Clover coverage report -

Coverage timestamp: So Nov 6 2005 14:19:51 CET

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file stats:	LOC:	108		Methods:	3
	NCLOC:	59		Classes:	1

Source file

Conditionals

Statements

Methods

TOTAL

HashDiskPersistenceListener.java

1		/*
2		* Copyright (c) 2002-2003 by OpenSymphony
3		* All rights reserved.
4		*/
5		package com.opensymphony.oscache.plugins.diskpersistence;
6
7		import com.opensymphony.oscache.base.Config;
8		import com.opensymphony.oscache.base.persistence.PersistenceListener;
9
10		import java.security.MessageDigest;
11		import java.security.NoSuchAlgorithmException;
12
13		/**
14		* Persists cache data to disk. Provides a hash of the standard key name as the file name.
15		*
16		* A configurable hash algorithm is used to create a digest of the cache key for the
17		* disk filename. This is to allow for more sane filenames for objects which dont generate
18		* friendly cache keys.
19		*
20		* @author <a href="mailto:jparrott@soe.sony.com">Jason Parrott</a>
21		*/
22		public class HashDiskPersistenceListener extends AbstractDiskPersistenceListener {
23		public final static String HASH_ALGORITHM_KEY = "cache.persistence.disk.hash.algorithm";
24		public final static String DEFAULT_HASH_ALGORITHM = "MD5";
25		protected MessageDigest md = null;
26
27		/**
28		* Initializes the <tt>HashDiskPersistenceListener</tt>. Namely this involves only setting up the
29		* message digester to hash the key values.
30		* @see com.opensymphony.oscache.base.persistence.PersistenceListener#configure(com.opensymphony.oscache.base.Config)
31		*/
32	0	public PersistenceListener configure(Config config) {
33	0	try {
34	0	if (config.getProperty(HashDiskPersistenceListener.HASH_ALGORITHM_KEY) != null) {
35	0	try {
36	0	md = MessageDigest.getInstance(config.getProperty(HashDiskPersistenceListener.HASH_ALGORITHM_KEY));
37		} catch (NoSuchAlgorithmException e) {
38	0	md = MessageDigest.getInstance(HashDiskPersistenceListener.DEFAULT_HASH_ALGORITHM);
39		}
40		} else {
41	0	md = MessageDigest.getInstance(HashDiskPersistenceListener.DEFAULT_HASH_ALGORITHM);
42		}
43		} catch (NoSuchAlgorithmException e) {
44	0	e.printStackTrace();
45	0	throw new RuntimeException("No hash algorithm available for disk persistence", e);
46		}
47
48	0	return super.configure(config);
49		}
50
51		/**
52		* Generates a file name for the given cache key. In this case the file name is attempted to be
53		* generated from the hash of the standard key name. Cache algorithm is configured via the
54		* <em>cache.persistence.disk.hash.algorithm</em> configuration variable.
55		* @param key cache entry key
56		* @return char[] file name
57		*/
58	0	protected char[] getCacheFileName(String key) {
59	0	byte[] digest;
60
61	0	if ((key == null) \|\| (key.length() == 0)) {
62	0	throw new IllegalArgumentException("Invalid key '" + key + "' specified to getCacheFile.");
63		}
64
65	0	digest = md.digest(key.getBytes());
66
67	0	String hexString = byteArrayToHexString(digest);
68	0	return hexString.toCharArray();
69		}
70
71		/**
72		* Nibble conversion. Thanks to our friends at:
73		* http://www.devx.com/tips/Tip/13540
74		* @param in the byte array to convert
75		* @return a java.lang.String based version of they byte array
76		*/
77	0	static String byteArrayToHexString(byte[] in) {
78	0	byte ch = 0x00;
79	0	int i = 0;
80
81	0	if ((in == null) \|\| (in.length <= 0)) {
82	0	return null;
83		}
84
85	0	String[] pseudo = {
86		"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D",
87		"E", "F"
88		};
89	0	StringBuffer out = new StringBuffer(in.length * 2);
90
91	0	while (i < in.length) {
92	0	ch = (byte) (in[i] & 0xF0); // Strip off high nibble
93	0	ch = (byte) (ch >>> 4);
94
95		// shift the bits down
96	0	ch = (byte) (ch & 0x0F);
97
98		// must do this is high order bit is on!
99	0	out.append(pseudo[(int) ch]); // convert the nibble to a String Character
100	0	ch = (byte) (in[i] & 0x0F); // Strip off low nibble
101	0	out.append(pseudo[(int) ch]); // convert the nibble to a String Character
102	0	i++;
103		}
104
105	0	String rslt = new String(out);
106	0	return rslt;
107		}
108		}