/**
* 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.Group;
import com.foundationdb.ais.model.Table;
import com.foundationdb.qp.row.HKey;
import com.foundationdb.qp.row.Row;
import com.foundationdb.qp.rowtype.*;
import com.foundationdb.server.api.dml.ColumnSelector;
import com.foundationdb.server.explain.*;
import com.foundationdb.server.explain.std.LookUpOperatorExplainer;
import com.foundationdb.util.ArgumentValidation;
import com.foundationdb.util.tap.InOutTap;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Collection;
import java.util.List;
import java.util.Set;
import static java.lang.Math.min;
/**
<h1>Overview</h1>
Given an index row or group row, BranchLookup_Nested locates a
related branch, i.e., a related row and all of its descendents.
Branches are located
using the hkey in a row of the current query's QueryContext.
Unlike AncestorLookup, BranchLookup always retrieves a subtree under a
targeted row.
<h1>Arguments</h1>
<ul>
<li><b>Group group:</b> The group containing the ancestors of interest.
<li><b>RowType inputRowType:</b> Bound row will be of this type.
<li><b>RowType sourceRowType:</b> Branches will be located for input
rows of this type. Possibly a subrow of inputRowType.
<li><b>TableRowType ancestorRowType:</b> Identifies the table in the group at which branching occurs.
Must be an ancestor of both inputRowType's table and outputRowTypes' tables.
<li><b>TableRowType outputRowTypes:</b> Types within the branch to be
retrieved.
<li><b>API.InputPreservationOption flag:</b> Indicates whether rows of type rowType
will be preserved in the output stream (flag = KEEP_INPUT), or
discarded (flag = DISCARD_INPUT).
<li><b>int inputBindingPosition:</b> Indicates input row's position in the query context. The hkey
of this row will be used to locate ancestors.
<li><b>int lookaheadQuantum:</b> Number of cursors to try to keep open by looking
ahead in bindings stream.
</ul>
inputRowType may be an index row type, a user table row type, or an hkey row type. flag = KEEP_INPUT is permitted
only for user table row types.
The groupTable, inputRowType, and outputRowTypes must belong to the
same group.
ancestorRowType's table must be an ancestor of
inputRowType's table and outputRowTypes' tables.
<h1>Behavior</h1>
When this operator's cursor is opened, the row at position inputBindingPosition in the
query context is accessed. The hkey from this row is obtained. The hkey is transformed to
yield an hkey that will locate the corresponding row of the output row
type. Then the entire subtree under that hkey is retrieved. Orphan
rows will be retrieved, even if there is no row of the outputRowType.
All the retrieved records are written to the output stream in hkey
order (ancestors before descendents), as is the input row if KEEP_INPUT
behavior is specified.
If KEEP_INPUT is specified, then the input row appears either before all the
rows of the branch or after all the rows of the branch. If
outputRowType is an ancestor of inputRowType, then the input row is
emitted after all the rows of the branch. Otherwise: inputRowType and
outputRowType have some common ancestor, and outputRowType is the
common ancestor's child. inputRowType has an ancestor, A, that is a
different child of the common ancestor. The ordering is determined by
comparing the ordinals of A and outputRowType.
<h1>Output</h1>
Nothing else to say.
<h1>Assumptions</h1>
None.
<h1>Performance</h1>
For each input row, BranchLookup_Nested does one random access, and
as many sequential accesses as are needed to retrieve the entire
branch.
<h1>Memory Requirements</h1>
BranchLookup_Nested stores one row in memory.
*/
public class BranchLookup_Nested extends Operator
{
// Object interface
@Override
public String toString()
{
return String.format("%s(%s %s -> %s)",
getClass().getSimpleName(),
group.getRoot().getName(),
sourceRowType,
outputRowTypes);
}
// Operator interface
@Override
public void findDerivedTypes(Set<RowType> derivedTypes)
{
}
@Override
public Cursor cursor(QueryContext context, QueryBindingsCursor bindingsCursor)
{
if (lookaheadQuantum <= 1) {
return new Execution(context, bindingsCursor);
}
else {
return new LookaheadExecution(context, bindingsCursor,
context.getStore(commonAncestor),
lookaheadQuantum);
}
}
@Override
public String describePlan()
{
return toString();
}
// BranchLookup_Nested interface
public BranchLookup_Nested(Group group,
RowType inputRowType,
RowType sourceRowType,
TableRowType ancestorRowType,
Collection<TableRowType> outputRowTypes,
API.InputPreservationOption flag,
int inputBindingPosition,
int lookaheadQuantum)
{
ArgumentValidation.notNull("group", group);
ArgumentValidation.notNull("inputRowType", inputRowType);
ArgumentValidation.notNull("sourceRowType", sourceRowType);
ArgumentValidation.notEmpty("outputRowTypes", outputRowTypes);
ArgumentValidation.notNull("flag", flag);
ArgumentValidation.isTrue("sourceRowType instanceof TableRowType || flag == API.InputPreservationOption.DISCARD_INPUT",
sourceRowType instanceof TableRowType || flag == API.InputPreservationOption.DISCARD_INPUT);
ArgumentValidation.isGTE("hKeyBindingPosition", inputBindingPosition, 0);
TableRowType inputTableType = null;
if (sourceRowType instanceof TableRowType) {
inputTableType = (TableRowType) sourceRowType;
} else if (sourceRowType instanceof IndexRowType) {
inputTableType = ((IndexRowType) sourceRowType).tableType();
} else if (sourceRowType instanceof HKeyRowType) {
Schema schema = outputRowTypes.iterator().next().schema();
inputTableType = schema.tableRowType(sourceRowType.hKey().table());
}
assert inputTableType != null : sourceRowType;
Table inputTable = inputTableType.table();
ArgumentValidation.isSame("inputTable.getGroup()", inputTable.getGroup(),
"group", group);
Table commonAncestor;
if (ancestorRowType == null) {
commonAncestor = inputTable;
} else {
commonAncestor = ancestorRowType.table();
ArgumentValidation.isTrue("ancestorRowType.ancestorOf(inputTableType)",
ancestorRowType.ancestorOf(inputTableType));
}
for (TableRowType outputRowType : outputRowTypes) {
Table outputTable = outputRowType.table();
ArgumentValidation.isSame("outputTable.getGroup()", outputTable.getGroup(),
"group", group);
if (ancestorRowType == null) {
commonAncestor = commonAncestor(commonAncestor, outputTable);
}
else {
ArgumentValidation.isTrue("ancestorRowType.ancestorOf(outputRowType)",
ancestorRowType.ancestorOf(outputRowType));
}
}
this.group = group;
this.inputRowType = inputRowType;
this.sourceRowType = sourceRowType;
this.outputRowTypes = new ArrayList<>(outputRowTypes);
Collections.sort(this.outputRowTypes,
new Comparator<TableRowType>()
{
@Override
public int compare(TableRowType x, TableRowType y)
{
return x.table().getDepth() - y.table().getDepth();
}
});
this.commonAncestor = commonAncestor;
this.keepInput = flag == API.InputPreservationOption.KEEP_INPUT;
this.inputBindingPosition = inputBindingPosition;
this.lookaheadQuantum = lookaheadQuantum;
// See whether there is a single branch beneath commonAncestor
// with all output row types.
Table outputTable = this.outputRowTypes.get(0).table();
boolean allOneBranch;
if (outputTable == commonAncestor) {
allOneBranch = false;
}
else {
while (outputTable.getParentTable() != commonAncestor) {
outputTable = outputTable.getParentTable();
}
TableRowType outputTableRowType = this.outputRowTypes.get(0).schema().tableRowType(outputTable);
allOneBranch = true;
for (int i = 1; i < this.outputRowTypes.size(); i++) {
if (!outputTableRowType.ancestorOf(this.outputRowTypes.get(i))) {
allOneBranch = false;
break;
}
}
}
if (allOneBranch) {
branchRootOrdinal = ordinal(outputTable);
}
else {
branchRootOrdinal = -1;
}
// branchRootOrdinal = -1 means that outputTable is an ancestor of inputTable. In this case, inputPrecedesBranch
// is false. Otherwise, branchRoot's parent is the common ancestor. Find inputTable's ancestor that is also
// a child of the common ancestor. Then compare these ordinals to determine whether input precedes branch.
if (this.branchRootOrdinal == -1) {
this.inputPrecedesBranch = false;
} else if (inputTable == commonAncestor) {
this.inputPrecedesBranch = true;
} else {
Table ancestorOfInputAndChildOfCommon = inputTable;
while (ancestorOfInputAndChildOfCommon.getParentTable() != commonAncestor) {
ancestorOfInputAndChildOfCommon = ancestorOfInputAndChildOfCommon.getParentTable();
}
this.inputPrecedesBranch = ordinal(ancestorOfInputAndChildOfCommon) < branchRootOrdinal;
}
}
// For use by this class
private static Table commonAncestor(Table inputTable, Table outputTable)
{
int minLevel = min(inputTable.getDepth(), outputTable.getDepth());
Table inputAncestor = inputTable;
while (inputAncestor.getDepth() > minLevel) {
inputAncestor = inputAncestor.getParentTable();
}
Table outputAncestor = outputTable;
while (outputAncestor.getDepth() > minLevel) {
outputAncestor = outputAncestor.getParentTable();
}
while (inputAncestor != outputAncestor) {
inputAncestor = inputAncestor.getParentTable();
outputAncestor = outputAncestor.getParentTable();
}
return outputAncestor;
}
// Class state
private static final Logger LOG = LoggerFactory.getLogger(BranchLookup_Nested.class);
private static final InOutTap TAP_OPEN = OPERATOR_TAP.createSubsidiaryTap("operator: BranchLookup_Nested open");
private static final InOutTap TAP_NEXT = OPERATOR_TAP.createSubsidiaryTap("operator: BranchLookup_Nested next");
// Object state
private final Group group;
private final RowType inputRowType, sourceRowType;
private final List<TableRowType> outputRowTypes;
private final boolean keepInput;
// If keepInput is true, inputPrecedesBranch controls whether input row appears before the retrieved branch.
private final boolean inputPrecedesBranch;
private final int inputBindingPosition;
private final int lookaheadQuantum;
private final Table commonAncestor;
private final int branchRootOrdinal;
@Override
public CompoundExplainer getExplainer(ExplainContext context)
{
Attributes atts = new Attributes();
atts.put(Label.BINDING_POSITION, PrimitiveExplainer.getInstance(inputBindingPosition));
for (TableRowType outputRowType : outputRowTypes) {
atts.put(Label.OUTPUT_TYPE, outputRowType.getExplainer(context));
}
TableRowType outputRowType = outputRowTypes.get(0);
TableRowType ancestorRowType = outputRowType.schema().tableRowType(commonAncestor);
if ((ancestorRowType != sourceRowType) && (ancestorRowType != outputRowType)) {
atts.put(Label.ANCESTOR_TYPE, ancestorRowType.getExplainer(context));
}
atts.put(Label.PIPELINE, PrimitiveExplainer.getInstance(lookaheadQuantum));
return new LookUpOperatorExplainer(getName(), atts, sourceRowType, false, null, context);
}
// Inner classes
private class Execution extends LeafCursor
{
// Cursor interface
@Override
public void open()
{
TAP_OPEN.in();
try {
super.open();
Row rowFromBindings = bindings.getRow(inputBindingPosition);
assert rowFromBindings.rowType() == inputRowType : rowFromBindings;
if (inputRowType != sourceRowType) {
rowFromBindings = rowFromBindings.subRow(sourceRowType);
}
if (LOG_EXECUTION) {
LOG.debug("BranchLookup_Nested: open using {}", rowFromBindings);
}
computeLookupRowHKey(rowFromBindings);
cursor.rebind(hKey, true);
cursor.open();
inputRow = rowFromBindings;
} finally {
TAP_OPEN.out();
}
}
@Override
public Row next()
{
if (TAP_NEXT_ENABLED) {
TAP_NEXT.in();
}
try {
if (CURSOR_LIFECYCLE_ENABLED) {
CursorLifecycle.checkIdleOrActive(this);
}
checkQueryCancelation();
Row row;
if (keepInput && inputPrecedesBranch && inputRow != null) {
row = inputRow;
inputRow = null;
} else {
do {
row = cursor.next();
} while ((row != null) && !outputRowTypes.contains(row.rowType()));
if (row == null) {
if (keepInput && !inputPrecedesBranch) {
assert inputRow != null;
row = inputRow;
inputRow = null;
}
setIdle();
}
}
if (LOG_EXECUTION) {
LOG.debug("BranchLookup_Nested: yield {}", row);
}
if (row == null) {
setIdle();
}
return row;
} finally {
if (TAP_NEXT_ENABLED) {
TAP_NEXT.out();
}
}
}
@Override
public void close()
{
super.close();
cursor.close();
}
// Execution interface
Execution(QueryContext context, QueryBindingsCursor bindingsCursor)
{
super(context, bindingsCursor);
this.cursor = adapter().newGroupCursor(group);
this.hKey = adapter().getKeyCreator().newHKey(outputRowTypes.get(0).hKey());
}
// For use by this class
private void computeLookupRowHKey(Row row)
{
HKey ancestorHKey = row.ancestorHKey(commonAncestor);
ancestorHKey.copyTo(hKey);
if (branchRootOrdinal != -1) {
hKey.extendWithOrdinal(branchRootOrdinal);
}
}
// Object state
private final GroupCursor cursor;
private final HKey hKey;
private Row inputRow;
}
private class BranchCursor extends RowCursorImpl implements BindingsAwareCursor
{
// BindingsAwareCursor interface
@Override
public void open() {
super.open();
Row rowFromBindings = bindings.getRow(inputBindingPosition);
assert rowFromBindings.rowType() == inputRowType : rowFromBindings;
if (inputRowType != sourceRowType) {
rowFromBindings = rowFromBindings.subRow(sourceRowType);
}
computeLookupRowHKey(rowFromBindings);
cursor.rebind(hKey, true);
cursor.open();
inputRow = rowFromBindings;
}
@Override
public Row next() {
Row row = null;
if (keepInput && inputPrecedesBranch && inputRow != null) {
row = inputRow;
inputRow = null;
} else {
do {
row = cursor.next();
} while ((row != null) && !outputRowTypes.contains(row.rowType()));
if (row == null) {
if (keepInput && !inputPrecedesBranch) {
assert inputRow != null;
row = inputRow;
inputRow = null;
}
setIdle();
}
}
if (ExecutionBase.LOG_EXECUTION) {
LOG.debug("BranchLookup#BranchCursor yield: {} ", row );
}
return row;
}
@Override
public void jump(Row row, ColumnSelector columnSelector) {
cursor.jump(row, columnSelector);
state = CursorLifecycle.CursorState.ACTIVE;
}
@Override
public void close() {
try {
inputRow = null;
cursor.close();
} finally {
super.close();
}
}
@Override
public void rebind(QueryBindings bindings) {
this.bindings = bindings;
}
// BranchCursor interface
public BranchCursor(StoreAdapter adapter) {
this.cursor = adapter.newGroupCursor(group);
this.hKey = adapter.getKeyCreator().newHKey(outputRowTypes.get(0).hKey());
}
// For use by this class
private void computeLookupRowHKey(Row row)
{
HKey ancestorHKey = row.ancestorHKey(commonAncestor);
ancestorHKey.copyTo(hKey);
if (branchRootOrdinal != -1) {
hKey.extendWithOrdinal(branchRootOrdinal);
}
}
// Object state
private final GroupCursor cursor;
private final HKey hKey;
private Row inputRow;
private QueryBindings bindings;
}
private class LookaheadExecution extends LookaheadLeafCursor<BranchCursor>
{
// 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 {
Row row = super.next();
if (LOG_EXECUTION) {
LOG.debug("BranchLookup_Nested: yield {}", row);
}
return row;
} finally {
if (TAP_NEXT_ENABLED) {
TAP_NEXT.out();
}
}
}
// LookaheadLeafCursor interface
@Override
protected BranchCursor newCursor(QueryContext context, StoreAdapter adapter) {
return new BranchCursor(adapter);
}
@Override
protected BranchCursor openACursor(QueryBindings bindings, boolean lookahead) {
BranchCursor cursor = super.openACursor(bindings, lookahead);
if (LOG_EXECUTION) {
LOG.debug("BranchLookup_Nested: open{} using {}", lookahead ? " lookahead" : "", cursor.inputRow);
}
return cursor;
}
// LookaheadExecution interface
LookaheadExecution(QueryContext context, QueryBindingsCursor bindingsCursor,
StoreAdapter adapter, int quantum) {
super(context, bindingsCursor, adapter, quantum);
}
}
}