Clover coverage report -
Coverage timestamp: So Nov 6 2005 14:19:51 CET
file stats: LOC: 108   Methods: 3
NCLOC: 59   Classes: 1
 
 Source file Conditionals Statements Methods TOTAL
HashDiskPersistenceListener.java 0% 0% 0% 0%
coverage
 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    }