MAPREDUCE-7332. Fix SpillCallBackPathsFinder to use JDK7 on branch-2.10. Contributed by Ahmed Hussein.

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/security/SpillCallBackPathsFinder.java

@@ -24,7 +24,6 @@ import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
-import java.util.WeakHashMap;
 import java.util.concurrent.ConcurrentHashMap;
 
 import org.slf4j.Logger;
@@ -60,13 +59,24 @@ public class SpillCallBackPathsFinder extends SpillCallBackInjector {
   /**
    * Index spill files.
    */
-  private final Set<Path> indexSpillFiles =
-      Collections.newSetFromMap(new WeakHashMap<Path, Boolean>());
+  private final Set<Path> indexSpillFiles = getPosConcSet();
   /**
    * Paths that were not found in the maps.
    */
-  private final Set<Path> negativeCache =
-      Collections.newSetFromMap(new WeakHashMap<Path, Boolean>());
+  private final Set<Path> negativeCache = getPosConcSet();
+
+  private static <T> Set<T> getPosConcSet() {
+    return Collections.newSetFromMap(new ConcurrentHashMap<T, Boolean>());
+  }
+
+  private static Set<Long> getConcMapValue(
+      ConcurrentHashMap<Path, Set<Long>> currMap, Path path) {
+    if (!currMap.containsKey(path)) {
+      Set<Long> newPositions = getPosConcSet();
+      currMap.putIfAbsent(path, newPositions);
+    }
+    return currMap.get(path);
+  }
 
   protected ConcurrentHashMap<Path, Set<Long>> getFilesMap(
       Configuration config) {
@@ -82,15 +92,7 @@ public class SpillCallBackPathsFinder extends SpillCallBackInjector {
     long outPos = 0;
     try {
       outPos = out.getPos();
-      Set<Long> positions = getFilesMap(conf).get(path);
-      if (positions == null) {
-        Set<Long> newPositions =
-            Collections.newSetFromMap(new WeakHashMap<Long, Boolean>());
-        positions = getFilesMap(conf).putIfAbsent(path, newPositions);
-        if (positions == null) {
-          positions = newPositions;
-        }
-      }
+      Set<Long> positions = getConcMapValue(getFilesMap(conf), path);
       positions.add(outPos);
     } catch (IOException e) {
       LOG.debug("writeSpillFileCB.. exception getting position of the stream."
@@ -104,23 +106,16 @@ public class SpillCallBackPathsFinder extends SpillCallBackInjector {
     if (path == null) {
       return;
     }
-    Set<Long> pathEntries = getFilesMap(conf).get(path);
-    if (pathEntries != null) {
+    ConcurrentHashMap<Path, Set<Long>> currMap = getFilesMap(conf);
+    if (currMap.containsKey(path)) {
       try {
         long isPos = CryptoStreamUtils.getInputStreamOffset(is);
+        Set<Long> pathEntries = currMap.get(path);
         if (pathEntries.contains(isPos)) {
           LOG.debug("getSpillFileCB... Path {}; Pos: {}", path, isPos);
           return;
         }
-        Set<Long> positions = invalidAccessMap.get(path);
-        if (positions == null) {
-          Set<Long> newPositions =
-              Collections.newSetFromMap(new WeakHashMap<Long, Boolean>());
-          positions = invalidAccessMap.putIfAbsent(path, newPositions);
-          if (positions == null) {
-            positions = newPositions;
-          }
-        }
+        Set<Long> positions = getConcMapValue(invalidAccessMap, path);
         positions.add(isPos);
         LOG.debug("getSpillFileCB... access incorrect position.. "
             + "Path {}; Pos: {}", path, isPos);
@@ -181,7 +176,7 @@ public class SpillCallBackPathsFinder extends SpillCallBackInjector {
   }
 
   public Set<Path> getEncryptedSpilledFiles() {
-    return Collections.unmodifiableSet(encryptedSpillFiles.keySet());
+    return Collections.unmodifiableSet(((Map) encryptedSpillFiles).keySet());
   }
 
   /**