rpc: speedup get_output_distribution

and decrease the amount of data carried around

src/rpc/core_rpc_server.cpp

@@ -2133,7 +2133,7 @@ namespace cryptonote
           return false;
         }
 
-        res.distributions.push_back({std::move(*data), amount, req.binary});
+        res.distributions.push_back({std::move(*data), amount, "", req.binary, req.compress});
       }
     }
     catch (const std::exception &e)
@@ -2147,6 +2147,47 @@ namespace cryptonote
     return true;
   }
   //------------------------------------------------------------------------------------------------------------------------------
+  bool core_rpc_server::on_get_output_distribution_bin(const COMMAND_RPC_GET_OUTPUT_DISTRIBUTION::request& req, COMMAND_RPC_GET_OUTPUT_DISTRIBUTION::response& res)
+  {
+    PERF_TIMER(on_get_output_distribution_bin);
+
+    bool r;
+    if (use_bootstrap_daemon_if_necessary<COMMAND_RPC_GET_OUTPUT_DISTRIBUTION>(invoke_http_mode::BIN, "/get_output_distribution.bin", req, res, r))
+      return r;
+
+    res.status = "Failed";
+
+    if (!req.binary)
+    {
+      res.status = "Binary only call";
+      return false;
+    }
+    try
+    {
+      // 0 is placeholder for the whole chain
+      const uint64_t req_to_height = req.to_height ? req.to_height : (m_core.get_current_blockchain_height() - 1);
+      for (uint64_t amount: req.amounts)
+      {
+        auto data = rpc::RpcHandler::get_output_distribution([this](uint64_t amount, uint64_t from, uint64_t to, uint64_t &start_height, std::vector<uint64_t> &distribution, uint64_t &base) { return m_core.get_output_distribution(amount, from, to, start_height, distribution, base); }, amount, req.from_height, req_to_height, req.cumulative);
+        if (!data)
+        {
+          res.status = "Failed to get output distribution";
+          return false;
+        }
+
+        res.distributions.push_back({std::move(*data), amount, "", req.binary, req.compress});
+      }
+    }
+    catch (const std::exception &e)
+    {
+      res.status = "Failed to get output distribution";
+      return false;
+    }
+
+    res.status = CORE_RPC_STATUS_OK;
+    return true;
+  }
+  //------------------------------------------------------------------------------------------------------------------------------
 
 
   const command_line::arg_descriptor<std::string, false, true, 2> core_rpc_server::arg_rpc_bind_port = {