提交 384e5195 authored 作者: Evgenij Ryazanov's avatar Evgenij Ryazanov

Remove MultiVersionIndex (PageStore+MVCC)

上级 acf1f91e
/*
* Copyright 2004-2018 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.index;
import org.h2.engine.Session;
import org.h2.engine.SysProperties;
import org.h2.message.DbException;
import org.h2.result.Row;
import org.h2.result.SearchRow;
/**
* The cursor implementation for the multi-version index.
*/
public class MultiVersionCursor implements Cursor {
private final MultiVersionIndex index;
private final Session session;
private final Cursor baseCursor, deltaCursor;
private final Object sync;
private SearchRow baseRow;
private Row deltaRow;
private boolean onBase;
private boolean end;
private boolean needNewDelta, needNewBase;
private boolean reverse;
MultiVersionCursor(Session session, MultiVersionIndex index, Cursor base,
Cursor delta, Object sync) {
this.session = session;
this.index = index;
this.baseCursor = base;
this.deltaCursor = delta;
this.sync = sync;
needNewDelta = true;
needNewBase = true;
}
/**
* Load the current row.
*/
void loadCurrent() {
synchronized (sync) {
baseRow = baseCursor.getSearchRow();
deltaRow = deltaCursor.get();
needNewDelta = false;
needNewBase = false;
}
}
private void loadNext(boolean base) {
synchronized (sync) {
if (base) {
if (step(baseCursor)) {
baseRow = baseCursor.getSearchRow();
} else {
baseRow = null;
}
} else {
if (step(deltaCursor)) {
deltaRow = deltaCursor.get();
} else {
deltaRow = null;
}
}
}
}
private boolean step(Cursor cursor) {
return reverse ? cursor.previous() : cursor.next();
}
@Override
public Row get() {
synchronized (sync) {
if (end) {
return null;
}
return onBase ? baseCursor.get() : deltaCursor.get();
}
}
@Override
public SearchRow getSearchRow() {
synchronized (sync) {
if (end) {
return null;
}
return onBase ? baseCursor.getSearchRow() : deltaCursor.getSearchRow();
}
}
@Override
public boolean next() {
synchronized (sync) {
if (SysProperties.CHECK && end) {
DbException.throwInternalError();
}
while (true) {
if (needNewDelta) {
loadNext(false);
needNewDelta = false;
}
if (needNewBase) {
loadNext(true);
needNewBase = false;
}
if (deltaRow == null) {
if (baseRow == null) {
end = true;
return false;
}
onBase = true;
needNewBase = true;
return true;
}
int sessionId = deltaRow.getSessionId();
boolean isThisSession = sessionId == session.getId();
boolean isDeleted = deltaRow.isDeleted();
if (isThisSession && isDeleted) {
needNewDelta = true;
continue;
}
if (baseRow == null) {
if (isDeleted) {
if (isThisSession) {
end = true;
return false;
}
// the row was deleted by another session: return it
onBase = false;
needNewDelta = true;
return true;
}
DbException.throwInternalError();
}
int compare = index.compareRows(deltaRow, baseRow);
if (compare == 0) {
// can't use compareKeys because the
// version would be compared as well
long k1 = deltaRow.getKey();
long k2 = baseRow.getKey();
compare = Long.compare(k1, k2);
}
if (compare == 0) {
if (isDeleted) {
if (isThisSession) {
DbException.throwInternalError();
}
// another session updated the row
} else {
if (isThisSession) {
onBase = false;
needNewBase = true;
needNewDelta = true;
return true;
}
// another session inserted the row: ignore
needNewBase = true;
needNewDelta = true;
continue;
}
}
if (compare > 0) {
onBase = true;
needNewBase = true;
return true;
}
onBase = false;
needNewDelta = true;
return true;
}
}
}
@Override
public boolean previous() {
reverse = true;
try {
return next();
} finally {
reverse = false;
}
}
}
/*
* Copyright 2004-2018 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.index;
import java.util.ArrayList;
import org.h2.api.ErrorCode;
import org.h2.command.dml.AllColumnsForPlan;
import org.h2.engine.Database;
import org.h2.engine.DbObject;
import org.h2.engine.Session;
import org.h2.message.DbException;
import org.h2.result.Row;
import org.h2.result.SearchRow;
import org.h2.result.SortOrder;
import org.h2.schema.Schema;
import org.h2.table.Column;
import org.h2.table.IndexColumn;
import org.h2.table.RegularTable;
import org.h2.table.Table;
import org.h2.table.TableFilter;
import org.h2.value.Value;
import org.h2.value.ValueNull;
/**
* A multi-version index is a combination of a regular index,
* and a in-memory tree index that contains uncommitted changes.
* Uncommitted changes can include new rows, and deleted rows.
*/
public class MultiVersionIndex implements Index {
private final Index base;
private final TreeIndex delta;
private final RegularTable table;
private final Object sync;
private final Column firstColumn;
public MultiVersionIndex(Index base, RegularTable table) {
this.base = base;
this.table = table;
IndexType deltaIndexType = IndexType.createNonUnique(false);
if (base instanceof SpatialIndex) {
throw DbException.get(ErrorCode.FEATURE_NOT_SUPPORTED_1,
"MVCC & spatial index");
}
this.delta = new TreeIndex(table, -1, "DELTA", base.getIndexColumns(),
deltaIndexType);
delta.setMultiVersion(true);
this.sync = base.getDatabase();
this.firstColumn = base.getColumns()[0];
}
@Override
public void add(Session session, Row row) {
synchronized (sync) {
base.add(session, row);
if (removeIfExists(session, row)) {
// for example rolling back a delete operation
} else if (row.getSessionId() != 0) {
// don't insert rows that are added when creating an index
delta.add(session, row);
}
}
}
@Override
public void close(Session session) {
synchronized (sync) {
base.close(session);
}
}
@Override
public boolean isFindUsingFullTableScan() {
return base.isFindUsingFullTableScan();
}
@Override
public Cursor find(TableFilter filter, SearchRow first, SearchRow last) {
synchronized (sync) {
Cursor baseCursor = base.find(filter, first, last);
Cursor deltaCursor = delta.find(filter, first, last);
return new MultiVersionCursor(filter.getSession(), this,
baseCursor, deltaCursor, sync);
}
}
@Override
public Cursor find(Session session, SearchRow first, SearchRow last) {
synchronized (sync) {
Cursor baseCursor = base.find(session, first, last);
Cursor deltaCursor = delta.find(session, first, last);
return new MultiVersionCursor(session, this, baseCursor, deltaCursor, sync);
}
}
@Override
public Cursor findNext(Session session, SearchRow first, SearchRow last) {
throw DbException.throwInternalError(toString());
}
@Override
public boolean canFindNext() {
// TODO possible, but more complicated
return false;
}
@Override
public boolean canGetFirstOrLast() {
return base.canGetFirstOrLast() && delta.canGetFirstOrLast();
}
@Override
public Cursor findFirstOrLast(Session session, boolean first) {
if (first) {
// TODO optimization: this loops through NULL elements
Cursor cursor = find(session, null, null);
while (cursor.next()) {
SearchRow row = cursor.getSearchRow();
Value v = row.getValue(firstColumn.getColumnId());
if (v != ValueNull.INSTANCE) {
return cursor;
}
}
return cursor;
}
Cursor baseCursor = base.findFirstOrLast(session, false);
Cursor deltaCursor = delta.findFirstOrLast(session, false);
MultiVersionCursor cursor = new MultiVersionCursor(session, this,
baseCursor, deltaCursor, sync);
cursor.loadCurrent();
// TODO optimization: this loops through NULL elements
while (cursor.previous()) {
SearchRow row = cursor.getSearchRow();
if (row == null) {
break;
}
Value v = row.getValue(firstColumn.getColumnId());
if (v != ValueNull.INSTANCE) {
return cursor;
}
}
return cursor;
}
@Override
public double getCost(Session session, int[] masks,
TableFilter[] filters, int filter, SortOrder sortOrder,
AllColumnsForPlan allColumnsSet) {
return base.getCost(session, masks, filters, filter, sortOrder, allColumnsSet);
}
@Override
public boolean needRebuild() {
return base.needRebuild();
}
/**
* Check if there is an uncommitted row with the given key
* within a different session.
*
* @param session the original session
* @param row the row (only the key is checked)
* @return true if there is an uncommitted row
*/
public boolean isUncommittedFromOtherSession(Session session, Row row) {
Cursor c = delta.find(session, row, row);
while (c.next()) {
Row r = c.get();
return r.getSessionId() != session.getId();
}
return false;
}
private boolean removeIfExists(Session session, Row row) {
// maybe it was inserted by the same session just before
Cursor c = delta.find(session, row, row);
while (c.next()) {
Row r = c.get();
if (r.getKey() == row.getKey() && r.getVersion() == row.getVersion()) {
if (r != row && table.getScanIndex(session).compareRows(r, row) != 0) {
row.setVersion(r.getVersion() + 1);
} else {
delta.remove(session, r);
return true;
}
}
}
return false;
}
@Override
public void remove(Session session, Row row) {
synchronized (sync) {
base.remove(session, row);
if (removeIfExists(session, row)) {
// added and deleted in the same transaction: no change
} else {
delta.add(session, row);
}
}
}
@Override
public void remove(Session session) {
synchronized (sync) {
base.remove(session);
}
}
@Override
public void truncate(Session session) {
synchronized (sync) {
delta.truncate(session);
base.truncate(session);
}
}
@Override
public void commit(int operation, Row row) {
synchronized (sync) {
removeIfExists(null, row);
}
}
@Override
public int compareRows(SearchRow rowData, SearchRow compare) {
return base.compareRows(rowData, compare);
}
@Override
public int getColumnIndex(Column col) {
return base.getColumnIndex(col);
}
@Override
public boolean isFirstColumn(Column column) {
return base.isFirstColumn(column);
}
@Override
public Column[] getColumns() {
return base.getColumns();
}
@Override
public IndexColumn[] getIndexColumns() {
return base.getIndexColumns();
}
@Override
public String getCreateSQL() {
return base.getCreateSQL();
}
@Override
public String getCreateSQLForCopy(Table forTable, String quotedName) {
return base.getCreateSQLForCopy(forTable, quotedName);
}
@Override
public String getDropSQL() {
return base.getDropSQL();
}
@Override
public IndexType getIndexType() {
return base.getIndexType();
}
@Override
public String getPlanSQL() {
return base.getPlanSQL();
}
@Override
public long getRowCount(Session session) {
return base.getRowCount(session);
}
@Override
public Table getTable() {
return base.getTable();
}
@Override
public int getType() {
return base.getType();
}
@Override
public void removeChildrenAndResources(Session session) {
synchronized (sync) {
table.removeIndex(this);
remove(session);
}
}
@Override
public String getSQL() {
return base.getSQL();
}
@Override
public Schema getSchema() {
return base.getSchema();
}
@Override
public void checkRename() {
base.checkRename();
}
@Override
public ArrayList<DbObject> getChildren() {
return base.getChildren();
}
@Override
public String getComment() {
return base.getComment();
}
@Override
public Database getDatabase() {
return base.getDatabase();
}
@Override
public int getId() {
return base.getId();
}
@Override
public String getName() {
return base.getName();
}
@Override
public boolean isTemporary() {
return base.isTemporary();
}
@Override
public void rename(String newName) {
base.rename(newName);
}
@Override
public void setComment(String comment) {
base.setComment(comment);
}
@Override
public void setTemporary(boolean temporary) {
base.setTemporary(temporary);
}
@Override
public long getRowCountApproximation() {
return base.getRowCountApproximation();
}
@Override
public long getDiskSpaceUsed() {
return base.getDiskSpaceUsed();
}
public Index getBaseIndex() {
return base;
}
@Override
public Row getRow(Session session, long key) {
return base.getRow(session, key);
}
@Override
public boolean isHidden() {
return base.isHidden();
}
@Override
public boolean isRowIdIndex() {
return base.isRowIdIndex() && delta.isRowIdIndex();
}
@Override
public boolean canScan() {
return base.canScan();
}
@Override
public void setSortedInsertMode(boolean sortedInsertMode) {
base.setSortedInsertMode(sortedInsertMode);
delta.setSortedInsertMode(sortedInsertMode);
}
@Override
public IndexLookupBatch createLookupBatch(TableFilter[] filters, int filter) {
// Lookup batching is not supported.
return null;
}
}
......@@ -24,7 +24,6 @@ import org.h2.engine.SysProperties;
import org.h2.index.Cursor;
import org.h2.index.Index;
import org.h2.index.IndexType;
import org.h2.index.MultiVersionIndex;
import org.h2.index.PageBtreeIndex;
import org.h2.index.PageBtreeLeaf;
import org.h2.index.PageBtreeNode;
......@@ -1731,13 +1730,7 @@ public class PageStore implements CacheWriter {
}
meta = table.addIndex(session, "I" + id, id, cols, indexType, false, null);
}
PageIndex index;
if (meta instanceof MultiVersionIndex) {
index = (PageIndex) ((MultiVersionIndex) meta).getBaseIndex();
} else {
index = (PageIndex) meta;
}
metaObjects.put(id, index);
metaObjects.put(id, (PageIndex) meta);
}
/**
......
......@@ -42,7 +42,6 @@ import org.h2.expression.ValueExpression;
import org.h2.index.Index;
import org.h2.index.IndexType;
import org.h2.index.MetaIndex;
import org.h2.index.MultiVersionIndex;
import org.h2.jdbc.JdbcSQLException;
import org.h2.message.DbException;
import org.h2.mvstore.FileStore;
......@@ -935,13 +934,7 @@ public class MetaTable extends Table {
}
}
IndexColumn[] cols = index.getIndexColumns();
String indexClass;
if (index instanceof MultiVersionIndex) {
indexClass = ((MultiVersionIndex) index).
getBaseIndex().getClass().getName();
} else {
indexClass = index.getClass().getName();
}
String indexClass = index.getClass().getName();
for (int k = 0; k < cols.length; k++) {
IndexColumn idxCol = cols[k];
Column column = idxCol.column;
......
......@@ -26,7 +26,6 @@ import org.h2.index.Cursor;
import org.h2.index.HashIndex;
import org.h2.index.Index;
import org.h2.index.IndexType;
import org.h2.index.MultiVersionIndex;
import org.h2.index.NonUniqueHashIndex;
import org.h2.index.PageBtreeIndex;
import org.h2.index.PageDataIndex;
......@@ -141,19 +140,7 @@ public class RegularTable extends TableBase {
trace.error(e2, "could not undo operation");
throw e2;
}
DbException de = DbException.convert(e);
if (de.getErrorCode() == ErrorCode.DUPLICATE_KEY_1) {
for (Index index : indexes) {
if (index.getIndexType().isUnique() && index instanceof MultiVersionIndex) {
MultiVersionIndex mv = (MultiVersionIndex) index;
if (mv.isUncommittedFromOtherSession(session, row)) {
throw DbException.get(
ErrorCode.CONCURRENT_UPDATE_1, index.getName());
}
}
}
}
throw de;
throw DbException.convert(e);
}
analyzeIfRequired(session);
}
......@@ -259,9 +246,6 @@ public class RegularTable extends TableBase {
index = new TreeIndex(this, indexId, indexName, cols, indexType);
}
}
if (database.isMVStore()) {
index = new MultiVersionIndex(index, this);
}
if (index.needRebuild() && rowCount > 0) {
try {
Index scan = getScanIndex(session);
......
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