Support printing previous stats files

tools/benchmark/benchmark.go

@@ -25,6 +25,8 @@ type Config struct {
 
 // Run executes the benchmark and calculates statistics about its performance
 func (c Config) Run() (stats *Stats, err error) {
+	fmt.Printf("Benchmark %s\n", c.Name)
+
 	run := func() {
 		windowConfig := c.WindowConfig
 		if windowConfig.Title == "" {
@@ -74,7 +76,6 @@ func (c Config) Run() (stats *Stats, err error) {
 		}
 	}
 
-	fmt.Printf("Running benchmark: %s\n", c.Name)
 	opengl.Run(run)
 
 	return stats, err

tools/cmd/bench.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"encoding/json"
 	"fmt"
 	"os"
 	"text/tabwriter"
@@ -11,7 +12,11 @@ import (
 
 func init() {
 	benchRunCmd.Flags().StringP("output", "o", "", "Output path for statistics file")
-	benchCmd.AddCommand(benchListCmd, benchRunCmd)
+
+	benchStatsCmd.Flags().StringP("input", "i", "", "Input path for statistics file")
+	benchStatsCmd.MarkFlagRequired("input")
+
+	benchCmd.AddCommand(benchListCmd, benchRunCmd, benchStatsCmd)
 }
 
 var (
@@ -67,4 +72,32 @@ var (
 			}
 		},
 	}
+	benchStatsCmd = &cobra.Command{
+		Use:   "stats -i [path/to/stats.json]",
+		Short: "Pretty print the contents of a stats file",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			input, err := cmd.Flags().GetString("input")
+			if err != nil {
+				return err
+			}
+			cmd.SilenceUsage = true
+
+			bytes, err := os.ReadFile(input)
+			if err != nil {
+				return err
+			}
+
+			var benchStats benchmark.StatsCollection
+			if err := json.Unmarshal(bytes, &benchStats); err != nil {
+				return err
+			}
+
+			for _, stats := range benchStats {
+				fmt.Printf("Benchmark %s\n", stats.Name)
+				stats.Print()
+			}
+
+			return nil
+		},
+	}
 )