Merge pull request #147 from benbjohnson/stats

Add streaming stats to bolt bench.

cmd/bolt/bench.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/binary"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io/ioutil"
@@ -42,6 +43,11 @@ func Bench(options *BenchOptions) {
 	}
 	defer db.Close()
 
+	// Enable streaming stats.
+	if options.StatsInterval > 0 {
+		go printStats(db, options.StatsInterval)
+	}
+
 	// Start profiling for writes.
 	if options.ProfileMode == "rw" || options.ProfileMode == "w" {
 		benchStartProfiling(options)
@@ -73,9 +79,9 @@ func Bench(options *BenchOptions) {
 	}
 
 	// Print results.
-	fmt.Printf("# Write\t%v\t(%v/op)\t(%v op/sec)\n", results.WriteDuration, results.WriteOpDuration(), results.WriteOpsPerSecond())
-	fmt.Printf("# Read\t%v\t(%v/op)\t(%v op/sec)\n", results.ReadDuration, results.ReadOpDuration(), results.ReadOpsPerSecond())
-	fmt.Println("")
+	fmt.Fprintf(os.Stderr, "# Write\t%v\t(%v/op)\t(%v op/sec)\n", results.WriteDuration, results.WriteOpDuration(), results.WriteOpsPerSecond())
+	fmt.Fprintf(os.Stderr, "# Read\t%v\t(%v/op)\t(%v op/sec)\n", results.ReadDuration, results.ReadOpDuration(), results.ReadOpsPerSecond())
+	fmt.Fprintln(os.Stderr, "")
 }
 
 // Writes to the database.
@@ -233,6 +239,29 @@ func benchStopProfiling() {
 	}
 }
 
+// Continuously prints stats on the database at given intervals.
+func printStats(db *bolt.DB, interval time.Duration) {
+	var prevStats = db.Stats()
+	var encoder = json.NewEncoder(os.Stdout)
+
+	for {
+		// Wait for the stats interval.
+		time.Sleep(interval)
+
+		// Retrieve new stats and find difference from previous iteration.
+		var stats = db.Stats()
+		var diff = stats.Sub(&prevStats)
+
+		// Print as JSON to STDOUT.
+		if err := encoder.Encode(diff); err != nil {
+			fatal(err)
+		}
+
+		// Save stats for next iteration.
+		prevStats = stats
+	}
+}
+
 // BenchOptions represents the set of options that can be passed to Bench().
 type BenchOptions struct {
 	ProfileMode   string
@@ -245,6 +274,7 @@ type BenchOptions struct {
 	CPUProfile    string
 	MemProfile    string
 	BlockProfile  string
+	StatsInterval time.Duration
 }
 
 // BenchResults represents the performance results of the benchmark.

cmd/bolt/main.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"time"
 
 	"github.com/codegangsta/cli"
 )
@@ -104,8 +105,14 @@ func NewApp() *cli.App {
 				&cli.StringFlag{Name: "cpuprofile", Usage: "CPU profile output path"},
 				&cli.StringFlag{Name: "memprofile", Usage: "Memory profile output path"},
 				&cli.StringFlag{Name: "blockprofile", Usage: "Block profile output path"},
+				&cli.StringFlag{Name: "stats-interval", Value: "0s", Usage: "Continuous stats interval"},
 			},
 			Action: func(c *cli.Context) {
+				statsInterval, err := time.ParseDuration(c.String("stats-interval"))
+				if err != nil {
+					fatal(err)
+				}
+
 				Bench(&BenchOptions{
 					ProfileMode:   c.String("profile-mode"),
 					WriteMode:     c.String("write-mode"),
@@ -117,6 +124,7 @@ func NewApp() *cli.App {
 					CPUProfile:    c.String("cpuprofile"),
 					MemProfile:    c.String("memprofile"),
 					BlockProfile:  c.String("blockprofile"),
+					StatsInterval: statsInterval,
 				})
 			},
 		}}