Examples of org.mapdb.HTreeMap


        final double cacheSizeInGB = 1.0;


        // Create cache backed by off-heap store
        // In this case store will use ByteBuffers backed by byte[].
        HTreeMap cache = DBMaker.newCache(cacheSizeInGB);


        // Other alternative is to use Direct ByteBuffers.
        // In this case the memory is not released if cache is not correctly closed.


        //  cache = DBMaker.newCacheDirect(cacheSizeInGB);


        //generates random key and values
        Random r = new Random();
        //used to print store statistics
        Store store = Store.forEngine(cache.getEngine());




        // insert some stuff in cycle
        for(long counter=1; counter<1e8; counter++){
            long key = r.nextLong();
            byte[] value = new byte[1000];
            r.nextBytes(value);


            cache.put(key,value);


            if(counter%1e5==0){
                System.out.printf("Map size: %,d, counter %,d, store size: %,d, store free size: %,d\n",
                        cache.sizeLong(), counter, store.getCurrSize(),  store.getFreeSize());
            }


        }


        // and release memory. Only necessary with `DBMaker.newCacheDirect()`
        cache.close();


    }

                .transactionDisable()   //better performance
                .make();


        //create map, entries are expired if not accessed (get,iterate) for 10 seconds or 30 seconds after 'put'
        //There is also maximal size limit to prevent OutOfMemoryException
        HTreeMap map = db
                .createHashMap("cache")
                .expireMaxSize(1000000)
                .expireAfterWrite(30, TimeUnit.SECONDS)
                .expireAfterAccess(10, TimeUnit.SECONDS)
                .make();


        //load stuff
        for(int i = 0;i<100000;i++){
            map.put(i, randomString(1000));
        }


        //one can monitor two space usage numbers:


        //free space in store

Examples of org.mapdb.HTreeMap

Related Classes of org.mapdb.HTreeMap