Class MVTempResult

java.lang.Object

org.h2.mvstore.db.MVTempResult

All Implemented Interfaces:

ResultExternal

Direct Known Subclasses:

MVPlainTempResult, MVSortedTempResult

public abstract class MVTempResult
extends Object
implements ResultExternal

Temporary result.

A separate MVStore in a temporary file is used for each result. The file is removed when this result and all its copies are closed. TempFileDeleter is also used to delete this file if results are not closed properly.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	MVTempResult.CloseImpl

Field Summary

Fields

Modifier and Type	Field	Description
(package private) int	childCount	Count of child results.
private final MVTempResult.CloseImpl	closeable	Closeable to close the storage.
(package private) boolean	closed	Whether this result is closed.
private final Database	database
(package private) final Expression[]	expressions	Column expressions.
private final Reference<?>	fileRef	Reference to the record in the temporary file deleter.
(package private) final MVTempResult	parent	Parent store for copies.
(package private) final int	resultColumnCount	Total count of columns.
(package private) int	rowCount	Count of rows.
(package private) final MVStore	store	MVStore.
private final TempFileDeleter	tempFileDeleter	Temporary file deleter.
(package private) final int	visibleColumnCount	Count of visible columns.

Constructor Summary

Constructors

Constructor	Description
MVTempResult(Database database, Expression[] expressions, int visibleColumnCount, int resultColumnCount)	Creates a new temporary result.
MVTempResult(MVTempResult parent)	Creates a shallow copy of the result.

Method Summary

Modifier and Type	Method	Description
int	addRows(Collection<Value[]> rows)	Add a number of rows to the result.
void	close()	Close this object and delete the temporary file.
private void	closeChild()
private void	delete()
static ResultExternal	of(Database database, Expression[] expressions, boolean distinct, int[] distinctIndexes, int visibleColumnCount, int resultColumnCount, SortOrder sort)	Creates MVStore-based temporary result.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface ResultExternal

addRow, contains, createShallowCopy, next, removeRow, reset

Field Details

database

private final Database database

store

final MVStore store

MVStore.

expressions

final Expression[] expressions

Column expressions.

visibleColumnCount

final int visibleColumnCount

Count of visible columns.

resultColumnCount

final int resultColumnCount

Total count of columns.

rowCount

int rowCount

Count of rows. Used only in a root results, copies always have 0 value.

parent

final MVTempResult parent

Parent store for copies. If null this result is a root result.

childCount

int childCount

Count of child results.

closed

boolean closed

Whether this result is closed.

tempFileDeleter

private final TempFileDeleter tempFileDeleter

Temporary file deleter.

closeable

private final MVTempResult.CloseImpl closeable

Closeable to close the storage.

fileRef

private final Reference<?> fileRef

Reference to the record in the temporary file deleter.

Constructor Details

MVTempResult

MVTempResult(MVTempResult parent)

Creates a shallow copy of the result.

Parameters:

parent - parent result

MVTempResult

MVTempResult(Database database,
 Expression[] expressions,
 int visibleColumnCount,
 int resultColumnCount)

Creates a new temporary result.

Parameters:

database - database

expressions - column expressions

visibleColumnCount - count of visible columns

resultColumnCount - total count of columns

Method Details

of

public static ResultExternal of(Database database,
 Expression[] expressions,
 boolean distinct,
 int[] distinctIndexes,
 int visibleColumnCount,
 int resultColumnCount,
 SortOrder sort)

Creates MVStore-based temporary result.

Parameters:

database - database

expressions - expressions

distinct - is output distinct

distinctIndexes - indexes of distinct columns for DISTINCT ON results

visibleColumnCount - count of visible columns

resultColumnCount - the number of columns including visible columns and additional virtual columns for ORDER BY and DISTINCT ON clauses

sort - sort order, or null

Returns:

temporary result

addRows

public int addRows(Collection<Value[]> rows)

Description copied from interface: ResultExternal

Add a number of rows to the result.

Specified by:

addRows in interface ResultExternal

Parameters:

rows - the list of rows to add

Returns:

the new number of rows in this object

close

public void close()

Description copied from interface: ResultExternal

Close this object and delete the temporary file.

Specified by:

close in interface ResultExternal

closeChild

private void closeChild()

delete

private void delete()