HADOOP-6150. Users should be able to instantiate comparator using TFile

API. (Hong Tang via rangadi)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@797274 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -891,6 +891,9 @@ Trunk (unreleased changes)
     HADOOP-6132. RPC client create an extra connection because of incorrect
     key for connection cache. (Kan Zhang via rangadi)
 
+    HADOOP-6150. Users should be able to instantiate comparator using TFile
+    API. (Hong Tang via rangadi)
+
 Release 0.20.1 - Unreleased
 
   INCOMPATIBLE CHANGES

src/java/org/apache/hadoop/io/file/tfile/TFile.java

@@ -161,6 +161,17 @@ public class TFile {
   /** comparator prefix: java class */
   public static final String COMPARATOR_JCLASS = "jclass:";
 
+  /**
+   * Make a raw comparator from a string name.
+   * 
+   * @param name
+   *          Comparator name
+   * @return A RawComparable comparator.
+   */
+  static public Comparator<RawComparable> makeComparator(String name) {
+    return TFileMeta.makeComparator(name);
+  }
+
   // Prevent the instantiation of TFiles
   private TFile() {
     // nothing
@@ -1947,7 +1958,7 @@ public class TFile {
     }
 
     @SuppressWarnings("unchecked")
-    private static BytesComparator makeComparator(String comparator) {
+    static BytesComparator makeComparator(String comparator) {
       if (comparator.length() == 0) {
         // unsorted keys
         return null;