Refine errno handling and ET read completion semantics

Agent-Logs-Url: https://github.com/WEBcodeX1/http-1.2/sessions/52de29c4-0332-4c1e-9fd4-e87a34608c1f

Co-authored-by: clauspruefer <17313789+clauspruefer@users.noreply.github.com>

Author: Copilot

src/Client.cpp

@@ -22,6 +22,8 @@ Client::~Client()
 
 ssize_t Client::receiveData()
 {
+    ssize_t TotalRcvBytes = 0;
+
     for (;;) {
         const ssize_t RcvBytes = read(_ClientFD, _ReceiveBuffer, SOCKET_RECEIVE_BUFFER_SIZE);
         const int ReadErrno = errno;
@@ -30,6 +32,7 @@ ssize_t Client::receiveData()
 
         if (RcvBytes > 0) {
             appendBuffer(_ReceiveBuffer, RcvBytes);
+            TotalRcvBytes += RcvBytes;
             continue;
         }
 
@@ -41,6 +44,13 @@ ssize_t Client::receiveData()
             continue;
         }
 
+        if (
+            (ReadErrno == EAGAIN || ReadErrno == EWOULDBLOCK) &&
+            TotalRcvBytes > 0
+        ) {
+            return TotalRcvBytes;
+        }
+
         errno = ReadErrno;
         return -1;
     }

src/ClientHandler.cpp

@@ -84,18 +84,19 @@ void ClientHandler::readClientData(const uint16_t FDCount)
 
         if (Clients.contains(ReadFD)) {
             const auto RecvStatus = Clients[ReadFD]->receiveData();
-            const int RecvErrno = errno;
             if (RecvStatus == 0) {
                 Clients.erase(ReadFD);
                 close(ReadFD);
-            } else if (
-                RecvStatus < 0 &&
-                RecvErrno != EAGAIN &&
-                RecvErrno != EWOULDBLOCK &&
-                RecvErrno != EINTR
-            ) {
-                Clients.erase(ReadFD);
-                close(ReadFD);
+            } else if (RecvStatus < 0) {
+                const int RecvErrno = errno;
+                if (
+                    RecvErrno != EAGAIN &&
+                    RecvErrno != EWOULDBLOCK &&
+                    RecvErrno != EINTR
+                ) {
+                    Clients.erase(ReadFD);
+                    close(ReadFD);
+                }
             }
         }
     }