Java tutorial
/* * 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.phoenix.spark.datasource.v2.reader; import java.io.IOException; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.sql.Statement; import java.util.List; import java.util.Properties; import org.apache.hadoop.hbase.TableName; import org.apache.hadoop.hbase.client.Scan; import org.apache.hadoop.hbase.util.Bytes; import org.apache.phoenix.compile.QueryPlan; import org.apache.phoenix.compile.StatementContext; import org.apache.phoenix.coprocessor.BaseScannerRegionObserver; import org.apache.phoenix.iterate.ConcatResultIterator; import org.apache.phoenix.iterate.LookAheadResultIterator; import org.apache.phoenix.iterate.MapReduceParallelScanGrouper; import org.apache.phoenix.iterate.PeekingResultIterator; import org.apache.phoenix.iterate.ResultIterator; import org.apache.phoenix.iterate.RoundRobinResultIterator; import org.apache.phoenix.iterate.SequenceResultIterator; import org.apache.phoenix.iterate.TableResultIterator; import org.apache.phoenix.jdbc.PhoenixResultSet; import org.apache.phoenix.jdbc.PhoenixStatement; import org.apache.phoenix.mapreduce.PhoenixInputSplit; import org.apache.phoenix.monitoring.ReadMetricQueue; import org.apache.phoenix.monitoring.ScanMetricsHolder; import org.apache.phoenix.query.ConnectionQueryServices; import org.apache.phoenix.util.PhoenixRuntime; import org.apache.spark.SerializableWritable; import org.apache.spark.executor.InputMetrics; import org.apache.spark.sql.catalyst.InternalRow; import org.apache.spark.sql.execution.datasources.SparkJdbcUtil; import org.apache.spark.sql.sources.v2.reader.InputPartitionReader; import org.apache.spark.sql.types.StructType; import com.google.common.base.Preconditions; import com.google.common.collect.Lists; import scala.collection.Iterator; public class PhoenixInputPartitionReader implements InputPartitionReader<InternalRow> { private SerializableWritable<PhoenixInputSplit> phoenixInputSplit; private StructType schema; private Iterator<InternalRow> iterator; private PhoenixResultSet resultSet; private InternalRow currentRow; private PhoenixDataSourceReadOptions options; public PhoenixInputPartitionReader(PhoenixDataSourceReadOptions options, StructType schema, SerializableWritable<PhoenixInputSplit> phoenixInputSplit) { this.options = options; this.phoenixInputSplit = phoenixInputSplit; this.schema = schema; initialize(); } private QueryPlan getQueryPlan() throws SQLException { String scn = options.getScn(); String tenantId = options.getTenantId(); String zkUrl = options.getZkUrl(); Properties overridingProps = new Properties(); if (scn != null) { overridingProps.put(PhoenixRuntime.CURRENT_SCN_ATTRIB, scn); } if (tenantId != null) { overridingProps.put(PhoenixRuntime.TENANT_ID_ATTRIB, tenantId); } try (Connection conn = DriverManager.getConnection("jdbc:phoenix:" + zkUrl, overridingProps)) { final Statement statement = conn.createStatement(); final String selectStatement = options.getSelectStatement(); Preconditions.checkNotNull(selectStatement); final PhoenixStatement pstmt = statement.unwrap(PhoenixStatement.class); // Optimize the query plan so that we potentially use secondary indexes final QueryPlan queryPlan = pstmt.optimizeQuery(selectStatement); return queryPlan; } } private void initialize() { try { final QueryPlan queryPlan = getQueryPlan(); final List<Scan> scans = phoenixInputSplit.value().getScans(); List<PeekingResultIterator> iterators = Lists.newArrayListWithExpectedSize(scans.size()); StatementContext ctx = queryPlan.getContext(); ReadMetricQueue readMetrics = ctx.getReadMetricsQueue(); String tableName = queryPlan.getTableRef().getTable().getPhysicalName().getString(); // Clear the table region boundary cache to make sure long running jobs stay up to date byte[] tableNameBytes = queryPlan.getTableRef().getTable().getPhysicalName().getBytes(); ConnectionQueryServices services = queryPlan.getContext().getConnection().getQueryServices(); services.clearTableRegionCache(TableName.valueOf(tableNameBytes)); long renewScannerLeaseThreshold = queryPlan.getContext().getConnection().getQueryServices() .getRenewLeaseThresholdMilliSeconds(); for (Scan scan : scans) { // For MR, skip the region boundary check exception if we encounter a split. ref: PHOENIX-2599 scan.setAttribute(BaseScannerRegionObserver.SKIP_REGION_BOUNDARY_CHECK, Bytes.toBytes(true)); PeekingResultIterator peekingResultIterator; ScanMetricsHolder scanMetricsHolder = ScanMetricsHolder.getInstance(readMetrics, tableName, scan, queryPlan.getContext().getConnection().getLogLevel()); final TableResultIterator tableResultIterator = new TableResultIterator( queryPlan.getContext().getConnection().getMutationState(), scan, scanMetricsHolder, renewScannerLeaseThreshold, queryPlan, MapReduceParallelScanGrouper.getInstance()); peekingResultIterator = LookAheadResultIterator.wrap(tableResultIterator); iterators.add(peekingResultIterator); } ResultIterator iterator = queryPlan.useRoundRobinIterator() ? RoundRobinResultIterator.newIterator(iterators, queryPlan) : ConcatResultIterator.newIterator(iterators); if (queryPlan.getContext().getSequenceManager().getSequenceCount() > 0) { iterator = new SequenceResultIterator(iterator, queryPlan.getContext().getSequenceManager()); } // Clone the row projector as it's not thread safe and would be used simultaneously by // multiple threads otherwise. this.resultSet = new PhoenixResultSet(iterator, queryPlan.getProjector().cloneIfNecessary(), queryPlan.getContext()); this.iterator = SparkJdbcUtil.resultSetToSparkInternalRows(resultSet, schema, new InputMetrics()); } catch (SQLException e) { throw new RuntimeException(e); } } @Override public boolean next() { if (!iterator.hasNext()) { return false; } currentRow = iterator.next(); return true; } @Override public InternalRow get() { return currentRow; } @Override public void close() throws IOException { if (resultSet != null) { try { resultSet.close(); } catch (SQLException e) { throw new IOException(e); } } } }