query watcher

querywatch.go

package main

import "flag"
import "labix.org/v2/mgo"
import "labix.org/v2/mgo/bson"
import "fmt"
import "time"
import "encoding/json"

type ProfileOp struct {
	Op             string                 `bson:"op"`
	Ns             string                 `bson:"ns"`
	Query          map[string]interface{} `bson:"query"`
	Command        map[string]interface{} `bson:"command"`
	NtoReturn      int                    `bson:"ntoreturn"`
	NtoSkip        int                    `bson:"ntoskip"`
	KeyUpdates     int                    `bson:"keyupdates"`
	UpdateObj      map[string]interface{} `bson:"updateobj"`
	NumYields      int                    `bson:"numyields"`
	Nreturned      int                    `bson:"nreturned"`
	ResponseLength int                    `bson:"responseLength"`
	Millis         int                    `bson:"millis"`
	Ts             time.Time              `bson:"ts"`
}

func (self *ProfileOp) String() (string, error){
	part1 := fmt.Sprintf("%dms\t%s\t(%s): ", self.Millis, self.Op, self.Ns)
 	var part2 string

	if self.Op == "query" || self.Op == "remove" || self.Op == "update"{
		queryJson, err := json.Marshal(self.Query)
		if err != nil {
			return "", err
		}
		if self.Op == "query" {
			part2 = string(queryJson)
		}else if self.Op == "update"{
			updateJson, err := json.Marshal(self.UpdateObj)
			if err != nil {
				return "", err
			}
			part2 = string(queryJson) + " update: " +string(updateJson)
		}
	}

	if self.Op == "command"{
		commandJson, err := json.Marshal(self.Command)
		if err != nil {
			return "", err
		}
		part2 = " command: " +string(commandJson)
	}
	return part1 + " " + part2, nil

}

var dbname string
var host string

func main() {

 	flag.StringVar(&dbname, "d", "test", "database to use")
 	flag.StringVar(&host, "h", "127.0.0.1", "mongo host to connect to")
 	flag.StringVar(&host, "host", "127.0.0.1", "mongo host to connect to in format 'hostname:port'")
    flag.Parse()
 
	session, _ := mgo.Dial(host)
	c := session.DB(dbname).C("system.profile")

	pOp := ProfileOp{}
	iter := c.Find(bson.M{"ts": bson.M{"$gt": time.Now()}, "ns": bson.M{"$ne": dbname + ".system.profile"}}).Tail(5 * time.Second)
	lastTs := time.Now()
	for {
		for iter.Next(&pOp) {
			opstr, err := pOp.String()
			if err != nil {
				fmt.Println(err)
				return
			}
			fmt.Println(opstr)
			lastTs = pOp.Ts
		}
		if err := iter.Close(); err != nil {
			fmt.Println(err)
			return
		}
		if iter.Timeout(){
			//
		}else{
			iter = c.Find(bson.M{"ts": bson.M{"$gt": lastTs}, "ns": bson.M{"$ne": dbname + ".system.profile"}}).Tail(5 * time.Second)
		}
	}
}