/**
* Copyright (c) 2010 Yahoo! Inc. 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. See accompanying
* LICENSE file.
*/
package com.yahoo.ycsb;
import java.util.HashMap;
import java.util.Properties;
import java.util.Set;
import java.util.Enumeration;
import java.util.Vector;
/**
* Basic DB that just prints out the requested operations, instead of doing them against a database.
*/
public class BasicDB extends DB
{
public static final String VERBOSE="basicdb.verbose";
public static final String VERBOSE_DEFAULT="true";
public static final String SIMULATE_DELAY="basicdb.simulatedelay";
public static final String SIMULATE_DELAY_DEFAULT="0";
boolean verbose;
int todelay;
public BasicDB()
{
todelay=0;
}
void delay()
{
if (todelay>0)
{
try
{
Thread.sleep((long)Utils.random().nextInt(todelay));
}
catch (InterruptedException e)
{
//do nothing
}
}
}
/**
* Initialize any state for this DB.
* Called once per DB instance; there is one DB instance per client thread.
*/
@SuppressWarnings("unchecked")
public void init()
{
verbose=Boolean.parseBoolean(getProperties().getProperty(VERBOSE, VERBOSE_DEFAULT));
todelay=Integer.parseInt(getProperties().getProperty(SIMULATE_DELAY, SIMULATE_DELAY_DEFAULT));
if (verbose)
{
System.out.println("***************** properties *****************");
Properties p=getProperties();
if (p!=null)
{
for (Enumeration e=p.propertyNames(); e.hasMoreElements(); )
{
String k=(String)e.nextElement();
System.out.println("\""+k+"\"=\""+p.getProperty(k)+"\"");
}
}
System.out.println("**********************************************");
}
}
/**
* Read a record from the database. Each field/value pair from the result will be stored in a HashMap.
*
* @param table The name of the table
* @param key The record key of the record to read.
* @param fields The list of fields to read, or null for all of them
* @param result A HashMap of field/value pairs for the result
* @return Zero on success, a non-zero error code on error
*/
public int read(String table, String key, Set<String> fields, HashMap<String,ByteIterator> result)
{
delay();
if (verbose)
{
System.out.print("READ "+table+" "+key+" [ ");
if (fields!=null)
{
for (String f : fields)
{
System.out.print(f+" ");
}
}
else
{
System.out.print("<all fields>");
}
System.out.println("]");
}
return 0;
}
/**
* Perform a range scan for a set of records in the database. Each field/value pair from the result will be stored in a HashMap.
*
* @param table The name of the table
* @param startkey The record key of the first record to read.
* @param recordcount The number of records to read
* @param fields The list of fields to read, or null for all of them
* @param result A Vector of HashMaps, where each HashMap is a set field/value pairs for one record
* @return Zero on success, a non-zero error code on error
*/
public int scan(String table, String startkey, int recordcount, Set<String> fields, Vector<HashMap<String,ByteIterator>> result)
{
delay();
if (verbose)
{
System.out.print("SCAN "+table+" "+startkey+" "+recordcount+" [ ");
if (fields!=null)
{
for (String f : fields)
{
System.out.print(f+" ");
}
}
else
{
System.out.print("<all fields>");
}
System.out.println("]");
}
return 0;
}
/**
* Update a record in the database. Any field/value pairs in the specified values HashMap will be written into the record with the specified
* record key, overwriting any existing values with the same field name.
*
* @param table The name of the table
* @param key The record key of the record to write.
* @param values A HashMap of field/value pairs to update in the record
* @return Zero on success, a non-zero error code on error
*/
public int update(String table, String key, HashMap<String,ByteIterator> values)
{
delay();
if (verbose)
{
System.out.print("UPDATE "+table+" "+key+" [ ");
if (values!=null)
{
for (String k : values.keySet())
{
System.out.print(k+"="+values.get(k)+" ");
}
}
System.out.println("]");
}
return 0;
}
/**
* Insert a record in the database. Any field/value pairs in the specified values HashMap will be written into the record with the specified
* record key.
*
* @param table The name of the table
* @param key The record key of the record to insert.
* @param values A HashMap of field/value pairs to insert in the record
* @return Zero on success, a non-zero error code on error
*/
public int insert(String table, String key, HashMap<String,ByteIterator> values)
{
delay();
if (verbose)
{
System.out.print("INSERT "+table+" "+key+" [ ");
if (values!=null)
{
for (String k : values.keySet())
{
System.out.print(k+"="+values.get(k)+" ");
}
}
System.out.println("]");
}
return 0;
}
/**
* Delete a record from the database.
*
* @param table The name of the table
* @param key The record key of the record to delete.
* @return Zero on success, a non-zero error code on error
*/
public int delete(String table, String key)
{
delay();
if (verbose)
{
System.out.println("DELETE "+table+" "+key);
}
return 0;
}
/**
* Short test of BasicDB
*/
/*
public static void main(String[] args)
{
BasicDB bdb=new BasicDB();
Properties p=new Properties();
p.setProperty("Sky","Blue");
p.setProperty("Ocean","Wet");
bdb.setProperties(p);
bdb.init();
HashMap<String,String> fields=new HashMap<String,String>();
fields.put("A","X");
fields.put("B","Y");
bdb.read("table","key",null,null);
bdb.insert("table","key",fields);
fields=new HashMap<String,String>();
fields.put("C","Z");
bdb.update("table","key",fields);
bdb.delete("table","key");
}*/
}