feat(pwsh): cache prompt for repainting

src/cache/cache.go

@@ -33,6 +33,7 @@ var (
 	TEMPLATECACHE    = fmt.Sprintf("template_cache_%s", pid())
 	TOGGLECACHE      = fmt.Sprintf("toggle_cache_%s", pid())
 	PROMPTCOUNTCACHE = fmt.Sprintf("prompt_count_cache_%s", pid())
+	PROMPTCACHE      = fmt.Sprintf("prompt_cache_%s", pid())
 )
 
 type Entry struct {

src/cli/print.go

@@ -19,6 +19,7 @@ var (
 	terminalWidth int
 	eval          bool
 	cleared       bool
+	cached        bool
 
 	command      string
 	shellVersion string
@@ -64,6 +65,7 @@ var printCmd = &cobra.Command{
 			Plain:         plain,
 			Primary:       args[0] == "primary",
 			Cleared:       cleared,
+			Cached:        cached,
 			NoExitCode:    noStatus,
 			Column:        column,
 		}
@@ -108,6 +110,7 @@ func init() {
 	printCmd.Flags().StringVar(&command, "command", "", "tooltip command")
 	printCmd.Flags().BoolVarP(&plain, "plain", "p", false, "plain text output (no ANSI)")
 	printCmd.Flags().BoolVar(&cleared, "cleared", false, "do we have a clear terminal or not")
+	printCmd.Flags().BoolVar(&cached, "cached", false, "use a cached prompt")
 	printCmd.Flags().BoolVar(&eval, "eval", false, "output the prompt for eval")
 	printCmd.Flags().IntVar(&column, "column", 0, "the column position of the cursor")
 	// Deprecated flags

src/prompt/engine.go

@@ -1,8 +1,10 @@
 package prompt
 
 import (
+	"encoding/json"
 	"strings"
 
+	"github.com/jandedobbeleer/oh-my-posh/src/cache"
 	"github.com/jandedobbeleer/oh-my-posh/src/color"
 	"github.com/jandedobbeleer/oh-my-posh/src/config"
 	"github.com/jandedobbeleer/oh-my-posh/src/regex"
@@ -12,9 +14,14 @@ import (
 	"github.com/jandedobbeleer/oh-my-posh/src/terminal"
 )
 
-var (
+var cycle *color.Cycle = &color.Cycle{}
-	cycle *color.Cycle = &color.Cycle{}
+
-)
+type promptCache struct {
+	Prompt            string
+	CurrentLineLength int
+	RPrompt           string
+	RPromptLength     int
+}
 
 type Engine struct {
 	Config *config.Config
@@ -28,6 +35,8 @@ type Engine struct {
 
 	activeSegment         *config.Segment
 	previousActiveSegment *config.Segment
+
+	promptCache *promptCache
 }
 
 func (e *Engine) write(text string) {
@@ -500,3 +509,80 @@ func (e *Engine) adjustTrailingDiamondColorOverrides() {
 		adjustOverride(match[terminal.ANCHOR], color.Ansi(match[terminal.FG]))
 	}
 }
+
+func (e *Engine) checkPromptCache() bool {
+	data, ok := e.Env.Cache().Get(cache.PROMPTCACHE)
+	if !ok {
+		return false
+	}
+
+	e.promptCache = &promptCache{}
+	err := json.Unmarshal([]byte(data), e.promptCache)
+	if err != nil {
+		return false
+	}
+
+	e.write(e.promptCache.Prompt)
+	e.currentLineLength = e.promptCache.CurrentLineLength
+	e.rprompt = e.promptCache.RPrompt
+	e.rpromptLength = e.promptCache.RPromptLength
+
+	return true
+}
+
+func (e *Engine) updatePromptCache(value *promptCache) {
+	cacheJSON, err := json.Marshal(value)
+	if err != nil {
+		return
+	}
+	e.Env.Cache().Set(cache.PROMPTCACHE, string(cacheJSON), 1440)
+}
+
+// New returns a prompt engine initialized with the
+// given configuration options, and is ready to print any
+// of the prompt components.
+func New(flags *runtime.Flags) *Engine {
+	env := &runtime.Terminal{
+		CmdFlags: flags,
+	}
+
+	env.Init()
+	cfg := config.Load(env)
+
+	if cfg.PatchPwshBleed {
+		patchPowerShellBleed(env.Shell(), flags)
+	}
+
+	env.Var = cfg.Var
+	flags.HasTransient = cfg.TransientPrompt != nil
+
+	terminal.Init(env.Shell())
+	terminal.BackgroundColor = shell.ConsoleBackgroundColor(env, cfg.TerminalBackground)
+	terminal.Colors = cfg.MakeColors()
+	terminal.Plain = flags.Plain
+
+	eng := &Engine{
+		Config: cfg,
+		Env:    env,
+		Plain:  flags.Plain,
+	}
+
+	return eng
+}
+
+func patchPowerShellBleed(sh string, flags *runtime.Flags) {
+	// when in PowerShell, and force patching the bleed bug
+	// we need to reduce the terminal width by 1 so the last
+	// character isn't cut off by the ANSI escape sequences
+	// See https://github.com/JanDeDobbeleer/oh-my-posh/issues/65
+	if sh != shell.PWSH && sh != shell.PWSH5 {
+		return
+	}
+
+	// only do this when relevant
+	if flags.TerminalWidth <= 0 {
+		return
+	}
+
+	flags.TerminalWidth--
+}

src/prompt/extra.go

@@ -11,6 +11,16 @@ import (
 	"github.com/jandedobbeleer/oh-my-posh/src/terminal"
 )
 
+type ExtraPromptType int
+
+const (
+	Transient ExtraPromptType = iota
+	Valid
+	Error
+	Secondary
+	Debug
+)
+
 func (e *Engine) ExtraPrompt(promptType ExtraPromptType) string {
 	// populate env with latest context
 	e.Env.LoadTemplateCache()

src/prompt/new.go

@@ -1,57 +0,0 @@
-package prompt
-
-import (
-	"github.com/jandedobbeleer/oh-my-posh/src/config"
-	"github.com/jandedobbeleer/oh-my-posh/src/runtime"
-	"github.com/jandedobbeleer/oh-my-posh/src/shell"
-	"github.com/jandedobbeleer/oh-my-posh/src/terminal"
-)
-
-// New returns a prompt engine initialized with the
-// given configuration options, and is ready to print any
-// of the prompt components.
-func New(flags *runtime.Flags) *Engine {
-	env := &runtime.Terminal{
-		CmdFlags: flags,
-	}
-
-	env.Init()
-	cfg := config.Load(env)
-
-	if cfg.PatchPwshBleed {
-		patchPowerShellBleed(env.Shell(), flags)
-	}
-
-	env.Var = cfg.Var
-	flags.HasTransient = cfg.TransientPrompt != nil
-
-	terminal.Init(env.Shell())
-	terminal.BackgroundColor = shell.ConsoleBackgroundColor(env, cfg.TerminalBackground)
-	terminal.Colors = cfg.MakeColors()
-	terminal.Plain = flags.Plain
-
-	eng := &Engine{
-		Config: cfg,
-		Env:    env,
-		Plain:  flags.Plain,
-	}
-
-	return eng
-}
-
-func patchPowerShellBleed(sh string, flags *runtime.Flags) {
-	// when in PowerShell, and force patching the bleed bug
-	// we need to reduce the terminal width by 1 so the last
-	// character isn't cut off by the ANSI escape sequences
-	// See https://github.com/JanDeDobbeleer/oh-my-posh/issues/65
-	if sh != shell.PWSH && sh != shell.PWSH5 {
-		return
-	}
-
-	// only do this when relevant
-	if flags.TerminalWidth <= 0 {
-		return
-	}
-
-	flags.TerminalWidth--
-}

src/prompt/primary.go

@@ -9,70 +9,76 @@ import (
 	"github.com/jandedobbeleer/oh-my-posh/src/terminal"
 )
 
-type ExtraPromptType int
-
-const (
-	Transient ExtraPromptType = iota
-	Valid
-	Error
-	Secondary
-	Debug
-)
-
 func (e *Engine) Primary() string {
-	if e.Config.ShellIntegration {
-		exitCode, _ := e.Env.StatusCodes()
-		e.write(terminal.CommandFinished(exitCode, e.Env.Flags().NoExitCode))
-		e.write(terminal.PromptStart())
-	}
-
-	// cache a pointer to the color cycle
-	cycle = &e.Config.Cycle
-	var cancelNewline, didRender bool
-
 	needsPrimaryRPrompt := e.needsPrimaryRPrompt()
 
-	for i, block := range e.Config.Blocks {
+	var (
-		// do not print a leading newline when we're at the first row and the prompt is cleared
+		useCache    bool
-		if i == 0 {
+		updateCache bool
-			row, _ := e.Env.CursorPosition()
+	)
-			cancelNewline = e.Env.Flags().Cleared || e.Env.Flags().PromptCount == 1 || row == 1
-		}
 
-		// skip setting a newline when we didn't print anything yet
+	if e.Env.Shell() == shell.PWSH || e.Env.Shell() == shell.PWSH5 {
-		if i != 0 {
+		// For PowerShell, use a cached prompt if available, otherwise render a new prompt.
-			cancelNewline = !didRender
+		if e.Env.Flags().Cached && e.checkPromptCache() {
-		}
+			useCache = true
-
+		} else {
-		if block.Type == config.RPrompt && !needsPrimaryRPrompt {
+			updateCache = true
-			continue
-		}
-
-		if e.renderBlock(block, cancelNewline) {
-			didRender = true
 		}
 	}
 
-	if len(e.Config.ConsoleTitleTemplate) > 0 && !e.Env.Flags().Plain {
+	if !useCache {
-		title := e.getTitleTemplateText()
+		if e.Config.ShellIntegration {
-		e.write(terminal.FormatTitle(title))
+			exitCode, _ := e.Env.StatusCodes()
-	}
+			e.write(terminal.CommandFinished(exitCode, e.Env.Flags().NoExitCode))
+			e.write(terminal.PromptStart())
+		}
 
-	if e.Config.FinalSpace {
+		// cache a pointer to the color cycle
-		e.write(" ")
+		cycle = &e.Config.Cycle
-		e.currentLineLength++
+		var cancelNewline, didRender bool
-	}
 
-	if e.Config.ITermFeatures != nil && e.isIterm() {
+		for i, block := range e.Config.Blocks {
-		host, _ := e.Env.Host()
+			// do not print a leading newline when we're at the first row and the prompt is cleared
-		e.write(terminal.RenderItermFeatures(e.Config.ITermFeatures, e.Env.Shell(), e.Env.Pwd(), e.Env.User(), host))
+			if i == 0 {
-	}
+				row, _ := e.Env.CursorPosition()
+				cancelNewline = e.Env.Flags().Cleared || e.Env.Flags().PromptCount == 1 || row == 1
+			}
 
-	if e.Config.ShellIntegration && e.Config.TransientPrompt == nil {
+			// skip setting a newline when we didn't print anything yet
-		e.write(terminal.CommandStart())
+			if i != 0 {
-	}
+				cancelNewline = !didRender
+			}
 
-	e.pwd()
+			if block.Type == config.RPrompt && !needsPrimaryRPrompt {
+				continue
+			}
+
+			if e.renderBlock(block, cancelNewline) {
+				didRender = true
+			}
+		}
+
+		if len(e.Config.ConsoleTitleTemplate) > 0 && !e.Env.Flags().Plain {
+			title := e.getTitleTemplateText()
+			e.write(terminal.FormatTitle(title))
+		}
+
+		if e.Config.FinalSpace {
+			e.write(" ")
+			e.currentLineLength++
+		}
+
+		if e.Config.ITermFeatures != nil && e.isIterm() {
+			host, _ := e.Env.Host()
+			e.write(terminal.RenderItermFeatures(e.Config.ITermFeatures, e.Env.Shell(), e.Env.Pwd(), e.Env.User(), host))
+		}
+
+		if e.Config.ShellIntegration && e.Config.TransientPrompt == nil {
+			e.write(terminal.CommandStart())
+		}
+
+		e.pwd()
+	}
 
 	switch e.Env.Shell() {
 	case shell.ZSH:
@@ -94,6 +100,16 @@ func (e *Engine) Primary() string {
 
 		return prompt
 	default:
+		if updateCache {
+			// Cache the new prompt.
+			e.updatePromptCache(&promptCache{
+				Prompt:            e.prompt.String(),
+				CurrentLineLength: e.currentLineLength,
+				RPrompt:           e.rprompt,
+				RPromptLength:     e.rpromptLength,
+			})
+		}
+
 		if !needsPrimaryRPrompt {
 			break
 		}

src/prompt/tooltip.go

@@ -1,7 +1,6 @@
 package prompt
 
 import (
-	"slices"
 	"strings"
 
 	"github.com/jandedobbeleer/oh-my-posh/src/config"
@@ -10,18 +9,6 @@ import (
 )
 
 func (e *Engine) Tooltip(tip string) string {
-	supportedShells := []string{
-		shell.ZSH,
-		shell.CMD,
-		shell.FISH,
-		shell.PWSH,
-		shell.PWSH5,
-		shell.GENERIC,
-	}
-	if !slices.Contains(supportedShells, e.Env.Shell()) {
-		return ""
-	}
-
 	tip = strings.Trim(tip, " ")
 	tooltips := make([]*config.Segment, 0, 1)
 
@@ -56,6 +43,15 @@ func (e *Engine) Tooltip(tip string) string {
 
 	switch e.Env.Shell() {
 	case shell.PWSH, shell.PWSH5:
+		defer func() {
+			// If a prompt cache is available, we update the right prompt to the new tooltip for reuse.
+			if e.checkPromptCache() {
+				e.promptCache.RPrompt = text
+				e.promptCache.RPromptLength = length
+				e.updatePromptCache(e.promptCache)
+			}
+		}()
+
 		e.rprompt = text
 		e.currentLineLength = e.Env.Flags().Column
 		space, ok := e.canWriteRightBlock(length, true)

src/runtime/os.go

@@ -60,6 +60,7 @@ type Flags struct {
 	HasTransient  bool
 	PromptCount   int
 	Cleared       bool
+	Cached        bool
 	NoExitCode    bool
 	Column        int
 }
@@ -233,7 +234,9 @@ func (term *Terminal) Init() {
 
 	term.tmplCache = &cache.Template{}
 
-	term.SetPromptCount()
+	if !term.CmdFlags.Cached {
+		term.SetPromptCount()
+	}
 }
 
 func (term *Terminal) resolveConfigPath() {
@@ -1003,7 +1006,7 @@ func returnOrBuildCachePath(path string) string {
 	if _, err := os.Stat(cachePath); err == nil {
 		return cachePath
 	}
-	if err := os.Mkdir(cachePath, 0755); err != nil {
+	if err := os.Mkdir(cachePath, 0o755); err != nil {
 		return ""
 	}
 	return cachePath

src/shell/scripts/omp.ps1

@@ -17,6 +17,9 @@ New-Module -Name "oh-my-posh-core" -ScriptBlock {
     # Check `ConstrainedLanguage` mode.
     $script:ConstrainedLanguageMode = $ExecutionContext.SessionState.LanguageMode -eq "ConstrainedLanguage"
 
+    # This indicates whether a new prompt should be rendered instead of using the cached one.
+    $script:NewPrompt = $true
+
     # Prompt related backup.
     $script:OriginalPromptFunction = $Function:prompt
     $script:OriginalContinuationPrompt = (Get-PSReadLineOption).ContinuationPrompt
@@ -159,7 +162,22 @@ New-Module -Name "oh-my-posh-core" -ScriptBlock {
                     $terminalWidth = Get-TerminalWidth
                     $cleanPSWD = Get-CleanPSWD
                     $stackCount = global:Get-PoshStackCount
-                    $standardOut = (Start-Utf8Process $script:OMPExecutable @("print", "tooltip", "--status=$script:ErrorCode", "--shell=$script:ShellName", "--pswd=$cleanPSWD", "--execution-time=$script:ExecutionTime", "--stack-count=$stackCount", "--config=$env:POSH_THEME", "--command=$command", "--shell-version=$script:PSVersion", "--column=$column", "--terminal-width=$terminalWidth", "--no-status=$script:NoExitCode")) -join ''
+                    $arguments = @(
+                        "print"
+                        "tooltip"
+                        "--status=$script:ErrorCode"
+                        "--shell=$script:ShellName"
+                        "--pswd=$cleanPSWD"
+                        "--execution-time=$script:ExecutionTime"
+                        "--stack-count=$stackCount"
+                        "--config=$env:POSH_THEME"
+                        "--command=$command"
+                        "--shell-version=$script:PSVersion"
+                        "--column=$column"
+                        "--terminal-width=$terminalWidth"
+                        "--no-status=$script:NoExitCode"
+                    )
+                    $standardOut = (Start-Utf8Process $script:OMPExecutable $arguments) -join ''
                     if (!$standardOut) {
                         return
                     }
@@ -191,6 +209,7 @@ New-Module -Name "oh-my-posh-core" -ScriptBlock {
                 [Microsoft.PowerShell.PSConsoleReadLine]::GetBufferState([ref]$null, [ref]$null, [ref]$parseErrors, [ref]$null)
                 $executingCommand = $parseErrors.Count -eq 0
                 if ($executingCommand) {
+                    $script:NewPrompt = $true
                     $script:TooltipCommand = ''
                     if ('::TRANSIENT::' -eq 'true') {
                         Set-TransientPrompt
@@ -211,6 +230,7 @@ New-Module -Name "oh-my-posh-core" -ScriptBlock {
                 [Microsoft.PowerShell.PSConsoleReadLine]::GetSelectionState([ref]$start, [ref]$null)
                 # only render a transient prompt when no text is selected
                 if ($start -eq -1) {
+                    $script:NewPrompt = $true
                     $script:TooltipCommand = ''
                     if ('::TRANSIENT::' -eq 'true') {
                         Set-TransientPrompt
@@ -397,7 +417,7 @@ Example:
         }
     }
 
-    function prompt {
+    $promptFunction = {
         # store the orignal last command execution status
         if ($global:NVS_ORIGINAL_LASTEXECUTIONSTATUS -is [bool]) {
             # make it compatible with NVS auto-switching, if enabled
@@ -410,7 +430,14 @@ Example:
         $script:OriginalLastExitCode = $global:LASTEXITCODE
 
         Set-PoshPromptType
+
+        # Whether we should use a cached prompt.
+        $useCache = !$script:NewPrompt
+
         if ($script:PromptType -ne 'transient') {
+            if ($script:NewPrompt) {
+                $script:NewPrompt = $false
+            }
             Update-PoshErrorCode
         }
         $cleanPSWD = Get-CleanPSWD
@@ -422,7 +449,21 @@ Example:
         $env:POSH_CURSOR_LINE = $Host.UI.RawUI.CursorPosition.Y + 1
         $env:POSH_CURSOR_COLUMN = $Host.UI.RawUI.CursorPosition.X + 1
 
-        $standardOut = Start-Utf8Process $script:OMPExecutable @("print", $script:PromptType, "--status=$script:ErrorCode", "--pswd=$cleanPSWD", "--execution-time=$script:ExecutionTime", "--stack-count=$stackCount", "--config=$env:POSH_THEME", "--shell-version=$script:PSVersion", "--terminal-width=$terminalWidth", "--shell=$script:ShellName", "--no-status=$script:NoExitCode")
+        $arguments = @(
+            "print"
+            $script:PromptType
+            "--status=$script:ErrorCode"
+            "--pswd=$cleanPSWD"
+            "--execution-time=$script:ExecutionTime"
+            "--stack-count=$stackCount"
+            "--config=$env:POSH_THEME"
+            "--shell-version=$script:PSVersion"
+            "--terminal-width=$terminalWidth"
+            "--shell=$script:ShellName"
+            "--no-status=$script:NoExitCode"
+            "--cached=$useCache"
+        )
+        $standardOut = Start-Utf8Process $script:OMPExecutable $arguments
         # make sure PSReadLine knows if we have a multiline prompt
         Set-PSReadLineOption -ExtraPromptLineCount (($standardOut | Measure-Object -Line).Lines - 1)
 
@@ -436,6 +477,8 @@ Example:
         $global:LASTEXITCODE = $script:OriginalLastExitCode
     }
 
+    $Function:prompt = $promptFunction
+
     # set secondary prompt
     Set-PSReadLineOption -ContinuationPrompt ((Start-Utf8Process $script:OMPExecutable @("print", "secondary", "--config=$env:POSH_THEME", "--shell=$script:ShellName")) -join "`n")