hbaseScan

sequence:

client

->HTable.getScanner(Scan scan)

->ClientScanner.nextScanner(int nbRows, boolean done)

->ClientScanner.getScannerCallable(byte[] localStartKey, int nbRows)

->ScannerCallable.call()//rpc远程regionserver上调用

->this.server.openScanner(this.location.getRegionInfo().getRegionName(),this.scan)

server:

->打开scanner:HRegionServer.openScanner

->通知协处理器：r.getCoprocessorHost().preScannerOpen(scan)

->scanner生成：HRegion.getScanner(Scan scan,List additionalScanners)

->定位startrow：RegionScannerImpl: HRegion.instantiateRegionScanner(Scan scan,List additionalScanners)

:->store.getScanner(scan,entry.getValue());

• ScanQueryMatcher.match->MatchCode处理当前的kv

• hfile的迭代操作：HFile.Reader

• index定位keyvalue:ScannerV2(HFileScanner)
• 返回List = StoreFileScanner+memStoreScanners
• selectScannersFrom（）：passesTimerangeFilter，passesBloomFilter
• scanner.requestSeek(matcher.getStartKey(), false, true);
• seekAtOrAfter->HFileReaderV2.AbstractScannerV2.seekTo->ScannerV2.blockBuffer->startRow
  • hfilescanner.cur = hfs.getKeyValue() = new KeyValue(blockBuffer.array(),blockBuffer.arrayOffset() + blockBuffer.position());
• heap = new KeyValueHeap(scanners, store.comparator)
• this.current = pollRealKV();
• HRegionServer.addScanner(RegionScannerImpl)->map中

HRegionServer.next->RegionScannerImpl.next->KeyValueHeap.next->StoreScanner.next

StoreScanner.next(List, int):

SEEK_NEXT_COL

INCLUDE_AND_SEEK_NEXT_ROW

SEEK_NEXT_COL

INCLUDE_AND_SEEK_NEXT_ROW