/**
* Copyright (C) 2009-2013 FoundationDB, LLC
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* 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. See the
* GNU Affero General Public License for more details.
*
* 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/>.
*/
package com.foundationdb.qp.operator;
import com.foundationdb.ais.model.HKeyColumn;
import com.foundationdb.ais.model.HKeySegment;
import com.foundationdb.qp.row.HKey;
import com.foundationdb.qp.row.ProjectedRow;
import com.foundationdb.qp.row.Row;
import com.foundationdb.qp.row.ValuesHKey;
import com.foundationdb.qp.rowtype.HKeyRowType;
import com.foundationdb.qp.rowtype.RowType;
import com.foundationdb.server.explain.*;
import com.foundationdb.server.types.texpressions.TEvaluatableExpression;
import com.foundationdb.server.types.texpressions.TPreparedExpression;
import com.foundationdb.util.ArgumentValidation;
import com.foundationdb.util.tap.InOutTap;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.*;
/**
<h1>Overview</h1>
HKeyRow_Default builds an HKey entirely from evaluated expressions.
<h1>Arguments</h1>
<li><b>RowType rowType:</b> Type of HKey rows to be built. Must be non-null.
<li><b>List<Expression> expressions:</b> Expressions computing key fields.
<h1>Behavior</h1>
An HKey is constructed by evaluating the given expressions (once).
<h1>Output</h1>
A single HKey row.
<h1>Assumptions</h1>
None.
<h1>Performance</h1>
HKeyRow_Default does no IO. It therefore compares favorably with an IndexScan of the PRIMARY index, when the complete key is known.
<h1>Memory Requirements</h1>
None.
*/
class HKeyRow_Default extends Operator
{
// Object interface
@Override
public String toString() {
return String.format("hkey for %s (%s)",
rowType.hKey().table().getName(),
expressions.toString());
}
// Operator interface
@Override
protected Cursor cursor(QueryContext context, QueryBindingsCursor bindingsCursor) {
return new Execution(context, bindingsCursor);
}
// HKeyRow_Default interface
public HKeyRow_Default(RowType rowType, List<? extends TPreparedExpression> expressions) {
ArgumentValidation.notNull("rowType", rowType);
ArgumentValidation.isTrue("invalid row type", rowType instanceof HKeyRowType);
this.rowType = (HKeyRowType)rowType;
ArgumentValidation.notEmpty("expressions", expressions);
ArgumentValidation.isSame("expressions length", expressions.size(),
"hkey field count", this.rowType.nFields());
this.expressions = expressions;
}
// Class state
private static final InOutTap TAP_OPEN = OPERATOR_TAP.createSubsidiaryTap("operator: HKeyRow_Default open");
private static final InOutTap TAP_NEXT = OPERATOR_TAP.createSubsidiaryTap("operator: HKeyRow_Default next");
private static final Logger LOG = LoggerFactory.getLogger(HKeyRow_Default.class);
// Object state
protected final HKeyRowType rowType;
private final List<? extends TPreparedExpression> expressions;
@Override
public CompoundExplainer getExplainer(ExplainContext context) {
Attributes att = new Attributes();
att.put(Label.NAME, PrimitiveExplainer.getInstance(getName()));
att.put(Label.OUTPUT_TYPE, rowType.getExplainer(context));
for (TPreparedExpression ex : expressions)
att.put(Label.PROJECTION, ex.getExplainer(context));
if (context.hasExtraInfo(this))
att.putAll(context.getExtraInfo(this).get());
return new CompoundExplainer(Type.HKEY_OPERATOR, att);
}
// Inner classes
private class Execution extends LeafCursor {
// Cursor interface
@Override
public void open() {
TAP_OPEN.in();
try {
super.open();
} finally {
TAP_OPEN.out();
}
}
@Override
public Row next() {
if (TAP_NEXT_ENABLED) {
TAP_NEXT.in();
}
try {
if (CURSOR_LIFECYCLE_ENABLED) {
CursorLifecycle.checkIdleOrActive(this);
}
if (isIdle()) {
return null;
}
checkQueryCancelation();
Row row = buildHKeyRow();
if (LOG_EXECUTION) {
LOG.debug("HKeyRow_Default: yield {}", row);
}
setIdle();
return row;
} finally {
if (TAP_NEXT_ENABLED) {
TAP_NEXT.out();
}
}
}
// For use by this class
private Row buildHKeyRow() {
StoreAdapter store = adapter(rowType.hKey().table());
HKey hkey = store.newHKey(rowType.hKey());
if (hkey instanceof ValuesHKey) {
int columnIndex = 0;
for (HKeySegment segment : rowType.hKey().segments()) {
for (HKeyColumn column : segment.columns()) {
TEvaluatableExpression evalExpr = evalExprs.get(columnIndex);
evalExpr.with(context);
evalExpr.with(bindings);
evalExpr.evaluate();
((ValuesHKey)hkey).copyValueTo(evalExpr.resultValue(), columnIndex++);
}
}
return (Row)hkey;
} else {
throw new UnsupportedOperationException ("Not using ValuesHKey");
}
}
// Execution interface
Execution(QueryContext context, QueryBindingsCursor bindingsCursor) {
super(context, bindingsCursor);
evalExprs = ProjectedRow.createTEvaluatableExpressions(expressions);
}
// Object state
private final List<TEvaluatableExpression> evalExprs;
}
}