Refactor query code so that it is possible to query by polling, rather

than blocking on a query function.

Subversion-branch: /trunk/chocolate-doom
Subversion-revision: 2379

3 files changed, 151 insertions, 109 deletions

diff --git a/src/d_main.c b/src/d_main.c
index c6979712..613db3c1 100644
--- a/src/d_main.c
+++ b/src/d_main.c
@@ -890,9 +890,7 @@ void D_DoomMain (void)
 
     if (M_CheckParm("-search"))
     {
-        printf("\nSearching for servers on Internet ...\n");
-        p = NET_MasterQuery(NET_QueryPrintCallback, NULL);
-        printf("\n%i server(s) found.\n", p);
+        NET_MasterQuery();
         exit(0);
     }
 
@@ -920,9 +918,7 @@ void D_DoomMain (void)
 
     if (M_CheckParm("-localsearch"))
     {
-        printf("\nSearching for servers on local LAN ...\n");
-        p = NET_LANQuery(NET_QueryPrintCallback, NULL);
-        printf("\n%i server(s) found.\n", p);
+        NET_LANQuery();
         exit(0);
     }
 
diff --git a/src/net_query.c b/src/net_query.c
index 24af1863..0e35bccf 100644
--- a/src/net_query.c
+++ b/src/net_query.c
@@ -85,6 +85,7 @@ static int num_targets;
 
 static boolean query_loop_running = false;
 static boolean printed_header = false;
+static int last_query_time = 0;
 
 // Resolve the master server address.
 
@@ -376,6 +377,13 @@ static void SendOneQuery(void)
 
     now = I_GetTimeMS();
 
+    // Rate limit - only send one query every 50ms.
+
+    if (now - last_query_time < 50)
+    {
+        return;
+    }
+
     for (i = 0; i < num_targets; ++i)
     {
         // Not queried yet?
@@ -414,8 +422,10 @@ static void SendOneQuery(void)
 
     //printf("Queried %s\n", NET_AddrToString(targets[i].addr));
     targets[i].state = QUERY_TARGET_QUERIED;
-    targets[i].query_time = I_GetTimeMS();
+    targets[i].query_time = now;
     ++targets[i].query_attempts;
+
+    last_query_time = now;
 }
 
 // Time out servers that have been queried and not responded.
@@ -429,6 +439,12 @@ static void CheckTargetTimeouts(void)
 
     for (i = 0; i < num_targets; ++i)
     {
+        /*
+        printf("target %i: state %i, queries %i, query time %i\n",
+               i, targets[i].state, targets[i].query_attempts,
+               now - targets[i].query_time);
+        */
+
         // We declare a target to be "no response" when we've sent
         // multiple query packets to it (QUERY_MAX_ATTEMPTS) and
         // received no response to any of them.
@@ -438,6 +454,12 @@ static void CheckTargetTimeouts(void)
          && now - targets[i].query_time > QUERY_TIMEOUT_SECS * 1000)
         {
             targets[i].state = QUERY_TARGET_NO_RESPONSE;
+
+            if (targets[i].type == QUERY_TARGET_MASTER)
+            {
+                fprintf(stderr, "NET_MasterQuery: no response "
+                                "from master server.\n");
+            }
         }
     }
 }
@@ -460,6 +482,26 @@ static boolean AllTargetsDone(void)
     return true;
 }
 
+// Polling function, invoked periodically to send queries and
+// interpret new responses received from remote servers.
+// Returns zero when the query sequence has completed and all targets
+// have returned responses or timed out.
+
+int NET_Query_Poll(net_query_callback_t callback, void *user_data)
+{
+    CheckTargetTimeouts();
+
+    // Send a query.  This will only send a single query at once.
+
+    SendOneQuery();
+
+    // Check for a response
+
+    NET_Query_GetResponse(callback, user_data);
+
+    return !AllTargetsDone();
+}
+
 // Stop the query loop
 
 static void NET_Query_ExitLoop(void)
@@ -470,27 +512,15 @@ static void NET_Query_ExitLoop(void)
 // Loop waiting for responses.
 // The specified callback is invoked when a new server responds.
 
-static void NET_Query_QueryLoop(net_query_callback_t callback,
-                                void *user_data)
+static void NET_Query_QueryLoop(net_query_callback_t callback, void *user_data)
 {
     query_loop_running = true;
 
-    while (query_loop_running && !AllTargetsDone())
+    while (query_loop_running && NET_Query_Poll(callback, user_data))
     {
-        // Send a query.  This will only send a single query.
-        // Because of the delay below, this is therefore rate limited.
-
-        SendOneQuery();
-
-        // Check for a response
-
-        NET_Query_GetResponse(callback, user_data);
-
         // Don't thrash the CPU
 
         I_Sleep(50);
-
-        CheckTargetTimeouts();
     }
 }
 
@@ -554,87 +584,21 @@ static int GetNumResponses(void)
     return result;
 }
 
-void NET_QueryAddress(char *addr_str)
+int NET_StartLANQuery(void)
 {
-    net_addr_t *addr;
     query_target_t *target;
 
     NET_Query_Init();
 
-    addr = NET_ResolveAddress(query_context, addr_str);
-
-    if (addr == NULL)
-    {
-        I_Error("NET_QueryAddress: Host '%s' not found!", addr_str);
-    }
-
-    // Add the address to the list of targets.
-
-    target = GetTargetForAddr(addr, true);
-
-    printf("\nQuerying '%s'...\n", addr_str);
-
-    // Run query loop.
-
-    NET_Query_QueryLoop(NET_Query_ExitCallback, NULL);
-
-    // Check if the target responded.
-
-    if (target->state == QUERY_TARGET_RESPONDED)
-    {
-        NET_QueryPrintCallback(addr, &target->data, target->ping_time, NULL);
-    }
-    else
-    {
-        I_Error("No response from '%s'", addr_str);
-    }
-}
-
-net_addr_t *NET_FindLANServer(void)
-{
-    query_target_t *target;
-    query_target_t *responder;
-
-    NET_Query_Init();
-
     // Add a broadcast target to the list.
 
     target = GetTargetForAddr(NULL, true);
     target->type = QUERY_TARGET_BROADCAST;
 
-    // Run the query loop, and stop at the first target found.
-
-    NET_Query_QueryLoop(NET_Query_ExitCallback, NULL);
-
-    responder = FindFirstResponder();
-
-    if (responder != NULL)
-    {
-        return responder->addr;
-    }
-    else
-    {
-        return NULL;
-    }
+    return 1;
 }
 
-int NET_LANQuery(net_query_callback_t callback, void *user_data)
-{
-    query_target_t *target;
-
-    NET_Query_Init();
-
-    // Add a broadcast target to the list.
-
-    target = GetTargetForAddr(NULL, true);
-    target->type = QUERY_TARGET_BROADCAST;
-
-    NET_Query_QueryLoop(callback, user_data);
-
-    return GetNumResponses();
-}
-
-int NET_MasterQuery(net_query_callback_t callback, void *user_data)
+int NET_StartMasterQuery(void)
 {
     net_addr_t *master;
     query_target_t *target;
@@ -653,19 +617,11 @@ int NET_MasterQuery(net_query_callback_t callback, void *user_data)
     target = GetTargetForAddr(master, true);
     target->type = QUERY_TARGET_MASTER;
 
-    NET_Query_QueryLoop(callback, user_data);
-
-    // Check that we got a response from the master, and display
-    // a warning if we didn't.
-
-    if (target->state == QUERY_TARGET_NO_RESPONSE)
-    {
-        fprintf(stderr, "NET_MasterQuery: no response from master server.\n");
-    }
-
-    return GetNumResponses();
+    return 1;
 }
 
+// -----------------------------------------------------------------------
+
 static void formatted_printf(int wide, char *s, ...)
 {
     va_list args;
@@ -721,10 +677,10 @@ static void PrintHeader(void)
 
 // Callback function that just prints information in a table.
 
-void NET_QueryPrintCallback(net_addr_t *addr,
-                            net_querydata_t *data,
-                            unsigned int ping_time,
-                            void *user_data)
+static void NET_QueryPrintCallback(net_addr_t *addr,
+                                   net_querydata_t *data,
+                                   unsigned int ping_time,
+                                   void *user_data)
 {
     // If this is the first server, print the header.
 
@@ -753,3 +709,91 @@ void NET_QueryPrintCallback(net_addr_t *addr,
     NET_SafePuts(data->description);
 }
 
+void NET_LANQuery(void)
+{
+    if (NET_StartLANQuery())
+    {
+        printf("\nSearching for servers on local LAN ...\n");
+
+        NET_Query_QueryLoop(NET_QueryPrintCallback, NULL);
+
+        printf("\n%i server(s) found.\n", GetNumResponses());
+    }
+}
+
+void NET_MasterQuery(void)
+{
+    if (NET_StartMasterQuery())
+    {
+        printf("\nSearching for servers on Internet ...\n");
+
+        NET_Query_QueryLoop(NET_QueryPrintCallback, NULL);
+
+        printf("\n%i server(s) found.\n", GetNumResponses());
+    }
+}
+
+void NET_QueryAddress(char *addr_str)
+{
+    net_addr_t *addr;
+    query_target_t *target;
+
+    NET_Query_Init();
+
+    addr = NET_ResolveAddress(query_context, addr_str);
+
+    if (addr == NULL)
+    {
+        I_Error("NET_QueryAddress: Host '%s' not found!", addr_str);
+    }
+
+    // Add the address to the list of targets.
+
+    target = GetTargetForAddr(addr, true);
+
+    printf("\nQuerying '%s'...\n", addr_str);
+
+    // Run query loop.
+
+    NET_Query_QueryLoop(NET_Query_ExitCallback, NULL);
+
+    // Check if the target responded.
+
+    if (target->state == QUERY_TARGET_RESPONDED)
+    {
+        NET_QueryPrintCallback(addr, &target->data, target->ping_time, NULL);
+    }
+    else
+    {
+        I_Error("No response from '%s'", addr_str);
+    }
+}
+
+net_addr_t *NET_FindLANServer(void)
+{
+    query_target_t *target;
+    query_target_t *responder;
+
+    NET_Query_Init();
+
+    // Add a broadcast target to the list.
+
+    target = GetTargetForAddr(NULL, true);
+    target->type = QUERY_TARGET_BROADCAST;
+
+    // Run the query loop, and stop at the first target found.
+
+    NET_Query_QueryLoop(NET_Query_ExitCallback, NULL);
+
+    responder = FindFirstResponder();
+
+    if (responder != NULL)
+    {
+        return responder->addr;
+    }
+    else
+    {
+        return NULL;
+    }
+}
+
diff --git a/src/net_query.h b/src/net_query.h
index 01e059cb..5a30bd0d 100644
--- a/src/net_query.h
+++ b/src/net_query.h
@@ -32,13 +32,15 @@ typedef void (*net_query_callback_t)(net_addr_t *addr,
                                      unsigned int ping_time,
                                      void *user_data);
 
-extern int NET_LANQuery(net_query_callback_t callback, void *user_data);
-extern int NET_MasterQuery(net_query_callback_t callback, void *user_data);
+extern int NET_StartLANQuery(void);
+extern int NET_StartMasterQuery(void);
+
+extern void NET_LANQuery(void);
+extern void NET_MasterQuery(void);
 extern void NET_QueryAddress(char *addr);
 extern net_addr_t *NET_FindLANServer(void);
 
-extern void NET_QueryPrintCallback(net_addr_t *addr, net_querydata_t *data,
-                                   unsigned int ping_time, void *user_data);
+extern int NET_Query_Poll(net_query_callback_t callback, void *user_data);
 
 extern net_addr_t *NET_Query_ResolveMaster(net_context_t *context);
 extern void NET_Query_AddToMaster(net_addr_t *master_addr);