namespace java fx.sunjoy.server.gen

struct Pair {
  1: string key,
  2: binary value,
}

service	TreapDBService{
	void put(1:string key, 2:binary value);
	binary get(1:string key),
	void bulkPut(1:map<string,binary> kvMap);
	list<Pair> bulkGet(1:list<string> keyList);
	list<Pair> prefix(1:string prefixStr,2:i32 limit,3:string startK,4:bool asc),
	list<Pair> bulkPrefix(1:list<string> prefixList,2:i32 limit,3:string startK,4:bool asc),
	list<Pair> kmax(1:i32 k),
	list<Pair> kmin(1:i32 k),
	list<Pair> range(1:string kStart, 2:string kEnd,3:i32 limit),
	list<Pair> before(1:string key,2:i32 limit),
	list<Pair> after(1:string key,2:i32 limit),
	i32 length(),
	bool remove(1:string key),
	bool removePrefix(1:string key),
	void optimize(1:i32 amount)
}

Operations of TreapDB

Operation	Usage	Parameters
put	insert a new key-value pair, or replace an old key-value pair	key and value
get	get the value of the indicated key	key
bulkPut	inset 2 or more key-value pairs together	map of key and value
bulkGet	get the value of 2 or more indicated keys	list of keys
prefix	get the value of the keys with the indicated prefix string	prefix and number of result
bulkPrefix	get the value of the keys with the indicated prefix strings	list of prefix, number of result, beginning key, sort the key-value pairs in ascending or descending order
kmax	get the k maximum key-value pairs	k
kmin	get the k minimum key-value pairs	k
range	get the key-value pairs whose key is between the indicated keys	beginning key and ending key
before	get the key-value pairs whose key is before the indicated key in alphabetical order	key and number of result
after	get the key-value pairs whose key is after the indicated key in alphabetical order	key and number of result
length	get the number of key-value pairs	none
remove	delete the indicated key-value pair	key
removePrefix	delete value of the keys with indicated prefix string	prefix
optimize	optimize the space usage of index file	number of nodes need to be optimized(1024 is recommended value)

Sample

http://code.google.com/p/treapdb/wiki/SomeBenchmark

RPC Server

memcached protocol compatible server for test usage
thrift-based server for production usage

Download & Configure

click here to download http://code.google.com/p/treapdb/downloads/list

./treapdb.sh conf/TreapDBConf.xml(master mode)
./treapdb.sh conf/TreapDBConf_Slave.xml(slave mode)

configuration:

TreapDBConf.xml

     
      <?xml version="1.0" encoding="UTF-8"?>
      <TreapDB>
	<Params>
		<Port>
			<Memcache>11811</Memcache> 
                         //Listening port of memcache protocol
			<Thrift>11812</Thrift>     
                         //Listening port of thrift protocol
		</Port>
		<Index>
			<FilePath>/var/log/treapdb/master</FilePath> 
                          //Index file name
			<BlockSize>64</BlockSize>  
                          //size of index-block-item;
                          //default key length is 26(=64-38),38 is the node-overhead, 
                          //TreapDB supports max key-length: 127 bytes)

		</Index>
		<MMapSize>128</MMapSize> //the more the better, 128MB is enough for 2 Million keys
		<Replication>
			<Role>Master</Role>
		</Replication>
	</Params>
       </TreapDB>

TreapDBConf_Slave.xml

       <?xml version="1.0" encoding="UTF-8"?>
       <TreapDB>
	 <Params>
		<Port>
			<Memcache>11911</Memcache>
			<Thrift>11912</Thrift>
		</Port>
		<Index>
			<FilePath>/var/log/treapdb/slave</FilePath>
			<BlockSize>64</BlockSize>
		</Index>
		<MMapSize>128</MMapSize>
		<Replication>
			<Role>Slave</Role>
			<Source>10.61.1.170:11811</Source>
                       //Set master address and port here!
		</Replication>
	 </Params>
       </TreapDB>

How to build from source

svn checkout http://treapdb.googlecode.com/svn/trunk/
ant dist
use the jars generated in build/dist

How to write client code

Java:

     String host = "localhost";
     Integer port = 11812; //thrift port
     TreapDBClient client = TreapDBClientFactory.getClient(host, port);
     client.put(...)
     client.get(...)
     client.prefix(...)
     ...

Python:

     import pytreap
     client = pytreap.connect('localhost',11812) //thrift port
     client.get(...)
     client.put(...)
     client.remove(...)

Can TreapDB be used in an embedded way?

Yes,put libtreap-xx.jar in your app's classpath.

    DiskTreap<String, Serializable> treap = new DiskTreap<String,Serializable>
(new File("/usr/local/indexpath")); 

    treap.put(...)
    treap.get(...)
    ...

    /* key can be any type which implements Comparable;
    value can be any type which implements Serializable*/

Only Java?

TreapDB server is based on thrift, so you can generate your client in

any programming language.

For example, generate the python client code.

thrift --gen py res/service.txt

res/service.txt is a service specification:

Python client: http://code.google.com/p/treapdb/wiki/PythonClientExample

What is treap?

In computer science, the treap and the randomized binary search tree are two closely-related forms of binary search tree data structures that maintain a dynamic set of ordered keys and allow binary searches among the keys. After any sequence of insertions and deletions of keys, the shape of the tree is a random variable with the same probability distribution as a random binary tree; in particular, with high probability its height is proportional to the logarithm of the number of keys, so that each search, insertion, or deletion operation takes logarithmic time to perform.

http://en.wikipedia.org/wiki/Treap

Contact the author

Junyi Sun, Qiang Ma
E-mail: ccnusjy (#$) gmail.com
Sponsor: Sino-German Joint Laboratory of Software Integration

Welcome your valuable suggestions. My microblog: http://www.weibo.com/treapdb