com.netflix.astyanax.cql.reads.CFRowSliceQueryGen Maven / Gradle / Ivy

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package com.netflix.astyanax.cql.reads;

import static com.datastax.driver.core.querybuilder.QueryBuilder.desc;
import static com.datastax.driver.core.querybuilder.QueryBuilder.eq;
import static com.datastax.driver.core.querybuilder.QueryBuilder.gt;
import static com.datastax.driver.core.querybuilder.QueryBuilder.gte;
import static com.datastax.driver.core.querybuilder.QueryBuilder.lt;
import static com.datastax.driver.core.querybuilder.QueryBuilder.lte;

import java.util.List;
import java.util.concurrent.atomic.AtomicReference;

import com.datastax.driver.core.Session;
import com.datastax.driver.core.querybuilder.QueryBuilder;
import com.datastax.driver.core.querybuilder.Select;
import com.datastax.driver.core.querybuilder.Select.Where;
import com.netflix.astyanax.cql.reads.model.CqlColumnSlice;
import com.netflix.astyanax.cql.schema.CqlColumnFamilyDefinitionImpl;
import com.netflix.astyanax.ddl.ColumnDefinition;
import com.netflix.astyanax.query.RowSliceQuery;
import com.netflix.astyanax.serializers.CompositeRangeBuilder.CompositeByteBufferRange;
import com.netflix.astyanax.serializers.CompositeRangeBuilder.RangeQueryOp;
import com.netflix.astyanax.serializers.CompositeRangeBuilder.RangeQueryRecord;

/**
 * Base class that contains the utilities for generating queries for read operations via the 
 * {@link RowSliceQuery} class. 
 * 
 * Note that this class is just a place holder for some useful generic utilities. 
 * See {@link CFRowKeysQueryGen} and {@link CFRowRangeQueryGen} which are the 2 extending classes 
 * for functionality that actually supports the queries. 
 * 
 * @author poberai
 */
public class CFRowSliceQueryGen {

	// Thread safe reference to the underlying session object. We need the session object to be able to "prepare" query statements
	protected final AtomicReference sessionRef = new AtomicReference(null);
	// the keyspace being queried. Used for all the underlying queries being generated
	protected final String keyspace; 
	// the cf definition which helps extending classes construct the right query as per the schema
	protected final CqlColumnFamilyDefinitionImpl cfDef;

	// Other useful derivatives of the cf definition that are frequently used by query generators
	protected final String partitionKeyCol;
	protected final String[] allPrimayKeyCols;
	protected final List clusteringKeyCols;
	protected final List regularCols;
	
	// Condition tracking whether the underlying schema uses composite columns. This is imp since it influences how 
	// a single Column (composite column) can be decomposed into it's individual components that form different parts of the query.
	protected boolean isCompositeColumn; 
	
	// bind marker for generating the prepared statements
	protected static final String BIND_MARKER = "?";
	
	public CFRowSliceQueryGen(Session session, String keyspaceName, CqlColumnFamilyDefinitionImpl cfDefinition) {

		this.keyspace = keyspaceName;
		this.cfDef = cfDefinition;
		this.sessionRef.set(session);

		partitionKeyCol = cfDef.getPartitionKeyColumnDefinition().getName();
		allPrimayKeyCols = cfDef.getAllPkColNames();
		clusteringKeyCols = cfDef.getClusteringKeyColumnDefinitionList();
		regularCols = cfDef.getRegularColumnDefinitionList();

		isCompositeColumn = (clusteringKeyCols.size() > 1);
	}
	
	/**
	 * 
	 *   SOME BASIC UTILITY METHODS USED BY ALL THE ROW SLICE QUERY GENERATORS
	 */
	
	protected Select selectAllColumnsFromKeyspaceAndCF() {

		Select.Selection select = QueryBuilder.select();
		for (int i=0; i columnSlice) {

		String clusteringKeyCol = clusteringKeyCols.get(0).getName();

		if (!columnSlice.isRangeQuery()) {
			return where;
		}
		if (columnSlice.getStartColumn() != null) {
			where.and(gte(clusteringKeyCol, columnSlice.getStartColumn()));
		}
		if (columnSlice.getEndColumn() != null) {
			where.and(lte(clusteringKeyCol, columnSlice.getEndColumn()));
		}

		if (columnSlice.getReversed()) {
			where.orderBy(desc(clusteringKeyCol));
		}

		if (columnSlice.getLimit() != -1) {
			where.limit(columnSlice.getLimit());
		}

		return where;
	}
	
	protected void bindWhereClauseForColumnRange(List