Move RWBackend::reply_is_complete into rwsplitsession.cc

The function is now defined in the correct file. Removed the debug output
as it can be logged inside RWBackend::set_reply_state.

server/modules/routing/readwritesplit/rwsplitsession.cc

@@ -85,6 +85,92 @@ void RWBackend::close(close_type type)
     mxs::Backend::close(type);
 }
 
+static inline bool have_next_packet(GWBUF* buffer)
+{
+    uint32_t len = MYSQL_GET_PAYLOAD_LEN(GWBUF_DATA(buffer)) + MYSQL_HEADER_LEN;
+    return gwbuf_length(buffer) > len;
+}
+
+/**
+ * @brief Check if we have received a complete reply from the backend
+ *
+ * @param backend Backend reference
+ * @param buffer  Buffer containing the response
+ *
+ * @return True if the complete response has been received
+ */
+bool RWBackend::reply_is_complete(GWBUF *buffer)
+{
+    if (get_reply_state() == REPLY_STATE_START &&
+        (!mxs_mysql_is_result_set(buffer) || GWBUF_IS_COLLECTED_RESULT(buffer)))
+    {
+        if (GWBUF_IS_COLLECTED_RESULT(buffer) ||
+            current_command() == MXS_COM_STMT_PREPARE ||
+            !mxs_mysql_is_ok_packet(buffer) ||
+            !mxs_mysql_more_results_after_ok(buffer))
+        {
+            /** Not a result set, we have the complete response */
+            set_reply_state(REPLY_STATE_DONE);
+        }
+        else
+        {
+            // This is an OK packet and more results will follow
+            ss_dassert(mxs_mysql_is_ok_packet(buffer) &&
+                mxs_mysql_more_results_after_ok(buffer));
+
+            if (have_next_packet(buffer))
+            {
+                set_reply_state(REPLY_STATE_RSET_COLDEF);
+                return reply_is_complete(buffer);
+            }
+        }
+    }
+    else
+    {
+        bool more = false;
+        modutil_state state = {is_large_packet()};
+        int n_old_eof = get_reply_state() == REPLY_STATE_RSET_ROWS ? 1 : 0;
+        int n_eof = modutil_count_signal_packets(buffer, n_old_eof, &more, &state);
+        set_large_packet(state.state);
+
+        if (n_eof > 2)
+        {
+            /**
+             * We have multiple results in the buffer, we only care about
+             * the state of the last one. Skip the complete result sets and act
+             * like we're processing a single result set.
+             */
+            n_eof = n_eof % 2 ? 1 : 2;
+        }
+
+        if (n_eof == 0)
+        {
+            /** Waiting for the EOF packet after the column definitions */
+            set_reply_state(REPLY_STATE_RSET_COLDEF);
+        }
+        else if (n_eof == 1 && current_command() != MXS_COM_FIELD_LIST)
+        {
+            /** Waiting for the EOF packet after the rows */
+            set_reply_state(REPLY_STATE_RSET_ROWS);
+        }
+        else
+        {
+            /** We either have a complete result set or a response to
+             * a COM_FIELD_LIST command */
+            ss_dassert(n_eof == 2 || (n_eof == 1 && current_command() == MXS_COM_FIELD_LIST));
+            set_reply_state(REPLY_STATE_DONE);
+
+            if (more)
+            {
+                /** The server will send more resultsets */
+                set_reply_state(REPLY_STATE_START);
+            }
+        }
+    }
+
+    return get_reply_state() == REPLY_STATE_DONE;
+}
+
 uint32_t get_internal_ps_id(RWSplitSession* rses, GWBUF* buffer)
 {
     uint32_t rval = 0;