Merge pull request #740 from restic/add-debug-profiles

Add debug memory/cpu profile options

src/cmds/restic/global_debug.go

@@ -0,0 +1,60 @@
+// +build debug
+
+package main
+
+import (
+	"fmt"
+	"net/http"
+	_ "net/http/pprof"
+	"os"
+	"restic/errors"
+
+	"github.com/pkg/profile"
+)
+
+var (
+	listenMemoryProfile string
+	memProfilePath      string
+	cpuProfilePath      string
+
+	prof interface {
+		Stop()
+	}
+)
+
+func init() {
+	f := cmdRoot.PersistentFlags()
+	f.StringVar(&listenMemoryProfile, "listen-profile", "", "listen on this `address:port` for memory profiling")
+	f.StringVar(&memProfilePath, "mem-profile", "", "write memory profile to `dir`")
+	f.StringVar(&cpuProfilePath, "cpu-profile", "", "write cpu profile to `dir`")
+}
+
+func runDebug() error {
+	if listenMemoryProfile != "" {
+		fmt.Fprintf(os.Stderr, "running memory profile HTTP server on %v\n", listenMemoryProfile)
+		go func() {
+			err := http.ListenAndServe(listenMemoryProfile, nil)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "memory profile listen failed: %v\n", err)
+			}
+		}()
+	}
+
+	if memProfilePath != "" && cpuProfilePath != "" {
+		return errors.Fatal("only one profile (memory or CPU) may be activated at the same time")
+	}
+
+	if memProfilePath != "" {
+		prof = profile.Start(profile.Quiet, profile.MemProfile, profile.ProfilePath(memProfilePath))
+	} else if memProfilePath != "" {
+		prof = profile.Start(profile.Quiet, profile.CPUProfile, profile.ProfilePath(memProfilePath))
+	}
+
+	return nil
+}
+
+func shutdownDebug() {
+	if prof != nil {
+		prof.Stop()
+	}
+}

src/cmds/restic/global_release.go

@@ -0,0 +1,9 @@
+// +build !debug
+
+package main
+
+// runDebug is a noop without the debug tag.
+func runDebug() error { return nil }
+
+// shutdownDebug is a noop without the debug tag.
+func shutdownDebug() {}

src/cmds/restic/main.go

@@ -22,6 +22,15 @@ directories in an encrypted repository stored on different backends.
 `,
 	SilenceErrors: true,
 	SilenceUsage:  true,
+
+	// run the debug functions for all subcommands (if build tag "debug" is
+	// enabled)
+	PersistentPreRunE: func(*cobra.Command, []string) error {
+		return runDebug()
+	},
+	PersistentPostRun: func(*cobra.Command, []string) {
+		shutdownDebug()
+	},
 }
 
 func init() {