MJL 4/4/07 Added upload of any dictonary entries starting with 'read_data_' as HTTP options in data read reques to histogram server, allows read data source & format to be adjusted on-the-fly.

r1795 | mle | 2007-04-04 07:57:29 +1000 (Wed, 04 Apr 2007) | 2 lines

site_ansto/anstohttp.c

@@ -59,6 +59,12 @@ typedef struct {
         int pause;
         int failCount;
         int asyncRunning;
+        // Keep a local copy of the dictionary pointer in our internal data structure.
+        // We initialize this pointer with the one passed in when the object is created.
+        // This is used to allow certain functions (like AnstoHttpGetHistogram) to access
+        // the dictionary, even though a pointer to the dictionary isn't passed in.
+        // Hopefully this will not have any side effects.
+        pStringDict pOption;
 }anstoHttp, *pAnstoHttp;
 /*------------------------------------------------------------------*/
 static int anstoHttpGetPrepare(pAnstoHttp self, char *request){
@@ -631,7 +637,7 @@ static int AnstoHttpGetData(pHistDriver self,SConnection *pCon){
 /*-------------------------------------------------------------------*/
 static int AnstoHttpGetHistogram(pHistDriver self, SConnection *pCon,
     int bank, int start, int end, HistInt *data){
-    char command[256];
+    char command[1024]; // can be quite long now, if read_data_xxx options are appended
     HistInt *hmdata;
     pAnstoHttp pPriv = NULL;
     int status, len, i;
@@ -678,9 +684,33 @@ static int AnstoHttpGetHistogram(pHistDriver self, SConnection *pCon,
 		int size=((end-start)>(MAX_HTTP_REQUEST_BYTES/sizeof(int)))
 			?(MAX_HTTP_REQUEST_BYTES/sizeof(int)):(end-start);
 		
-	    snprintf(command,255,"%s?bank=%d&start=%d&end=%d",gethm,bank,
+		// Send traditional SICS bank,start,end parameters to the server
-	        start,start+size);
+		// bank is now ignored by the server though, and start and end
-		
+		// may be overridden by supplementary settings (see below).
+		int ncommand=snprintf(command,1023,"%s?bank=%d&start=%d&end=%d",gethm,bank,
+			start,start+size);
+	    	// Now add specific items read_data_xxxx in the string dictionary
+	    	// to the HTTP request.  These act to selectively override the
+	    	// default read-data configuration at the server, so we can select
+		// different dataypes and formats.
+		// We use the internally-stored dictionary pointer for this purpose,
+		// since one isn't provided in the argument list.
+		char *pcommand_build=command+ncommand;
+		char pValue[256];
+		const char *pItem=NULL;
+	 	do
+	 	{
+	 		pItem=StringDictGetNext(pPriv->pOption,pValue,256);
+			if (pItem)
+	 		{
+				if (strncasecmp(pItem,"read_data_",10)==0)
+		   		{
+		   			pcommand_build+=sprintf(pcommand_build,"&%s=%s",pItem,pValue);
+		   		}
+		   	}
+		} while(pItem);
+	    
+	    // Send our request
 	    status = anstoHttpGet(pPriv,command);
 	    if(status != 1){
 	        return HWFault;
@@ -796,6 +826,10 @@ pHistDriver CreateAnstoHttpDriver(pStringDict pOption){
         return NULL;
     }
     
+    // Save a pointer to the string dictionary internally,
+    // for the use of those functions that require it and
+    // don't get a pOption passed in via the argument list.
+    pInternal->pOption=pOption;
 
     /* configure all those functions */
     pNew->Configure      = AnstoHttpConfigure;