1 files changed, 95 insertions, 0 deletions
diff --git a/profiling.go b/profiling.go
new file mode 100644
index 0000000..11d6326
--- /dev/null
+++ b/profiling.go
@@ -0,0 +1,95 @@
+package main
+
+import (
+	"os"
+	"runtime/pprof"
+	"runtime/trace"
+	"time"
+
+	"github.com/rfjakob/gocryptfs/internal/exitcodes"
+	"github.com/rfjakob/gocryptfs/internal/tlog"
+)
+
+// setupCpuprofile is called to handle a non-empty "-cpuprofile" cli argument
+func setupCpuprofile(cpuprofileArg string) func() {
+	tlog.Info.Printf("Writing CPU profile to %s", cpuprofileArg)
+	f, err := os.Create(cpuprofileArg)
+	if err != nil {
+		tlog.Fatal.Println(err)
+		os.Exit(exitcodes.Profiler)
+	}
+	err = pprof.StartCPUProfile(f)
+	if err != nil {
+		tlog.Fatal.Println(err)
+		os.Exit(exitcodes.Profiler)
+	}
+	return func() {
+		pprof.StopCPUProfile()
+	}
+}
+
+// setupTrace is called to handle a non-empty "-memprofile" cli argument
+func setupMemprofile(memprofileArg string) func() {
+	tlog.Info.Printf("Will write memory profile to %q", memprofileArg)
+	f, err := os.Create(memprofileArg)
+	if err != nil {
+		tlog.Fatal.Println(err)
+		os.Exit(exitcodes.Profiler)
+	}
+	exiting := false
+	// Write the memory profile to disk every 60 seconds to get the in-use
+	// memory stats.
+	go func() {
+		for {
+			time.Sleep(60 * time.Second)
+			if exiting {
+				return
+			}
+			_, err = f.Seek(0, 0)
+			if err != nil {
+				tlog.Warn.Printf("memprofile: Seek failed: %v", err)
+				return
+			}
+			err = f.Truncate(0)
+			if err != nil {
+				tlog.Warn.Printf("memprofile: Truncate failed: %v", err)
+				return
+			}
+			err = pprof.WriteHeapProfile(f)
+			if err == nil {
+				tlog.Info.Printf("memprofile: periodic write to %q succeeded",
+					memprofileArg)
+			} else {
+				tlog.Warn.Printf("memprofile: periodic WriteHeapProfile failed: %v", err)
+				return
+			}
+		}
+	}()
+	// Final write on exit.
+	return func() {
+		exiting = true
+		err = pprof.WriteHeapProfile(f)
+		if err != nil {
+			tlog.Warn.Printf("memprofile: on-exit WriteHeapProfile failed: %v", err)
+		}
+		f.Close()
+	}
+}
+
+// setupTrace is called to handle a non-empty "-trace" cli argument
+func setupTrace(traceArg string) func() {
+	tlog.Info.Printf("Writing execution trace to %s", traceArg)
+	f, err := os.Create(traceArg)
+	if err != nil {
+		tlog.Fatal.Println(err)
+		os.Exit(exitcodes.Profiler)
+	}
+	err = trace.Start(f)
+	if err != nil {
+		tlog.Fatal.Println(err)
+		os.Exit(exitcodes.Profiler)
+	}
+	return func() {
+		trace.Stop()
+	}
+}