Make lotus-bench import analyze multithreaded and less RAM hungry

Signed-off-by: Jakub Sztandera <kubuxu@protocol.ai>

cmd/lotus-bench/import.go

@@ -255,7 +255,55 @@ var importAnalyzeCmd = &cli.Command{
 		}
 		dec := json.NewDecoder(fi)
 
-		var results []TipSetExec
+		const nWorkers = 16
+		tseIn := make(chan TipSetExec, 2*nWorkers)
+		type result struct {
+			totalTime       time.Duration
+			chargeDeltas    map[string][]float64
+			expensiveInvocs []Invocation
+		}
+
+		results := make(chan result, nWorkers)
+
+		for i := 0; i < nWorkers; i++ {
+			go func() {
+				chargeDeltas := make(map[string][]float64)
+				var totalTime time.Duration
+				var expensiveInvocs []Invocation
+				var leastExpensiveInvoc = time.Duration(0)
+
+				for {
+					tse, ok := <-tseIn
+					if !ok {
+						results <- result{
+							totalTime:       totalTime,
+							chargeDeltas:    chargeDeltas,
+							expensiveInvocs: expensiveInvocs,
+						}
+						return
+					}
+					totalTime += tse.Duration
+					for _, inv := range tse.Trace {
+						if inv.Duration > leastExpensiveInvoc {
+							expensiveInvocs = append(expensiveInvocs, Invocation{
+								TipSet: tse.TipSet,
+								Invoc:  inv,
+							})
+						}
+
+						tallyGasCharges(chargeDeltas, &inv.ExecutionTrace)
+					}
+					sort.Slice(expensiveInvocs, func(i, j int) bool {
+						return expensiveInvocs[i].Invoc.Duration > expensiveInvocs[j].Invoc.Duration
+					})
+					if len(expensiveInvocs) != 0 {
+						leastExpensiveInvoc = expensiveInvocs[len(expensiveInvocs)-1].Invoc.Duration
+					}
+				}
+			}()
+		}
+
+		var totalTipsets int64
 		for {
 			var tse TipSetExec
 			if err := dec.Decode(&tse); err != nil {
@@ -267,32 +315,31 @@ var importAnalyzeCmd = &cli.Command{
 				}
 				break
 			}
-			results = append(results, tse)
+			totalTipsets++
+			tseIn <- tse
+			if totalTipsets%10 == 0 {
+				fmt.Printf("\rProcessed %d tipsets", totalTipsets)
+			}
 		}
-
-		chargeDeltas := make(map[string][]float64)
+		close(tseIn)
+		fmt.Printf("\n")
+		fmt.Printf("Collecting results\n")
 
 		var invocs []Invocation
 		var totalTime time.Duration
-		for i, r := range results {
-			_ = i
-			totalTime += r.Duration
-
-			for _, inv := range r.Trace {
-				invocs = append(invocs, Invocation{
-					TipSet: r.TipSet,
-					Invoc:  inv,
-				})
-
-				cgas, vgas := countGasCosts(&inv.ExecutionTrace)
-				fmt.Printf("Invocation: %d %s: %s %d -> %0.2f\n", inv.Msg.Method, inv.Msg.To, inv.Duration, cgas+vgas, float64(GasPerNs*inv.Duration.Nanoseconds())/float64(cgas+vgas))
-
-				tallyGasCharges(chargeDeltas, &inv.ExecutionTrace)
-
+		var keys []string
+		var chargeDeltas = make(map[string][]float64)
+		for i := 0; i < nWorkers; i++ {
+			fmt.Printf("\rProcessing results from worker %d/%d", i+1, nWorkers)
+			res := <-results
+			invocs = append(invocs, res.expensiveInvocs...)
+			for k, v := range res.chargeDeltas {
+				chargeDeltas[k] = append(chargeDeltas[k], v...)
 			}
+			totalTime += res.totalTime
 		}
 
-		var keys []string
+		fmt.Printf("\nCollecting gas keys\n")
 		for k := range chargeDeltas {
 			keys = append(keys, k)
 		}
@@ -311,7 +358,7 @@ var importAnalyzeCmd = &cli.Command{
 		})
 
 		fmt.Println("Total time: ", totalTime)
-		fmt.Println("Average time per epoch: ", totalTime/time.Duration(len(results)))
+		fmt.Println("Average time per epoch: ", totalTime/time.Duration(totalTipsets))
 
 		n := 30
 		if len(invocs) < n {