public int getValueOffset() {
      if (!needsValue) {
        return 0;
      }
      int result = deltaIdBytesLength
          // + 8 /* HACK DEBUG */
          + drIdLength + 1/* opcode */
          + 4/* value length */;
      if (!notToUseUserBits) {
        result++;
      }
      if (EntryBits.isWithVersions(userBits) && versionsBytes != null) {
        result += versionsBytes.length;
      }

      return result;
    }
Returns the offset to the first byte of the value bytes.
geode-core/src/main/java/org/apache/geode/internal/cache/Oplog.java