public ICacheElement ARC()

in src/experimental/org/apache/commons/jcs/engine/memory/arc/ARCMemoryCache.java [206:340]
100 lines of code
21 McCabe index (conditional complexity)

    public ICacheElement<K, V> ARC( ICacheElement<K, V> ce, boolean isGet )
    {
        cnt++;
        logStatsOccassionally( ce, isGet );
        if ( !isGet )
        {
            putCnt++;
        }

        ElementDescriptor temp = (ElementDescriptor) map.get( ce.getKey() );
        boolean isHit = true;

        if ( temp != null )
        {
            if ( isGet )
            {
                hitCnt++;
            }

            // determine where the element lives.
            switch ( temp.listNum )
            {
                case _T1_:
                    handleFoundInT1( temp );
                    break;

                case _T2_:
                    handleFoundInT2( temp );
                    break;

                case _B1_:
                    temp = handleFoundInB1( ce, isGet, temp );
                    break;

                case _B2_:
                    temp = handleFoundInB2( ce, isGet, temp );
                    break;
            }
        }
        else
        {
            /* Element is not in cache */
            isHit = false;
            if ( isGet )
            {
                missCnt++;
            }
            if ( log.isDebugEnabled() )
            {
                log.debug( "Element is not in cache" );
            }
        }

        // ////////////////////////////////////////////////////////////////////////////
        // Do some size Checks if this is a put
        if ( !isGet && !isHit )
        {
            if ( T1.size() + B1.size() >= maxSize )
            {
                /* B1 + T1 full? */
                if ( T1.size() < maxSize )
                {
                    /* Still room in T1? */
                    temp = (ElementDescriptor) B1.removeLast();
                    if ( temp != null )
                    {
                        map.remove( temp.key );
                    }
                    /* yes: take page off B1 */
                    // temp->pointer = replace(); /* find new place to put page
                    // */
                    replace( temp );
                }
                else
                {
                    /* no: B1 must be empty */
                    temp = (ElementDescriptor) T1.removeLast(); /*
                                                                 * take page //
                                                                 * off // T1
                                                                 */
                    map.remove( temp.ce.getKey() );
                    // if (temp->dirty) destage(temp); /* if dirty, evict before
                    // overwrite */
                    replace( temp );
                }
            }
            else
            {
                /* B1 + T1 have less than the maxSize elements */
                if ( T1.size() + T2.size() + B1.size() + B2.size() >= maxSize )
                {
                    /* cache full? */
                    /* Yes, cache full: */
                    if ( T1.size() + T2.size() + B1.size() + B2.size() >= 2 * maxSize )
                    {
                        /* cache is full: */
                        /* x find and reuse B2�s LRU */
                        temp = (ElementDescriptor) B2.removeLast();
                        if ( temp != null )
                        {
                            map.remove( temp.key );
                        }
                    }
                    else
                    {
                        /* cache directory not full, easy case */
                        // nop
                    }
                    replace( temp );
                }
                else
                {
                    /* cache not full, easy case */
                    // nop
                }
            }
        }

        if ( !isGet && !isHit )
        {
            temp = new ElementDescriptor( ce );
            temp.ce = ce;
            temp.listNum = _T1_;
            T1.addFirst( temp );
            // seen once recently, put on T1
            this.map.put( temp.ce.getKey(), temp );
        }
        // end if put

        if ( temp == null )
        {
            return null;
        }
        return temp.ce;
    }