com.dell.doradus.service.db.DBTransaction Maven / Gradle / Ivy
/*
* Copyright (C) 2014 Dell, Inc.
*
* 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.
*/
package com.dell.doradus.service.db;
import java.util.Collection;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Abstract class that encapsulates a set of updates that will be committed together.
* Provides methods to post updates based on a tabular model: add/replace column, delete
* column, and delete row. These methods operate on a "store", which is a ColumnFamily in
* Cassandra.
*
* Because the application schema model is central to Doradus, methods are also provided
* to add columns to an application's definition row and to delete an application's
* definition row. These operations are performed on the Applications ColumnFamily in
* Cassandra.
*
* The accumulated updates are commited by calling {@link DBService#commit(DBTransaction)}
* which also clears the updates. Updates can also be cleared by calling {@link #clear()}.
* The transaction object subsequently can be reused, causing the same timestamp to be
* used for all new updates. To use a new timestamp, a new object must be created.
*/
public abstract class DBTransaction {
// Protected logger available to concrete services:
protected final Logger m_logger = LoggerFactory.getLogger(getClass().getSimpleName());
//----- General methods
/**
* Clear all updates defined in this transaction.
*/
public abstract void clear();
/**
* Get the total number of updates (column updates/deletes and row deletes) queued
* in this transaction so far.
*
* @return Total number of updates queued in this transaction so far.
*/
public abstract int getUpdateCount();
//----- Column/row update methods
/**
* Add or set a column to the given row in the given table with a null value.
*
* @param storeName Name of store that owns row.
* @param rowKey Key of row that owns column.
* @param colName Name of column.
* @param colValue Column value as a string.
*/
public abstract void addColumn(String storeName, String rowKey, String colName);
/**
* Add or set a column with the given string value.
*
* @param storeName Name of store that owns row.
* @param rowKey Key of row that owns column.
* @param colName Name of column.
* @param colValue Column value as a string.
*/
public abstract void addColumn(String storeName, String rowKey, String colName, String colValue);
/**
* Add or set a column with the given binary value.
*
* @param storeName Name of store that owns row.
* @param rowKey Key of row that owns column.
* @param colName Name of column.
* @param colValue Column value in binary.
*/
public abstract void addColumn(String storeName, String rowKey, String colName, byte[] colValue);
/**
* Add or set a column with the given long value. The column value is converted to
* binary form using Long.toString(colValue), which is then converted to a String using
* UTF-8.
*
* @param storeName Name of store that owns row.
* @param rowKey Key of row that owns column.
* @param colName Name of column.
* @param colValue Column value as a long.
*/
public abstract void addColumn(String storeName, String rowKey, String colName, long colValue);
/**
* Add an update that will delete the row with the given row key from the given store.
*
* @param storeName Name of store from which to delete an object row.
* @param rowKey Row key in string form.
*/
public abstract void deleteRow(String storeName, String rowKey);
/**
* Add an update that will delete the column for the given store, row key, and column
* name. If a column update exists for the same store/row/column, the results are
* undefined when the transaction is committed.
*
* @param storeName Name of store that owns row.
* @param rowKey Row key in string form.
* @param colName Column name in string form.
*/
public abstract void deleteColumn(String storeName, String rowKey, String colName);
/**
* Add updates that will delete all given columns names for the given store name and
* row key. If a column update exists for the same store/row/column, the results are
* undefined when the transaction is committed.
*
* @param storeName Name of store that owns row.
* @param rowKey Row key in string form.
* @param colNames Collection of column names in string form.
*/
public abstract void deleteColumns(String storeName, String rowKey, Collection colNames);
} // DBTransaction