--- /dev/null
+/*\r
+ * The Alphanum Algorithm is an improved sorting algorithm for strings\r
+ * containing numbers. Instead of sorting numbers in ASCII order like\r
+ * a standard sort, this algorithm sorts numbers in numeric order.\r
+ *\r
+ * The Alphanum Algorithm is discussed at http://www.DaveKoelle.com\r
+ *\r
+ *\r
+ * This library is free software; you can redistribute it and/or\r
+ * modify it under the terms of the GNU Lesser General Public\r
+ * License as published by the Free Software Foundation; either\r
+ * version 2.1 of the License, or any later version.\r
+ *\r
+ * This library is distributed in the hope that it will be useful,\r
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of\r
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU\r
+ * Lesser General Public License for more details.\r
+ *\r
+ * You should have received a copy of the GNU Lesser General Public\r
+ * License along with this library; if not, write to the Free Software\r
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA\r
+ *\r
+ */\r
+package org.simantics.utils.strings;\r
+\r
+import java.nio.CharBuffer;\r
+import java.util.Comparator;\r
+\r
+/**\r
+ * This is an updated version with enhancements made by Daniel Migowski, Andre\r
+ * Bogus, and David Koelle\r
+ * \r
+ * To convert to use Templates (Java 1.5+): - Change "implements Comparator" to\r
+ * "implements Comparator<String>" - Change "compare(Object o1, Object o2)" to\r
+ * "compare(String s1, String s2)" - Remove the type checking and casting in\r
+ * compare().\r
+ * \r
+ * To use this class: Use the static "sort" method from the\r
+ * java.util.Collections class: Collections.sort(your list, new\r
+ * AlphanumComparator());\r
+ * \r
+ * Modified by Tuukka Lehtonen to re-use two CharBuffer instances compared to\r
+ * 2*chunk-count StringBuilders per single comparison for some added efficiency.\r
+ */\r
+public class AlphanumComparator implements Comparator<Object>\r
+{\r
+ private static final CaseInsensitiveComparator CASE_INSENSITIVE_ORDER = new CaseInsensitiveComparator();\r
+\r
+ private static class CaseInsensitiveComparator implements Comparator<CharBuffer>, java.io.Serializable {\r
+\r
+ private static final long serialVersionUID = 5247677019801470582L;\r
+\r
+ @Override\r
+ public int compare(CharBuffer s1, CharBuffer s2) {\r
+ int n1 = s1.limit(), n2 = s2.limit();\r
+ for (int i1 = 0, i2 = 0; i1 < n1 && i2 < n2; i1++, i2++) {\r
+ char c1 = s1.charAt(i1);\r
+ char c2 = s2.charAt(i2);\r
+ if (c1 != c2) {\r
+ c1 = Character.toUpperCase(c1);\r
+ c2 = Character.toUpperCase(c2);\r
+ if (c1 != c2) {\r
+ c1 = Character.toLowerCase(c1);\r
+ c2 = Character.toLowerCase(c2);\r
+ if (c1 != c2) {\r
+ return c1 - c2;\r
+ }\r
+ }\r
+ }\r
+ }\r
+ return n1 - n2;\r
+ }\r
+ }\r
+\r
+ public static final AlphanumComparator COMPARATOR = new AlphanumComparator(null);\r
+ public static final AlphanumComparator CASE_INSENSITIVE_COMPARATOR = new AlphanumComparator(CASE_INSENSITIVE_ORDER);\r
+\r
+ private final Comparator<CharBuffer> comparator;\r
+\r
+ private static class Buffers {\r
+ CharBuffer b1 = CharBuffer.allocate(0);\r
+ CharBuffer b2 = b1;\r
+ }\r
+\r
+ private static final ThreadLocal<Buffers> buffers = new ThreadLocal<Buffers>() {\r
+ protected Buffers initialValue() {\r
+ return new Buffers();\r
+ }\r
+ };\r
+\r
+ private AlphanumComparator(Comparator<CharBuffer> comparator) {\r
+ this.comparator = comparator;\r
+ }\r
+\r
+ private final boolean isDigit(char ch)\r
+ {\r
+ return ch >= 48 && ch <= 57;\r
+ }\r
+\r
+ /** Length of string is passed in for improved efficiency (only need to calculate it once) **/\r
+ private final CharBuffer getChunk(String s, int slength, int marker, CharBuffer chunk)\r
+ {\r
+ if (chunk == null || chunk.capacity() < slength) {\r
+ chunk = CharBuffer.allocate(slength);\r
+ } else {\r
+ chunk.rewind();\r
+ chunk.limit(chunk.capacity());\r
+ }\r
+\r
+ char c = s.charAt(marker);\r
+ chunk.append(c);\r
+ marker++;\r
+ if (isDigit(c))\r
+ {\r
+ while (marker < slength)\r
+ {\r
+ c = s.charAt(marker);\r
+ if (!isDigit(c))\r
+ break;\r
+ chunk.append(c);\r
+ marker++;\r
+ }\r
+ } else\r
+ {\r
+ while (marker < slength)\r
+ {\r
+ c = s.charAt(marker);\r
+ if (isDigit(c))\r
+ break;\r
+ chunk.append(c);\r
+ marker++;\r
+ }\r
+ }\r
+ chunk.limit(chunk.position());\r
+ chunk.rewind();\r
+ return chunk;\r
+ }\r
+\r
+ @Override\r
+ public int compare(Object o1, Object o2)\r
+ {\r
+ if (o1 == o2)\r
+ return 0;\r
+\r
+ String s1 = o1.toString();\r
+ String s2 = o2.toString();\r
+\r
+ int thisMarker = 0;\r
+ int thatMarker = 0;\r
+ int s1Length = s1.length();\r
+ int s2Length = s2.length();\r
+\r
+ Buffers bufs = buffers.get();\r
+ CharBuffer thisChunk = bufs.b1;\r
+ CharBuffer thatChunk = bufs.b2;\r
+\r
+ try {\r
+ while (thisMarker < s1Length && thatMarker < s2Length)\r
+ {\r
+ thisChunk = getChunk(s1, s1Length, thisMarker, thisChunk);\r
+ thisMarker += thisChunk.limit();\r
+\r
+ thatChunk = getChunk(s2, s2Length, thatMarker, thatChunk);\r
+ thatMarker += thatChunk.limit();\r
+\r
+ // If both chunks contain numeric characters, sort them numerically\r
+ int result = 0;\r
+ if (isDigit(thisChunk.charAt(0)) && isDigit(thatChunk.charAt(0)))\r
+ {\r
+ // Simple chunk comparison by length.\r
+ int thisChunkLength = thisChunk.limit();\r
+ result = thisChunkLength - thatChunk.limit();\r
+ // If equal, the first different number counts\r
+ if (result == 0)\r
+ {\r
+ for (int i = 0; i < thisChunkLength; i++)\r
+ {\r
+ result = thisChunk.charAt(i) - thatChunk.charAt(i);\r
+ if (result != 0)\r
+ {\r
+ return result;\r
+ }\r
+ }\r
+ }\r
+ } else\r
+ {\r
+ result = comparator != null ? comparator.compare(thisChunk, thatChunk) : thisChunk.compareTo(thatChunk);\r
+ }\r
+\r
+ if (result != 0)\r
+ return result;\r
+ }\r
+\r
+ return s1Length - s2Length;\r
+ } finally {\r
+ bufs.b1 = reset(thisChunk);\r
+ bufs.b2 = reset(thatChunk);\r
+ }\r
+ }\r
+\r
+ private static CharBuffer reset(CharBuffer buffer) {\r
+ buffer.rewind();\r
+ buffer.limit(buffer.capacity());\r
+ return buffer;\r
+ }\r
+\r
+}\r
Code Review / simantics / platform.git / blobdiff