Pass modutil function state as a struct

This allows the type to change without changing it at the call sites.

include/maxscale/modutil.h

@@ -52,6 +52,15 @@ GWBUF*          modutil_create_mysql_err_msg(int             packet_number,
                                              const char      *statemsg,
                                              const char      *msg);
 
+/** Struct used for tracking the state inside the modutil functions */
+typedef struct
+{
+    uint8_t state;
+} modutil_state;
+
+/** Static initialization define for modutil_state */
+#define MODUTIL_STATE_INIT {0}
+
 /**
  * @brief Count the number of EOF and ERR packets in the buffer.
  *
@@ -59,19 +68,20 @@ GWBUF*          modutil_create_mysql_err_msg(int             packet_number,
  * whole packets. If partial packets are in the buffer, they are ignored.
  * The caller must handle the detection of partial packets in buffers.
  *
- * On the first invocation, the value pointed by @c skip should be set to false.
- * On all subsequent calls, for partial result sets, the function uses it to
- * store the internal state. When the value pointed by @c skip is set to true,
- * the next call must be done with only unprocessed packets in @c reply.
+ * Before the first invocation, the value pointed by the @c state parameter
+ * should be initialized with MODUTIL_STATE_INIT. All subsequent calls with a
+ * partially processed result set must be made with only unprocessed packets
+ * in @c reply.
  *
  * @param reply      Buffer to use
  * @param n_found    Number of previous found packets
- * @param more       Set to true of more results exist
- * @param skip       Internal state of the function used for handling large payloads.
+ * @param more       Set to true if more results exist
+ * @param state      Internal state of the function, NULL if the function is
+ *                   only called once per result set
  *
  * @return Total number of EOF and ERR packets including the ones already found
  */
-int modutil_count_signal_packets(GWBUF *reply, int n_found, bool* more, bool* skip);
+int modutil_count_signal_packets(GWBUF *reply, int n_found, bool* more, modutil_state* state);
 
 mxs_pcre2_result_t modutil_mysql_wildcard_match(const char* pattern, const char* string);
 

server/core/modutil.cc

@@ -636,13 +636,13 @@ GWBUF* modutil_get_complete_packets(GWBUF **p_readbuf)
     return complete;
 }
 
-int modutil_count_signal_packets(GWBUF *reply, int n_found, bool* more, bool* skip)
+int modutil_count_signal_packets(GWBUF *reply, int n_found, bool* more, modutil_state* state)
 {
     unsigned int len = gwbuf_length(reply);
     int eof = 0;
     int err = 0;
     size_t offset = 0;
-    bool skip_next = skip ? *skip : false;
+    bool skip_next = state ? state->state : false;
 
     while (offset < len)
     {
@@ -689,9 +689,9 @@ int modutil_count_signal_packets(GWBUF *reply, int n_found, bool* more, bool* sk
 
     int total = err + eof + n_found;
 
-    if (skip)
+    if (state)
     {
-        *skip = skip_next;
+        state->state = skip_next;
     }
 
     return total;

server/modules/routing/readwritesplit/readwritesplit.cc

@@ -523,10 +523,10 @@ bool reply_is_complete(SRWBackend backend, GWBUF *buffer)
     else
     {
         bool more = false;
-        bool skip = backend->get_skip_packet();
+        modutil_state state = backend->get_modutil_state();
         int old_eof = backend->get_reply_state() == REPLY_STATE_RSET_ROWS ? 1 : 0;
-        int n_eof = modutil_count_signal_packets(buffer, old_eof, &more, &skip);
-        backend->set_skip_packet(skip);
+        int n_eof = modutil_count_signal_packets(buffer, old_eof, &more, &state);
+        backend->set_modutil_state(state);
 
         if (n_eof == 0)
         {

server/modules/routing/readwritesplit/rwsplitsession.cc

@@ -17,7 +17,7 @@
 RWBackend::RWBackend(SERVER_REF* ref):
     mxs::Backend(ref),
     m_reply_state(REPLY_STATE_DONE),
-    m_skip(false)
+    m_modutil_state(MODUTIL_STATE_INIT)
 {
 }
 
@@ -35,14 +35,14 @@ void RWBackend::set_reply_state(reply_state_t state)
     m_reply_state = state;
 }
 
-void RWBackend::set_skip_packet(bool state)
+void RWBackend::set_modutil_state(const modutil_state& state)
 {
-    m_skip = state;
+    m_modutil_state = state;
 }
 
-bool RWBackend::get_skip_packet() const
+modutil_state RWBackend::get_modutil_state() const
 {
-    return m_skip;
+    return m_modutil_state;
 }
 
 bool RWBackend::execute_session_command()

server/modules/routing/readwritesplit/rwsplitsession.hh

@@ -15,6 +15,8 @@
 #include "readwritesplit.hh"
 #include "rwsplit_ps.hh"
 
+#include <maxscale/modutil.h>
+
 
 /** Enum for tracking client reply state */
 enum reply_state_t
@@ -50,15 +52,15 @@ public:
     bool execute_session_command();
     bool write(GWBUF* buffer, response_type type = EXPECT_RESPONSE);
 
-    void set_skip_packet(bool state);
-    bool get_skip_packet() const;
+    void set_modutil_state(const modutil_state& state);
+    modutil_state get_modutil_state() const;
 
 private:
     reply_state_t    m_reply_state;
     BackendHandleMap m_ps_handles; /**< Internal ID to backend PS handle mapping */
-    bool             m_skip;       /**< Used to store the state of the EOF packet
-                                    * calculation for result sets when the result
-                                    * contains very large rows */
+    modutil_state    m_modutil_state; /**< Used to store the state of the EOF packet
+                                       * calculation for result sets when the result
+                                       * contains very large rows */
 };
 
 typedef std::tr1::shared_ptr<RWBackend> SRWBackend;