Copied RandomAccessFile code into the util package because of compiler

version in maven dependencies.

src/main/java/info/fetter/logstashforwarder/util/KMPMatch.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright 1998-2009 University Corporation for Atmospheric Research/Unidata
+ *
+ * Portions of this software were developed by the Unidata Program at the
+ * University Corporation for Atmospheric Research.
+ *
+ * Access and use of this software shall impose the following obligations
+ * and understandings on the user. The user is granted the right, without
+ * any fee or cost, to use, copy, modify, alter, enhance and distribute
+ * this software, and any derivative works thereof, and its supporting
+ * documentation for any purpose whatsoever, provided that this entire
+ * notice appears in all copies of the software, derivative works and
+ * supporting documentation.  Further, UCAR requests that the user credit
+ * UCAR/Unidata in any publications that result from the use of this
+ * software or in any product that includes this software. The names UCAR
+ * and/or Unidata, however, may not be used in any advertising or publicity
+ * to endorse or promote any products or commercial entity unless specific
+ * written permission is obtained from UCAR/Unidata. The user also
+ * understands that UCAR/Unidata is not obligated to provide the user with
+ * any support, consulting, training or assistance of any kind with regard
+ * to the use, operation and performance of this software nor to provide
+ * the user with any updates, revisions, new versions or "bug fixes."
+ *
+ * THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
+ * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
+ * WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+package info.fetter.logstashforwarder.util;
+
+/**
+ * Knuth-Morris-Pratt Algorithm for Pattern Matching.
+ * Immutable
+ *
+ * @author caron
+ * @see <a href="http://www.fmi.uni-sofia.bg/fmi/logic/vboutchkova/sources/KMPMatch_java.html">http://www.fmi.uni-sofia.bg/fmi/logic/vboutchkova/sources/KMPMatch_java.html</a>
+ * @since May 9, 2008
+ */
+public class KMPMatch {
+
+  private final byte[] match;
+  private final int[] failure;
+
+  /**
+   * Constructor
+   * @param match search for this byte pattern
+   */
+  public KMPMatch(byte[] match) {
+    this.match = match;
+    failure = computeFailure(match);
+  }
+
+  public int getMatchLength() { return match.length; }
+
+  /**
+   * Finds the first occurrence of match in data.
+   * @param data search in this byte block
+   * @param start start at data[start]
+   * @param max end at data[start+max]
+   * @return index into data[] of first match, else -1 if not found.
+   */
+  public int indexOf(byte[] data, int start, int max) {
+    int j = 0;
+    if (data.length == 0) return -1;
+
+    for (int i = start; i < start + max; i++) {
+      while (j > 0 && match[j] != data[i])
+        j = failure[j - 1];
+
+      if (match[j] == data[i])
+        j++;
+
+      if (j == match.length)
+        return i - match.length + 1;
+
+    }
+    return -1;
+  }
+
+  /*
+   * Finds the first occurrence of match in data.
+   * @param data search in this byte block
+   * @param start start at data[start]
+   * @param max end at data[start+max]
+   * @return index into block of first match, else -1 if not found.
+   *
+  public int scan(InputStream is, int start, int max) {
+    int j = 0;
+    if (data.length == 0) return -1;
+
+    for (int i = start; i < start + max; i++) {
+      while (j > 0 && match[j] != data[i])
+        j = failure[j - 1];
+
+      if (match[j] == data[i])
+        j++;
+
+      if (j == match.length)
+        return i - match.length + 1;
+
+    }
+    return -1;
+  } // */
+
+
+  private int[] computeFailure(byte[] match) {
+    int[] result = new int[match.length];
+
+    int j = 0;
+    for (int i = 1; i < match.length; i++) {
+      while (j > 0 && match[j] != match[i])
+        j = result[j - 1];
+
+      if (match[i] == match[i])
+        j++;
+
+      result[i] = j;
+    }
+
+    return result;
+  }
+}
+