package liquibase.lockservice;
import liquibase.configuration.GlobalConfiguration;
import liquibase.configuration.LiquibaseConfiguration;
import liquibase.database.Database;
import liquibase.database.ObjectQuotingStrategy;
import liquibase.database.core.DerbyDatabase;
import liquibase.database.core.MSSQLDatabase;
import liquibase.exception.DatabaseException;
import liquibase.exception.LiquibaseException;
import liquibase.exception.LockException;
import liquibase.exception.UnexpectedLiquibaseException;
import liquibase.executor.Executor;
import liquibase.executor.ExecutorService;
import liquibase.logging.LogFactory;
import liquibase.snapshot.InvalidExampleException;
import liquibase.snapshot.SnapshotGeneratorFactory;
import liquibase.sql.Sql;
import liquibase.sqlgenerator.SqlGeneratorFactory;
import liquibase.statement.SqlStatement;
import liquibase.statement.core.*;
import liquibase.structure.core.Table;
import java.text.DateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;
public class StandardLockService implements LockService {
protected Database database;
protected boolean hasChangeLogLock = false;
private Long changeLogLockPollRate;
private Long changeLogLockRecheckTime;
private Boolean hasDatabaseChangeLogLockTable = null;
private boolean isDatabaseChangeLogLockTableInitialized = false;
private ObjectQuotingStrategy quotingStrategy;
public StandardLockService() {
}
@Override
public int getPriority() {
return PRIORITY_DEFAULT;
}
@Override
public boolean supports(Database database) {
return true;
}
@Override
public void setDatabase(Database database) {
this.database = database;
}
public Long getChangeLogLockWaitTime() {
if (changeLogLockPollRate != null) {
return changeLogLockPollRate;
}
return LiquibaseConfiguration.getInstance().getConfiguration(GlobalConfiguration.class).getDatabaseChangeLogLockWaitTime();
}
@Override
public void setChangeLogLockWaitTime(long changeLogLockWaitTime) {
this.changeLogLockPollRate = changeLogLockWaitTime;
}
@Override
public void setChangeLogLockRecheckTime(long changeLogLockRecheckTime) {
this.changeLogLockRecheckTime = changeLogLockRecheckTime;
}
public Long getChangeLogLockRecheckTime() {
if (changeLogLockRecheckTime != null) {
return changeLogLockRecheckTime;
}
return LiquibaseConfiguration.getInstance().getConfiguration(GlobalConfiguration.class).getDatabaseChangeLogLockPollRate();
}
@Override
public void init() throws DatabaseException {
boolean createdTable = false;
Executor executor = ExecutorService.getInstance().getExecutor(database);
if (!hasDatabaseChangeLogLockTable()) {
try {
executor.comment("Create Database Lock Table");
executor.execute(new CreateDatabaseChangeLogLockTableStatement());
database.commit();
LogFactory.getLogger().debug("Created database lock table with name: " + database.escapeTableName(database.getLiquibaseCatalogName(), database.getLiquibaseSchemaName(), database.getDatabaseChangeLogLockTableName()));
} catch (DatabaseException e) {
if (e.getMessage() != null && e.getMessage().contains("exists")) {
//hit a race condition where the table got created by another node.
LogFactory.getLogger().debug("Database lock table already appears to exist, due to exception: " + e.getMessage()+". Continuing on");
} else {
throw e;
}
}
this.hasDatabaseChangeLogLockTable = true;
createdTable = true;
hasDatabaseChangeLogLockTable = true;
}
if (!isDatabaseChangeLogLockTableInitialized(createdTable)) {
executor.comment("Initialize Database Lock Table");
executor.execute(new InitializeDatabaseChangeLogLockTableStatement());
database.commit();
}
if (executor.updatesDatabase() && database instanceof DerbyDatabase && ((DerbyDatabase) database).supportsBooleanDataType()) { //check if the changelog table is of an old smallint vs. boolean format
String lockTable = database.escapeTableName(database.getLiquibaseCatalogName(), database.getLiquibaseSchemaName(), database.getDatabaseChangeLogLockTableName());
Object obj = executor.queryForObject(new RawSqlStatement("select min(locked) as test from " + lockTable + " fetch first row only"), Object.class);
if (!(obj instanceof Boolean)) { //wrong type, need to recreate table
executor.execute(new DropTableStatement(database.getLiquibaseCatalogName(), database.getLiquibaseSchemaName(), database.getDatabaseChangeLogLockTableName(), false));
executor.execute(new CreateDatabaseChangeLogLockTableStatement());
executor.execute(new InitializeDatabaseChangeLogLockTableStatement());
}
}
}
public boolean isDatabaseChangeLogLockTableInitialized(final boolean tableJustCreated) throws DatabaseException {
if (!isDatabaseChangeLogLockTableInitialized) {
Executor executor = ExecutorService.getInstance().getExecutor(database);
try {
isDatabaseChangeLogLockTableInitialized = executor.queryForInt(new RawSqlStatement("select count(*) from " + database.escapeTableName(database.getLiquibaseCatalogName(), database.getLiquibaseSchemaName(), database.getDatabaseChangeLogLockTableName()))) > 0;
} catch (LiquibaseException e) {
if (executor.updatesDatabase()) {
throw new UnexpectedLiquibaseException(e);
} else {
//probably didn't actually create the table yet.
isDatabaseChangeLogLockTableInitialized = !tableJustCreated;
}
}
}
return isDatabaseChangeLogLockTableInitialized;
}
@Override
public boolean hasChangeLogLock() {
return hasChangeLogLock;
}
public boolean hasDatabaseChangeLogLockTable() throws DatabaseException {
if (hasDatabaseChangeLogLockTable == null) {
try {
hasDatabaseChangeLogLockTable = SnapshotGeneratorFactory.getInstance().hasDatabaseChangeLogLockTable(database);
} catch (LiquibaseException e) {
throw new UnexpectedLiquibaseException(e);
}
}
return hasDatabaseChangeLogLockTable;
}
@Override
public void waitForLock() throws LockException {
boolean locked = false;
long timeToGiveUp = new Date().getTime() + (getChangeLogLockWaitTime() * 1000 * 60);
while (!locked && new Date().getTime() < timeToGiveUp) {
locked = acquireLock();
if (!locked) {
LogFactory.getLogger().info("Waiting for changelog lock....");
try {
Thread.sleep(getChangeLogLockRecheckTime() * 1000);
} catch (InterruptedException e) {
;
}
}
}
if (!locked) {
DatabaseChangeLogLock[] locks = listLocks();
String lockedBy;
if (locks.length > 0) {
DatabaseChangeLogLock lock = locks[0];
lockedBy = lock.getLockedBy() + " since " + DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT).format(lock.getLockGranted());
} else {
lockedBy = "UNKNOWN";
}
throw new LockException("Could not acquire change log lock. Currently locked by " + lockedBy);
}
}
@Override
public boolean acquireLock() throws LockException {
if (hasChangeLogLock) {
return true;
}
quotingStrategy = database.getObjectQuotingStrategy();
Executor executor = ExecutorService.getInstance().getExecutor(database);
try {
database.rollback();
this.init();
Boolean locked = (Boolean) ExecutorService.getInstance().getExecutor(database).queryForObject(new SelectFromDatabaseChangeLogLockStatement("LOCKED"), Boolean.class);
if (locked) {
return false;
} else {
executor.comment("Lock Database");
int rowsUpdated = executor.update(new LockDatabaseChangeLogStatement());
if (rowsUpdated == -1 && database instanceof MSSQLDatabase) {
LogFactory.getLogger().debug("Database did not return a proper row count (Might have NOCOUNT enabled)");
database.rollback();
Sql[] sql = SqlGeneratorFactory.getInstance().generateSql(new LockDatabaseChangeLogStatement(), database);
if (sql.length != 1) {
throw new UnexpectedLiquibaseException("Did not expect "+sql.length+" statements");
}
rowsUpdated = executor.update(new RawSqlStatement("EXEC sp_executesql N'SET NOCOUNT OFF "+sql[0].toSql().replace("'", "''")+"'"));
}
if (rowsUpdated > 1) {
throw new LockException("Did not update change log lock correctly");
}
if (rowsUpdated == 0)
{
// another node was faster
return false;
}
database.commit();
LogFactory.getLogger().info("Successfully acquired change log lock");
hasChangeLogLock = true;
database.setCanCacheLiquibaseTableInfo(true);
return true;
}
} catch (Exception e) {
throw new LockException(e);
} finally {
try {
database.rollback();
} catch (DatabaseException e) {
;
}
}
}
@Override
public void releaseLock() throws LockException {
ObjectQuotingStrategy incomingQuotingStrategy = null;
if (this.quotingStrategy != null) {
incomingQuotingStrategy = database.getObjectQuotingStrategy();
database.setObjectQuotingStrategy(this.quotingStrategy);
}
Executor executor = ExecutorService.getInstance().getExecutor(database);
try {
if (this.hasDatabaseChangeLogLockTable()) {
executor.comment("Release Database Lock");
database.rollback();
int updatedRows = executor.update(new UnlockDatabaseChangeLogStatement());
if (updatedRows == -1 && database instanceof MSSQLDatabase) {
LogFactory.getLogger().debug("Database did not return a proper row count (Might have NOCOUNT enabled.)");
database.rollback();
Sql[] sql = SqlGeneratorFactory.getInstance().generateSql(new UnlockDatabaseChangeLogStatement(), database);
if (sql.length != 1) {
throw new UnexpectedLiquibaseException("Did not expect "+sql.length+" statements");
}
updatedRows = executor.update(new RawSqlStatement("EXEC sp_executesql N'SET NOCOUNT OFF "+sql[0].toSql().replace("'", "''")+"'"));
}
if (updatedRows != 1) {
throw new LockException("Did not update change log lock correctly.\n\n" + updatedRows + " rows were updated instead of the expected 1 row using executor " + executor.getClass().getName()+" there are "+executor.queryForInt(new RawSqlStatement("select count(*) from "+database.getDatabaseChangeLogLockTableName()))+" rows in the table");
}
database.commit();
}
} catch (Exception e) {
throw new LockException(e);
} finally {
try {
hasChangeLogLock = false;
database.setCanCacheLiquibaseTableInfo(false);
LogFactory.getLogger().info("Successfully released change log lock");
database.rollback();
} catch (DatabaseException e) {
;
}
if (incomingQuotingStrategy != null) {
database.setObjectQuotingStrategy(incomingQuotingStrategy);
}
}
}
@Override
public DatabaseChangeLogLock[] listLocks() throws LockException {
try {
if (!this.hasDatabaseChangeLogLockTable()) {
return new DatabaseChangeLogLock[0];
}
List<DatabaseChangeLogLock> allLocks = new ArrayList<DatabaseChangeLogLock>();
SqlStatement sqlStatement = new SelectFromDatabaseChangeLogLockStatement("ID", "LOCKED", "LOCKGRANTED", "LOCKEDBY");
List<Map<String, ?>> rows = ExecutorService.getInstance().getExecutor(database).queryForList(sqlStatement);
for (Map columnMap : rows) {
Object lockedValue = columnMap.get("LOCKED");
Boolean locked;
if (lockedValue instanceof Number) {
locked = ((Number) lockedValue).intValue() == 1;
} else {
locked = (Boolean) lockedValue;
}
if (locked != null && locked) {
allLocks.add(new DatabaseChangeLogLock(((Number) columnMap.get("ID")).intValue(), (Date) columnMap.get("LOCKGRANTED"), (String) columnMap.get("LOCKEDBY")));
}
}
return allLocks.toArray(new DatabaseChangeLogLock[allLocks.size()]);
} catch (Exception e) {
throw new LockException(e);
}
}
@Override
public void forceReleaseLock() throws LockException, DatabaseException {
this.init();
releaseLock();
/*try {
releaseLock();
} catch (LockException e) {
// ignore ?
LogFactory.getLogger().info("Ignored exception in forceReleaseLock: " + e.getMessage());
}*/
}
@Override
public void reset() {
hasChangeLogLock = false;
hasDatabaseChangeLogLockTable = null;
isDatabaseChangeLogLockTableInitialized = false;
}
@Override
public void destroy() throws DatabaseException {
try {
if (SnapshotGeneratorFactory.getInstance().has(new Table().setName(database.getDatabaseChangeLogLockTableName()).setSchema(database.getLiquibaseCatalogName(), database.getLiquibaseSchemaName()), database)) {
ExecutorService.getInstance().getExecutor(database).execute(new DropTableStatement(database.getLiquibaseCatalogName(), database.getLiquibaseSchemaName(), database.getDatabaseChangeLogLockTableName(), false));
hasDatabaseChangeLogLockTable = null;
}
reset();
} catch (InvalidExampleException e) {
throw new UnexpectedLiquibaseException(e);
}
}
}