, pBlock->maxKey.ts, pBlockData->nRow,
           pBlock->minVersion, pBlock->maxVersion, elapsedTime, pReader->idStr);
 return TSDB_CODE_SUCCESS;

_error:
 tsdbError("%p error occurs in loading file block, global index:%d, table index:%d, brange:%" PRId64 "-%" PRId64 ", rows:%d, %s",
           pReader, pBlockIter->index, pFBlock->tbBlockIdx, pBlock->minKey.ts, pBlock->maxKey.ts, pBlock->nRow, pReader->idStr);
 return code;
}

// static int32_t handleDataMergeIfNeeded(STsdbReader* pTsdbReadHandle, SBlock* pBlock, STableBlockScanInfo* pCheckInfo) {
//   SQueryFilePos* cur = &pTsdbReadHandle->cur;
//   STsdbCfg*      pCfg = REPO_CFG(pTsdbReadHandle->pTsdb);
//   SDataBlockInfo binfo = GET_FILE_DATA_BLOCK_INFO(pCheckInfo, pBlock);
//   TSKEY          key;
//   int32_t        code = TSDB_CODE_SUCCESS;

//   /*bool hasData = */ initTableMemIterator(pTsdbReadHandle, pCheckInfo);
//   assert(cur->pos >= 0 && cur->pos <= binfo.rows);

//   key = extractFirstTraverseKey(pCheckInfo, pTsdbReadHandle->order, pCfg->update, TD_VER_MAX);

//   if (key != TSKEY_INITIAL_VAL) {
//     tsdbDebug("%p key in mem:%" PRId64 ", %s", pTsdbReadHandle, key, pTsdbReadHandle->idStr);
//   } else {
//     tsdbDebug("%p no data in mem, %s", pTsdbReadHandle, pTsdbReadHandle->idStr);
//   }

//   bool ascScan = ASCENDING_TRAVERSE(pTsdbReadHandle->order);

//   if ((ascScan && (key != TSKEY_INITIAL_VAL && key <= binfo.window.ekey)) ||
//       (!ascScan && (key != TSKEY_INITIAL_VAL && key >= binfo.window.skey))) {
//     bool cacheDataInFileBlockHole = (ascScan && (key != TSKEY_INITIAL_VAL && key < binfo.window.skey)) ||
//                                     (!ascScan && (key != TSKEY_INITIAL_VAL && key > binfo.window.ekey));
//     if (cacheDataInFileBlockHole) {
//       // do not load file block into buffer
//       int32_t step = ascScan ? 1 : -1;

//       TSKEY maxKey = ascScan ? (binfo.window.skey - step) : (binfo.window.ekey - step);
//       cur->rows =
//           tsdbReadRowsFromCache(pCheckInfo, maxKey, pTsdbReadHandle->outputCapacity, &cur->win, pTsdbReadHandle);
//       pTsdbReadHandle->realNumOfRows = cur->rows;

//       // update the last key value
//       pCheckInfo->lastKey = cur->win.ekey + step;

//       if (!ascScan) {
//         TSWAP(cur->win.skey, cur->win.ekey);
//       }

//       cur->mixBlock = true;
//       cur->blockCompleted = false;
//       return code;
//     }

//     // return error, add test cases
//     if ((code = doLoadFileBlockData(pTsdbReadHandle, pBlock, pCheckInfo, cur->slot)) != TSDB_CODE_SUCCESS) {
//       return code;
//     }

//     doMergeTwoLevelData(pTsdbReadHandle, pCheckInfo, pBlock);
//   } else {
//     /*
//      * no data in cache, only load data from file
//      * during the query processing, data in cache will not be checked anymore.
//      * Here the buffer is not enough, so only part of file block can be loaded into memory buffer
//      */
//     int32_t endPos = getEndPosInDataBlock(pTsdbReadHandle, &binfo);

//     bool wholeBlockReturned = ((abs(cur->pos - endPos) + 1) == binfo.rows);
//     if (wholeBlockReturned) {
//       pTsdbReadHandle->realNumOfRows = binfo.rows;

//       cur->rows = binfo.rows;
//       cur->win = binfo.window;
//       cur->mixBlock = false;
//       cur->blockCompleted = true;

//       if (ascScan) {
//         cur->lastKey = binfo.window.ekey + 1;
//         cur->pos = binfo.rows;
//       } else {
//         cur->lastKey = binfo.window.skey - 1;
//         cur->pos = -1;
//       }
//     } else {  // partially copy to dest buffer
//       // make sure to only load once
//       bool firstTimeExtract = ((cur->pos == 0 && ascScan) || (cur->pos == binfo.rows - 1 && (!ascScan)));
//       if (pTsdbReadHandle->outputCapacity < binfo.rows && firstTimeExtract) {
//         code = doLoadFileBlockData(pTsdbReadHandle, pBlock, pCheckInfo, cur->slot);
//         if (code != TSDB_CODE_SUCCESS) {
//           return code;
//         }
//       }

//       copyAllRemainRowsFromFileBlock(pTsdbReadHandle, pCheckInfo, &binfo, endPos);
//       cur->mixBlock = true;
//     }

//     if (pTsdbReadHandle->outputCapacity >= binfo.rows) {
//       ASSERT(cur->blockCompleted || cur->mixBlock);
//     }

//     if (cur->rows == binfo.rows) {
//       tsdbDebug("%p whole file block qualified, brange:%" PRId64 "-%" PRId64 ", rows:%d, lastKey:%" PRId64 ", %s",
//                 pTsdbReadHandle, cur->win.skey, cur->win.ekey, cur->rows, cur->lastKey, pTsdbReadHandle->idStr);
//     } else {
//       tsdbDebug("%p create data block from remain file block, brange:%" PRId64 "-%" PRId64
//                 ", rows:%d, total:%d, lastKey:%" PRId64 ", %s",
//                 pTsdbReadHandle, cur->win.skey, cur->win.ekey, cur->rows, binfo.rows, cur->lastKey,
//                 pTsdbReadHandle->idStr);
//     }
//   }

//   return code;
// }

// static int32_t loadFileDataBlock(STsdbReader* pTsdbReadHandle, SBlock* pBlock, STableBlockScanInfo* pCheckInfo,
//                                  bool* exists) {
//   SQueryFilePos* cur = &pTsdbReadHandle->cur;
//   int32_t        code = TSDB_CODE_SUCCESS;
//   bool           asc = ASCENDING_TRAVERSE(pTsdbReadHandle->order);

//   if (asc) {
//     // query ended in/started from current block
//     if (pTsdbReadHandle->window.ekey < pBlock->maxKey.ts || pCheckInfo->lastKey > pBlock->minKey.ts) {
//       if ((code = doLoadFileBlockData(pTsdbReadHandle, pBlock, pCheckInfo, cur->slot)) != TSDB_CODE_SUCCESS) {
//         *exists = false;
//         return code;
//       }

//       SDataCols* pTSCol = pTsdbReadHandle->rhelper.pDCols[0];
//       assert(pTSCol->cols->type == TSDB_DATA_TYPE_TIMESTAMP && pTSCol->numOfRows == pBlock->numOfRows);

//       if (pCheckInfo->lastKey > pBlock->minKey.ts) {
//         cur->pos =
//             binarySearchForKey(pTSCol->cols[0].pData, pBlock->numOfRows, pCheckInfo->lastKey,
//             pTsdbReadHandle->order);
//       } else {
//         cur->pos = 0;
//       }

//       assert(pCheckInfo->lastKey <= pBlock->maxKey.ts);
//       doMergeTwoLevelData(pTsdbReadHandle, pCheckInfo, pBlock);
//     } else {  // the whole block is loaded in to buffer
//       cur->pos = asc ? 0 : (pBlock->numOfRows - 1);
//       code = handleDataMergeIfNeeded(pTsdbReadHandle, pBlock, pCheckInfo);
//     }
//   } else {  // desc order, query ended in current block
//     if (pTsdbReadHandle->window.ekey > pBlock->minKey.ts || pCheckInfo->lastKey < pBlock->maxKey.ts) {
//       if ((code = doLoadFileBlockData(pTsdbReadHandle, pBlock, pCheckInfo, cur->slot)) != TSDB_CODE_SUCCESS) {
//         *exists = false;
//         return code;
//       }

//       SDataCols* pTsCol = pTsdbReadHandle->rhelper.pDCols[0];
//       if (pCheckInfo->lastKey < pBlock->maxKey.ts) {
//         cur->pos =
//             binarySearchForKey(pTsCol->cols[0].pData, pBlock->numOfRows, pCheckInfo->lastKey,
//             pTsdbReadHandle->order);
//       } else {
//         cur->pos = pBlock->numOfRows - 1;
//       }

//       assert(pCheckInfo->lastKey >= pBlock->minKey.ts);
//       doMergeTwoLevelData(pTsdbReadHandle, pCheckInfo, pBlock);
//     } else {
//       cur->pos = asc ? 0 : (pBlock->numOfRows - 1);
//       code = handleDataMergeIfNeeded(pTsdbReadHandle, pBlock, pCheckInfo);
//     }
//   }

//   *exists = pTsdbReadHandle->realNumOfRows > 0;
//   return code;
// }

// static int doBinarySearchKey(char* pValue, int num, TSKEY key, int order) {
//   int    firstPos, lastPos, midPos = -1;
//   int    numOfRows;
//   TSKEY* keyList;

//   assert(order == TSDB_ORDER_ASC || order == TSDB_ORDER_DESC);

//   if (num <= 0) return -1;

//   keyList = (TSKEY*)pValue;
//   firstPos = 0;
//   lastPos = num - 1;

//   if (order == TSDB_ORDER_DESC) {
//     // find the first position which is smaller than the key
//     while (1) {
//       if (key >= keyList[lastPos]) return lastPos;
//       if (key == keyList[firstPos]) return firstPos;
//       if (key < keyList[firstPos]) return firstPos - 1;

//       numOfRows = lastPos - firstPos + 1;
//       midPos = (numOfRows >> 1) + firstPos;

//       if (key < keyList[midPos]) {
//         lastPos = midPos - 1;
//       } else if (key > keyList[midPos]) {
//         firstPos = midPos + 1;
//       } else {
//         break;
//       }
//     }

//   } else {
//     // find the first position which is bigger than the key
//     while (1) {
//       if (key <= keyList[firstPos]) return firstPos;
//       if (key == keyList[lastPos]) return lastPos;

//       if (key > keyList[lastPos]) {
//         lastPos = lastPos + 1;
//         if (lastPos >= num)
//           return -1;
//         else
//           return lastPos;
//       }

//       numOfRows = lastPos - firstPos + 1;
//       midPos = (numOfRows >> 1) + firstPos;

//       if (key < keyList[midPos]) {
//         lastPos = midPos - 1;
//       } else if (key > keyList[midPos]) {
//         firstPos = midPos + 1;
//       } else {
//         break;
//       }
//     }
//   }

//   return midPos;
// }

// static int32_t doCopyRowsFromFileBlock(STsdbReader* pTsdbReadHandle, int32_t capacity, int32_t numOfRows, int32_t
// start,
//                                        int32_t end) {
//   SDataCols* pCols = pTsdbReadHandle->rhelper.pDCols[0];
//   TSKEY*     tsArray = pCols->cols[0].pData;

//   int32_t num = end - start + 1;
//   assert(num >= 0);

//   if (num == 0) {
//     return numOfRows;
//   }

//   bool    ascScan = ASCENDING_TRAVERSE(pTsdbReadHandle->order);
//   int32_t trueStart = ascScan ? start : end;
//   int32_t trueEnd = ascScan ? end : start;
//   int32_t step = ascScan ? 1 : -1;

//   int32_t requiredNumOfCols = (int32_t)taosArrayGetSize(pTsdbReadHandle->pColumns);

//   // data in buffer has greater timestamp, copy data in file block
//   int32_t i = 0, j = 0;
//   while (i < requiredNumOfCols && j < pCols->numOfCols) {
//     SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pColumns, i);

//     SDataCol* src = &pCols->cols[j];
//     if (src->colId < pColInfo->info.colId) {
//       j++;
//       continue;
//     }

//     if (!isAllRowsNull(src) && pColInfo->info.colId == src->colId) {
//       if (!IS_VAR_DATA_TYPE(pColInfo->info.type)) {  // todo opt performance
//         //        memmove(pData, (char*)src->pData + bytes * start, bytes * num);
//         int32_t rowIndex = numOfRows;
//         for (int32_t k = trueStart; ((ascScan && k <= trueEnd) || (!ascScan && k >= trueEnd)); k += step, ++rowIndex)
//         {
//           SCellVal sVal = {0};
//           if (tdGetColDataOfRow(&sVal, src, k, pCols->bitmapMode) < 0) {
//             TASSERT(0);
//           }

//           if (sVal.valType == TD_VTYPE_NORM) {
//             colDataAppend(pColInfo, rowIndex, sVal.val, false);
//           } else {
//             colDataAppendNULL(pColInfo, rowIndex);
//           }
//         }
//       } else {  // handle the var-string
//         int32_t rowIndex = numOfRows;

//         // todo refactor, only copy one-by-one
//         for (int32_t k = trueStart; ((ascScan && k <= trueEnd) || (!ascScan && k >= trueEnd)); k += step, ++rowIndex)
//         {
//           SCellVal sVal = {0};
//           if (tdGetColDataOfRow(&sVal, src, k, pCols->bitmapMode) < 0) {
//             TASSERT(0);
//           }

//           if (sVal.valType == TD_VTYPE_NORM) {
//             colDataAppend(pColInfo, rowIndex, sVal.val, false);
//           } else {
//             colDataAppendNULL(pColInfo, rowIndex);
//           }
//         }
//       }

//       j++;
//       i++;
//     } else {  // pColInfo->info.colId < src->colId, it is a NULL data
//       colDataAppendNNULL(pColInfo, numOfRows, num);
//       i++;
//     }
//   }

//   while (i < requiredNumOfCols) {  // the remain columns are all null data
//     SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pColumns, i);
//     colDataAppendNNULL(pColInfo, numOfRows, num);
//     i++;
//   }

//   pTsdbReadHandle->cur.win.ekey = tsArray[trueEnd];
//   pTsdbReadHandle->cur.lastKey = tsArray[trueEnd] + step;

//   return numOfRows + num;
// }

// static int32_t mergeTwoRowFromMem(STsdbReader* pTsdbReadHandle, int32_t capacity, int32_t* curRow, STSRow* row1,
//                                   STSRow* row2, int32_t numOfCols, uint64_t uid, STSchema* pSchema1, STSchema*
//                                   pSchema2, bool update, TSKEY* lastRowKey) {
// #if 1
//   STSchema* pSchema;
//   STSRow*   row;
//   int16_t   colId;
//   int16_t   offset;

//   bool     isRow1DataRow = TD_IS_TP_ROW(row1);
//   bool     isRow2DataRow;
//   bool     isChosenRowDataRow;
//   int32_t  chosen_itr;
//   SCellVal sVal = {0};
//   TSKEY    rowKey = TSKEY_INITIAL_VAL;
//   int32_t  nResult = 0;
//   int32_t  mergeOption = 0;  // 0 discard 1 overwrite 2 merge

//   // the schema version info is embeded in STSRow
//   int32_t numOfColsOfRow1 = 0;

//   if (pSchema1 == NULL) {
//     pSchema1 = metaGetTbTSchema(REPO_META(pTsdbReadHandle->pTsdb), uid, TD_ROW_SVER(row1));
//   }

// #ifdef TD_DEBUG_PRINT_ROW
//   char   flags[70] = {0};
//   STsdb* pTsdb = pTsdbReadHandle->rhelper.pRepo;
//   snprintf(flags, 70, "%s:%d vgId:%d dir:%s row1%s=NULL,row2%s=NULL", __func__, __LINE__, TD_VID(pTsdb->pVnode),
//            pTsdb->dir, row1 ? "!" : "", row2 ? "!" : "");
//   tdSRowPrint(row1, pSchema1, flags);
// #endif

//   if (isRow1DataRow) {
//     numOfColsOfRow1 = schemaNCols(pSchema1);
//   } else {
//     numOfColsOfRow1 = tdRowGetNCols(row1);
//   }

//   int32_t numOfColsOfRow2 = 0;
//   if (row2) {
//     isRow2DataRow = TD_IS_TP_ROW(row2);
//     if (pSchema2 == NULL) {
//       pSchema2 = metaGetTbTSchema(REPO_META(pTsdbReadHandle->pTsdb), uid, TD_ROW_SVER(row2));
//     }
//     if (isRow2DataRow) {
//       numOfColsOfRow2 = schemaNCols(pSchema2);
//     } else {
//       numOfColsOfRow2 = tdRowGetNCols(row2);
//     }
//   }

//   int32_t i = 0, j = 0, k = 0;
//   while (i < numOfCols && (j < numOfColsOfRow1 || k < numOfColsOfRow2)) {
//     SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pColumns, i);

//     int32_t colIdOfRow1;
//     if (j >= numOfColsOfRow1) {
//       colIdOfRow1 = INT32_MAX;
//     } else if (isRow1DataRow) {
//       colIdOfRow1 = pSchema1->columns[j].colId;
//     } else {
//       colIdOfRow1 = tdKvRowColIdAt(row1, j);
//     }

//     int32_t colIdOfRow2;
//     if (k >= numOfColsOfRow2) {
//       colIdOfRow2 = INT32_MAX;
//     } else if (isRow2DataRow) {
//       colIdOfRow2 = pSchema2->columns[k].colId;
//     } else {
//       colIdOfRow2 = tdKvRowColIdAt(row2, k);
//     }

//     if (colIdOfRow1 < colIdOfRow2) {  // the most probability
//       if (colIdOfRow1 < pColInfo->info.colId) {
//         ++j;
//         continue;
//       }
//       row = row1;
//       pSchema = pSchema1;
//       isChosenRowDataRow = isRow1DataRow;
//       chosen_itr = j;
//     } else if (colIdOfRow1 == colIdOfRow2) {
//       if (colIdOfRow1 < pColInfo->info.colId) {
//         ++j;
//         ++k;
//         continue;
//       }
//       row = row1;
//       pSchema = pSchema1;
//       isChosenRowDataRow = isRow1DataRow;
//       chosen_itr = j;
//     } else {
//       if (colIdOfRow2 < pColInfo->info.colId) {
//         ++k;
//         continue;
//       }
//       row = row2;
//       pSchema = pSchema2;
//       chosen_itr = k;
//       isChosenRowDataRow = isRow2DataRow;
//     }

//     if (isChosenRowDataRow) {
//       colId = pSchema->columns[chosen_itr].colId;
//       offset = pSchema->columns[chosen_itr].offset;
//       // TODO: use STSRowIter
//       tdSTpRowGetVal(row, colId, pSchema->columns[chosen_itr].type, pSchema->flen, offset, chosen_itr - 1, &sVal);
//       if (colId == PRIMARYKEY_TIMESTAMP_COL_ID) {
//         rowKey = *(TSKEY*)sVal.val;
//         if (rowKey != *lastRowKey) {
//           mergeOption = 1;
//           if (*lastRowKey != TSKEY_INITIAL_VAL) {
//             ++(*curRow);
//           }
//           *lastRowKey = rowKey;
//           ++nResult;
//         } else if (update) {
//           mergeOption = 2;
//         } else {
//           mergeOption = 0;
//           break;
//         }
//       }
//     } else {
//       // TODO: use STSRowIter
//       if (chosen_itr == 0) {
//         colId = PRIMARYKEY_TIMESTAMP_COL_ID;
//         tdSKvRowGetVal(row, PRIMARYKEY_TIMESTAMP_COL_ID, -1, -1, &sVal);
//         rowKey = *(TSKEY*)sVal.val;
//         if (rowKey != *lastRowKey) {
//           mergeOption = 1;
//           if (*lastRowKey != TSKEY_INITIAL_VAL) {
//             ++(*curRow);
//           }
//           *lastRowKey = rowKey;
//           ++nResult;
//         } else if (update) {
//           mergeOption = 2;
//         } else {
//           mergeOption = 0;
//           break;
//         }
//       } else {
//         SKvRowIdx* pColIdx = tdKvRowColIdxAt(row, chosen_itr - 1);
//         colId = pColIdx->colId;
//         offset = pColIdx->offset;
//         tdSKvRowGetVal(row, colId, offset, chosen_itr - 1, &sVal);
//       }
//     }

//     ASSERT(rowKey != TSKEY_INITIAL_VAL);

//     if (colId == pColInfo->info.colId) {
//       if (tdValTypeIsNorm(sVal.valType)) {
//         colDataAppend(pColInfo, *curRow, sVal.val, false);
//       } else if (tdValTypeIsNull(sVal.valType)) {
//         colDataAppend(pColInfo, *curRow, NULL, true);
//       } else if (tdValTypeIsNone(sVal.valType)) {
//         // TODO: Set null if nothing append for this row
//         if (mergeOption == 1) {
//           colDataAppend(pColInfo, *curRow, NULL, true);
//         }
//       } else {
//         ASSERT(0);
//       }

//       ++i;

//       if (row == row1) {
//         ++j;
//       } else {
//         ++k;
//       }
//     } else {
//       if (mergeOption == 1) {
//         colDataAppend(pColInfo, *curRow, NULL, true);
//       }
//       ++i;
//     }
//   }

//   if (mergeOption == 1) {
//     while (i < numOfCols) {  // the remain columns are all null data
//       SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pColumns, i);
//       colDataAppend(pColInfo, *curRow, NULL, true);
//       ++i;
//     }
//   }

//   return nResult;
// #endif
// }

// static void getQualifiedRowsPos(STsdbReader* pTsdbReadHandle, int32_t startPos, int32_t endPos, int32_t numOfExisted,
//                                 int32_t* start, int32_t* end) {
//   *start = -1;

//   if (ASCENDING_TRAVERSE(pTsdbReadHandle->order)) {
//     int32_t remain = endPos - startPos + 1;
//     if (remain + numOfExisted > pTsdbReadHandle->outputCapacity) {
//       *end = (pTsdbReadHandle->outputCapacity - numOfExisted) + startPos - 1;
//     } else {
//       *end = endPos;
//     }

//     *start = startPos;
//   } else {
//     int32_t remain = (startPos - endPos) + 1;
//     if (remain + numOfExisted > pTsdbReadHandle->outputCapacity) {
//       *end = startPos + 1 - (pTsdbReadHandle->outputCapacity - numOfExisted);
//     } else {
//       *end = endPos;
//     }

//     *start = *end;
//     *end = startPos;
//   }
// }

// static void updateInfoAfterMerge(STsdbReader* pTsdbReadHandle, STableBlockScanInfo* pCheckInfo, int32_t numOfRows,
//                                  int32_t endPos) {
//   SQueryFilePos* cur = &pTsdbReadHandle->cur;

//   pCheckInfo->lastKey = cur->lastKey;
//   pTsdbReadHandle->realNumOfRows = numOfRows;
//   cur->rows = numOfRows;
//   cur->pos = endPos;
// }

// static void doCheckGeneratedBlockRange(STsdbReader* pTsdbReadHandle) {
//   SQueryFilePos* cur = &pTsdbReadHandle->cur;

//   if (cur->rows > 0) {
//     if (ASCENDING_TRAVERSE(pTsdbReadHandle->order)) {
//       assert(cur->win.skey >= pTsdbReadHandle->window.skey && cur->win.ekey <= pTsdbReadHandle->window.ekey);
//     } else {
//       assert(cur->win.skey >= pTsdbReadHandle->window.ekey && cur->win.ekey <= pTsdbReadHandle->window.skey);
//     }

//     SColumnInfoData* pColInfoData = taosArrayGet(pTsdbReadHandle->pColumns, 0);
//     assert(cur->win.skey == ((TSKEY*)pColInfoData->pData)[0] &&
//            cur->win.ekey == ((TSKEY*)pColInfoData->pData)[cur->rows - 1]);
//   } else {
//     cur->win = pTsdbReadHandle->window;

//     int32_t step = ASCENDING_TRAVERSE(pTsdbReadHandle->order) ? 1 : -1;
//     cur->lastKey = pTsdbReadHandle->window.ekey + step;
//   }
// }

// static void copyAllRemainRowsFromFileBlock(STsdbReader* pTsdbReadHandle, STableBlockScanInfo* pCheckInfo,
//                                            SDataBlockInfo* pBlockInfo, int32_t endPos) {
//   SQueryFilePos* cur = &pTsdbReadHandle->cur;

//   SDataCols* pCols = pTsdbReadHandle->rhelper.pDCols[0];
//   TSKEY*     tsArray = pCols->cols[0].pData;

//   bool ascScan = ASCENDING_TRAVERSE(pTsdbReadHandle->order);

//   int32_t step = ascScan ? 1 : -1;

//   int32_t start = cur->pos;
//   int32_t end = endPos;

//   if (!ascScan) {
//     TSWAP(start, end);
//   }

//   assert(pTsdbReadHandle->outputCapacity >= (end - start + 1));
//   int32_t numOfRows = doCopyRowsFromFileBlock(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, 0, start, end);

//   // the time window should always be ascending order: skey <= ekey
//   cur->win = (STimeWindow){.skey = tsArray[start], .ekey = tsArray[end]};
//   cur->mixBlock = (numOfRows != pBlockInfo->rows);
//   cur->lastKey = tsArray[endPos] + step;
//   cur->blockCompleted = (ascScan ? (endPos == pBlockInfo->rows - 1) : (endPos == 0));

//   // The value of pos may be -1 or pBlockInfo->rows, and it is invalid in both cases.
//   int32_t pos = endPos + step;
//   updateInfoAfterMerge(pTsdbReadHandle, pCheckInfo, numOfRows, pos);
//   doCheckGeneratedBlockRange(pTsdbReadHandle);

//   tsdbDebug("%p uid:%" PRIu64 ", data block created, mixblock:%d, brange:%" PRIu64 "-%" PRIu64 " rows:%d, %s",
//             pTsdbReadHandle, pCheckInfo->tableId, cur->mixBlock, cur->win.skey, cur->win.ekey, cur->rows,
//             pTsdbReadHandle->idStr);
// }

// int32_t getEndPosInDataBlock(STsdbReader* pTsdbReadHandle, SDataBlockInfo* pBlockInfo) {
//   // NOTE: reverse the order to find the end position in data block
//   int32_t endPos = -1;
//   bool    ascScan = ASCENDING_TRAVERSE(pTsdbReadHandle->order);
//   int32_t order = ascScan ? TSDB_ORDER_DESC : TSDB_ORDER_ASC;

//   SQueryFilePos* cur = &pTsdbReadHandle->cur;
//   SDataCols*     pCols = pTsdbReadHandle->rhelper.pDCols[0];

//   if (pTsdbReadHandle->outputCapacity >= pBlockInfo->rows) {
//     if (ascScan && pTsdbReadHandle->window.ekey >= pBlockInfo->window.ekey) {
//       endPos = pBlockInfo->rows - 1;
//       cur->mixBlock = (cur->pos != 0);
//     } else if ((!ascScan) && pTsdbReadHandle->window.ekey <= pBlockInfo->window.skey) {
//       endPos = 0;
//       cur->mixBlock = (cur->pos != pBlockInfo->rows - 1);
//     } else {
//       assert(pCols->numOfRows > 0);
//       endPos = doBinarySearchKey(pCols->cols[0].pData, pCols->numOfRows, pTsdbReadHandle->window.ekey, order);
//       cur->mixBlock = true;
//     }
//   } else {
//     if (ascScan && pTsdbReadHandle->window.ekey >= pBlockInfo->window.ekey) {
//       endPos = TMIN(cur->pos + pTsdbReadHandle->outputCapacity - 1, pBlockInfo->rows - 1);
//     } else if ((!ascScan) && pTsdbReadHandle->window.ekey <= pBlockInfo->window.skey) {
//       endPos = TMAX(cur->pos - pTsdbReadHandle->outputCapacity + 1, 0);
//     } else {
//       ASSERT(pCols->numOfRows > 0);
//       endPos = doBinarySearchKey(pCols->cols[0].pData, pCols->numOfRows, pTsdbReadHandle->window.ekey, order);

//       // current data is more than the capacity
//       int32_t size = abs(cur->pos - endPos) + 1;
//       if (size > pTsdbReadHandle->outputCapacity) {
//         int32_t delta = size - pTsdbReadHandle->outputCapacity;
//         if (ascScan) {
//           endPos -= delta;
//         } else {
//           endPos += delta;
//         }
//       }
//     }
//     cur->mixBlock = true;
//   }

//   return endPos;
// }

// // only return the qualified data to client in terms of query time window, data rows in the same block but do not
// // be included in the query time window will be discarded
// static void doMergeTwoLevelData(STsdbReader* pTsdbReadHandle, STableBlockScanInfo* pCheckInfo, SBlock* pBlock) {
//   SQueryFilePos* cur = &pTsdbReadHandle->cur;
//   SDataBlockInfo blockInfo = GET_FILE_DATA_BLOCK_INFO(pCheckInfo, pBlock);
//   STsdbCfg*      pCfg = REPO_CFG(pTsdbReadHandle->pTsdb);

//   initTableMemIterator(pTsdbReadHandle, pCheckInfo);

//   SDataCols* pCols = pTsdbReadHandle->rhelper.pDCols[0];
//   assert(pCols->cols[0].type == TSDB_DATA_TYPE_TIMESTAMP && pCols->cols[0].colId == PRIMARYKEY_TIMESTAMP_COL_ID &&
//          cur->pos >= 0 && cur->pos < pBlock->numOfRows);
//   // Even Multi-Version supported, the records with duplicated TSKEY would be merged inside of tsdbLoadData
//   interface. TSKEY* tsArray = pCols->cols[0].pData; assert(pCols->numOfRows == pBlock->numOfRows && tsArray[0] ==
//   pBlock->minKey.ts &&
//          tsArray[pBlock->numOfRows - 1] == pBlock->maxKey.ts);

//   bool    ascScan = ASCENDING_TRAVERSE(pTsdbReadHandle->order);
//   int32_t step = ascScan ? 1 : -1;

//   // for search the endPos, so the order needs to reverse
//   int32_t order = ascScan ? TSDB_ORDER_DESC : TSDB_ORDER_ASC;

//   int32_t numOfCols = (int32_t)(QH_GET_NUM_OF_COLS(pTsdbReadHandle));
//   int32_t endPos = getEndPosInDataBlock(pTsdbReadHandle, &blockInfo);

//   STimeWindow* pWin = &blockInfo.window;
//   tsdbDebug("%p uid:%" PRIu64 " start merge data block, file block range:%" PRIu64 "-%" PRIu64
//             " rows:%d, start:%d, end:%d, %s",
//             pTsdbReadHandle, pCheckInfo->tableId, pWin->skey, pWin->ekey, blockInfo.rows, cur->pos, endPos,
//             pTsdbReadHandle->idStr);

//   // compared with the data from in-memory buffer, to generate the correct timestamp array list
//   int32_t numOfRows = 0;
//   int32_t curRow = 0;

//   int16_t   rv1 = -1;
//   int16_t   rv2 = -1;
//   STSchema* pSchema1 = NULL;
//   STSchema* pSchema2 = NULL;

//   int32_t pos = cur->pos;
//   cur->win = TSWINDOW_INITIALIZER;
//   bool adjustPos = false;

//   // no data in buffer, load data from file directly
//   if (pCheckInfo->iiter == NULL && pCheckInfo->iter == NULL) {
//     copyAllRemainRowsFromFileBlock(pTsdbReadHandle, pCheckInfo, &blockInfo, endPos);
//     return;
//   } else if (pCheckInfo->iter != NULL || pCheckInfo->iiter != NULL) {
//     SSkipListNode* node = NULL;
//     TSKEY          lastKeyAppend = TSKEY_INITIAL_VAL;

//     do {
//       STSRow* row2 = NULL;
//       STSRow* row1 = getSRowInTableMem(pCheckInfo, pTsdbReadHandle->order, pCfg->update, &row2, TD_VER_MAX);
//       if (row1 == NULL) {
//         break;
//       }

//       TSKEY key = TD_ROW_KEY(row1);
//       if ((key > pTsdbReadHandle->window.ekey && ascScan) || (key < pTsdbReadHandle->window.ekey && !ascScan)) {
//         break;
//       }

//       if (adjustPos) {
//         if (key == lastKeyAppend) {
//           pos -= step;
//         }
//         adjustPos = false;
//       }

//       if (((pos > endPos || tsArray[pos] > pTsdbReadHandle->window.ekey) && ascScan) ||
//           ((pos < endPos || tsArray[pos] < pTsdbReadHandle->window.ekey) && !ascScan)) {
//         break;
//       }

//       if ((key < tsArray[pos] && ascScan) || (key > tsArray[pos] && !ascScan)) {
//         if (rv1 != TD_ROW_SVER(row1)) {
//           //          pSchema1 = tsdbGetTableSchemaByVersion(pTable, memRowVersion(row1));
//           rv1 = TD_ROW_SVER(row1);
//         }
//         if (row2 && rv2 != TD_ROW_SVER(row2)) {
//           //          pSchema2 = tsdbGetTableSchemaByVersion(pTable, memRowVersion(row2));
//           rv2 = TD_ROW_SVER(row2);
//         }

//         numOfRows +=
//             mergeTwoRowFromMem(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, &curRow, row1, row2, numOfCols,
//                                pCheckInfo->tableId, pSchema1, pSchema2, pCfg->update, &lastKeyAppend);
//         if (cur->win.skey == TSKEY_INITIAL_VAL) {
//           cur->win.skey = key;
//         }

//         cur->win.ekey = key;
//         cur->lastKey = key + step;
//         cur->mixBlock = true;
//         moveToNextRowInMem(pCheckInfo);
//       } else if (key == tsArray[pos]) {  // data in buffer has the same timestamp of data in file block, ignore it
//         if (TD_SUPPORT_UPDATE(pCfg->update)) {
//           if (lastKeyAppend != key) {
//             if (lastKeyAppend != TSKEY_INITIAL_VAL) {
//               ++curRow;
//             }
//             lastKeyAppend = key;
//           }
//           // load data from file firstly
//           numOfRows = doCopyRowsFromFileBlock(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, curRow, pos, pos);

//           if (rv1 != TD_ROW_SVER(row1)) {
//             rv1 = TD_ROW_SVER(row1);
//           }
//           if (row2 && rv2 != TD_ROW_SVER(row2)) {
//             rv2 = TD_ROW_SVER(row2);
//           }

//           // still assign data into current row
//           numOfRows +=
//               mergeTwoRowFromMem(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, &curRow, row1, row2, numOfCols,
//                                  pCheckInfo->tableId, pSchema1, pSchema2, pCfg->update, &lastKeyAppend);

//           if (cur->win.skey == TSKEY_INITIAL_VAL) {
//             cur->win.skey = key;
//           }

//           cur->win.ekey = key;
//           cur->lastKey = key + step;
//           cur->mixBlock = true;

//           moveToNextRowInMem(pCheckInfo);

//           pos += step;
//           adjustPos = true;
//         } else {
//           // discard the memory record
//           moveToNextRowInMem(pCheckInfo);
//         }
//       } else if ((key > tsArray[pos] && ascScan) || (key < tsArray[pos] && !ascScan)) {
//         if (cur->win.skey == TSKEY_INITIAL_VAL) {
//           cur->win.skey = tsArray[pos];
//         }

//         int32_t end = doBinarySearchKey(pCols->cols[0].pData, pCols->numOfRows, key, order);
//         assert(end != -1);

//         if (tsArray[end] == key) {  // the value of key in cache equals to the end timestamp value, ignore it
// #if 0
//           if (pCfg->update == TD_ROW_DISCARD_UPDATE) {
//             moveToNextRowInMem(pCheckInfo);
//           } else {
//             end -= step;
//           }
// #endif
//           if (!TD_SUPPORT_UPDATE(pCfg->update)) {
//             moveToNextRowInMem(pCheckInfo);
//           } else {
//             end -= step;
//           }
//         }

//         int32_t qstart = 0, qend = 0;
//         getQualifiedRowsPos(pTsdbReadHandle, pos, end, numOfRows, &qstart, &qend);

//         if ((lastKeyAppend != TSKEY_INITIAL_VAL) && (lastKeyAppend != (ascScan ? tsArray[qstart] : tsArray[qend]))) {
//           ++curRow;
//         }

//         numOfRows = doCopyRowsFromFileBlock(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, curRow, qstart, qend);
//         pos += (qend - qstart + 1) * step;
//         if (numOfRows > 0) {
//           curRow = numOfRows - 1;
//         }

//         cur->win.ekey = ascScan ? tsArray[qend] : tsArray[qstart];
//         cur->lastKey = cur->win.ekey + step;
//         lastKeyAppend = cur->win.ekey;
//       }
//     } while (numOfRows < pTsdbReadHandle->outputCapacity);

//     if (numOfRows < pTsdbReadHandle->outputCapacity) {
//       /**
//        * if cache is empty, load remain file block data. In contrast, if there are remain data in cache, do NOT
//        * copy them all to result buffer, since it may be overlapped with file data block.
//        */
//       if (node == NULL || ((TD_ROW_KEY((STSRow*)SL_GET_NODE_DATA(node)) > pTsdbReadHandle->window.ekey) && ascScan)
//       ||
//           ((TD_ROW_KEY((STSRow*)SL_GET_NODE_DATA(node)) < pTsdbReadHandle->window.ekey) && !ascScan)) {
//         // no data in cache or data in cache is greater than the ekey of time window, load data from file block
//         if (cur->win.skey == TSKEY_INITIAL_VAL) {
//           cur->win.skey = tsArray[pos];
//         }

//         int32_t start = -1, end = -1;
//         getQualifiedRowsPos(pTsdbReadHandle, pos, endPos, numOfRows, &start, &end);

//         numOfRows = doCopyRowsFromFileBlock(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, numOfRows, start, end);
//         pos += (end - start + 1) * step;

//         cur->win.ekey = ascScan ? tsArray[end] : tsArray[start];
//         cur->lastKey = cur->win.ekey + step;
//         cur->mixBlock = true;
//       }
//     }
//   }

//   cur->blockCompleted = (((pos > endPos || cur->lastKey > pTsdbReadHandle->window.ekey) && ascScan) ||
//                          ((pos < endPos || cur->lastKey < pTsdbReadHandle->window.ekey) && !ascScan));

//   if (!ascScan) {
//     TSWAP(cur->win.skey, cur->win.ekey);
//   }

//   updateInfoAfterMerge(pTsdbReadHandle, pCheckInfo, numOfRows, pos);
//   doCheckGeneratedBlockRange(pTsdbReadHandle);

//   tsdbDebug("%p uid:%" PRIu64 ", data block created, mixblock:%d, brange:%" PRIu64 "-%" PRIu64 " rows:%d, %s",
//             pTsdbReadHandle, pCheckInfo->tableId, cur->mixBlock, cur->win.skey, cur->win.ekey, cur->rows,
//             pTsdbReadHandle->idStr);
// }

// int32_t binarySearchForKey(char* pValue, int num, TSKEY key, int order) {
//   int    firstPos, lastPos, midPos = -1;
//   int    numOfRows;
//   TSKEY* keyList;

//   if (num <= 0) return -1;

//   keyList = (TSKEY*)pValue;
//   firstPos = 0;
//   lastPos = num - 1;

//   if (order == TSDB_ORDER_DESC) {
//     // find the first position which is smaller than the key
//     while (1) {
//       if (key >= keyList[lastPos]) return lastPos;
//       if (key == keyList[firstPos]) return firstPos;
//       if (key < keyList[firstPos]) return firstPos - 1;

//       numOfRows = lastPos - firstPos + 1;
//       midPos = (numOfRows >> 1) + firstPos;

//       if (key < keyList[midPos]) {
//         lastPos = midPos - 1;
//       } else if (key > keyList[midPos]) {
//         firstPos = midPos + 1;
//       } else {
//         break;
//       }
//     }

//   } else {
//     // find the first position which is bigger than the key
//     while (1) {
//       if (key <= keyList[firstPos]) return firstPos;
//       if (key == keyList[lastPos]) return lastPos;

//       if (key > keyList[lastPos]) {
//         lastPos = lastPos + 1;
//         if (lastPos >= num)
//           return -1;
//         else
//           return lastPos;
//       }

//       numOfRows = lastPos - firstPos + 1;
//       midPos = (numOfRows >> 1) + firstPos;

//       if (key < keyList[midPos]) {
//         lastPos = midPos - 1;
//       } else if (key > keyList[midPos]) {
//         firstPos = midPos + 1;
//       } else {
//         break;
//       }
//     }
//   }

//   return midPos;
// }

static void cleanupBlockOrderSupporter(SBlockOrderSupporter* pSup) {
  taosMemoryFreeClear(pSup->numOfBlocksPerTable);
  taosMemoryFreeClear(pSup->indexPerTable);

  for (int32_t i = 0; i < pSup->numOfTables; ++i) {
    SBlockOrderWrapper* pBlockInfo = pSup->pDataBlockInfo[i];
    taosMemoryFreeClear(pBlockInfo);
  }

  taosMemoryFreeClear(pSup->pDataBlockInfo);
}

static int32_t initBlockOrderSupporter(SBlockOrderSupporter* pSup, int32_t numOfTables) {
  ASSERT(numOfTables >= 1);

  pSup->numOfBlocksPerTable = taosMemoryCalloc(1, sizeof(int32_t) * numOfTables);
  pSup->indexPerTable       = taosMemoryCalloc(1, sizeof(int32_t) * numOfTables);
  pSup->pDataBlockInfo      = taosMemoryCalloc(1, POINTER_BYTES * numOfTables);

  if (pSup->numOfBlocksPerTable == NULL || pSup->indexPerTable == NULL || pSup->pDataBlockInfo == NULL) {
    cleanupBlockOrderSupporter(pSup);
    return TSDB_CODE_OUT_OF_MEMORY;
  }

  return TSDB_CODE_SUCCESS;
}

static int32_t fileDataBlockOrderCompar(const void* pLeft, const void* pRight, void* param) {
  int32_t leftIndex  = *(int32_t*)pLeft;
  int32_t rightIndex = *(int32_t*)pRight;

  SBlockOrderSupporter* pSupporter = (SBlockOrderSupporter*)param;

  int32_t leftTableBlockIndex = pSupporter->indexPerTable[leftIndex];
  int32_t rightTableBlockIndex = pSupporter->indexPerTable[rightIndex];

  if (leftTableBlockIndex > pSupporter->numOfBlocksPerTable[leftIndex]) {
    /* left block is empty */
    return 1;
  } else if (rightTableBlockIndex > pSupporter->numOfBlocksPerTable[rightIndex]) {
    /* right block is empty */
    return -1;
  }

  SBlockOrderWrapper* pLeftBlock  = &pSupporter->pDataBlockInfo[leftIndex][leftTableBlockIndex];
  SBlockOrderWrapper* pRightBlock = &pSupporter->pDataBlockInfo[rightIndex][rightTableBlockIndex];

  return pLeftBlock->pBlock->aSubBlock[0].offset > pRightBlock->pBlock->aSubBlock[0].offset ? 1 : -1;
}

static int32_t initBlockIterator(STsdbReader* pReader, SDataBlockIter* pBlockIter, int32_t numOfBlocks) {
 pBlockIter->numOfBlocks = numOfBlocks;

 // access data blocks according to the offset of each block in asc/desc order.
 int32_t numOfTables = (int32_t)taosHashGetSize(pReader->status.pTableMap);

 SBlockOrderSupporter sup = {0};
 int32_t code = initBlockOrderSupporter(&sup, numOfTables);
 if (code != TSDB_CODE_SUCCESS) {
   return code;
 }

 int32_t cnt = 0;
 void* ptr = NULL;
 while(1) {
   ptr = taosHashIterate(pReader->status.pTableMap, &ptr);
   if (ptr == NULL) {
     break;
   }

   STableBlockScanInfo* pTableScanInfo = (STableBlockScanInfo*)ptr;
   if (pTableScanInfo->pBlockList == NULL || taosArrayGetSize(pTableScanInfo->pBlockList) == 0) {
     continue;
   }

   size_t num = taosArrayGetSize(pTableScanInfo->pBlockList);
   sup.numOfBlocksPerTable[sup.numOfTables] = num;

   char* buf = taosMemoryMalloc(sizeof(SBlockOrderWrapper) * num);
   if (buf == NULL) {
     cleanupBlockOrderSupporter(&sup);
     return TSDB_CODE_TDB_OUT_OF_MEMORY;
   }

   sup.pDataBlockInfo[sup.numOfTables] = (SBlockOrderWrapper*)buf;
   for (int32_t k = 0; k < num; ++k) {
     SBlockOrderWrapper wrapper = {0};
     wrapper.pBlock = (SBlock*)taosArrayGet(pTableScanInfo->pBlockList, k);
     wrapper.uid = pTableScanInfo->uid;

     sup.pDataBlockInfo[sup.numOfTables][k] = wrapper;
     cnt++;
   }

   sup.numOfTables += 1;
 }

 ASSERT(numOfBlocks == cnt);

 // since there is only one table qualified, blocks are not sorted
 if (sup.numOfTables == 1) {
   for(int32_t i = 0; i < numOfBlocks; ++i) {
     SFileDataBlockInfo blockInfo = {.uid = sup.pDataBlockInfo[0][i].uid, .tbBlockIdx = i};
     taosArrayPush(pBlockIter->blockList, &blockInfo);
   }
   tsdbDebug("%p create blocks info struct completed for one table, %d blocks not sorted %s",
       pReader, cnt, pReader->idStr);
   return TSDB_CODE_SUCCESS;
 }

 tsdbDebug("%p create data blocks info struct completed, %d blocks in %d tables %s", pReader, cnt, sup.numOfTables, pReader->idStr);
 assert(cnt <= numOfBlocks && sup.numOfTables <= numOfTables);  // the pTableQueryInfo[j]->numOfBlocks may be 0

 SMultiwayMergeTreeInfo* pTree = NULL;
 
 uint8_t ret = tMergeTreeCreate(&pTree, sup.numOfTables, &sup, fileDataBlockOrderCompar);
 if (ret != TSDB_CODE_SUCCESS) {
   cleanupBlockOrderSupporter(&sup);
   return TSDB_CODE_TDB_OUT_OF_MEMORY;
 }

 int32_t numOfTotal = 0;
 while (numOfTotal < cnt) {
   int32_t pos = tMergeTreeGetChosenIndex(pTree);
   int32_t index = sup.indexPerTable[pos]++;

   SFileDataBlockInfo blockInfo = {.uid = sup.pDataBlockInfo[pos][index].uid, .tbBlockIdx = index};
   taosArrayPush(pBlockIter->blockList, &blockInfo);

   // set data block index overflow, in order to disable the offset comparator
   if (sup.indexPerTable[pos] >= sup.numOfBlocksPerTable[pos]) {
     sup.indexPerTable[pos] = sup.numOfBlocksPerTable[pos] + 1;
   }

   numOfTotal += 1;
   tMergeTreeAdjust(pTree, tMergeTreeGetAdjustIndex(pTree));
 }

 tsdbDebug("%p %d data blocks sort completed, %s", pReader, cnt, pReader->idStr);
 cleanupBlockOrderSupporter(&sup);
 taosMemoryFree(pTree);

 pBlockIter->index = 0;
 return TSDB_CODE_SUCCESS;
}

// static int32_t getFirstFileDataBlock(STsdbReader* pTsdbReadHandle, bool* exists);

//static int32_t getDataBlock(STsdbReader* pTsdbReadHandle, SFileBlockInfo* pNext, bool* exists) {
// int32_t        step = ASCENDING_TRAVERSE(pTsdbReadHandle->order) ? 1 : -1;
// SQueryFilePos* cur = &pTsdbReadHandle->cur;
//
// while (1) {
//   int32_t code = loadFileDataBlock(pTsdbReadHandle, pNext->compBlock, pNext->pTableCheckInfo, exists);
//   if (code != TSDB_CODE_SUCCESS || *exists) {
//     return code;
//   }
//
//   if ((cur->slot == pTsdbReadHandle->numOfBlocks - 1 && ASCENDING_TRAVERSE(pTsdbReadHandle->order)) ||
//       (cur->slot == 0 && !ASCENDING_TRAVERSE(pTsdbReadHandle->order))) {
//     // all data blocks in current file has been checked already, try next file if exists
//     return getFirstFileDataBlock(pTsdbReadHandle, exists);
//   } else {  // next block of the same file
//     cur->slot += step;
//     cur->mixBlock = false;
//     cur->blockCompleted = false;
//     pNext = &pTsdbReadHandle->pDataBlockInfo[cur->slot];
//   }
// }
//}

// static int32_t getFirstFileDataBlock(STsdbReader* pTsdbReadHandle, bool* exists) {
//   pTsdbReadHandle->numOfBlocks = 0;
//   SQueryFilePos* cur = &pTsdbReadHandle->cur;

//   int32_t code = TSDB_CODE_SUCCESS;

//   int32_t numOfBlocks = 0;
//   int32_t numOfTables = (int32_t)taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);

//   STsdbKeepCfg* pCfg = REPO_KEEP_CFG(pTsdbReadHandle->pTsdb);
//   STimeWindow   win = TSWINDOW_INITIALIZER;

//   while (true) {
//     tsdbRLockFS(REPO_FS(pTsdbReadHandle->pTsdb));

//     if ((pTsdbReadHandle->pFileGroup = tsdbFSIterNext(&pTsdbReadHandle->fileIter)) == NULL) {
//       tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));
//       break;
//     }

//     tsdbGetFidKeyRange(pCfg->days, pCfg->precision, pTsdbReadHandle->pFileGroup->fid, &win.skey, &win.ekey);

//     // current file are not overlapped with query time window, ignore remain files
//     if ((ASCENDING_TRAVERSE(pTsdbReadHandle->order) && win.skey > pTsdbReadHandle->window.ekey) ||
//         (!ASCENDING_TRAVERSE(pTsdbReadHandle->order) && win.ekey < pTsdbReadHandle->window.ekey)) {
//       tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));
//       tsdbDebug("%p remain files are not qualified for qrange:%" PRId64 "-%" PRId64 ", ignore, %s", pTsdbReadHandle,
//                 pTsdbReadHandle->window.skey, pTsdbReadHandle->window.ekey, pTsdbReadHandle->idStr);
//       pTsdbReadHandle->pFileGroup = NULL;
//       assert(pTsdbReadHandle->numOfBlocks == 0);
//       break;
//     }

//     if (tsdbSetAndOpenReadFSet(&pTsdbReadHandle->rhelper, pTsdbReadHandle->pFileGroup) < 0) {
//       tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));
//       code = terrno;
//       break;
//     }

//     tsdbUnLockFS(REPO_FS(pTsdbReadHandle->pTsdb));

//     if (tsdbLoadBlockIdx(&pTsdbReadHandle->rhelper) < 0) {
//       code = terrno;
//       break;
//     }

//     if ((code = getFileCompInfo(pTsdbReadHandle, &numOfBlocks)) != TSDB_CODE_SUCCESS) {
//       break;
//     }

//     tsdbDebug("%p %d blocks found in file for %d table(s), fid:%d, %s", pTsdbReadHandle, numOfBlocks, numOfTables,
//               pTsdbReadHandle->pFileGroup->fid, pTsdbReadHandle->idStr);

//     assert(numOfBlocks >= 0);
//     if (numOfBlocks == 0) {
//       continue;
//     }

//     // todo return error code to query engine
//     if ((code = createDataBlocksInfo(pTsdbReadHandle, numOfBlocks, &pTsdbReadHandle->numOfBlocks)) !=
//         TSDB_CODE_SUCCESS) {
//       break;
//     }

//     assert(numOfBlocks >= pTsdbReadHandle->numOfBlocks);
//     if (pTsdbReadHandle->numOfBlocks > 0) {
//       break;
//     }
//   }

//   // no data in file anymore
//   if (pTsdbReadHandle->numOfBlocks <= 0 || code != TSDB_CODE_SUCCESS) {
//     if (code == TSDB_CODE_SUCCESS) {
//       assert(pTsdbReadHandle->pFileGroup == NULL);
//     }

//     cur->fid = INT32_MIN;  // denote that there are no data in file anymore
//     *exists = false;
//     return code;
//   }

//   assert(pTsdbReadHandle->pFileGroup != NULL && pTsdbReadHandle->numOfBlocks > 0);
//   cur->slot = ASCENDING_TRAVERSE(pTsdbReadHandle->order) ? 0 : pTsdbReadHandle->numOfBlocks - 1;
//   cur->fid = pTsdbReadHandle->pFileGroup->fid;

//   SFileBlockInfo* pBlockInfo = &pTsdbReadHandle->pDataBlockInfo[cur->slot];
//   return getDataBlock(pTsdbReadHandle, pBlockInfo, exists);
// }

// static bool isEndFileDataBlock(SQueryFilePos* cur, int32_t numOfBlocks, bool ascTrav) {
//   assert(cur != NULL && numOfBlocks > 0);
//   return (cur->slot == numOfBlocks - 1 && ascTrav) || (cur->slot == 0 && !ascTrav);
// }

// static void moveToNextDataBlockInCurrentFile(STsdbReader* pTsdbReadHandle) {
//   int32_t step = ASCENDING_TRAVERSE(pTsdbReadHandle->order) ? 1 : -1;

//   SQueryFilePos* cur = &pTsdbReadHandle->cur;
//   assert(cur->slot < pTsdbReadHandle->numOfBlocks && cur->slot >= 0);

//   cur->slot += step;
//   cur->mixBlock = false;
//   cur->blockCompleted = false;
// }

// static int32_t getBucketIndex(int32_t startRow, int32_t bucketRange, int32_t numOfRows) {
//   return (numOfRows - startRow) / bucketRange;
// }

// query ended in/started from current block
static int32_t dataBlockPartialRequired(STimeWindow* pWindow, SBlock* pBlock) {
 return ((pWindow->ekey < pBlock->maxKey.ts && pWindow->ekey >= pBlock->minKey.ts) ||
     (pWindow->skey <= pBlock->maxKey.ts && pWindow->skey > pBlock->minKey.ts));
}

static SFileDataBlockInfo* getCurrentBlockInfo(SDataBlockIter* pBlockIter) {
  SFileDataBlockInfo* pFBlockInfo = taosArrayGet(pBlockIter->blockList, pBlockIter->index);
  return pFBlockInfo;
}

static bool overlapWithNeighborBlock(SBlock* pBlock, int32_t blockIndex) {
  return false;
}

static bool bufferDataInFileBlockGap(int32_t order, int64_t key, SBlock* pBlock) {
  bool ascScan = ASCENDING_TRAVERSE(order);

  return (ascScan && (key != TSKEY_INITIAL_VAL && key <= pBlock->minKey.ts)) ||
       (!ascScan && (key != TSKEY_INITIAL_VAL && key >= pBlock->maxKey.ts));
}

static int32_t buildInmemDataBlock(STsdbReader* pReader, STableBlockScanInfo* pBlockScanInfo, SBlock* pBlock, TSDBKEY *key) {
  int32_t code = TSDB_CODE_SUCCESS;

  bool ascScan = ASCENDING_TRAVERSE(pReader->order);
  bool cacheDataInFileBlockHole = (ascScan && (key->ts != TSKEY_INITIAL_VAL && key->ts < pBlock->minKey.ts)) ||
                                  (!ascScan && (key->ts != TSKEY_INITIAL_VAL && key->ts > pBlock->maxKey.ts));
  ASSERT(cacheDataInFileBlockHole);

  // do not load file block into buffer
  int32_t step = ascScan ? 1 : -1;

  TSDBKEY maxKey = {.version = pReader->endVersion};
  maxKey.ts = ascScan ? (pBlock->minKey.ts - step) : (pBlock->maxKey.ts - step);

  pBlockScanInfo->memHasVal = tsdbTbDataIterNext(&pBlockScanInfo->iter);
  pBlockScanInfo->imemHasVal = tsdbTbDataIterNext(&pBlockScanInfo->iiter);

  code = tsdbReadRowsFromCache(pBlockScanInfo, maxKey, pReader->capacity, pReader);
  return code;
}

static int32_t buildComposedDataBlock(STsdbReader* pReader, STableBlockScanInfo* pBlockScanInfo) {
  SFileBlockDumpInfo *pDumpInfo = &pReader->status.fBlockDumpInfo;
  SBlockData* pData = &pReader->status.fileBlockData;

  STSchema* pSchema = NULL;
  SRowMerger merge = {0};

  int64_t key = pData->aTSKEY[0];
  TSDBROW* pRow = getValidRow(&pBlockScanInfo->iter, &pBlockScanInfo->memHasVal, pReader);
  TSDBROW* piRow = getValidRow(&pBlockScanInfo->iiter, &pBlockScanInfo->imemHasVal, pReader);

  if (pBlockScanInfo->memHasVal && pBlockScanInfo->imemHasVal) {
    TSDBKEY k = TSDBROW_KEY(pRow);
    TSDBKEY ik = TSDBROW_KEY(piRow);

    // todo check version in file
    if (key < k.ts || key < ik.ts) {
      tRowMergerInit(&merge, NULL, pSchema);
      STSRow* pTsRow = NULL;
      doLoadRowsOfIdenticalTsInFileBlock(pData, pDumpInfo, key, &merge, pReader, &pTsRow);

    }
  }

  return TSDB_CODE_SUCCESS;
}

static int32_t loadDataInFiles(STsdbReader* pReader, bool* exists) {
  SReaderStatus* pStatus = &pReader->status;
  SFileSetIter*  pFIter = &pStatus->fileIter;

  if (pFIter->index < pFIter->numOfFiles) {
    if (pReader->status.blockIter.index == -1) {
      int32_t numOfBlocks = 0;

      while (1) {
        bool hasNext = nextFilesetIterator(&pStatus->fileIter, pReader->order, pReader);
        if (!hasNext) {
          // no data files on disk
          break;
        }

        SArray* pIndexList = taosArrayInit(4, sizeof(SBlockIdx));
        int32_t code = doLoadBlockIndex(pReader, pReader->pFileReader, pIndexList);
        if (code != TSDB_CODE_SUCCESS) {
          return code;
        }

        if (taosArrayGetSize(pIndexList) > 0) {
          uint32_t numOfValidTable = 0;
          code = doLoadFileBlock(pReader, pIndexList, &numOfValidTable);
          if (code != TSDB_CODE_SUCCESS) {
            return code;
          }

          if (numOfValidTable > 0) {
            break;
          }
        }

        // no blocks in current file, try next files
      }

      SDataBlockIter* pBlockIter = &pReader->status.blockIter;
      int32_t code = initBlockIterator(pReader, pBlockIter, numOfBlocks);
      if (code != TSDB_CODE_SUCCESS) {
        return code;
      }

      int64_t key = 0; // todo get the first qualified key in buffer

      SFileDataBlockInfo* pFBlock = getCurrentBlockInfo(pBlockIter);
      STableBlockScanInfo* pScanInfo = taosHashGet(pReader->status.pTableMap, &pFBlock->uid, sizeof(pFBlock->uid));
      SBlock* pBlock = taosArrayGet(pScanInfo->pBlockList, pFBlock->tbBlockIdx);

      if (pScanInfo->iterInit == false) {
        STbData* d = NULL;
        tsdbGetTbDataFromMemTable(pReader->pTsdb->mem, pReader->suid, pScanInfo->uid, &d);

        TSDBKEY startKey = {.ts = pReader->window.skey, .version = pReader->startVersion};
        tsdbTbDataIterOpen(d, &startKey, 0, &pScanInfo->iter);

        STbData* di = NULL;
        tsdbGetTbDataFromMemTable(pReader->pTsdb->imem, pReader->suid, pScanInfo->uid, &di);
        tsdbTbDataIterOpen(di, &startKey, 0, &pScanInfo->iiter);

        pScanInfo->iterInit = true;
      }

      if (dataBlockPartialRequired(&pReader->window, pBlock) || overlapWithNeighborBlock(pBlock, pFBlock->tbBlockIdx)) {
        SBlockData data = {0};
        doLoadFileBlockData(pReader, pBlockIter, pScanInfo, &data);
        // build composed data block
        
      } else if (bufferDataInFileBlockGap(pReader->order, key, pBlock)) {
        // data in memory that are earlier than current file block
        TSDBKEY maxKey = {.ts = pReader->window.ekey, .version = pReader->endVersion};
        buildInmemDataBlock(pReader, pScanInfo, pBlock, &maxKey);
        // build data block from in-memory buffer data completed.
      } else { // whole block is required, return it directly
        SDataBlockInfo info = {0};
        info.rows = pBlock->nRow;
        info.uid  = pScanInfo->uid;
        info.window.skey = pBlock->minKey.ts;
        info.window.ekey = pBlock->maxKey.ts;
      }

    } else {

    }
  }

  return TSDB_CODE_SUCCESS;
}

// static bool doHasDataInBuffer(STsdbReader* pTsdbReadHandle) {
//   size_t numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);

//   while (pTsdbReadHandle->activeIndex < numOfTables) {
//     if (hasMoreDataInCache(pTsdbReadHandle)) {
//       return true;
//     }

//     pTsdbReadHandle->activeIndex += 1;
//   }

//   return false;
// }

// // todo not unref yet, since it is not support multi-group interpolation query
// static UNUSED_FUNC void changeQueryHandleForInterpQuery(STsdbReader* pHandle) {
//   // filter the queried time stamp in the first place
//   STsdbReader* pTsdbReadHandle = (STsdbReader*)pHandle;

//   // starts from the buffer in case of descending timestamp order check data blocks
//   size_t numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);

//   int32_t i = 0;
//   while (i < numOfTables) {
//     STableBlockScanInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, i);

//     // the first qualified table for interpolation query
//     //    if ((pTsdbReadHandle->window.skey <= pCheckInfo->pTableObj->lastKey) &&
//     //        (pCheckInfo->pTableObj->lastKey != TSKEY_INITIAL_VAL)) {
//     //      break;
//     //    }

//     i++;
//   }

//   // there are no data in all the tables
//   if (i == numOfTables) {
//     return;
//   }

//   STableBlockScanInfo info = *(STableBlockScanInfo*)taosArrayGet(pTsdbReadHandle->pTableCheckInfo, i);
//   taosArrayClear(pTsdbReadHandle->pTableCheckInfo);

//   info.lastKey = pTsdbReadHandle->window.skey;
//   taosArrayPush(pTsdbReadHandle->pTableCheckInfo, &info);
// }

TSDBROW* getValidRow(STbDataIter* pIter, bool* hasVal, STsdbReader* pReader) {
  if (!hasVal) {
    return NULL;
  }

  TSDBROW* pRow = tsdbTbDataIterGet(pIter);

  TSDBKEY key = TSDBROW_KEY(pRow);
  if (key.ts > pReader->window.ekey) {
    *hasVal = false;
    return NULL;
  }

  if (key.version <= pReader->endVersion) {
    return pRow;
  }

  while(1) {
    *hasVal = tsdbTbDataIterNext(pIter);
    if (!(*hasVal)) {
      return NULL;
    }

    pRow = tsdbTbDataIterGet(pIter);

    key = TSDBROW_KEY(pRow);
    if (key.ts > pReader->window.ekey) {
      *hasVal = false;
      return NULL;
    }

    if (key.version <= pReader->endVersion) {
      return pRow;
    }
  }
}

int32_t doLoadRowsOfIdenticalTs(STbDataIter *pIter, bool* hasVal, int64_t ts, SRowMerger* pMerger, STsdbReader* pReader) {
  while (1) {
    *hasVal = tsdbTbDataIterNext(pIter);
    if (!*hasVal) {
      break;
    }

    TSDBROW* pRow = getValidRow(pIter, hasVal, pReader);
    TSDBKEY k = TSDBROW_KEY(pRow);
    if (k.ts > ts) {
      break;
    }

    tRowMerge(pMerger, pRow);
  }

  return TSDB_CODE_SUCCESS;
}

int32_t doLoadRowsOfIdenticalTsInFileBlock(SBlockData* pData, SFileBlockDumpInfo* pDumpInfo, int64_t ts, SRowMerger *pMerger,
    STsdbReader* pReader, STSRow** pRow) {
  int64_t key = pData->aTSKEY[pDumpInfo->rowIndex];
  if ((pDumpInfo->rowIndex < pData->nRow - 1)) {
    if (pData->aTSKEY[pDumpInfo->rowIndex + 1] < key) {
      SRowMerger merger = {0};
      tRowMergerInit(&merger, NULL, NULL);
      int32_t rowIndex = pDumpInfo->rowIndex + 1;
      while (pData->aTSKEY[rowIndex] == key) {
        tRowMerge(&merger, NULL);
      }
      tRowMergerGetRow(&merger, pRow);
      tRowMergerClear(&merger);
    }
  } else {
  }
  return TSDB_CODE_SUCCESS;
}

int32_t tsdbGetNextRowInMem(STableBlockScanInfo* pBlockScanInfo, STsdbReader* pReader, STSRow** pTSRow) {
  STSchema* pSchema = NULL;  // todo set the correct schema
  TSKEY     mergeTs = TSKEY_INITIAL_VAL;

  SRowMerger merge = {0};

  TSDBROW* pRow  = getValidRow(&pBlockScanInfo->iter, &pBlockScanInfo->memHasVal, pReader);
  TSDBROW* piRow = getValidRow(&pBlockScanInfo->iiter, &pBlockScanInfo->imemHasVal, pReader);

  TSDBKEY k = {.ts = TSKEY_INITIAL_VAL};
  TSDBKEY ik = {.ts = TSKEY_INITIAL_VAL};

  if (pBlockScanInfo->memHasVal && pBlockScanInfo->imemHasVal) {
    k = TSDBROW_KEY(pRow);
    ik = TSDBROW_KEY(piRow);

    if (ik.ts <= k.ts) {
      tRowMergerInit(&merge, piRow, pSchema);
      doLoadRowsOfIdenticalTs(&pBlockScanInfo->iiter, &pBlockScanInfo->imemHasVal, ik.ts, &merge, pReader);

      if (k.ts == mergeTs) {
        doLoadRowsOfIdenticalTs(&pBlockScanInfo->iter, &pBlockScanInfo->memHasVal, k.ts, &merge, pReader);
      }

      tRowMergerGetRow(&merge, pTSRow);
      return TSDB_CODE_SUCCESS;
    } else {  // k.ts < ik.ts
      tRowMergerInit(&merge, pRow, pSchema);
      doLoadRowsOfIdenticalTs(&pBlockScanInfo->iter, &pBlockScanInfo->memHasVal, k.ts, &merge, pReader);
      tRowMergerGetRow(&merge, pTSRow);
      return TSDB_CODE_SUCCESS;
    }
  }

  if (pBlockScanInfo->memHasVal) {
    tRowMergerInit(&merge, pRow, pSchema);
    doLoadRowsOfIdenticalTs(&pBlockScanInfo->iter, &pBlockScanInfo->memHasVal, k.ts, &merge, pReader);
    tRowMergerGetRow(&merge, pTSRow);
    return TSDB_CODE_SUCCESS;
  }

  if (pBlockScanInfo->imemHasVal) {
    tRowMergerInit(&merge, piRow, pSchema);
    doLoadRowsOfIdenticalTs(&pBlockScanInfo->iiter, &pBlockScanInfo->imemHasVal, ik.ts, &merge, pReader);
    tRowMergerGetRow(&merge, pTSRow);
    return TSDB_CODE_SUCCESS;
  }

  return TSDB_CODE_SUCCESS;
}

int32_t tsdbReadRowsFromCache(STableBlockScanInfo* pBlockScanInfo, TSDBKEY maxKey, int32_t capacity, STsdbReader* pReader) {
  int32_t numOfRows = 0;
  int32_t numOfCols = (int32_t)taosArrayGetSize(pReader->pResBlock->pDataBlock);

  SSDataBlock* pBlock = pReader->pResBlock;

  int64_t st = taosGetTimestampUs();

  STSchema* pSchema = NULL;
  do {
    STSRow* pTSRow = NULL;
    tsdbGetNextRowInMem(pBlockScanInfo, pReader, &pTSRow);
    // todo assign to ssdatablock

    if (pBlockScanInfo->memHasVal) {
      TSDBROW* pRow = tsdbTbDataIterGet(&pBlockScanInfo->iter);
      TSDBKEY k = TSDBROW_KEY(pRow);
      if (k.ts >= maxKey.ts) {
        break;
      }
    }

    if (pBlockScanInfo->imemHasVal) {
      TSDBROW* pRow = tsdbTbDataIterGet(&pBlockScanInfo->iiter);
      TSDBKEY k = TSDBROW_KEY(pRow);
      if (k.ts >= maxKey.ts) {
        break;
      }
    }

    // no data in buffer, return immediately
    if (!(pBlockScanInfo->memHasVal || pBlockScanInfo->imemHasVal)) {
      break;
    }

    if (numOfRows >= capacity) {
      break;
    }
  } while (1);

  taosMemoryFreeClear(pSchema);
  assert(numOfRows <= capacity);

  int64_t elapsedTime = taosGetTimestampUs() - st;
  tsdbDebug("%p build data block from cache completed, elapsed time:%" PRId64 " us, numOfRows:%d, numOfCols:%d, %s",
            pReader, elapsedTime, pBlock->info.rows, numOfCols, pReader->idStr);

  return TSDB_CODE_SUCCESS;
}

// static void destroyHelper(void* param) {
//   if (param == NULL) {
//     return;
//   }

//   //  tQueryInfo* pInfo = (tQueryInfo*)param;
//   //  if (pInfo->optr != TSDB_RELATION_IN) {
//   //    taosMemoryFreeClear(pInfo->q);
//   //  } else {
//   //    taosHashCleanup((SHashObj *)(pInfo->q));
//   //  }

//   taosMemoryFree(param);
// }

// #define TSDB_PREV_ROW 0x1
// #define TSDB_NEXT_ROW 0x2

// static bool loadBlockOfActiveTable(STsdbReader* pTsdbReadHandle) {
//   if (pTsdbReadHandle->checkFiles) {
//     // check if the query range overlaps with the file data block
//     bool exists = true;

//     int32_t code = loadDataInFiles(pTsdbReadHandle, &exists);
//     if (code != TSDB_CODE_SUCCESS) {
//       pTsdbReadHandle->checkFiles = false;
//       return false;
//     }

//     if (exists) {
//       tsdbRetrieveDataBlock((STsdbReader**)pTsdbReadHandle, NULL);
//       if (pTsdbReadHandle->currentLoadExternalRows && pTsdbReadHandle->window.skey == pTsdbReadHandle->window.ekey) {
//         SColumnInfoData* pColInfo = taosArrayGet(pTsdbReadHandle->pColumns, 0);
//         assert(*(int64_t*)pColInfo->pData == pTsdbReadHandle->window.skey);
//       }

//       pTsdbReadHandle->currentLoadExternalRows = false;  // clear the flag, since the exact matched row is found.
//       return exists;
//     }

//     pTsdbReadHandle->checkFiles = false;
//   }

//   if (hasMoreDataInCache(pTsdbReadHandle)) {
//     pTsdbReadHandle->currentLoadExternalRows = false;
//     return true;
//   }

//   // current result is empty
//   if (pTsdbReadHandle->currentLoadExternalRows && pTsdbReadHandle->window.skey == pTsdbReadHandle->window.ekey &&
//       pTsdbReadHandle->cur.rows == 0) {
//     //    SMemTable* pMemRef = pTsdbReadHandle->pMemTable;

//     //    doGetExternalRow(pTsdbReadHandle, TSDB_PREV_ROW, pMemRef);
//     //    doGetExternalRow(pTsdbReadHandle, TSDB_NEXT_ROW, pMemRef);

//     bool result = tsdbGetExternalRow(pTsdbReadHandle);

//     //    pTsdbReadHandle->prev = doFreeColumnInfoData(pTsdbReadHandle->prev);
//     //    pTsdbReadHandle->next = doFreeColumnInfoData(pTsdbReadHandle->next);
//     pTsdbReadHandle->currentLoadExternalRows = false;

//     return result;
//   }

//   return false;
// }

// static bool loadCachedLastRow(STsdbReader* pTsdbReadHandle) {
//   // the last row is cached in buffer, return it directly.
//   // here note that the pTsdbReadHandle->window must be the TS_INITIALIZER
//   int32_t numOfCols = (int32_t)(QH_GET_NUM_OF_COLS(pTsdbReadHandle));
//   size_t  numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
//   assert(numOfTables > 0 && numOfCols > 0);

//   SQueryFilePos* cur = &pTsdbReadHandle->cur;

//   STSRow* pRow = NULL;
//   TSKEY   key = TSKEY_INITIAL_VAL;
//   int32_t step = ASCENDING_TRAVERSE(pTsdbReadHandle->order) ? 1 : -1;
//   TSKEY   lastRowKey = TSKEY_INITIAL_VAL;
//   int32_t curRow = 0;

//   if (++pTsdbReadHandle->activeIndex < numOfTables) {
//     STableBlockScanInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, pTsdbReadHandle->activeIndex);
//     //    int32_t ret = tsdbGetCachedLastRow(pCheckInfo->pTableObj, &pRow, &key);
//     //    if (ret != TSDB_CODE_SUCCESS) {
//     //      return false;
//     //    }
//     mergeTwoRowFromMem(pTsdbReadHandle, pTsdbReadHandle->outputCapacity, &curRow, pRow, NULL, numOfCols,
//                        pCheckInfo->tableId, NULL, NULL, true, &lastRowKey);
//     taosMemoryFreeClear(pRow);

//     // update the last key value
//     pCheckInfo->lastKey = key + step;

//     cur->rows = 1;  // only one row
//     cur->lastKey = key + step;
//     cur->mixBlock = true;
//     cur->win.skey = key;
//     cur->win.ekey = key;

//     return true;
//   }

//   return false;
// }

// static bool loadDataBlockFromTableSeq(STsdbReader* pTsdbReadHandle) {
//   size_t numOfTables = taosArrayGetSize(pTsdbReadHandle->pTableCheckInfo);
//   assert(numOfTables > 0);

//   int64_t stime = taosGetTimestampUs();

//   while (pTsdbReadHandle->activeIndex < numOfTables) {
//     if (loadBlockOfActiveTable(pTsdbReadHandle)) {
//       return true;
//     }

//     STableBlockScanInfo* pCheckInfo = taosArrayGet(pTsdbReadHandle->pTableCheckInfo, pTsdbReadHandle->activeIndex);
//     pCheckInfo->numOfBlocks = 0;

//     pTsdbReadHandle->activeIndex += 1;
//     pTsdbReadHandle->locateStart = false;
//     pTsdbReadHandle->checkFiles = true;
//     pTsdbReadHandle->cur.rows = 0;
//     pTsdbReadHandle->currentLoadExternalRows = pTsdbReadHandle->loadExternalRow;

//     terrno = TSDB_CODE_SUCCESS;

//     int64_t elapsedTime = taosGetTimestampUs() - stime;
//     pTsdbReadHandle->cost.checkForNextTime += elapsedTime;
//   }

//   return false;
// }

// bool tsdbGetExternalRow(STsdbReader* pHandle) {
//   STsdbReader*   pTsdbReadHandle = (STsdbReader*)pHandle;
//   SQueryFilePos* cur = &pTsdbReadHandle->cur;

//   cur->fid = INT32_MIN;
//   cur->mixBlock = true;
//   if (pTsdbReadHandle->prev == NULL || pTsdbReadHandle->next == NULL) {
//     cur->rows = 0;
//     return false;
//   }

//   int32_t numOfCols = (int32_t)QH_GET_NUM_OF_COLS(pTsdbReadHandle);
//   for (int32_t i = 0; i < numOfCols; ++i) {
//     SColumnInfoData* pColInfoData = taosArrayGet(pTsdbReadHandle->pColumns, i);
//     SColumnInfoData* first = taosArrayGet(pTsdbReadHandle->prev, i);

//     memcpy(pColInfoData->pData, first->pData, pColInfoData->info.bytes);

//     SColumnInfoData* sec = taosArrayGet(pTsdbReadHandle->next, i);
//     memcpy(((char*)pColInfoData->pData) + pColInfoData->info.bytes, sec->pData, pColInfoData->info.bytes);

//     if (i == 0 && pColInfoData->info.type == TSDB_DATA_TYPE_TIMESTAMP) {
//       cur->win.skey = *(TSKEY*)pColInfoData->pData;
//       cur->win.ekey = *(TSKEY*)(((char*)pColInfoData->pData) + TSDB_KEYSIZE);
//     }
//   }

//   cur->rows = 2;
//   return true;
// }

// static void* doFreeColumnInfoData(SArray* pColumnInfoData) {
//   if (pColumnInfoData == NULL) {
//     return NULL;
//   }

//   size_t cols = taosArrayGetSize(pColumnInfoData);
//   for (int32_t i = 0; i < cols; ++i) {
//     SColumnInfoData* pColInfo = taosArrayGet(pColumnInfoData, i);
//     colDataDestroy(pColInfo);
//   }

//   taosArrayDestroy(pColumnInfoData);
//   return NULL;
// }

// static void* destroyTableCheckInfo(SArray* pTableCheckInfo) {
//   size_t size = taosArrayGetSize(pTableCheckInfo);
//   for (int32_t i = 0; i < size; ++i) {
//     STableBlockScanInfo* p = taosArrayGet(pTableCheckInfo, i);
//     destroyTableMemIterator(p);

//     taosMemoryFreeClear(p->pCompInfo);
//   }

//   taosArrayDestroy(pTableCheckInfo);
//   return NULL;
// }

// ====================================== EXPOSED APIs ======================================
int32_t tsdbReaderOpen(SVnode* pVnode, SQueryTableDataCond* pCond, STableListInfo* pTableList, uint64_t qId, uint64_t taskId, STsdbReader** ppReader) {
  char buf[128] = {0};
  snprintf(buf, tListLen(buf), "TID:0x%" PRIx64 " QID:0x%" PRIx64, taskId, qId);

  int32_t code = tsdbReaderCreate(pVnode, pCond, ppReader, buf);
  if (code) {
    goto _err;
  }

  STsdbReader* pReader = *ppReader;
  if (isEmptyQueryTimeWindow(pReader)) {
    tsdbDebug("%p query window not overlaps with the data set, no result returned, %s", pReader, pReader->idStr);
    return TSDB_CODE_SUCCESS;
  }

  pReader->status.pTableMap = createDataBlockScanInfo(pReader, pCond->uidList, pCond->numOfTables);
  if (pReader->status.pTableMap == NULL) {
    tsdbReaderClose(pReader);
    *ppReader = NULL;
    
    code = TSDB_CODE_TDB_OUT_OF_MEMORY;
    goto _err;
  }

#if 0
  // int32_t code = setCurrentSchema(pVnode, pReader);
  // if (code != TSDB_CODE_SUCCESS) {
  //   terrno = code;
  //   return NULL;
  // }

  // int32_t  numOfCols = taosArrayGetSize(pReader->suppInfo.defaultLoadColumn);
  // int16_t* ids = pReader->suppInfo.defaultLoadColumn->pData;

  // STSchema* pSchema = pReader->pSchema;

  // int32_t i = 0, j = 0;
  // while (i < numOfCols && j < pSchema->numOfCols) {
  //   if (ids[i] == pSchema->columns[j].colId) {
  //     pReader->suppInfo.slotIds[i] = j;
  //     i++;
  //     j++;
  //   } else if (ids[i] > pSchema->columns[j].colId) {
  //     j++;
  //   } else {
  //     //    tsdbReaderClose(pTsdbReadHandle);
  //     terrno = TSDB_CODE_INVALID_PARA;
  //     return NULL;
  //   }
  // }
#endif

  tsdbDebug("%p total numOfTable:%d in this query %s", pReader, pCond->numOfTables, pReader->idStr);
  return code;

_err:
  tsdbError("failed to create tsdb reader, code: %s %s", tstrerror(code), pReader->idStr);
  return code;
}

void tsdbReaderClose(STsdbReader* pReader) {
   if (pReader == NULL) {
     return;
   }

   blockDataDestroy(pReader->pResBlock);

   taosMemoryFreeClear(pReader->suppInfo.pstatis);
   taosMemoryFreeClear(pReader->suppInfo.plist);
   taosMemoryFree(pReader->suppInfo.slotIds);

   if (!isEmptyQueryTimeWindow(pReader)) {
     //    tsdbMayUnTakeMemSnapshot(pTsdbReadHandle);
   } else {
     ASSERT(pReader->status.pTableMap == NULL);
   }
#if 0
//   if (pReader->status.pTableScanInfo != NULL) {
//     pReader->status.pTableScanInfo = destroyTableCheckInfo(pReader->status.pTableScanInfo);
//   }

//   tsdbDestroyReadH(&pReader->rhelper);

//   tdFreeDataCols(pReader->pDataCols);
//   pReader->pDataCols = NULL;
//
//   pReader->prev = doFreeColumnInfoData(pReader->prev);
//   pReader->next = doFreeColumnInfoData(pReader->next);
#endif

   SIOCostSummary* pCost = &pReader->cost;

   tsdbDebug("%p :io-cost summary: head-file read cnt:%" PRIu64 ", head-file time:%" PRIu64 " us, statis-info:%" PRId64
             " us, datablock:%" PRId64 " us, check data:%" PRId64 " us, %s",
             pReader, pCost->headFileLoad, pCost->headFileLoadTime, pCost->statisInfoLoadTime, pCost->blockLoadTime,
             pCost->checkForNextTime, pReader->idStr);

   taosMemoryFree(pReader->idStr);
   taosMemoryFree(pReader->pSchema);
   taosMemoryFreeClear(pReader);
}

bool tsdbNextDataBlock(STsdbReader* pReader) {
  bool ret = false;
  if (isEmptyQueryTimeWindow(pReader)) {
    return false;
  }

  // cleanup the data that belongs to the previous data block
  blockDataCleanup(pReader->pResBlock);

  int64_t stime = taosGetTimestampUs();
  int64_t elapsedTime = stime;

  if (pReader->type == BLOCK_LOAD_OFFSET_ORDER) {
    if (pReader->status.loadFromFile) {
      bool exists = true;
      int32_t code = loadDataInFiles(pReader, &exists);

    } else { // no data in files, let's try in-memory buffer

    }
  } else if (pReader->type == BLOCK_LOAD_TABLESEQ_ORDER) {

  } else if (pReader->type == BLOCK_LOAD_EXTERN_ORDER) {

  }
  // if (pReader->loadType == BLOCK_LOAD_TABLE_SEQ_ORDER) {
  //   return loadDataBlockFromTableSeq(pReader);
  // } else {  // loadType == RR and Offset Order
  //   if (pReader->checkFiles) {
  //     // check if the query range overlaps with the file data block
  //     bool exists = true;
  //     int32_t code = loadDataInFiles(pReader, &exists);
  //     if (code != TSDB_CODE_SUCCESS) {
  //       pReader->activeIndex = 0;
  //       pReader->checkFiles = false;

  //       return false;
  //     }

  //     if (exists) {
  //       pReader->cost.checkForNextTime += (taosGetTimestampUs() - stime);
  //       return exists;
  //     }

  //     pReader->activeIndex = 0;
  //     pReader->checkFiles = false;
  //   }

  //   // TODO: opt by consider the scan order
  //   bool ret = doHasDataInBuffer(pReader);
  //   terrno = TSDB_CODE_SUCCESS;

  //   elapsedTime = taosGetTimestampUs() - stime;
  //   pReader->cost.checkForNextTime += elapsedTime;
  //   return ret;
  // }
  return ret;
}

void tsdbRetrieveDataBlockInfo(STsdbReader* pReader, SDataBlockInfo* pDataBlockInfo) {
  //   SQueryFilePos* cur = &pReader->cur;

  //   uint64_t uid = 0;

  //   // there are data in file
  //   if (pReader->cur.fid != INT32_MIN) {
  //     SFileBlockInfo* pBlockInfo = &pReader->pDataBlockInfo[cur->slot];
  //     uid = pBlockInfo->pTableCheckInfo->tableId;
  //   } else {
  //     STableBlockScanInfo* pCheckInfo = taosArrayGet(pReader->pTableCheckInfo, pReader->activeIndex);
  //     uid = pCheckInfo->tableId;
  //   }

  //   tsdbDebug("data block generated, uid:%" PRIu64 " numOfRows:%d, tsrange:%" PRId64 " - %" PRId64 " %s", uid,
  //   cur->rows,
  //             cur->win.skey, cur->win.ekey, pReader->idStr);

  //   pDataBlockInfo->uid = uid;

  // #if 0
  //   // for multi-group data query processing test purpose
  //   pDataBlockInfo->groupId = uid;
  // #endif

  //   pDataBlockInfo->rows = cur->rows;
  //   pDataBlockInfo->window = cur->win;
}

int32_t tsdbRetrieveDataBlockStatisInfo(STsdbReader* pReader, SColumnDataAgg*** pBlockStatis, bool* allHave) {
  int32_t code = 0;
  // *allHave = false;

  // SQueryFilePos* c = &pReader->cur;
  // if (c->mixBlock) {
  //   *pBlockStatis = NULL;
  //   return TSDB_CODE_SUCCESS;
  // }

  // SFileBlockInfo* pBlockInfo = &pReader->pDataBlockInfo[c->slot];
  // assert((c->slot >= 0 && c->slot < pReader->numOfBlocks) || ((c->slot == pReader->numOfBlocks) && (c->slot == 0)));

  // // file block with sub-blocks has no statistics data
  // if (pBlockInfo->compBlock->numOfSubBlocks > 1) {
  //   *pBlockStatis = NULL;
  //   return TSDB_CODE_SUCCESS;
  // }

  // int64_t stime = taosGetTimestampUs();
  // int     statisStatus = tsdbLoadBlockStatis(&pReader->rhelper, pBlockInfo->compBlock);
  // if (statisStatus < TSDB_STATIS_OK) {
  //   return terrno;
  // } else if (statisStatus > TSDB_STATIS_OK) {
  //   *pBlockStatis = NULL;
  //   return TSDB_CODE_SUCCESS;
  // }

  // tsdbDebug("vgId:%d, succeed to load block statis part for uid %" PRIu64, REPO_ID(pReader->pTsdb),
  //           TSDB_READ_TABLE_UID(&pReader->rhelper));

  // int16_t* colIds = pReader->suppInfo.defaultLoadColumn->pData;

  // size_t numOfCols = QH_GET_NUM_OF_COLS(pReader);
  // memset(pReader->suppInfo.plist, 0, numOfCols * POINTER_BYTES);
  // memset(pReader->suppInfo.pstatis, 0, numOfCols * sizeof(SColumnDataAgg));

  // for (int32_t i = 0; i < numOfCols; ++i) {
  //   pReader->suppInfo.pstatis[i].colId = colIds[i];
  // }

  // *allHave = true;
  // tsdbGetBlockStatis(&pReader->rhelper, pReader->suppInfo.pstatis, (int)numOfCols, pBlockInfo->compBlock);

  // // always load the first primary timestamp column data
  // SColumnDataAgg* pPrimaryColStatis = &pReader->suppInfo.pstatis[0];
  // assert(pPrimaryColStatis->colId == PRIMARYKEY_TIMESTAMP_COL_ID);

  // pPrimaryColStatis->numOfNull = 0;
  // pPrimaryColStatis->min = pBlockInfo->compBlock->minKey.ts;
  // pPrimaryColStatis->max = pBlockInfo->compBlock->maxKey.ts;
  // pReader->suppInfo.plist[0] = &pReader->suppInfo.pstatis[0];

  // // update the number of NULL data rows
  // int32_t* slotIds = pReader->suppInfo.slotIds;
  // for (int32_t i = 1; i < numOfCols; ++i) {
  //   ASSERT(colIds[i] == pReader->pSchema->columns[slotIds[i]].colId);
  //   if (IS_BSMA_ON(&(pReader->pSchema->columns[slotIds[i]]))) {
  //     if (pReader->suppInfo.pstatis[i].numOfNull == -1) {  // set the column data are all NULL
  //       pReader->suppInfo.pstatis[i].numOfNull = pBlockInfo->compBlock->numOfRows;
  //     }

  //     pReader->suppInfo.plist[i] = &pReader->suppInfo.pstatis[i];
  //   } else {
  //     *allHave = false;
  //   }
  // }

  // int64_t elapsed = taosGetTimestampUs() - stime;
  // pReader->cost.statisInfoLoadTime += elapsed;

  // *pBlockStatis = pReader->suppInfo.plist;
  return code;
}

SArray* tsdbRetrieveDataBlock(STsdbReader* pReader, SArray* pIdList) {
  // /**
  //  * In the following two cases, the data has been loaded to SColumnInfoData.
  //  * 1. data is from cache, 2. data block is not completed qualified to query time range
  //  */
  // if (pReader->cur.fid == INT32_MIN) {
  //   return pReader->pColumns;
  // } else {
  //   SFileBlockInfo* pBlockInfo = &pReader->pDataBlockInfo[pReader->cur.slot];
  //   STableBlockScanInfo* pCheckInfo = pBlockInfo->pTableCheckInfo;

  //   if (pReader->cur.mixBlock) {
  //     return pReader->pColumns;
  //   } else {
  //     SDataBlockInfo binfo = GET_FILE_DATA_BLOCK_INFO(pCheckInfo, pBlockInfo->compBlock);
  //     assert(pReader->realNumOfRows <= binfo.rows);

  //     // data block has been loaded, todo extract method
  //     SDataBlockLoadInfo* pBlockLoadInfo = &pReader->dataBlockLoadInfo;

  //     if (pBlockLoadInfo->slot == pReader->cur.slot && pBlockLoadInfo->fileGroup->fid == pReader->cur.fid &&
  //         pBlockLoadInfo->uid == pCheckInfo->tableId) {
  //       return pReader->pColumns;
  //     } else {  // only load the file block
  //       SBlock* pBlock = pBlockInfo->compBlock;
  //       if (doLoadFileBlockData(pReader, pBlock, pCheckInfo, pReader->cur.slot) != TSDB_CODE_SUCCESS) {
  //         return NULL;
  //       }

  //       int32_t numOfRows = doCopyRowsFromFileBlock(pReader, pReader->outputCapacity, 0, 0, pBlock->numOfRows - 1);
  //       return pReader->pColumns;
  //     }
  //   }
  // }
  return NULL;
}

void tsdbResetReadHandle(STsdbReader* pReader, SQueryTableDataCond* pCond, int32_t tWinIdx) {
  // if (isEmptyQueryTimeWindow(pReader)) {
  //   if (pCond->order != pReader->order) {
  //     pReader->order = pCond->order;
  //     TSWAP(pReader->window.skey, pReader->window.ekey);
  //   }

  //   return;
  // }

  // pReader->order = pCond->order;
  // setQueryTimewindow(pReader, pCond, tWinIdx);
  // pReader->type = TSDB_QUERY_TYPE_ALL;
  // pReader->cur.fid = -1;
  // pReader->cur.win = TSWINDOW_INITIALIZER;
  // pReader->checkFiles = true;
  // pReader->activeIndex = 0;  // current active table index
  // pReader->locateStart = false;
  // pReader->loadExternalRow = pCond->loadExternalRows;

  // if (ASCENDING_TRAVERSE(pCond->order)) {
  //   assert(pReader->window.skey <= pReader->window.ekey);
  // } else {
  //   assert(pReader->window.skey >= pReader->window.ekey);
  // }

  // // allocate buffer in order to load data blocks from file
  // memset(pReader->suppInfo.pstatis, 0, sizeof(SColumnDataAgg));
  // memset(pReader->suppInfo.plist, 0, POINTER_BYTES);

  // tsdbInitDataBlockLoadInfo(&pReader->dataBlockLoadInfo);
  // tsdbInitCompBlockLoadInfo(&pReader->compBlockLoadInfo);

  // resetCheckInfo(pReader);
}

int32_t tsdbGetFileBlocksDistInfo(STsdbReader* pReader, STableBlockDistInfo* pTableBlockInfo) {
  int32_t code = 0;
  // pTableBlockInfo->totalSize = 0;
  // pTableBlockInfo->totalRows = 0;

  // STsdbFS* pFileHandle = REPO_FS(pReader->pTsdb);

  // // find the start data block in file
  // pReader->locateStart = true;
  // STsdbKeepCfg* pCfg = REPO_KEEP_CFG(pReader->pTsdb);
  // int32_t       fid = getFileIdFromKey(pReader->window.skey, pCfg->days, pCfg->precision);

  // tsdbRLockFS(pFileHandle);
  // tsdbFSIterInit(&pReader->fileIter, pFileHandle, pReader->order);
  // tsdbFSIterSeek(&pReader->fileIter, fid);
  // tsdbUnLockFS(pFileHandle);

  // STsdbCfg* pc = REPO_CFG(pReader->pTsdb);
  // pTableBlockInfo->defMinRows = pc->minRows;
  // pTableBlockInfo->defMaxRows = pc->maxRows;

  // int32_t bucketRange = ceil((pc->maxRows - pc->minRows) / 20.0);

  // pTableBlockInfo->numOfFiles += 1;

  // int32_t     code = TSDB_CODE_SUCCESS;
  // int32_t     numOfBlocks = 0;
  // int32_t     numOfTables = (int32_t)taosArrayGetSize(pReader->pTableCheckInfo);
  // int         defaultRows = 4096;
  // STimeWindow win = TSWINDOW_INITIALIZER;

  // while (true) {
  //   numOfBlocks = 0;
  //   tsdbRLockFS(REPO_FS(pReader->pTsdb));

  //   if ((pReader->pFileGroup = tsdbFSIterNext(&pReader->fileIter)) == NULL) {
  //     tsdbUnLockFS(REPO_FS(pReader->pTsdb));
  //     break;
  //   }

  //   tsdbGetFidKeyRange(pCfg->days, pCfg->precision, pReader->pFileGroup->fid, &win.skey, &win.ekey);

  //   // current file are not overlapped with query time window, ignore remain files
  //   if ((win.skey > pReader->window.ekey) /* || (!ascTraverse && win.ekey < pTsdbReadHandle->window.ekey)*/) {
  //     tsdbUnLockFS(REPO_FS(pReader->pTsdb));
  //     tsdbDebug("%p remain files are not qualified for qrange:%" PRId64 "-%" PRId64 ", ignore, %s", pReader,
  //               pReader->window.skey, pReader->window.ekey, pReader->idStr);
  //     pReader->pFileGroup = NULL;
  //     break;
  //   }

  //   pTableBlockInfo->numOfFiles += 1;
  //   if (tsdbSetAndOpenReadFSet(&pReader->rhelper, pReader->pFileGroup) < 0) {
  //     tsdbUnLockFS(REPO_FS(pReader->pTsdb));
  //     code = terrno;
  //     break;
  //   }

  //   tsdbUnLockFS(REPO_FS(pReader->pTsdb));

  //   if (tsdbLoadBlockIdx(&pReader->rhelper) < 0) {
  //     code = terrno;
  //     break;
  //   }

  //   if ((code = getFileCompInfo(pReader, &numOfBlocks)) != TSDB_CODE_SUCCESS) {
  //     break;
  //   }

  //   tsdbDebug("%p %d blocks found in file for %d table(s), fid:%d, %s", pReader, numOfBlocks, numOfTables,
  //             pReader->pFileGroup->fid, pReader->idStr);

  //   if (numOfBlocks == 0) {
  //     continue;
  //   }

  //   pTableBlockInfo->numOfBlocks += numOfBlocks;

  //   for (int32_t i = 0; i < numOfTables; ++i) {
  //     STableBlockScanInfo* pCheckInfo = taosArrayGet(pReader->pTableCheckInfo, i);

  //     SBlock* pBlock = pCheckInfo->pCompInfo->blocks;

  //     for (int32_t j = 0; j < pCheckInfo->numOfBlocks; ++j) {
  //       pTableBlockInfo->totalSize += pBlock[j].len;

  //       int32_t numOfRows = pBlock[j].numOfRows;
  //       pTableBlockInfo->totalRows += numOfRows;

  //       if (numOfRows > pTableBlockInfo->maxRows) {
  //         pTableBlockInfo->maxRows = numOfRows;
  //       }

  //       if (numOfRows < pTableBlockInfo->minRows) {
  //         pTableBlockInfo->minRows = numOfRows;
  //       }

  //       if (numOfRows < defaultRows) {
  //         pTableBlockInfo->numOfSmallBlocks += 1;
  //       }

  //       int32_t bucketIndex = getBucketIndex(pTableBlockInfo->defMinRows, bucketRange, numOfRows);
  //       pTableBlockInfo->blockRowsHisto[bucketIndex]++;
  //     }
  //   }
  // }

  // pTableBlockInfo->numOfTables = numOfTables;
  return code;
}

int64_t tsdbGetNumOfRowsInMemTable(STsdbReader* pReader) {
  int64_t    rows = 0;
  SMemTable* pMemTable = NULL;  // pTsdbReadHandle->pMemTable;

  // if (pMemTable == NULL) {
  //   return rows;
  // }

  // size_t size = taosArrayGetSize(pReader->pTableCheckInfo);
  // for (int32_t i = 0; i < size; ++i) {
  //   STableBlockScanInfo* pCheckInfo = taosArrayGet(pReader->pTableCheckInfo, i);

  //   //    if (pMemT && pCheckInfo->tableId < pMemT->maxTables) {
  //   //      pMem = pMemT->tData[pCheckInfo->tableId];
  //   //      rows += (pMem && pMem->uid == pCheckInfo->tableId) ? pMem->numOfRows : 0;
  //   //    }
  //   //    if (pIMemT && pCheckInfo->tableId < pIMemT->maxTables) {
  //   //      pIMem = pIMemT->tData[pCheckInfo->tableId];
  //   //      rows += (pIMem && pIMem->uid == pCheckInfo->tableId) ? pIMem->numOfRows : 0;
  //   //    }
  // }

  return rows;
}