1 package book.jcp.ch01.basic;
2
3 import java.math.BigInteger;
4
5 public class CachedFactorizer {
6
7 private BigInteger lastNumberBigInteger;
8 private BigInteger[] lastFactorsBigIntegers;
9 private long hits;
10 private long cacheHits;
11
12 public synchronized long getHits() {
13 return hits;
14 }
15
16 public synchronized double getHitRatio() {
17 return (double) cacheHits / (double) hits;
18 }
19
20 public void service(int req, int resp) {
21 BigInteger i = extractFromRequest(req);
22 BigInteger[] newFactors = null;
23 synchronized (this) {
24 ++hits;
25 if (i.equals(lastNumberBigInteger)) {
26 ++cacheHits;
27 newFactors = lastFactorsBigIntegers.clone();
28 }
29 }
30 if (newFactors == null) {
31 newFactors = factor(i);
32 synchronized (this) {
33 lastNumberBigInteger = i;
34 lastFactorsBigIntegers = newFactors.clone();
35 }
36 }
37 encodeIntoResponse(resp, newFactors);
38 }
39
40 private BigInteger[] factor(BigInteger i) {
41 // TODO Auto-generated method stub
42 return null;
43 }
44
45 private void encodeIntoResponse(int resp, BigInteger[] factors) {
46 // TODO Auto-generated method stub
47
48 }
49
50 private BigInteger extractFromRequest(int req) {
51 // TODO Auto-generated method stub
52 return null;
53 }
54 }
