private ByteBuffer processAsciiCommand(ByteBuffer buffer, Cache cache) {
    CharBuffer flb = getFirstLineBuffer();
    getAsciiDecoder().reset();
    getAsciiDecoder().decode(buffer, flb, false);
    flb.flip();
    String firstLine = getFirstLine();
    String[] firstLineElements = firstLine.split(" ");

    assert "decr".equals(firstLineElements[0]);
    String key = firstLineElements[1];
    String decrByStr = stripNewline(firstLineElements[2]);
    Long decrBy = Long.parseLong(decrByStr);
    boolean noReply = firstLineElements.length > 3;

    Region<Object, ValueWrapper> r = getMemcachedRegion(cache);
    String reply = Reply.NOT_FOUND.toString();
    ByteBuffer newVal = ByteBuffer.allocate(8);
    while (true) {
      ValueWrapper oldValWrapper = r.get(key);
      if (oldValWrapper == null) {
        break;
      }
      newVal.clear();
      byte[] oldVal = oldValWrapper.getValue();
      long oldLong = getLongFromByteArray(oldVal);
      long newLong = oldLong - decrBy;
      newVal.putLong(newLong);
      ValueWrapper newValWrapper = ValueWrapper.getWrappedValue(newVal.array(), 0 /*flags*/);
      if (r.replace(key, oldValWrapper, newValWrapper)) {
        reply = newLong + "\r\n";
        break;
      }
    }
    return noReply ? null : asciiCharset.encode(reply);
  }
  private ByteBuffer processBinaryProtocol(RequestReader request, Cache cache) {
    ByteBuffer buffer = request.getRequest();
    int extrasLength = buffer.get(EXTRAS_LENGTH_INDEX);
    final KeyWrapper key = getKey(buffer, HEADER_LENGTH + extrasLength);

    long decrBy = buffer.getLong(HEADER_LENGTH);
    long initialVal = buffer.getLong(HEADER_LENGTH + LONG_LENGTH);
    int expiration = buffer.getInt(HEADER_LENGTH + LONG_LENGTH + LONG_LENGTH);

    final Region<Object, ValueWrapper> r = getMemcachedRegion(cache);
    ByteBuffer newVal = ByteBuffer.allocate(8);
    boolean notFound = false;
    ValueWrapper newValWrapper = null;

    try {
      while (true) {
        ValueWrapper oldValWrapper = r.get(key);
        if (oldValWrapper == null) {
          if (expiration == -1) {
            notFound = true;
          } else {
            newVal.putLong(0, initialVal);
            newValWrapper = ValueWrapper.getWrappedValue(newVal.array(), 0 /*flags*/);
            r.put(key, newValWrapper);
          }
          break;
        }
        byte[] oldVal = oldValWrapper.getValue();
        long oldLong = getLongFromByteArray(oldVal);
        long newLong = oldLong - decrBy;
        if (newLong < 0) {
          newLong = 0;
        }
        newVal.putLong(0, newLong);
        newValWrapper = ValueWrapper.getWrappedValue(newVal.array(), 0 /*flags*/);
        if (r.replace(key, oldValWrapper, newValWrapper)) {
          break;
        }
      }
    } catch (Exception e) {
      return handleBinaryException(key, request, request.getResponse(), "decrement", e);
    }

    if (expiration > 0) {
      StorageCommand.getExpiryExecutor()
          .schedule(
              new Runnable() {
                @Override
                public void run() {
                  r.destroy(key);
                }
              },
              expiration,
              TimeUnit.SECONDS);
    }

    if (getLogger().fineEnabled()) {
      getLogger()
          .fine(
              "decr:key:"
                  + key
                  + " decrBy:"
                  + decrBy
                  + " initVal:"
                  + initialVal
                  + " exp:"
                  + expiration
                  + " notFound:"
                  + notFound);
    }

    ByteBuffer response = null;
    if (notFound) {
      response = request.getResponse();
      response.putShort(POSITION_RESPONSE_STATUS, ResponseStatus.KEY_NOT_FOUND.asShort());
    } else {
      if (isQuiet()) {
        return null;
      }
      response = request.getResponse(HEADER_LENGTH + LONG_LENGTH);
      response.putInt(TOTAL_BODY_LENGTH_INDEX, LONG_LENGTH);
      response.putLong(HEADER_LENGTH, newVal.getLong(0));
      response.putLong(POSITION_CAS, newValWrapper.getVersion());
    }
    return response;
  }
  @SuppressWarnings({"rawtypes", "unchecked"})
  private void doRegionTest(final RegionShortcut rs, final String rName, boolean compressed) {
    boolean isPersistent =
        rs == RegionShortcut.LOCAL_PERSISTENT
            || rs == RegionShortcut.REPLICATE_PERSISTENT
            || rs == RegionShortcut.PARTITION_PERSISTENT;
    GemFireCacheImpl gfc = createCache(isPersistent);
    Region r = null;
    try {
      gfc.setCopyOnRead(true);
      final MemoryAllocator ma = gfc.getOffHeapStore();
      assertNotNull(ma);
      assertEquals(0, ma.getUsedMemory());
      Compressor compressor = null;
      if (compressed) {
        compressor = SnappyCompressor.getDefaultInstance();
      }
      r = gfc.createRegionFactory(rs).setOffHeap(true).setCompressor(compressor).create(rName);
      assertEquals(true, r.isEmpty());
      assertEquals(0, ma.getUsedMemory());
      Object data = new Integer(123456789);
      r.put("key1", data);
      // System.out.println("After put of Integer value off heap used memory=" +
      // ma.getUsedMemory());
      assertTrue(ma.getUsedMemory() == 0);
      assertEquals(data, r.get("key1"));
      r.invalidate("key1");
      assertEquals(0, ma.getUsedMemory());
      r.put("key1", data);
      assertTrue(ma.getUsedMemory() == 0);
      long usedBeforeUpdate = ma.getUsedMemory();
      r.put("key1", data);
      assertEquals(usedBeforeUpdate, ma.getUsedMemory());
      assertEquals(data, r.get("key1"));
      r.destroy("key1");
      assertEquals(0, ma.getUsedMemory());

      data = new Long(0x007FFFFFL);
      r.put("key1", data);
      if (!compressed) {
        assertTrue(ma.getUsedMemory() == 0);
      }
      assertEquals(data, r.get("key1"));
      data = new Long(0xFF8000000L);
      r.put("key1", data);
      if (!compressed) {
        assertTrue(ma.getUsedMemory() == 0);
      }
      assertEquals(data, r.get("key1"));

      // now lets set data to something that will be stored offheap
      data = new Long(Long.MAX_VALUE);
      r.put("key1", data);
      assertEquals(data, r.get("key1"));
      // System.out.println("After put of Integer value off heap used memory=" +
      // ma.getUsedMemory());
      assertTrue(ma.getUsedMemory() > 0);
      data = new Long(Long.MIN_VALUE);
      r.put("key1", data);
      assertEquals(data, r.get("key1"));
      // System.out.println("After put of Integer value off heap used memory=" +
      // ma.getUsedMemory());
      assertTrue(ma.getUsedMemory() > 0);
      r.invalidate("key1");
      assertEquals(0, ma.getUsedMemory());
      r.put("key1", data);
      assertTrue(ma.getUsedMemory() > 0);
      usedBeforeUpdate = ma.getUsedMemory();
      r.put("key1", data);
      assertEquals(usedBeforeUpdate, ma.getUsedMemory());
      assertEquals(data, r.get("key1"));
      r.destroy("key1");
      assertEquals(0, ma.getUsedMemory());

      // confirm that byte[] do use off heap
      {
        byte[] originalBytes = new byte[1024];
        Object oldV = r.put("byteArray", originalBytes);
        long startUsedMemory = ma.getUsedMemory();
        assertEquals(null, oldV);
        byte[] readBytes = (byte[]) r.get("byteArray");
        if (originalBytes == readBytes) {
          fail("Expected different byte[] identity");
        }
        if (!Arrays.equals(readBytes, originalBytes)) {
          fail("Expected byte array contents to be equal");
        }
        assertEquals(startUsedMemory, ma.getUsedMemory());
        oldV = r.put("byteArray", originalBytes);
        if (!compressed) {
          assertEquals(null, oldV); // we default to old value being null for offheap
        }
        assertEquals(startUsedMemory, ma.getUsedMemory());

        readBytes = (byte[]) r.putIfAbsent("byteArray", originalBytes);
        if (originalBytes == readBytes) {
          fail("Expected different byte[] identity");
        }
        if (!Arrays.equals(readBytes, originalBytes)) {
          fail("Expected byte array contents to be equal");
        }
        assertEquals(startUsedMemory, ma.getUsedMemory());
        if (!r.replace("byteArray", readBytes, originalBytes)) {
          fail("Expected replace to happen");
        }
        assertEquals(startUsedMemory, ma.getUsedMemory());
        byte[] otherBytes = new byte[1024];
        otherBytes[1023] = 1;
        if (r.replace("byteArray", otherBytes, originalBytes)) {
          fail("Expected replace to not happen");
        }
        if (r.replace("byteArray", "bogus string", originalBytes)) {
          fail("Expected replace to not happen");
        }
        if (r.remove("byteArray", "bogus string")) {
          fail("Expected remove to not happen");
        }
        assertEquals(startUsedMemory, ma.getUsedMemory());

        if (!r.remove("byteArray", originalBytes)) {
          fail("Expected remove to happen");
        }
        assertEquals(0, ma.getUsedMemory());
        oldV = r.putIfAbsent("byteArray", "string value");
        assertEquals(null, oldV);
        assertEquals("string value", r.get("byteArray"));
        if (r.replace("byteArray", "string valuE", originalBytes)) {
          fail("Expected replace to not happen");
        }
        if (!r.replace("byteArray", "string value", originalBytes)) {
          fail("Expected replace to happen");
        }
        oldV = r.destroy("byteArray"); // we default to old value being null for offheap
        if (!compressed) {
          assertEquals(null, oldV);
        }
        MyCacheListener listener = new MyCacheListener();
        r.getAttributesMutator().addCacheListener(listener);
        try {
          Object valueToReplace = "string value1";
          r.put("byteArray", valueToReplace);
          assertEquals(null, listener.ohOldValue);
          if (!compressed) {
            assertEquals("string value1", listener.ohNewValue.getDeserializedForReading());
            valueToReplace = listener.ohNewValue;
          }
          if (!r.replace("byteArray", valueToReplace, "string value2")) {
            fail("expected replace to happen");
          }
          if (!compressed) {
            assertEquals("string value2", listener.ohNewValue.getDeserializedForReading());
            assertEquals("string value1", listener.ohOldValue.getDeserializedForReading());
          }
          // make sure that a custom equals/hashCode are not used when comparing values.

        } finally {
          r.getAttributesMutator().removeCacheListener(listener);
        }
      }
      assertTrue(ma.getUsedMemory() > 0);
      {
        Object key = "MyValueWithPartialEquals";
        MyValueWithPartialEquals v1 = new MyValueWithPartialEquals("s1");
        MyValueWithPartialEquals v2 = new MyValueWithPartialEquals("s2");
        MyValueWithPartialEquals v3 = new MyValueWithPartialEquals("s1");
        r.put(key, v1);
        try {
          if (r.replace(key, v2, "should not happen")) {
            fail("v1 should not be equal to v2 on an offheap region");
          }
          if (!r.replace(key, v3, "should happen")) {
            fail("v1 should be equal to v3 on an offheap region");
          }
          r.put(key, v1);
          if (r.remove(key, v2)) {
            fail("v1 should not be equal to v2 on an offheap region");
          }
          if (!r.remove(key, v3)) {
            fail("v1 should be equal to v3 on an offheap region");
          }
        } finally {
          r.remove(key);
        }
      }
      {
        Object key = "MyPdxWithPartialEquals";
        MyPdxWithPartialEquals v1 = new MyPdxWithPartialEquals("s", "1");
        MyPdxWithPartialEquals v2 = new MyPdxWithPartialEquals("s", "2");
        MyPdxWithPartialEquals v3 = new MyPdxWithPartialEquals("t", "1");
        r.put(key, v1);
        try {
          if (r.replace(key, v3, "should not happen")) {
            fail("v1 should not be equal to v3 on an offheap region");
          }
          if (!r.replace(key, v2, "should happen")) {
            fail("v1 should be equal to v2 on an offheap region");
          }
          r.put(key, v1);
          if (r.remove(key, v3)) {
            fail("v1 should not be equal to v3 on an offheap region");
          }
          if (!r.remove(key, v2)) {
            fail("v1 should be equal to v2 on an offheap region");
          }
        } finally {
          r.remove(key);
        }
      }
      byte[] value = new byte[1024];
      /*while (value != null) */ {
        r.put("byteArray", value);
      }
      r.remove("byteArray");
      assertEquals(0, ma.getUsedMemory());

      r.put("key1", data);
      assertTrue(ma.getUsedMemory() > 0);
      r.invalidateRegion();
      assertEquals(0, ma.getUsedMemory());

      r.put("key1", data);
      assertTrue(ma.getUsedMemory() > 0);
      try {
        r.clear();
        assertEquals(0, ma.getUsedMemory());
      } catch (UnsupportedOperationException ok) {
      }

      r.put("key1", data);
      assertTrue(ma.getUsedMemory() > 0);
      if (r.getAttributes().getDataPolicy().withPersistence()) {
        r.put("key2", Integer.valueOf(1234567890));
        r.put("key3", new Long(0x007FFFFFL));
        r.put("key4", new Long(0xFF8000000L));
        assertEquals(4, r.size());
        r.close();
        assertEquals(0, ma.getUsedMemory());
        // simple test of recovery
        r = gfc.createRegionFactory(rs).setOffHeap(true).create(rName);
        assertEquals(4, r.size());
        assertEquals(data, r.get("key1"));
        assertEquals(Integer.valueOf(1234567890), r.get("key2"));
        assertEquals(new Long(0x007FFFFFL), r.get("key3"));
        assertEquals(new Long(0xFF8000000L), r.get("key4"));
        closeCache(gfc, true);
        assertEquals(0, ma.getUsedMemory());
        gfc = createCache();
        if (ma != gfc.getOffHeapStore()) {
          fail("identity of offHeapStore changed when cache was recreated");
        }
        r = gfc.createRegionFactory(rs).setOffHeap(true).create(rName);
        assertTrue(ma.getUsedMemory() > 0);
        assertEquals(4, r.size());
        assertEquals(data, r.get("key1"));
        assertEquals(Integer.valueOf(1234567890), r.get("key2"));
        assertEquals(new Long(0x007FFFFFL), r.get("key3"));
        assertEquals(new Long(0xFF8000000L), r.get("key4"));
      }

      r.destroyRegion();
      assertEquals(0, ma.getUsedMemory());

    } finally {
      if (r != null && !r.isDestroyed()) {
        r.destroyRegion();
      }
      closeCache(gfc, false);
    }
  }