From d6f2bd0c2b294c5308708d79c9cbf7dbacc93060 Mon Sep 17 00:00:00 2001
From: mrbald <mail@bobah.net>
Date: Tue, 30 Apr 2024 18:39:21 +0000
Subject: [PATCH] better error handling in persistent connection read finisher

---
 CRUD/service/persistent_connection.hpp | 46 +++++++++++++++-----------
 1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/CRUD/service/persistent_connection.hpp b/CRUD/service/persistent_connection.hpp
index 4425b01..d00ad0e 100644
--- a/CRUD/service/persistent_connection.hpp
+++ b/CRUD/service/persistent_connection.hpp
@@ -76,16 +76,20 @@ class persistent_connection
         [this](boost::system::error_code ec, std::size_t bytes_transferred)
         {
             
-          if (!ec)
+          if (!ec) [[likely]]
           {
             request_parser::result_type result;
             char * data = nullptr;
             std::tie(result, data) = request_parser_.parse(
                 request_, buffer_.data(), buffer_.data() + bytes_transferred);
 
-            if (result == request_parser::good) {
-              read_data_if(data, bytes_transferred);
-              request_handler_.handle_request(request_, reply_);
+            if (result == request_parser::good) [[likely]]
+            {
+              ec = read_data_if(data, bytes_transferred);
+              if (!ec) [[likely]]
+              {
+                request_handler_.handle_request(request_, reply_);
+              }
               do_write();
             }
             else if (result == request_parser::bad)
@@ -122,24 +126,26 @@ class persistent_connection
         });
   }
 
-  void read_data_if(char *data, std::size_t bytes_transferred) {
+  boost::system::error_code read_data_if(char *data, std::size_t bytes_transferred) {
+    static constexpr auto is_content_length = [](const header &h) noexcept { return h.name == "content-length" ; };
 
-      auto itr = std::find_if( request_.headers.begin(),
-                               request_.headers.end(),
-                               [](const header &h) { return h.name == "content-length" ; }
-      ) ;
+    boost::system::error_code ec{};
+    if (data) {
+        auto itr = find_if(begin(request_.headers), end(request_.headers), is_content_length);
 
-      if (data && itr != request_.headers.end()) {
-          auto received_data_size = std::distance(data, buffer_.data() + bytes_transferred);
-          auto content_length_value = boost::lexical_cast<long>(itr->value);
-          request_.data = std::string(data, content_length_value);
-          if (received_data_size < content_length_value) {
-              auto left_over_size = content_length_value - received_data_size;
-              auto end_data_ptr = request_.data.data() + received_data_size;
-              auto left_over_buffer = boost::asio::buffer(end_data_ptr, left_over_size);
-              boost::asio::read(socket_, left_over_buffer);
-          }
-      }
+        if (itr != end(request_.headers)) {
+            auto received_data_size = std::distance(data, buffer_.data() + bytes_transferred);
+            auto content_length_value = boost::lexical_cast<long>(itr->value);
+            request_.data = std::string(data, content_length_value);
+            if (received_data_size < content_length_value) {
+                auto left_over_size = content_length_value - received_data_size;
+                auto end_data_ptr = request_.data.data() + received_data_size;
+                auto left_over_buffer = boost::asio::buffer(end_data_ptr, left_over_size);
+                boost::asio::read(socket_, left_over_buffer, ec);
+            }
+        }
+    }
+    return ec;
   }
 
   /// Socket for the persistent_connection.