Initial delivery of metrics code (#81)

* Initial delivery of metrics code

* Fix build issues

* Fix build issue with go vet

vendor/github.com/ibm-messaging/mq-golang/mqmetric/mqif.go

@@ -0,0 +1,237 @@
+package mqmetric
+
+/*
+  Copyright (c) IBM Corporation 2016
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific
+
+   Contributors:
+     Mark Taylor - Initial Contribution
+*/
+
+/*
+This file holds most of the calls to the MQI, so we
+don't need to repeat common setups eg of MQMD or MQSD structures.
+*/
+
+import (
+	"fmt"
+
+	"github.com/ibm-messaging/mq-golang/ibmmq"
+)
+
+var (
+	qMgr      ibmmq.MQQueueManager
+	cmdQObj   ibmmq.MQObject
+	replyQObj ibmmq.MQObject
+	statsQObj ibmmq.MQObject
+	getBuffer = make([]byte, 32768)
+
+	qmgrConnected     = false
+	queuesOpened      = false
+	statsQueuesOpened = false
+	subsOpened        = false
+)
+
+type ConnectionConfig struct {
+	ClientMode bool
+	UserId     string
+	Password   string
+}
+
+/*
+InitConnection connects to the queue manager, and then
+opens both the command queue and a dynamic reply queue
+to be used for all responses including the publications
+*/
+func InitConnection(qMgrName string, replyQ string, cc *ConnectionConfig) error {
+	return InitConnectionStats(qMgrName, replyQ, "", cc)
+}
+
+/*
+InitConnectionStats is the same as InitConnection with the addition
+of a call to open the queue manager statistics queue.
+*/
+func InitConnectionStats(qMgrName string, replyQ string, statsQ string, cc *ConnectionConfig) error {
+	var err error
+	gocno := ibmmq.NewMQCNO()
+	gocsp := ibmmq.NewMQCSP()
+
+	if cc.ClientMode {
+		gocno.Options = ibmmq.MQCNO_CLIENT_BINDING
+	} else {
+		gocno.Options = ibmmq.MQCNO_LOCAL_BINDING
+	}
+	gocno.Options |= ibmmq.MQCNO_HANDLE_SHARE_BLOCK
+
+	if cc.Password != "" {
+		gocsp.Password = cc.Password
+	}
+	if cc.UserId != "" {
+		gocsp.UserId = cc.UserId
+		gocno.SecurityParms = gocsp
+	}
+
+	qMgr, err = ibmmq.Connx(qMgrName, gocno)
+	if err == nil {
+		qmgrConnected = true
+	}
+
+	// MQOPEN of the COMMAND QUEUE
+	if err == nil {
+		mqod := ibmmq.NewMQOD()
+
+		openOptions := ibmmq.MQOO_OUTPUT | ibmmq.MQOO_FAIL_IF_QUIESCING
+
+		mqod.ObjectType = ibmmq.MQOT_Q
+		mqod.ObjectName = "SYSTEM.ADMIN.COMMAND.QUEUE"
+
+		cmdQObj, err = qMgr.Open(mqod, openOptions)
+
+	}
+
+	// MQOPEN of the statistics queue
+	if err == nil && statsQ != "" {
+		mqod := ibmmq.NewMQOD()
+		openOptions := ibmmq.MQOO_INPUT_AS_Q_DEF | ibmmq.MQOO_FAIL_IF_QUIESCING
+		mqod.ObjectType = ibmmq.MQOT_Q
+		mqod.ObjectName = statsQ
+		statsQObj, err = qMgr.Open(mqod, openOptions)
+		if err == nil {
+			statsQueuesOpened = true
+		}
+	}
+
+	// MQOPEN of a reply queue
+	if err == nil {
+		mqod := ibmmq.NewMQOD()
+		openOptions := ibmmq.MQOO_INPUT_AS_Q_DEF | ibmmq.MQOO_FAIL_IF_QUIESCING
+		mqod.ObjectType = ibmmq.MQOT_Q
+		mqod.ObjectName = replyQ
+		replyQObj, err = qMgr.Open(mqod, openOptions)
+		if err == nil {
+			queuesOpened = true
+		}
+	}
+
+	if err != nil {
+		return fmt.Errorf("Cannot access queue manager. Error: %v", err)
+	}
+
+	return err
+}
+
+/*
+EndConnection tidies up by closing the queues and disconnecting.
+*/
+func EndConnection() {
+
+	// MQCLOSE all subscriptions
+	if subsOpened {
+		for _, cl := range Metrics.Classes {
+			for _, ty := range cl.Types {
+				for _, hObj := range ty.subHobj {
+					hObj.Close(0)
+				}
+			}
+		}
+	}
+
+	// MQCLOSE the queues
+	if queuesOpened {
+		cmdQObj.Close(0)
+		replyQObj.Close(0)
+	}
+
+	if statsQueuesOpened {
+		statsQObj.Close(0)
+	}
+
+	// MQDISC regardless of other errors
+	if qmgrConnected {
+		qMgr.Disc()
+	}
+
+}
+
+/*
+getMessage returns a message from the replyQ. The only
+parameter to the function says whether this should block
+for 30 seconds or return immediately if there is no message
+available. When working with the command queue, blocking is
+required; when getting publications, non-blocking is better.
+
+A 32K buffer was created at the top of this file, and should always
+be big enough for what we are expecting.
+*/
+func getMessage(wait bool) ([]byte, error) {
+	return getMessageWithHObj(wait, replyQObj)
+}
+
+func getMessageWithHObj(wait bool, hObj ibmmq.MQObject) ([]byte, error) {
+	var err error
+	var datalen int
+	var mqreturn *ibmmq.MQReturn
+
+	getmqmd := ibmmq.NewMQMD()
+	gmo := ibmmq.NewMQGMO()
+	gmo.Options = ibmmq.MQGMO_NO_SYNCPOINT
+	gmo.Options |= ibmmq.MQGMO_FAIL_IF_QUIESCING
+	gmo.Options |= ibmmq.MQGMO_CONVERT
+
+	gmo.MatchOptions = ibmmq.MQMO_NONE
+
+	if wait {
+		gmo.Options |= ibmmq.MQGMO_WAIT
+		gmo.WaitInterval = 30 * 1000
+	}
+
+	datalen, err = replyQObj.Get(getmqmd, gmo, getBuffer)
+	if err != nil {
+		mqreturn = err.(*ibmmq.MQReturn)
+
+		if mqreturn.MQRC == ibmmq.MQRC_Q_MGR_NOT_AVAILABLE ||
+			mqreturn.MQRC == ibmmq.MQRC_Q_MGR_NAME_ERROR ||
+			mqreturn.MQRC == ibmmq.MQRC_Q_MGR_QUIESCING {
+			return nil, fmt.Errorf("Queue Manager error: %v", err)
+		}
+		if mqreturn.MQCC == ibmmq.MQCC_FAILED && mqreturn.MQRC != ibmmq.MQRC_NO_MSG_AVAILABLE {
+			return nil, fmt.Errorf("Get message error: %v", err)
+		}
+	}
+
+	return getBuffer[0:datalen], err
+}
+
+/*
+subscribe to the nominated topic. The previously-opened
+replyQ is used for publications; we do not use a managed queue here,
+so that everything can be read from one queue. The object handle for the
+subscription is returned so we can close it when it's no longer needed.
+*/
+func subscribe(topic string) (ibmmq.MQObject, error) {
+	var err error
+
+	mqsd := ibmmq.NewMQSD()
+	mqsd.Options = ibmmq.MQSO_CREATE
+	mqsd.Options |= ibmmq.MQSO_NON_DURABLE
+	mqsd.Options |= ibmmq.MQSO_FAIL_IF_QUIESCING
+
+	mqsd.ObjectString = topic
+
+	subObj, err := qMgr.Sub(mqsd, &replyQObj)
+	if err != nil {
+		return subObj, fmt.Errorf("Error subscribing to topic '%s': %v", topic, err)
+	}
+
+	return subObj, err
+}