Update README and sample

Author: ibmmqmet

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+=======
+### October 2018
+* Allow compilation against MQ v8
+
 ## October 2018 - v3.0.0
 * Added functions to the mqmetric package to assist with collecting channel status
 * Better handle truncated messages when listing the queues that match a pattern

README.md

@@ -6,8 +6,8 @@ This repository demonstrates how you can call IBM MQ from applications written i
 
 This repository previously contained sample programs that exported MQ statistics to some monitoring packages. These have now been moved to a new [GitHub repository called mq-metric-samples](https://github.com/ibm-messaging/mq-metric-samples).
 
-A minimum level of MQ V9 is required to build these packages.
-The monitoring data published by the queue manager is not available before that version; the interface also assumes availability of MQI structures from that level of MQ.
+A minimum level of MQ V8 is required to build these packages.
+However, note that the monitoring data published by the queue manager is not available before MQ V9.
 
 ## Health Warning
 

ibmmq/mqiMQCNO.go

@@ -36,15 +36,16 @@ void freeCCDTUrl(MQCNO *mqcno) {
 
 void setCCDTUrl(MQCNO *mqcno, PMQCHAR url, MQLONG length) {
 #if defined(MQCNO_VERSION_6) && MQCNO_CURRENT_VERSION >= MQCNO_VERSION_6
-	mqcno->Version = MQCNO_VERSION_6;
+  if (mqcno->Version < MQCNO_VERSION_6) {
+	  mqcno->Version = MQCNO_VERSION_6;
+	}
 	mqcno->CCDTUrlOffset = 0;
 	mqcno->CCDTUrlPtr = NULL;
 	mqcno->CCDTUrlLength = length;
 	if (url != NULL) {
 		mqcno->CCDTUrlPtr = url;
 	}
 #else
-	mqcno->Version = MQCNO_CURRENT_VERSION;
 	if (url != NULL) {
 		free(url);
 	}
@@ -177,6 +178,9 @@ func copyCNOtoC(mqcno *C.MQCNO, gocno *MQCNO) {
 		mqcno.SecurityParmsPtr = nil
 	}
 
+	// The CCDT URL option was introduced in MQ V9. To compile against older
+	// versions of MQ, setting of it has been moved to a C function that can use
+	// the pre-processor to decide whether it's needed.
 	C.setCCDTUrl(mqcno, C.PMQCHAR(C.CString(gocno.CCDTUrl)), C.MQLONG(len(gocno.CCDTUrl)))
 	return
 }

samples/clientconn/clientconn.go

@@ -77,9 +77,16 @@ func main() {
 	// Reference the CD structure from the CNO
 	// and indicate that we want to use the client
 	// connection method.
-	cno.ClientConn = cd
+	if true {
+	  cno.ClientConn = cd
+  } else {
+		// This is how you might reference a remote CCDT instead of
+		// explicitly putting in the CD structure.
+	  cno.CCDTUrl = "http://localhost:3030"
+	}
 	cno.Options = ibmmq.MQCNO_CLIENT_BINDING
 
+
 	// Also fill in the userid and password if the MQSAMP_USER_ID
 	// environment variable is set. This is the same as the C
 	// sample programs such as amqsput.