launch: determine mc max ram usage and allow overwrite

cmd/join.go

@@ -23,21 +23,26 @@ import (
 )
 
 func init() {
+	runner := &joinRunner{}
 	cmd := commands.New(&cobra.Command{
 		Use:     "join <ip/hostname>",
 		Short:   "Joins a compatible server without any setup",
 		Long:    `Servers have to be started with \"minepkg launch --server\" or include the minepkg-companion mod`,
 		Example: `  minepkg join demo.minepkg.host`,
 		Aliases: []string{"i-wanna-play-on", "connect"},
 		Args:    cobra.ExactArgs(1),
-	}, &joinRunner{})
+	}, runner)
+
+	cmd.Flags().IntVar(&runner.ramMiB, "ram", 0, "Overwrite the amount of RAM in MiB to use")
 
 	rootCmd.AddCommand(cmd.Command)
 }
 
-type joinRunner struct{}
+type joinRunner struct {
+	ramMiB int
+}
 
-func (i *joinRunner) RunE(cmd *cobra.Command, args []string) error {
+func (j *joinRunner) RunE(cmd *cobra.Command, args []string) error {
 
 	var resolvedModpack *api.Release
 	ip := "127.0.0.1"
@@ -108,6 +113,7 @@ func (i *joinRunner) RunE(cmd *cobra.Command, args []string) error {
 
 	opts := &instances.LaunchOptions{
 		JoinServer: ip + ":" + port,
+		RamMiB:     j.ramMiB,
 	}
 	err = cliLauncher.Launch(opts)
 	if err != nil {

cmd/launch.go

@@ -151,6 +151,7 @@ func (l *launchRunner) RunE(cmd *cobra.Command, args []string) error {
 		Server:         l.serverMode,
 		Debug:          l.debugMode,
 		Demo:           l.demo,
+		RamMiB:         l.overwrites.Ram,
 	}
 
 	launchErr := make(chan error)

cmd/launch/cli-flags.go

@@ -13,13 +13,15 @@ type OverwriteFlags struct {
 	FabricVersion    string
 	ForgeVersion     string
 	MinepkgCompanion string
+	Ram              int
 }
 
 func CmdOverwriteFlags(cmd *cobra.Command) *OverwriteFlags {
 	flags := OverwriteFlags{}
 	cmd.Flags().StringVarP(&flags.McVersion, "minecraft", "m", "", "Overwrite the required Minecraft version")
 	cmd.Flags().StringVar(&flags.FabricVersion, "fabricLoader", "", "Overwrite the required fabricLoader version")
 	cmd.Flags().StringVar(&flags.MinepkgCompanion, "minepkgCompanion", "", "Overwrite the required minepkg companion version (can also be \"none\")")
+	cmd.Flags().IntVar(&flags.Ram, "ram", 0, "Overwrite the amount of RAM in MiB to use")
 
 	return &flags
 }

cmd/root.go

@@ -27,9 +27,8 @@ var Version string
 var nextVersion string = "0.1.0-dev-local"
 
 var (
-	cfgFile       string
-	globalDir     = "/tmp"
-	disableColors bool
+	cfgFile   string
+	globalDir = "/tmp"
 )
 
 // rootCmd represents the base command when called without any subcommands
@@ -97,14 +96,12 @@ func initRoot() {
 	configPath := filepath.Join(configDir, "minepkg")
 
 	// Global flags
-	rootCmd.PersistentFlags().BoolVarP(&disableColors, "no-color", "", false, "disable color output")
 	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", fmt.Sprintf("config file (default is %s/config.toml)", configPath))
 	rootCmd.PersistentFlags().BoolP("accept-minecraft-eula", "a", false, "Accept Minecraft's eula. See https://www.minecraft.net/en-us/eula/")
 	rootCmd.PersistentFlags().BoolP("system-java", "", false, "Use system java instead of internal installation for launching Minecraft server or client")
 	rootCmd.PersistentFlags().BoolP("verbose", "", false, "More verbose logging. Not really implemented yet")
-	rootCmd.PersistentFlags().BoolP("non-interactive", "", false, "Use default answer for all prompts")
+	rootCmd.PersistentFlags().BoolP("non-interactive", "", false, "Do not prompt for anything (use defaults instead)")
 
-	viper.BindPFlag("noColor", rootCmd.PersistentFlags().Lookup("no-color"))
 	viper.BindPFlag("useSystemJava", rootCmd.PersistentFlags().Lookup("system-java"))
 	viper.BindPFlag("acceptMinecraftEula", rootCmd.PersistentFlags().Lookup("accept-minecraft-eula"))
 	viper.BindPFlag("verboseLogging", rootCmd.PersistentFlags().Lookup("verbose"))

cmd/try.go

@@ -163,6 +163,7 @@ func (t *tryRunner) RunE(cmd *cobra.Command, args []string) error {
 		Server:         t.serverMode,
 		Offline:        t.offlineMode,
 		StartSave:      startSave,
+		RamMiB:         t.overwrites.Ram,
 	}
 	err = cliLauncher.Launch(opts)
 	if err != nil {

go.mod

@@ -21,6 +21,7 @@ require (
 	github.com/mholt/archiver/v3 v3.5.0
 	github.com/mitchellh/mapstructure v1.4.1 // indirect
 	github.com/muesli/termenv v0.8.1 // indirect
+	github.com/pbnjay/memory v0.0.0-20201129165224-b12e5d931931 // indirect
 	github.com/pelletier/go-toml v1.9.1
 	github.com/spf13/cast v1.3.1 // indirect
 	github.com/spf13/cobra v1.1.3

go.sum

@@ -276,6 +276,8 @@ github.com/nwaples/rardecode v1.1.0 h1:vSxaY8vQhOcVr4mm5e8XllHWTiM4JF507A0Katqw7
 github.com/nwaples/rardecode v1.1.0/go.mod h1:5DzqNKiOdpKKBH87u8VlvAnPZMXcGRhxWkRpHbbfGS0=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
 github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
+github.com/pbnjay/memory v0.0.0-20201129165224-b12e5d931931 h1:EeWknjeRU+R3O4ghG7XZCpgSfJNStZyEP8aWyQwJM8s=
+github.com/pbnjay/memory v0.0.0-20201129165224-b12e5d931931/go.mod h1:RMU2gJXhratVxBDTFeOdNhd540tG57lt9FIUV0YLvIQ=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
 github.com/pelletier/go-toml v1.9.1 h1:a6qW1EVNZWH9WGI6CsYdD8WAylkoXBS5yv0XHlh17Tc=
 github.com/pelletier/go-toml v1.9.1/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=

internals/instances/launch.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"math"
 	"net/http"
 	"net/url"
 	"os"
@@ -21,6 +22,7 @@ import (
 	"github.com/minepkg/minepkg/internals/minecraft"
 	"github.com/minepkg/minepkg/internals/mojang"
 	"github.com/minepkg/minepkg/pkg/manifest"
+	"github.com/pbnjay/memory"
 )
 
 var (
@@ -67,6 +69,9 @@ type LaunchOptions struct {
 	// StartSave can be a savegame name to start after startup
 	StartSave string
 	Debug     bool
+	// RamMiB can be set to the amount of ram in MiB to start Minecraft with
+	// 0 determins the amount by modcount + available system ram
+	RamMiB int
 }
 
 // Launch will launch the minecraft instance
@@ -250,6 +255,22 @@ func (i *Instance) BuildLaunchCmd(opts *LaunchOptions) (*exec.Cmd, error) {
 		javaCpSeperator = ";"
 	}
 
+	var maxRamMiB int
+
+	if opts.RamMiB == 0 {
+		sysMemMiB := float64(memory.TotalMemory()) / 1024 / 1024
+
+		// 1GiB for base Minecraft + every dependency takes 25 MiB
+		maxRamMiB = 1024 + len(i.Lockfile.Dependencies)*25
+
+		// we take 1/4 of the system memory if that is more
+		maxRamMiB = int(math.Max(float64(maxRamMiB), sysMemMiB/4))
+		// but not more than 85% of the memory
+		maxRamMiB = int(math.Min(float64(maxRamMiB), sysMemMiB*0.85))
+	} else {
+		maxRamMiB = opts.RamMiB
+	}
+
 	cmdArgs := []string{
 		"-Xss128M",
 		"-Djava.library.path=" + tmpDir,
@@ -258,7 +279,7 @@ func (i *Instance) BuildLaunchCmd(opts *LaunchOptions) (*exec.Cmd, error) {
 		"-Dminecraft.client.jar=" + mcJar,
 		"-cp",
 		strings.Join(cpArgs, javaCpSeperator),
-		// "-Xmx2G", // TODO: option!
+		fmt.Sprintf("-Xmx%dM", maxRamMiB),
 		"-XX:+UnlockExperimentalVMOptions",
 		"-XX:+UseG1GC",
 		"-XX:G1NewSizePercent=20",
@@ -269,6 +290,10 @@ func (i *Instance) BuildLaunchCmd(opts *LaunchOptions) (*exec.Cmd, error) {
 		launchManifest.MainClass,
 	}
 
+	if opts.RamMiB != 0 {
+		cmdArgs = append([]string{fmt.Sprintf("-Xms%dM", opts.RamMiB)}, cmdArgs...)
+	}
+
 	// HACK: prepend this so macos does not crash
 	if runtime.GOOS == "darwin" {
 		cmdArgs = append([]string{"-XstartOnFirstThread"}, cmdArgs...)