Added Hashing cache

DHuckaby · Oct 28, 2012 · b02449f · b02449f
1 parent 0583083
commit b02449f
Showing 1 changed file with 19 additions and 7 deletions.
diff --git a/library/src/com/handlerexploit/common/utils/Hashing.java b/library/src/com/handlerexploit/common/utils/Hashing.java
@@ -10,23 +10,35 @@
  */
 public class Hashing {
 
-    private static final char[] hexDigits = "0123456789abcdef".toCharArray();
-    private static final MessageDigest messageDigest = getMessageDigest("SHA-1");
+    private static final LruCache<CharSequence, String> CACHE = new LruCache<CharSequence, String>(100);
+    private static final char[] DIGITS = "0123456789abcdef".toCharArray();
+    private static final MessageDigest DIGEST = getMessageDigest("SHA-1");
 
     public static String hashString(CharSequence input) {
+        String hash = CACHE.get(input);
+        if (hash != null) {
+            return hash;
+        }
+
         ByteBuffer scratch = ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN);
         for (int i = 0; i < input.length(); i++) {
             scratch.putChar(input.charAt(i));
-            messageDigest.update(scratch.array(), 0, Character.SIZE / Byte.SIZE);
+            DIGEST.update(scratch.array(), 0, Character.SIZE / Byte.SIZE);
             scratch.clear();
         }
 
-        byte[] bytes = messageDigest.digest();
-        StringBuilder sb = new StringBuilder(2 * bytes.length);
+        byte[] bytes = DIGEST.digest();
+        StringBuilder builder = new StringBuilder(2 * bytes.length);
         for (byte b : bytes) {
-            sb.append(hexDigits[(b >> 4) & 0xf]).append(hexDigits[b & 0xf]);
+            builder.append(DIGITS[(b >> 4) & 0xf]).append(DIGITS[b & 0xf]);
         }
-        return sb.toString();
+        hash = builder.toString();
+
+        if (hash != null) {
+            CACHE.put(input, hash);
+        }
+
+        return hash;
     }
 
     private static MessageDigest getMessageDigest(String algorithmName) {