ScanOperator in RAMCloud

MasterService.cc

...

MasterService::scan(const ScanRpc::Request& reqHdr,
                        ScanRpc::Response& respHdr,
                        Rpc& rpc)
{
   
   LOG(NOTICE, "Running scan operation on master service!");
   LOG(NOTICE, "Scan PARAMS: table=%i, column=%i, comaparator=%i, operand=%i",
               (int)reqHdr.tableId, (int)reqHdr.id, (int)reqHdr.comparator, (int)reqHdr.operand);
   
   getTable(reqHdr.tableId, reqHdr.id);

   LogEntryHandle handle = objectMap.lookup(reqHdr.tableId, reqHdr.id);
   if (handle == NULL || handle->type() != LOG_ENTRY_TYPE_OBJ) {
       throw ObjectDoesntExistException(HERE);
   }

   const Object* obj = handle->userData<Object>();
   int64_t* data = (int64_t*)obj->data;
   uint64_t length = obj->dataLength(handle->length()) / sizeof(int64_t);
   
   std::vector<int64_t>* result = new std::vector<int64_t>();
   
   /*scan operation */
   for (uint64_t i = 0; i < length;i++)
   {
       LOG(NOTICE, "SCAN: Checking %i at %i", (int)data[i], (int)i);
       
       if((reqHdr.comparator == 0 && data[i] == reqHdr.operand) ||
           (reqHdr.comparator == -1 && data[i] <= reqHdr.operand) ||
           (reqHdr.comparator == -2 && data[i] < reqHdr.operand) ||
           (reqHdr.comparator == 1 && data[i] >= reqHdr.operand) ||
           (reqHdr.comparator == 2 && data[i] > reqHdr.operand))
       {
           LOG(NOTICE, "SCAN: Adding matching value %i at position %i to result.", (int)data[i], (int)i);
           result->push_back(data[i]);
       }
   }
   
   uint32_t resultLength =  (uint32_t)result->size() * (uint32_t)sizeof(int64_t);
   LOG(NOTICE, "SCAN: ResultLength: %i", (int)resultLength);
   LOG(NOTICE, "SCAN: First Result Value: %i", (int)result->at(0));
  
  /*appending to buffer */
   Buffer::Chunk::appendToBuffer(&rpc.replyPayload, &(result->at(0)), resultLength);  
   
   int64_t check = 0;
   rpc.replyPayload.copy(sizeof(ScanRpc::Response), sizeof(int64_t), &check);
   LOG(NOTICE, "SCAN: Check First Value: %i", (int)check);
   
   respHdr.length = resultLength;
}

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