From 557f55b360bf661d28ca77c887073754a88e19ac Mon Sep 17 00:00:00 2001
From: Ben Perry <bhperry94@gmail.com>
Date: Fri, 23 Aug 2024 11:49:26 -0500
Subject: [PATCH] Benchmark command

---
 tools/cmd/bench.go | 166 +++++++++++++++++++++++++++++++++++++++++++++
 tools/cmd/root.go  |  18 +++--
 2 files changed, 177 insertions(+), 7 deletions(-)
 create mode 100644 tools/cmd/bench.go

diff --git a/tools/cmd/bench.go b/tools/cmd/bench.go
new file mode 100644
index 0000000..2d50e6d
--- /dev/null
+++ b/tools/cmd/bench.go
@@ -0,0 +1,166 @@
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"runtime"
+	"runtime/pprof"
+	"text/tabwriter"
+	"time"
+
+	"github.com/gopxl/pixel/tools/benchmark"
+	"github.com/gopxl/pixel/v2/backends/opengl"
+	"github.com/spf13/cobra"
+)
+
+var (
+	benchRunAll bool
+	benchRunOutput,
+	benchRunCpuprofile,
+	benchRunMemprofile string
+	benchRunDuration time.Duration
+
+	benchStatsInput string
+)
+
+func NewBenchCmd() *cobra.Command {
+	bench := &cobra.Command{
+		Use:   "bench",
+		Short: "Benchmark the pixel library",
+		Run: func(cmd *cobra.Command, args []string) {
+			cmd.Help()
+		},
+	}
+	bench.AddCommand(NewBenchLsCmd(), NewBenchRunCmd(), NewBenchStatsCmd())
+	return bench
+}
+
+func NewBenchRunCmd() *cobra.Command {
+	run := &cobra.Command{
+		Use:   "run [names...] [opts]",
+		Short: "Run one or more benchmark tests",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if benchRunAll {
+				args = benchmark.Benchmarks.ListNames()
+			} else if len(args) == 0 {
+				return fmt.Errorf("requires at least one benchmark")
+			}
+			cmd.SilenceUsage = true
+
+			// Start CPU profile
+			if benchRunCpuprofile != "" {
+				f, err := os.Create(benchRunCpuprofile)
+				if err != nil {
+					return fmt.Errorf("could not create CPU profile: %v", err)
+				}
+				defer f.Close()
+				if err := pprof.StartCPUProfile(f); err != nil {
+					return fmt.Errorf("could not start CPU profile: %v", err)
+				}
+				defer pprof.StopCPUProfile()
+			}
+
+			// Run benchmark(s)
+			benchStats := make(benchmark.StatsCollection, len(args))
+			var err error
+			run := func() {
+				var config benchmark.Config
+				for i, name := range args {
+					config, err = benchmark.Benchmarks.Get(name)
+					if err != nil {
+						return
+					}
+
+					if benchRunDuration != 0 {
+						config.Duration = benchRunDuration
+					}
+
+					var stats *benchmark.Stats
+					stats, err = config.Run()
+					if err != nil {
+						return
+					}
+					benchStats[i] = stats
+				}
+			}
+
+			opengl.Run(run)
+			if err != nil {
+				return err
+			}
+			fmt.Println()
+			benchStats.Print()
+
+			// Dump memory profile
+			if benchRunMemprofile != "" {
+				f, err := os.Create(benchRunMemprofile)
+				if err != nil {
+					return fmt.Errorf("could not create memory profile: %v", err)
+				}
+				defer f.Close()
+				runtime.GC() // get up-to-date statistics
+				if err := pprof.WriteHeapProfile(f); err != nil {
+					return fmt.Errorf("could not write memory profile: %v", err)
+				}
+			}
+
+			// Dump stats
+			if benchRunOutput != "" {
+				err := benchStats.Dump(benchRunOutput)
+				if err != nil {
+					return err
+				}
+			}
+			return nil
+		},
+	}
+
+	run.Flags().BoolVarP(&benchRunAll, "all", "a", false, "Run all registered benchmarks")
+	run.Flags().StringVarP(&benchRunOutput, "output", "o", "", "Output path for statistics file")
+	run.Flags().DurationVarP(&benchRunDuration, "duration", "d", 0, "Override duration for benchmark runs")
+	run.Flags().StringVarP(&benchRunCpuprofile, "cpuprofile", "c", "", "CPU profiling file")
+	run.Flags().StringVarP(&benchRunMemprofile, "memprofile", "m", "", "Memory profiling file")
+	return run
+}
+
+func NewBenchLsCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "ls",
+		Short: "List available benchmarks",
+		Args:  cobra.NoArgs,
+		Run: func(cmd *cobra.Command, args []string) {
+			w := tabwriter.NewWriter(os.Stdout, 1, 4, 8, ' ', 0)
+			for _, config := range benchmark.Benchmarks.List() {
+				fmt.Fprintf(w, "%s\t%s\n", config.Name, config.Description)
+			}
+			w.Flush()
+		},
+	}
+}
+
+func NewBenchStatsCmd() *cobra.Command {
+	stats := &cobra.Command{
+		Use:          "stats -i [path/to/stats.json]",
+		Short:        "Pretty print the contents of a stats file",
+		SilenceUsage: true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			bytes, err := os.ReadFile(benchStatsInput)
+			if err != nil {
+				return err
+			}
+
+			var benchStats benchmark.StatsCollection
+			if err := json.Unmarshal(bytes, &benchStats); err != nil {
+				return err
+			}
+			benchStats.Print()
+
+			return nil
+		},
+	}
+
+	stats.Flags().StringVarP(&benchStatsInput, "input", "i", "", "Input path for statistics file")
+	stats.MarkFlagRequired("input")
+	return stats
+}
diff --git a/tools/cmd/root.go b/tools/cmd/root.go
index 77d161c..a536cd4 100644
--- a/tools/cmd/root.go
+++ b/tools/cmd/root.go
@@ -7,16 +7,20 @@ import (
 	"github.com/spf13/cobra"
 )
 
-var rootCmd = &cobra.Command{
-	Use:   "pixeltools",
-	Short: "Pixel tools provide benchmarking and validation tools for developing the pixel library",
-	Run: func(cmd *cobra.Command, args []string) {
-		cmd.Help()
-	},
+func NewRootCmd() *cobra.Command {
+	root := &cobra.Command{
+		Use:   "pixeltools",
+		Short: "Pixel tools provide benchmarking and validation tools for developing the pixel library",
+		Run: func(cmd *cobra.Command, args []string) {
+			cmd.Help()
+		},
+	}
+	root.AddCommand(NewBenchCmd())
+	return root
 }
 
 func Execute() {
-	if err := rootCmd.Execute(); err != nil {
+	if err := NewRootCmd().Execute(); err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}