/* Copyright (c) 2001-2005, The HSQL Development Group
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*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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package org.hsqldb;
import org.hsqldb.lib.DoubleIntIndex;
import org.hsqldb.lib.HashMappedList;
import org.hsqldb.lib.HsqlArrayList;
import org.hsqldb.lib.LongKeyIntValueHashMap;
/**
* Manages rows involved in transactions
*
* @author fredt@users
* @version 1.8.0
* @since 1.8.0
*/
public class TransactionManager {
LongKeyIntValueHashMap rowSessionMap;
boolean reWriteProtect;
Database database;
TransactionManager(Database db) {
database = db;
rowSessionMap = new LongKeyIntValueHashMap(true);
}
public void setReWriteProtection(boolean value) {
reWriteProtect = value;
}
void checkDelete(Session session, Row row) throws HsqlException {}
void checkDelete(Session session,
HashMappedList rowSet) throws HsqlException {
if (!reWriteProtect) {
return;
}
int sessionid = session.getId();
for (int i = 0, size = rowSet.size(); i < size; i++) {
Row row = (Row) rowSet.getKey(i);
long rowid = row.getId();
if (rowSessionMap.get(rowid, sessionid) != sessionid) {
throw Trace.error(Trace.INVALID_TRANSACTION_STATE_NO_SUBCLASS,
Trace.ITSNS_OVERWRITE);
}
}
}
void checkDelete(Session session,
HsqlArrayList rowSet) throws HsqlException {
if (!reWriteProtect) {
return;
}
int sessionid = session.getId();
for (int i = 0, size = rowSet.size(); i < size; i++) {
Row row = (Row) rowSet.get(i);
long rowid = row.getId();
if (rowSessionMap.get(rowid, sessionid) != sessionid) {
throw Trace.error(Trace.INVALID_TRANSACTION_STATE_NO_SUBCLASS,
Trace.ITSNS_OVERWRITE);
}
}
}
void commit(Session session) {
Object[] list = session.rowActionList.getArray();
int size = session.rowActionList.size();
for (int i = 0; i < size; i++) {
Transaction tx = (Transaction) list[i];
long rowid = tx.row.getId();
tx.commit(session);
rowSessionMap.remove(rowid);
}
session.rowActionList.clear();
session.savepoints.clear();
}
synchronized void rollback(Session session) {
rollbackTransactions(session, 0, false);
session.savepoints.clear();
}
void rollbackSavepoint(Session session,
String name) throws HsqlException {
int index = session.savepoints.getIndex(name);
if (index < 0) {
throw Trace.error(Trace.SAVEPOINT_NOT_FOUND, name);
}
Integer oi = (Integer) session.savepoints.get(index);
int limit = oi.intValue();
rollbackTransactions(session, limit, false);
while (session.savepoints.size() > index) {
session.savepoints.remove(session.savepoints.size() - 1);
}
}
void rollbackTransactions(Session session, int limit, boolean log) {
Object[] list = session.rowActionList.getArray();
int size = session.rowActionList.size();
for (int i = size - 1; i >= limit; i--) {
Transaction tx = (Transaction) list[i];
tx.rollback(session, log);
}
for (int i = limit; i < size; i++) {
Transaction tx = (Transaction) list[i];
long rowid = tx.row.getId();
rowSessionMap.remove(rowid);
}
session.rowActionList.setSize(limit);
}
void addTransaction(Session session, Transaction transaction) {
if (reWriteProtect) {
rowSessionMap.put(transaction.row.getId(), session.getId());
}
}
private long globalActionTimestamp = 0;
/**
* gets the next timestamp for an action
*/
long nextActionTimestamp() {
globalActionTimestamp++;
return globalActionTimestamp;
}
/**
* Return an array of all transactions sorted by System Change No.
*/
Transaction[] getTransactionList() {
Session[] sessions = database.sessionManager.getAllSessions();
int[] tIndex = new int[sessions.length];
Transaction[] transactions;
int transactionCount = 0;
{
int actioncount = 0;
for (int i = 0; i < sessions.length; i++) {
actioncount += sessions[i].getTransactionSize();
}
transactions = new Transaction[actioncount];
}
while (true) {
boolean found = false;
long minChangeNo = Long.MAX_VALUE;
int sessionIndex = 0;
// find the lowest available SCN across all sessions
for (int i = 0; i < sessions.length; i++) {
int tSize = sessions[i].getTransactionSize();
if (tIndex[i] < tSize) {
Transaction current =
(Transaction) sessions[i].rowActionList.get(
tIndex[i]);
if (current.SCN < minChangeNo) {
minChangeNo = current.SCN;
sessionIndex = i;
}
found = true;
}
}
if (!found) {
break;
}
HsqlArrayList currentList = sessions[sessionIndex].rowActionList;
for (; tIndex[sessionIndex] < currentList.size(); ) {
Transaction current =
(Transaction) currentList.get(tIndex[sessionIndex]);
// if the next change no is in this session, continue adding
if (current.SCN == minChangeNo + 1) {
minChangeNo++;
}
if (current.SCN == minChangeNo) {
transactions[transactionCount++] = current;
tIndex[sessionIndex]++;
} else {
break;
}
}
}
return transactions;
}
/**
* Return a lookup of all transactions ids for cached tables.
*/
public DoubleIntIndex getTransactionIDList() {
Session[] sessions = database.sessionManager.getAllSessions();
DoubleIntIndex lookup = new DoubleIntIndex(10, false);
lookup.setKeysSearchTarget();
for (int i = 0; i < sessions.length; i++) {
HsqlArrayList tlist = sessions[i].rowActionList;
for (int j = 0, size = tlist.size(); j < size; j++) {
Transaction tx = (Transaction) tlist.get(j);
if (tx.tTable.getTableType() == Table.CACHED_TABLE) {
lookup.addUnique(tx.row.getPos(), 0);
}
}
}
return lookup;
}
/**
* Convert row ID's for cached table rows in transactions
*/
public void convertTransactionIDs(DoubleIntIndex lookup) {
Session[] sessions = database.sessionManager.getAllSessions();
for (int i = 0; i < sessions.length; i++) {
HsqlArrayList tlist = sessions[i].rowActionList;
for (int j = 0, size = tlist.size(); j < size; j++) {
Transaction tx = (Transaction) tlist.get(j);
if (tx.tTable.getTableType() == Table.CACHED_TABLE) {
int pos = lookup.lookupFirstEqual(tx.row.getPos());
tx.row.setPos(pos);
}
}
}
}
}