/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.regionserver.querymatcher;
import java.io.IOException;
import java.util.NavigableSet;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.filter.Filter.ReturnCode;
import org.apache.hadoop.hbase.io.TimeRange;
import org.apache.hadoop.hbase.regionserver.RegionCoprocessorHost;
import org.apache.hadoop.hbase.regionserver.ScanInfo;
/**
* Query matcher for user scan.
* <p>
* We do not consider mvcc here because
* {@link org.apache.hadoop.hbase.regionserver.StoreFileScanner} and
* {@link org.apache.hadoop.hbase.regionserver.SegmentScanner} will only return a cell whose mvcc is
* less than or equal to given read point. For
* {@link org.apache.hadoop.hbase.client.IsolationLevel#READ_UNCOMMITTED}, we just set the read
* point to {@link Long#MAX_VALUE}, i.e. still do not need to consider it.
*/
@InterfaceAudience.Private
public abstract class UserScanQueryMatcher extends ScanQueryMatcher {
protected final boolean hasNullColumn;
protected final Filter filter;
protected final byte[] stopRow;
protected final TimeRange tr;
private static Cell createStartKey(Scan scan, ScanInfo scanInfo) {
if (scan.includeStartRow()) {
return createStartKeyFromRow(scan.getStartRow(), scanInfo);
} else {
return CellUtil.createLastOnRow(scan.getStartRow());
}
}
protected UserScanQueryMatcher(Scan scan, ScanInfo scanInfo, ColumnTracker columns,
boolean hasNullColumn, long oldestUnexpiredTS, long now) {
super(createStartKey(scan, scanInfo), scanInfo, columns, oldestUnexpiredTS, now);
this.hasNullColumn = hasNullColumn;
this.filter = scan.getFilter();
this.stopRow = scan.getStopRow();
TimeRange timeRange = scan.getColumnFamilyTimeRange().get(scanInfo.getFamily());
if (timeRange == null) {
this.tr = scan.getTimeRange();
} else {
this.tr = timeRange;
}
}
@Override
public boolean hasNullColumnInQuery() {
return hasNullColumn;
}
@Override
public boolean isUserScan() {
return true;
}
@Override
public Filter getFilter() {
return filter;
}
@Override
public Cell getNextKeyHint(Cell cell) throws IOException {
if (filter == null) {
return null;
} else {
return filter.getNextCellHint(cell);
}
}
protected final MatchCode matchColumn(Cell cell, long timestamp, byte typeByte)
throws IOException {
int tsCmp = tr.compare(timestamp);
if (tsCmp > 0) {
return MatchCode.SKIP;
}
if (tsCmp < 0) {
return columns.getNextRowOrNextColumn(cell);
}
// STEP 1: Check if the column is part of the requested columns
MatchCode colChecker = columns.checkColumn(cell, typeByte);
if (colChecker != MatchCode.INCLUDE) {
return colChecker;
}
ReturnCode filterResponse = ReturnCode.SKIP;
// STEP 2: Yes, the column is part of the requested columns. Check if filter is present
if (filter != null) {
// STEP 3: Filter the key value and return if it filters out
filterResponse = filter.filterKeyValue(cell);
switch (filterResponse) {
case SKIP:
return MatchCode.SKIP;
case NEXT_COL:
return columns.getNextRowOrNextColumn(cell);
case NEXT_ROW:
return MatchCode.SEEK_NEXT_ROW;
case SEEK_NEXT_USING_HINT:
return MatchCode.SEEK_NEXT_USING_HINT;
default:
// It means it is either include or include and seek next
break;
}
}
/*
* STEP 4: Reaching this step means the column is part of the requested columns and either
* the filter is null or the filter has returned INCLUDE or INCLUDE_AND_NEXT_COL response.
* Now check the number of versions needed. This method call returns SKIP, INCLUDE,
* INCLUDE_AND_SEEK_NEXT_ROW, INCLUDE_AND_SEEK_NEXT_COL.
*
* FilterResponse ColumnChecker Desired behavior
* INCLUDE SKIP row has already been included, SKIP.
* INCLUDE INCLUDE INCLUDE
* INCLUDE INCLUDE_AND_SEEK_NEXT_COL INCLUDE_AND_SEEK_NEXT_COL
* INCLUDE INCLUDE_AND_SEEK_NEXT_ROW INCLUDE_AND_SEEK_NEXT_ROW
* INCLUDE_AND_SEEK_NEXT_COL SKIP row has already been included, SKIP.
* INCLUDE_AND_SEEK_NEXT_COL INCLUDE INCLUDE_AND_SEEK_NEXT_COL
* INCLUDE_AND_SEEK_NEXT_COL INCLUDE_AND_SEEK_NEXT_COL INCLUDE_AND_SEEK_NEXT_COL
* INCLUDE_AND_SEEK_NEXT_COL INCLUDE_AND_SEEK_NEXT_ROW INCLUDE_AND_SEEK_NEXT_ROW
*
* In all the above scenarios, we return the column checker return value except for
* FilterResponse (INCLUDE_AND_SEEK_NEXT_COL) and ColumnChecker(INCLUDE)
*/
colChecker = columns.checkVersions(cell, timestamp, typeByte, false);
if (filterResponse == ReturnCode.INCLUDE_AND_SEEK_NEXT_ROW) {
if (colChecker != MatchCode.SKIP) {
return MatchCode.INCLUDE_AND_SEEK_NEXT_ROW;
}
return MatchCode.SEEK_NEXT_ROW;
}
return (filterResponse == ReturnCode.INCLUDE_AND_NEXT_COL && colChecker == MatchCode.INCLUDE)
? MatchCode.INCLUDE_AND_SEEK_NEXT_COL : colChecker;
}
protected abstract boolean isGet();
protected abstract boolean moreRowsMayExistsAfter(int cmpToStopRow);
@Override
public boolean moreRowsMayExistAfter(Cell cell) {
// If a 'get' Scan -- we are doing a Get (every Get is a single-row Scan in implementation) --
// then we are looking at one row only, the one specified in the Get coordinate..so we know
// for sure that there are no more rows on this Scan
if (isGet()) {
return false;
}
// If no stopRow, return that there may be more rows. The tests that follow depend on a
// non-empty, non-default stopRow so this little test below short-circuits out doing the
// following compares.
if (this.stopRow == null || this.stopRow.length == 0) {
return true;
}
return moreRowsMayExistsAfter(rowComparator.compareRows(cell, stopRow, 0, stopRow.length));
}
public static UserScanQueryMatcher create(Scan scan, ScanInfo scanInfo,
NavigableSet<byte[]> columns, long oldestUnexpiredTS, long now,
RegionCoprocessorHost regionCoprocessorHost) throws IOException {
int maxVersions = scan.isRaw() ? scan.getMaxVersions()
: Math.min(scan.getMaxVersions(), scanInfo.getMaxVersions());
boolean hasNullColumn;
ColumnTracker columnTracker;
if (columns == null || columns.isEmpty()) {
// there is always a null column in the wildcard column query.
hasNullColumn = true;
// use a specialized scan for wildcard column tracker.
columnTracker = new ScanWildcardColumnTracker(scanInfo.getMinVersions(), maxVersions,
oldestUnexpiredTS);
} else {
// We can share the ExplicitColumnTracker, diff is we reset
// between rows, not between storefiles.
// whether there is null column in the explicit column query
hasNullColumn = columns.first().length == 0;
columnTracker = new ExplicitColumnTracker(columns, scanInfo.getMinVersions(), maxVersions,
oldestUnexpiredTS);
}
if (scan.isRaw()) {
return RawScanQueryMatcher.create(scan, scanInfo, columnTracker, hasNullColumn,
oldestUnexpiredTS, now);
} else {
return NormalUserScanQueryMatcher.create(scan, scanInfo, columnTracker, hasNullColumn,
oldestUnexpiredTS, now, regionCoprocessorHost);
}
}
}