这是一篇关于 powershell prompt的笔记！

首先，我需要新建一个powershell文件，就命名为git_status.ps1 把

touch git_status.ps1

新建工作目录

$mypath = "$HOME/Desktop"

我之前的 powershell prompt 是这样的

Johnny ω SierewMonitor (master ●●●| ●●●) λ pwdPath----D:\WorkSpace_C++\SierewMonitorJohnny ω SierewMonitor (master ●●●| ●●●) λ

我遇到的问题是 (master ●●●| ●●●) 输出总是很慢，后来定位到 posh-git 的 Get-GitStatus 命令。

Get-GitStatus 命令是一个函数，其代码位于

C:\Users\
    
     \Documents\WindowsPowerShell\Modules\posh-git\GitUtils.ps1
    

具体如下:

function Get-GitStatus($gitDir = (Get-GitDirectory)) {    $settings = $Global:GitPromptSettings    $enabled = (-not $settings) -or $settings.EnablePromptStatus    if ($enabled -and $gitDir)    {        if($settings.Debug) {            $sw = [Diagnostics.Stopwatch]::StartNew(); Write-Host ''        } else {            $sw = $null        }        $branch = $null        $aheadBy = 0        $behindBy = 0        $indexAdded = @()        $indexModified = @()        $indexDeleted = @()        $indexUnmerged = @()        $filesAdded = @()        $filesModified = @()        $filesDeleted = @()        $filesUnmerged = @()        $stashCount = 0        if($settings.EnableFileStatus -and !$(InDisabledRepository)) {            dbg 'Getting status' $sw            $status = git -c color.status=false status --short --branch 2>$null            $stashCount = $null | git stash list 2>$null | measure-object | select -expand Count        } else {            $status = @()        }        dbg 'Parsing status' $sw        $status | foreach {            dbg "Status: $_" $sw            if($_) {                switch -regex ($_) {                    '^(?
    
     [^#])(?
     
      .) (?
      
       .*?)(?: -> (?
       
        .*))?$' {                        switch ($matches['index']) {                            'A' { $indexAdded += $matches['path1'] }                            'M' { $indexModified += $matches['path1'] }                            'R' { $indexModified += $matches['path1'] }                            'C' { $indexModified += $matches['path1'] }                            'D' { $indexDeleted += $matches['path1'] }                            'U' { $indexUnmerged += $matches['path1'] }                        }                        switch ($matches['working']) {                            '?' { $filesAdded += $matches['path1'] }                            'A' { $filesAdded += $matches['path1'] }                            'M' { $filesModified += $matches['path1'] }                            'D' { $filesDeleted += $matches['path1'] }                            'U' { $filesUnmerged += $matches['path1'] }                        }                    }                    '^## (?
        
         \S+?)(?:\.\.\.(?
         
          \S+))?(?: \[(?:ahead (?
          
           \d+))?(?:, )?(?:behind (?
           
            \d+))?\])?$' { $branch = $matches['branch'] $upstream = $matches['upstream'] $aheadBy = [int]$matches['ahead'] $behindBy = [int]$matches['behind'] } '^## Initial commit on (?
            
             \S+)$' { $branch = $matches['branch'] } } } } if(!$branch) { $branch = Get-GitBranch $gitDir $sw } dbg 'Building status object' $sw $indexPaths = $indexAdded + $indexModified + $indexDeleted + $indexUnmerged $workingPaths = $filesAdded + $filesModified + $filesDeleted + $filesUnmerged $index = New-Object PSObject @(,@($indexPaths | ?{ $_ } | Select -Unique)) | Add-Member -PassThru NoteProperty Added $indexAdded | Add-Member -PassThru NoteProperty Modified $indexModified | Add-Member -PassThru NoteProperty Deleted $indexDeleted | Add-Member -PassThru NoteProperty Unmerged $indexUnmerged $working = New-Object PSObject @(,@($workingPaths | ?{ $_ } | Select -Unique)) | Add-Member -PassThru NoteProperty Added $filesAdded | Add-Member -PassThru NoteProperty Modified $filesModified | Add-Member -PassThru NoteProperty Deleted $filesDeleted | Add-Member -PassThru NoteProperty Unmerged $filesUnmerged $result = New-Object PSObject -Property @{ GitDir = $gitDir Branch = $branch AheadBy = $aheadBy BehindBy = $behindBy Upstream = $upstream HasIndex = [bool]$index Index = $index HasWorking = [bool]$working Working = $working HasUntracked = [bool]$filesAdded StashCount = $stashCount } dbg 'Finished' $sw if($sw) { $sw.Stop() } return $result }}
            
           
          
         
        
       
      
     
    

因此， (master ●●●| ●●●) 输出总是很慢的问题，等价就是 Get-GitStatus 运行很慢的问题。

拷贝 Get-GitStatus 到 git_status.ps1, 并重命名为 MyGet-GitStatus;

function writegitprompt($status){        if ($status) {         write-host ' (' -nonewline          write-host ($status.Branch) -nonewline         write-host ' ' -nonewline          if($status.HasWorking) {             write-host "$([char]0x25CF)" -nonewline -ForegroundColor @{$true='Green';$false='DarkGray'}[$status.Working.Added -and $status.Working.Added.Count -ge 0]             write-host "$([char]0x25CF)" -nonewline -ForegroundColor @{$true=(@{$true='Red';$false='Yellow'}[$status.Working.Unmerged -and $status.Working.Unmerged.Count -ge 0]);$false=(@{$true='Red';$false='DarkGray'}[$status.Working.Unmerged -and $status.Working.Unmerged.Count -ge 0])}[$status.Working.Modified -and $status.Working.Modified.Count -ge 0]             write-host "$([char]0x25CF)" -nonewline -ForegroundColor @{$true='Red';$false='DarkGray'}[$status.Working.Deleted -and $status.Working.Deleted.Count -ge 0]         } else {             write-host "$([char]0x25CF)$([char]0x25CF)$([char]0x25CF)" -nonewline -ForegroundColor DarkGray         }         if($status.HasIndex) {             write-host "| " -nonewline             write-host "$([char]0x25CF)" -nonewline -ForegroundColor @{$true='Green';$false='DarkGray'}[$status.Index.Added -and $status.Index.Added.Count -ge 0]             write-host "$([char]0x25CF)" -nonewline -ForegroundColor @{$true=(@{$true='Red';$false='Yellow'}[$status.Index.Unmerged -and $status.Index.Unmerged.Count -ge 0]);$false=(@{$true='Red';$false='DarkGray'}[$status.Working.Unmerged -and $status.Working.Unmerged.Count -ge 0])}[$status.Index.Modified -and $status.Index.Modified.Count -ge 0]             write-host "$([char]0x25CF)" -nonewline -ForegroundColor @{$true='Red';$false='DarkGray'}[$status.Index.Deleted -and $status.Index.Deleted.Count -ge 0]         }         write-host ')' -nonewline     }}

添加检查当前时间的函数，用于调试

function getTickCount {    $millisecondsUptime = [Environment]::TickCount    "# Now $millisecondsUptime ms "}

添加功能测试代码段

echo ""echo "========="echo "workdir is $args"echo ""$status = MyGet-GitStatus $argsecho "========="echo "MyGet-GitStatus: "echo $statusecho "========="echo "prompt: "echo ""writegitprompt ($status)echo " "

逐步检查 MyGet-GitStatus 代码

发现语句

$stashCount = $null | git stash list 2>$null | measure-object | select -expand Count

运行时间较长，我的机器上大约 200ms

其后检查 writegitprompt 函数，发现其仅处理 MyGet-GitStatus 返回结果的一部分，即

# $status.Branch # $status.HasWorking # status.HasIndex # $status.Index

于是修改 MyGet-GitStatus, 返回对象仅给出

$result = New-Object PSObject -Property @{            #GitDir          = $gitDir            Branch          = $branch            #AheadBy         = $aheadBy            #BehindBy        = $behindBy            #Upstream        = $upstream            HasIndex        = [bool]$index            Index           = $index            HasWorking      = [bool]$working            Working         = $working            #HasUntracked    = [bool]$filesAdded            #StashCount      = $stashCount        }

上图

参考链接：