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      1 /*
      2  * Optimum
      3  *
      4  * Authors: Lasse Collin <lasse.collin (at) tukaani.org>
      5  *          Igor Pavlov <http://7-zip.org/>
      6  *
      7  * This file has been put into the public domain.
      8  * You can do whatever you want with this file.
      9  */
     10 
     11 package org.tukaani.xz.lzma;
     12 
     13 final class Optimum {
     14     private static final int INFINITY_PRICE = 1 << 30;
     15 
     16     final State state = new State();
     17     final int[] reps = new int[LZMACoder.REPS];
     18 
     19     /**
     20      * Cumulative price of arriving to this byte.
     21      */
     22     int price;
     23 
     24     int optPrev;
     25     int backPrev;
     26     boolean prev1IsLiteral;
     27 
     28     boolean hasPrev2;
     29     int optPrev2;
     30     int backPrev2;
     31 
     32     /**
     33      * Resets the price.
     34      */
     35     void reset() {
     36         price = INFINITY_PRICE;
     37     }
     38 
     39     /**
     40      * Sets to indicate one LZMA symbol (literal, rep, or match).
     41      */
     42     void set1(int newPrice, int optCur, int back) {
     43         price = newPrice;
     44         optPrev = optCur;
     45         backPrev = back;
     46         prev1IsLiteral = false;
     47     }
     48 
     49     /**
     50      * Sets to indicate two LZMA symbols of which the first one is a literal.
     51      */
     52     void set2(int newPrice, int optCur, int back) {
     53         price = newPrice;
     54         optPrev = optCur + 1;
     55         backPrev = back;
     56         prev1IsLiteral = true;
     57         hasPrev2 = false;
     58     }
     59 
     60     /**
     61      * Sets to indicate three LZMA symbols of which the second one
     62      * is a literal.
     63      */
     64     void set3(int newPrice, int optCur, int back2, int len2, int back) {
     65         price = newPrice;
     66         optPrev = optCur + len2 + 1;
     67         backPrev = back;
     68         prev1IsLiteral = true;
     69         hasPrev2 = true;
     70         optPrev2 = optCur;
     71         backPrev2 = back2;
     72     }
     73 }
     74