From a2772762e1e0a4f3716d647f7946f0e43d6bf0b5 Mon Sep 17 00:00:00 2001
From: David Boreham <david@bozemanpass.com>
Date: Wed, 21 Sep 2022 13:33:15 -0600
Subject: [PATCH] Make pprof configurable, remove todos

---
 README.md      |  3 +++
 cmd/env.go     |  6 +++++-
 cmd/serve.go   | 11 +++++++----
 pkg/service.go |  3 +--
 4 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 96fd600..96fc6fd 100644
--- a/README.md
+++ b/README.md
@@ -123,6 +123,9 @@ An example config file:
     # path to custom chain config file (optional)
     # keep chainID same as that in chain config file
     chainConfig  = "./chain.json"           # ETH_CHAIN_CONFIG
+
+[debug]
+    pprof = false                           # Enable pprof agent listener on port 6060
 ```
 
 ### Local Setup
diff --git a/cmd/env.go b/cmd/env.go
index 1e20582..4fe244c 100644
--- a/cmd/env.go
+++ b/cmd/env.go
@@ -82,6 +82,8 @@ const (
 	DATABASE_MAX_CONN_LIFETIME    = "DATABASE_MAX_CONN_LIFETIME"
 	DATABASE_CONN_TIMEOUT         = "DATABSE_CONN_TIMEOUT"
 	DATABASE_MAX_CONN_IDLE_TIME   = "DATABASE_MAX_CONN_IDLE_TIME"
+
+	DEBUG_PPROF = "DEBUG_PPROF"
 )
 
 // Bind env vars for eth node and DB configuration
@@ -136,7 +138,7 @@ func init() {
 
 	viper.BindEnv("statediff.prerun", STATEDIFF_PRERUN)
 	viper.BindEnv("prerun.only", PRERUN_ONLY)
-	viper.BindEnv("prerun.only", PRERUN_PARALLEL)
+	viper.BindEnv("prerun.parallel", PRERUN_PARALLEL)
 	viper.BindEnv("prerun.start", PRERUN_RANGE_START)
 	viper.BindEnv("prerun.stop", PRERUN_RANGE_STOP)
 	viper.BindEnv("prerun.params.intermediateStateNodes", PRERUN_INTERMEDIATE_STATE_NODES)
@@ -148,4 +150,6 @@ func init() {
 
 	viper.BindEnv("log.level", LOG_LEVEL)
 	viper.BindEnv("log.file", LOG_FILE_PATH)
+
+	viper.BindEnv("debug.pprof", DEBUG_PPROF)
 }
diff --git a/cmd/serve.go b/cmd/serve.go
index cd53a60..b178132 100644
--- a/cmd/serve.go
+++ b/cmd/serve.go
@@ -68,15 +68,18 @@ func serve() {
 		logWithCommand.Fatal(err)
 	}
 
-	// short circuit if we only want to perform prerun
-	if viper.GetBool("prerun.only") {
-		// TODO: make pprof optional
+	// Enable the pprof agent if configured
+	if viper.GetBool("debug.pprof") {
 		// See: https://www.farsightsecurity.com/blog/txt-record/go-remote-profiling-20161028/
-		// Do not use the default http multiplexor elsewhere in this process.
+		// For security reasons: do not use the default http multiplexor elsewhere in this process.
 		go func() {
 			logWithCommand.Info("Starting pprof listener on port 6060")
 			logWithCommand.Fatal(http.ListenAndServe("localhost:6060", nil))
 		}()
+	}
+
+	// short circuit if we only want to perform prerun
+	if viper.GetBool("prerun.only") {
 		parallel := viper.GetBool("prerun.parallel")
 		if err := statediffService.Run(nil, parallel); err != nil {
 			logWithCommand.Fatal("unable to perform prerun: %v", err)
diff --git a/pkg/service.go b/pkg/service.go
index cefd726..0307236 100644
--- a/pkg/service.go
+++ b/pkg/service.go
@@ -133,7 +133,6 @@ func (sds *Service) Run(rngs []RangeRequest, parallel bool) error {
 			wg := new(sync.WaitGroup)
 			for i := 0; i < int(sds.workers); i++ {
 				blockRange := RangeRequest{
-					// TODO(dboreham): check this math doesn't leave gaps (are start/stop inclusive?)
 					Start:  preRun.Start + uint64(i)*chunkSize,
 					Stop:   preRun.Start + uint64(i)*chunkSize + chunkSize - 1,
 					Params: preRun.Params,
@@ -165,7 +164,7 @@ func (sds *Service) Run(rngs []RangeRequest, parallel bool) error {
 		}
 	}
 	sds.preruns = nil
-	// TODO(dboreham): seems like this code is never called so we have not written the parallel version
+	// At present this code is never called so we have not written the parallel version:
 	for _, rng := range rngs {
 		logrus.Infof("processing requested range (%d, %d)", rng.Start, rng.Stop)
 		for i := rng.Start; i <= rng.Stop; i++ {