class MergeSort extends java.lang.Object implements Sort
Modifier and Type | Field and Description |
---|---|
protected boolean |
alreadyInOrder
Whether the rows are expected to be in order on insert,
as passed in on create.
|
protected ColumnOrdering[] |
columnOrdering
The column ordering as passed in on create.
|
protected boolean[] |
columnOrderingAscendingMap
A lookup table to speed up lookup of Ascending state of a column,
|
protected int[] |
columnOrderingMap
A lookup table to speed up lookup of a column associated with the i'th
column to compare.
|
protected boolean[] |
columnOrderingNullsLowMap
A lookup table to speed up lookup of nulls-low ordering of a column,
|
private MergeInserter |
inserter
The inserter that's being used to insert rows into the sort.
|
private java.util.Vector |
mergeRuns
A vector of merge runs, produced by the MergeInserter.
|
(package private) static java.util.Properties |
properties
Properties for mergeSort
|
private Scan |
scan
The scan that's being used to return rows from the sort.
|
private SortBuffer |
sortBuffer
An ordered set of the leftover rows that didn't go
in the last merge run (might be all the rows if there
are no merge runs).
|
(package private) int |
sortBufferMax
The maximum number of entries a sort buffer can hold.
|
(package private) int |
sortBufferMin
The minimum number of entries a sort buffer can hold.
|
(package private) SortObserver |
sortObserver
The sort observer.
|
private int |
state
Maintains the current state of the sort as defined in
the preceding values.
|
private static int |
STATE_CLOSED |
private static int |
STATE_DONE_INSERTING |
private static int |
STATE_DONE_SCANNING |
private static int |
STATE_INITIALIZED |
private static int |
STATE_INSERTING |
private static int |
STATE_SCANNING |
protected DataValueDescriptor[] |
template
The template as passed in on create.
|
Constructor and Description |
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MergeSort() |
Modifier and Type | Method and Description |
---|---|
private boolean |
checkColumnOrdering(DataValueDescriptor[] template,
ColumnOrdering[] columnOrdering)
Check the column ordering against the template, making sure that each
column is present in the template, is not mentioned more than once, and
that the columns isn't
null . |
(package private) void |
checkColumnTypes(DataValueDescriptor[] row)
Check that the columns in the row agree with the columns
in the template, both in number and in type.
|
protected int |
compare(DataValueDescriptor[] r1,
DataValueDescriptor[] r2) |
(package private) long |
createMergeRun(TransactionManager tran,
SortBuffer sortBuffer)
Remove all the rows from the sort buffer and store them
in a temporary conglomerate.
|
(package private) void |
doneInserting(MergeInserter inserter,
SortBuffer sortBuffer,
java.util.Vector mergeRuns)
An inserter is closing.
|
(package private) void |
doneScanning(Scan scan,
SortBuffer sortBuffer) |
(package private) void |
doneScanning(Scan scan,
SortBuffer sortBuffer,
java.util.Vector mergeRuns) |
void |
drop(TransactionController tran)
Drop the sort.
|
(package private) void |
dropMergeRuns(TransactionManager tran)
Get rid of the merge runs, if there are any.
|
void |
initialize(DataValueDescriptor[] template,
ColumnOrdering[] columnOrdering,
SortObserver sortObserver,
boolean alreadyInOrder,
long estimatedRows,
int sortBufferMax)
Go from the CLOSED to the INITIALIZED state.
|
private void |
multiStageMerge(TransactionManager tran) |
SortController |
open(TransactionManager tran)
Open a sort controller.
|
ScanControllerRowSource |
openSortRowSource(TransactionManager tran)
Open a row source to get rows out of the sorter.
|
ScanController |
openSortScan(TransactionManager tran,
boolean hold)
Open a scan controller.
|
private static final int STATE_CLOSED
private static final int STATE_INITIALIZED
private static final int STATE_INSERTING
private static final int STATE_DONE_INSERTING
private static final int STATE_SCANNING
private static final int STATE_DONE_SCANNING
private int state
protected DataValueDescriptor[] template
protected ColumnOrdering[] columnOrdering
protected int[] columnOrderingMap
protected boolean[] columnOrderingAscendingMap
protected boolean[] columnOrderingNullsLowMap
SortObserver sortObserver
protected boolean alreadyInOrder
private MergeInserter inserter
private Scan scan
private java.util.Vector mergeRuns
private SortBuffer sortBuffer
int sortBufferMax
int sortBufferMin
static java.util.Properties properties
public SortController open(TransactionManager tran) throws StandardException
This implementation only supports a single sort controller per sort.
open
in interface Sort
StandardException
- Standard exception policy.Sort.open(org.apache.derby.iapi.store.access.conglomerate.TransactionManager)
public ScanController openSortScan(TransactionManager tran, boolean hold) throws StandardException
openSortScan
in interface Sort
StandardException
- Standard exception policy.Sort.openSortScan(org.apache.derby.iapi.store.access.conglomerate.TransactionManager, boolean)
public ScanControllerRowSource openSortRowSource(TransactionManager tran) throws StandardException
openSortRowSource
in interface Sort
StandardException
- Standard exception policy.Sort.openSortRowSource(org.apache.derby.iapi.store.access.conglomerate.TransactionManager)
public void drop(TransactionController tran) throws StandardException
drop
in interface Sort
StandardException
Sort.drop(org.apache.derby.iapi.store.access.TransactionController)
private boolean checkColumnOrdering(DataValueDescriptor[] template, ColumnOrdering[] columnOrdering)
null
.
Intended to be called as part of a sanity check. All columns are
orderable, since DataValueDescriptor
extends Orderable
.
true
if the ordering is valid, false
if not.void checkColumnTypes(DataValueDescriptor[] row) throws StandardException
XXX (nat) Currently checks that the classes implementing each column are the same -- is this right?
StandardException
protected int compare(DataValueDescriptor[] r1, DataValueDescriptor[] r2) throws StandardException
StandardException
public void initialize(DataValueDescriptor[] template, ColumnOrdering[] columnOrdering, SortObserver sortObserver, boolean alreadyInOrder, long estimatedRows, int sortBufferMax) throws StandardException
StandardException
void doneInserting(MergeInserter inserter, SortBuffer sortBuffer, java.util.Vector mergeRuns)
void doneScanning(Scan scan, SortBuffer sortBuffer)
void doneScanning(Scan scan, SortBuffer sortBuffer, java.util.Vector mergeRuns)
void dropMergeRuns(TransactionManager tran)
private void multiStageMerge(TransactionManager tran) throws StandardException
StandardException
long createMergeRun(TransactionManager tran, SortBuffer sortBuffer) throws StandardException
StandardException
Apache Derby V10.10 Internals - Copyright © 2004,2013 The Apache Software Foundation. All Rights Reserved.