diff options
Diffstat (limited to 'appc-dispatcher/appc-dispatcher-common/lock-manager-lib/lock-manager-impl/src/main/java/org/openecomp/appc/lockmanager/impl/sql/optimistic/SqlLockManager.java')
-rw-r--r-- | appc-dispatcher/appc-dispatcher-common/lock-manager-lib/lock-manager-impl/src/main/java/org/openecomp/appc/lockmanager/impl/sql/optimistic/SqlLockManager.java | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/appc-dispatcher/appc-dispatcher-common/lock-manager-lib/lock-manager-impl/src/main/java/org/openecomp/appc/lockmanager/impl/sql/optimistic/SqlLockManager.java b/appc-dispatcher/appc-dispatcher-common/lock-manager-lib/lock-manager-impl/src/main/java/org/openecomp/appc/lockmanager/impl/sql/optimistic/SqlLockManager.java new file mode 100644 index 000000000..52c75d2b2 --- /dev/null +++ b/appc-dispatcher/appc-dispatcher-common/lock-manager-lib/lock-manager-impl/src/main/java/org/openecomp/appc/lockmanager/impl/sql/optimistic/SqlLockManager.java @@ -0,0 +1,263 @@ +/*- + * ============LICENSE_START======================================================= + * openECOMP : APP-C + * ================================================================================ + * Copyright (C) 2017 AT&T Intellectual Property. All rights + * reserved. + * ================================================================================ + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * ============LICENSE_END========================================================= + */ + +package org.openecomp.appc.lockmanager.impl.sql.optimistic; + +import java.sql.Connection; +import java.sql.PreparedStatement; +import java.sql.ResultSet; +import java.sql.SQLException; + +import org.openecomp.appc.lockmanager.api.LockException; +import org.openecomp.appc.lockmanager.api.LockRuntimeException; +import org.openecomp.appc.lockmanager.impl.sql.JdbcLockManager; +import org.openecomp.appc.lockmanager.impl.sql.Messages; + +abstract class SqlLockManager extends JdbcLockManager { + + private static final String SQL_LOAD_LOCK_RECORD = "SELECT * FROM %s WHERE RESOURCE_ID=?"; + private static final String SQL_INSERT_LOCK_RECORD = "INSERT INTO %s (RESOURCE_ID, OWNER_ID, UPDATED, TIMEOUT, VER) VALUES (?, ?, ?, ?, ?)"; + private static final String SQL_UPDATE_LOCK_RECORD = "UPDATE %s SET OWNER_ID=?, UPDATED=?, TIMEOUT=?, VER=? WHERE RESOURCE_ID=? AND VER=?"; +// private static final String SQL_DELETE_LOCK_RECORD = "DELETE FROM %s WHERE RESOURCE_ID=? AND VER=?"; + private static final String SQL_CURRENT_TIMESTAMP = "SELECT CURRENT_TIMESTAMP()"; + + private String sqlLoadLockRecord; + private String sqlInsertLockRecord; + private String sqlUpdateLockRecord; +// private String sqlDeleteLockRecord; + + @Override + public boolean acquireLock(String resource, String owner) throws LockException { + return acquireLock(resource, owner, 0); + } + + @Override + public boolean acquireLock(String resource, String owner, long timeout) throws LockException { + if(owner == null) { + throw new LockRuntimeException(Messages.ERR_NULL_LOCK_OWNER.format(resource)); + } + boolean res = false; + Connection connection = openDbConnection(); + try { + res = lockResource(connection, resource, owner, timeout); + } finally { + closeDbConnection(connection); + } + return res; + } + + @Override + public void releaseLock(String resource, String owner) throws LockException { + Connection connection = openDbConnection(); + try { + unlockResource(connection, resource, owner); + } finally { + closeDbConnection(connection); + } + } + + @Override + public boolean isLocked(String resource) { + Connection connection=openDbConnection(); + try { + LockRecord lockRecord=loadLockRecord(connection,resource); + if(lockRecord==null){ + return false; + }else{ + if(lockRecord.getOwner()==null){ + return false; + }else if(isLockExpired(lockRecord, connection)){ + return false; + }else{ + return true; + } + } + } catch (SQLException e) { + throw new LockRuntimeException(Messages.EXP_LOCK.format(resource)); + }finally { + closeDbConnection(connection); + } + } + + private boolean lockResource(Connection connection, String resource, String owner, long timeout) throws LockException { + try { + boolean res = false; + LockRecord lockRecord = loadLockRecord(connection, resource); + if(lockRecord != null) { + // lock record already exists + String currentOwner = lockRecord.getOwner(); + if(currentOwner != null) { + if(isLockExpired(lockRecord, connection)) { + currentOwner = null; + } else if(!owner.equals(currentOwner)) { + throw new LockException(Messages.ERR_LOCK_LOCKED_BY_OTHER.format(resource, owner, currentOwner)); + } + } + // set new owner on the resource lock record + if(!updateLockRecord(connection, resource, owner, timeout, lockRecord.getVer())) { + // try again - maybe same owner updated the record + lockResource(connection, resource, owner, timeout); + } + if(currentOwner == null) { + // no one locked the resource before + res = true; + } + } else { + // resource record does not exist in lock table => create new record + try { + addLockRecord(connection, resource, owner, timeout); + res = true; + } catch(SQLException e) { + if(isDuplicatePkError(e)) { + // try again - maybe same owner inserted the record + lockResource(connection, resource, owner, timeout); + } else { + throw e; + } + } + } + return res; + } catch(SQLException e) { + throw new LockRuntimeException(Messages.EXP_LOCK.format(resource), e); + } + } + + protected boolean isDuplicatePkError(SQLException e) { + return e.getSQLState().startsWith("23"); + } + + private void unlockResource(Connection connection, String resource, String owner) throws LockException { + try { + LockRecord lockRecord = loadLockRecord(connection, resource); + if(lockRecord != null) { + // check if expired + if(isLockExpired(lockRecord, connection)) { + // lock is expired => no lock + lockRecord = null; + } + } + if((lockRecord == null) || (lockRecord.getOwner() == null)) { + // resource is not locked + throw new LockException(Messages.ERR_UNLOCK_NOT_LOCKED.format(resource)); + } + String currentOwner = lockRecord.getOwner(); + if(!owner.equals(currentOwner)) { + throw new LockException(Messages.ERR_UNLOCK_LOCKED_BY_OTHER.format(resource, owner, currentOwner)); + } + if (!updateLockRecord(connection, resource, null, 0, lockRecord.getVer())) { + unlockResource(connection, resource, owner); + } + // TODO delete record from table on lock release? +// deleteLockRecord(connection, resource, lockRecord.getVer()); + } catch(SQLException e) { + throw new LockRuntimeException(Messages.EXP_UNLOCK.format(resource), e); + } + } + + protected LockRecord loadLockRecord(Connection connection, String resource) throws SQLException { + LockRecord res = null; + if(sqlLoadLockRecord == null) { + sqlLoadLockRecord = String.format(SQL_LOAD_LOCK_RECORD, tableName); + } + try(PreparedStatement statement = connection.prepareStatement(sqlLoadLockRecord)) { + statement.setString(1, resource); + try(ResultSet resultSet = statement.executeQuery()) { + if(resultSet.next()) { + res = new LockRecord(resource); + res.setOwner(resultSet.getString(2)); + res.setUpdated(resultSet.getLong(3)); + res.setTimeout(resultSet.getLong(4)); + res.setVer(resultSet.getLong(5)); + } + } + } + return res; + } + + protected void addLockRecord(Connection connection, String resource, String owner, long timeout) throws SQLException { + if(sqlInsertLockRecord == null) { + sqlInsertLockRecord = String.format(SQL_INSERT_LOCK_RECORD, tableName); + } + try(PreparedStatement statement = connection.prepareStatement(sqlInsertLockRecord)) { + statement.setString(1, resource); + statement.setString(2, owner); + statement.setLong(3, getCurrentTime(connection)); + statement.setLong(4, timeout); + statement.setLong(5, 1); + statement.executeUpdate(); + } + } + + protected boolean updateLockRecord(Connection connection, String resource, String owner, long timeout, long ver) throws SQLException { + if(sqlUpdateLockRecord == null) { + sqlUpdateLockRecord = String.format(SQL_UPDATE_LOCK_RECORD, tableName); + } + try(PreparedStatement statement = connection.prepareStatement(sqlUpdateLockRecord)) { + long newVer = (ver >= Long.MAX_VALUE) ? 1 : (ver + 1); + statement.setString(1, owner); + statement.setLong(2, getCurrentTime(connection)); + statement.setLong(3, timeout); + statement.setLong(4, newVer); + statement.setString(5, resource); + statement.setLong(6, ver); + return (statement.executeUpdate() != 0); + } + } + +// protected void deleteLockRecord(Connection connection, String resource, long ver) throws SQLException { +// if(sqlDeleteLockRecord == null) { +// sqlDeleteLockRecord = String.format(SQL_DELETE_LOCK_RECORD, tableName); +// } +// try(PreparedStatement statement = connection.prepareStatement(sqlDeleteLockRecord)) { +// statement.setString(1, resource); +// statement.setLong(2, ver); +// statement.executeUpdate(); +// } +// } + + private boolean isLockExpired(LockRecord lockRecord, Connection connection) throws SQLException { + long timeout = lockRecord.getTimeout(); + if(timeout == 0) { + return false; + } + long updated = lockRecord.getUpdated(); + long now = getCurrentTime(connection); + long expiration = updated + timeout; + return (now > expiration); + } + + private long getCurrentTime(Connection connection) throws SQLException { + long res = -1; + if(connection != null) { + try(PreparedStatement statement = connection.prepareStatement(SQL_CURRENT_TIMESTAMP)) { + try(ResultSet resultSet = statement.executeQuery()) { + if(resultSet.next()) { + res = resultSet.getTimestamp(1).getTime(); + } + } + } + } + if(res == -1) { + res = System.currentTimeMillis(); + } + return res; + } +} |