Merge pull request #249 from DataSketches/FixFindBugs

Fix find bugs

Author: leerho

src/main/java/com/yahoo/sketches/cpc/CompressedState.java

@@ -42,13 +42,12 @@
  */
 final class CompressedState {
   private static final String LS = System.getProperty("line.separator");
+  private boolean csvIsValid = false;
+  private boolean windowIsValid = false;
   final int lgK;
   final short seedHash;
   int fiCol = 0;
   boolean mergeFlag = false; //compliment of HIP Flag
-  boolean csvIsValid = false;
-  boolean windowIsValid = false;
-
   long numCoupons = 0;
 
   double kxp;
@@ -60,7 +59,7 @@ final class CompressedState {
   int[] cwStream = null; //may be longer than required
   int cwLengthInts = 0;
 
-  int cpcRequiredBytes = 0;
+  //int cpcRequiredBytes = 0;
 
   private CompressedState(final int lgK, final short seedHash) {
     this.lgK = lgK;

src/main/java/com/yahoo/sketches/theta/CompactSketch.java

@@ -120,6 +120,7 @@ static final long[] compactCachePart(final long[] srcCache, final int lgArrLongs
     return cacheOut;
   }
 
+  //compactCache and dstMem must be valid
   static final Memory loadCompactMemory(final long[] compactCache, final short seedHash,
       final int curCount, final long thetaLong, final WritableMemory dstMem,
       final byte flags, final int preLongs) {
@@ -152,7 +153,7 @@ static final Memory loadCompactMemory(final long[] compactCache, final short see
     if (preLongs > 2) {
       insertThetaLong(dstMem, thetaLong);
     }
-    if ((compactCache != null) && (curCount > 0)) {
+    if (curCount > 0) {
       dstMem.putLongArray(preLongs << 3, compactCache, 0, curCount);
     }
     return dstMem;

src/main/java/com/yahoo/sketches/theta/ConcurrentDirectQuickSelectSketch.java

@@ -241,7 +241,8 @@ private void advanceEpoch() {
     ConcurrentPropagationService.resetExecutorService(Thread.currentThread().getId());
     //noinspection NonAtomicOperationOnVolatileField
     // this increment of a volatile field is done within the scope of the propagation
-    // synchronization and hence is done by a single thread
+    // synchronization and hence is done by a single thread.
+    // Ignore a FindBugs warning
     epoch_++;
     endPropagation(null, true);
     initBgPropagationService();

src/main/java/com/yahoo/sketches/theta/ConcurrentHeapQuickSelectSketch.java

@@ -239,6 +239,7 @@ private void advanceEpoch() {
     //noinspection NonAtomicOperationOnVolatileField
     // this increment of a volatile field is done within the scope of the propagation
     // synchronization and hence is done by a single thread
+    // Ignore a FindBugs warning
     epoch_++;
     endPropagation(null, true);
     initBgPropagationService();