work in progress

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>

jetty-util/src/main/java/org/eclipse/jetty/util/SearchPattern.java

@@ -0,0 +1,109 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2018 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.util;
+
+public class SearchPattern
+{
+    static final int alphabetSize = 256;
+    int[] table;
+    
+    private String pattern;
+
+    
+    /**
+     * @param pattern  The pattern to search for.
+     * @return A Pattern instance for the search pattern
+     */
+    static SearchPattern compile(String pattern)
+    {
+        SearchPattern sp = new SearchPattern();
+        sp.pattern = pattern;
+        
+        
+        /*
+        Build up pre-processed table for this pattern.
+        
+            function preprocess(pattern):
+                T ← new table of 256 integers
+                for i from 0 to 256 exclusive
+                    T[i] ← length(pattern)
+                for i from 0 to length(pattern) - 1 exclusive
+                    T[pattern[i]] ← length(pattern) - 1 - i
+                return T
+        */
+        
+        sp.table = new int[alphabetSize];
+        for(int i = 0; i<sp.table.length; ++i){
+            sp.table[i] = pattern.length();
+        }
+        
+        /*
+         for i from 0 to length(pattern) - 1 exclusive
+             T[pattern[i]] ← length(pattern) - 1 - i
+        */
+        for(int i = 0; i<pattern.length(); ++i){
+            int index = pattern;
+            sp.table[index] = pattern.length()-1-i;
+        }
+        
+        return sp;
+    }
+    
+    
+    /**
+     * Search for a complete match of the pattern within the data
+     * @param data The data in which to search for. The data may be arbitrary binary data, 
+     * but the pattern will always be {@link StandardCharsets#US_ASCII} encoded.
+     * @param offset The offset within the data to start the search
+     * @param length The length of the data to search
+     * @return The index within the data array at which the first instance of the pattern or -1 if not found
+     */
+    public int match(byte[] data, int offset, int length)
+    {
+        return -1;
+    }
+    
+    /**
+     * Search for a partial match of the pattern at the end of the data.
+     * @param data The data in which to search for. The data may be arbitrary binary data, 
+     * but the pattern will always be {@link StandardCharsets#US_ASCII} encoded.
+     * @param offset The offset within the data to start the search
+     * @param length The length of the data to search
+     * @return the length of the partial pattern matched or -1 for no match.
+     */
+    public int endsPartiallyWith(byte data, int offset, int length)
+    {
+        return -1;
+    }
+    
+    /**
+     * 
+     * Search for a partial match of the pattern at the start of the data.
+     * @param data The data in which to search for. The data may be arbitrary binary data, 
+     * but the pattern will always be {@link StandardCharsets#US_ASCII} encoded.
+     * @param offset The offset within the data to start the search
+     * @param length The length of the data to search
+     * @param matched The length of the partial pattern already matched
+     * @return the length of the partial pattern matched or -1 for no match.
+     */
+    public int startsPartialyWith(byte[] data, int offset, int length, int matched)
+    {
+        return -1;    
+    }
+}

jetty-util/src/test/java/org/eclipse/jetty/util/SearchPatternTest.java

@@ -0,0 +1,36 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2018 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.util;
+
+import static org.junit.Assert.*;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class SearchPatternTest
+{
+
+    @Test
+    public void test()
+    {
+        Assert.assertTrue(SearchPattern.compile("lol") == null);
+        System.out.println("Hello World!");
+    }
+
+}