Merge pull request #243 from apache/minor_fixes_to_main

Release Process: fixed some SpotBugs "dead stores" in test code.

.gitignore

@@ -16,6 +16,9 @@ datasketches-memory*/.gitignore
 # Netbeans project files
 nb-configuration.xml
 
+# VSCode project files
+**/.vscode/
+
 # Additional tools
 .clover/
 

src/test/java/org/apache/datasketches/memory/internal/MurmurHash3v3Test.java

@@ -21,6 +21,7 @@
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.apache.datasketches.memory.MurmurHash3.*;
+import static org.testng.Assert.assertTrue;
 import static org.testng.Assert.fail;
 
 import java.lang.foreign.Arena;
@@ -251,7 +252,8 @@ public void checkEmptyOrNullExceptions() {
       long[] arr = null;
       hash(arr, 1L);
       fail();
-    } catch (final IllegalArgumentException e) { }
+    }
+    catch (final IllegalArgumentException e) { }
     try {
       int[] arr = null; hash(arr, 1L); fail();
     } catch (final IllegalArgumentException e) { }
@@ -261,20 +263,20 @@ public void checkEmptyOrNullExceptions() {
     try {
       byte[] arr = null; hash(arr, 1L); fail();
     } catch (final IllegalArgumentException e) { }
+
+    long[] out = new long[2];
     try {
-      long[] out = new long[2];
       String in = null; hash(in, 1L, out); fail();
     } catch (final IllegalArgumentException e) { }
     try {
-      long[] out = new long[2];
       Memory mem = Memory.wrap(new byte[0]);
-      out = hash(mem, 0L, 4L, 1L, out);
+      hash(mem, 0L, 4L, 1L, out);
     } catch (final IllegalArgumentException e) { }
     try (Arena arena = Arena.ofConfined()) {
       Memory mem = WritableMemory.allocateDirect(8, 1, ByteOrder.nativeOrder(), memReqSvr, arena);
-      long[] out = new long[2];
       out = hash(mem, 0L, 4L, 1L, out);
-    } catch (Exception ee) {}
+    }
+    assertTrue((out[0] != 0) && (out[1] != 0));
   }
 
   @Test

src/test/java/org/apache/datasketches/memory/internal/NativeWritableBufferImplTest.java

@@ -403,71 +403,53 @@ public void checkDegenerateRegionReturn() {
   public void checkAsWritableMemoryRO() {
     ByteBuffer bb = ByteBuffer.allocate(64);
     WritableBuffer wbuf = WritableBuffer.writableWrap(bb);
-    WritableMemory wmem = wbuf.asWritableMemory(); //OK
-    assertNotNull(wmem);
 
     try {
       Buffer buf = Buffer.wrap(bb.asReadOnlyBuffer());
       wbuf = (WritableBuffer) buf;
-      wmem = wbuf.asWritableMemory();
+      wbuf.asWritableMemory();
       Assert.fail();
-    } catch (IllegalArgumentException expected) {
-      // expected
     }
+    catch (IllegalArgumentException expected) { }
   }
 
   @Test
   public void checkWritableDuplicateRO() {
     ByteBuffer bb = ByteBuffer.allocate(64);
     WritableBuffer wbuf = WritableBuffer.writableWrap(bb);
-    @SuppressWarnings("unused")
-    WritableBuffer wdup = wbuf.writableDuplicate();
 
     try {
       Buffer buf = Buffer.wrap(bb);
       wbuf = (WritableBuffer) buf;
-      @SuppressWarnings("unused")
-      WritableBuffer wdup2 = wbuf.writableDuplicate();
+      wbuf.writableDuplicate();
       Assert.fail();
-    } catch (IllegalArgumentException expected) {
-      // ignore
-    }
+    } catch (IllegalArgumentException expected) { }
   }
 
   @Test
   public void checkWritableRegionRO() {
     ByteBuffer bb = ByteBuffer.allocate(64);
     WritableBuffer wbuf = WritableBuffer.writableWrap(bb);
-    @SuppressWarnings("unused")
-    WritableBuffer wreg = wbuf.writableRegion();
 
     try {
       Buffer buf = Buffer.wrap(bb);
       wbuf = (WritableBuffer) buf;
-      @SuppressWarnings("unused")
-      WritableBuffer wreg2 = wbuf.writableRegion();
+      wbuf.writableRegion();
       Assert.fail();
-    } catch (IllegalArgumentException expected) {
-      // ignore
-    }
+    } catch (IllegalArgumentException expected) { }
   }
 
   @Test
   public void checkWritableRegionWithParamsRO() {
     ByteBuffer bb = ByteBuffer.allocate(64);
     WritableBuffer wbuf = WritableBuffer.writableWrap(bb);
-    @SuppressWarnings("unused")
-    WritableBuffer wreg = wbuf.writableRegion(0, 1, wbuf.getTypeByteOrder());
 
     try {
       Buffer buf = Buffer.wrap(bb);
       wbuf = (WritableBuffer) buf;
-      @SuppressWarnings("unused")
-      WritableBuffer wreg2 = wbuf.writableRegion(0, 1, wbuf.getTypeByteOrder());
+      wbuf.writableRegion(0, 1, wbuf.getTypeByteOrder());
       Assert.fail();
-    } catch (IllegalArgumentException expected) {
-      // ignore
-    }
+    } catch (IllegalArgumentException expected) { }
   }
 
   @Test

src/test/java/org/apache/datasketches/memory/internal/WritableMemoryTest.java

@@ -154,14 +154,19 @@ public void checkWrapWithBO() {
   }
 
   @Test
-  @SuppressWarnings("unused")
   public void checkOwnerClientCase() {
     WritableMemory owner = WritableMemory.allocate(64);
-    Memory client1 = owner; //Client1 cannot write (no API)
-    owner.putInt(0, 1); //But owner can write
-    ((WritableMemory)client1).putInt(0, 2); //Client1 can write, but with explicit effort.
-    Memory client2 = owner.region(0, owner.getCapacity()); //client2 cannot write (no API)
-    owner.putInt(0, 3); //But Owner should be able to write
+    owner.putInt(0, 1);     //owner contains 1
+    Memory client1 = owner; //owner can cast to a read-only alias, but underneath it is a writable MemorySegment
+    assertEquals(client1.getInt(0), 1); //client contains 1
+    //client1.putInt(0, 2) //no API to do this
+    ((WritableMemory)client1).putInt(0, 2); //can write to client1, but with explicit cast.
+    assertEquals(client1.getInt(0), 2); //client1 now contains 2
+    assertEquals(owner.getInt(0), 2);   //so now owner contains 2 also
+    Memory client2 = owner.region(0, owner.getCapacity()); //create a readOnly region (MemorySegment) from owner
+    try {
+      ((WritableMemory) client2).putInt(0, 3); //now you cannot make client2 writable
+    } catch (UnsupportedOperationException e) { }
   }
 
   @Test