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Revert the PR "Make ForEach-Object faster for its commonly used scenarios" (#10485)

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It turns out this optimization brings in a breaking change: `$MyInvocation` is different comparing to before the optimization change. I tried to fix the breaking change, but couldn't without introducing more hacky code. Given that, that PR should be reverted.
This commit is contained in:
Dongbo Wang
2019-09-04 22:12:30 -07:00
committed by GitHub
parent 5069c7d6a6
commit f6c220cdd9
2 changed files with 11 additions and 110 deletions
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src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs
+5 -110
View File
@@ -68,7 +68,7 @@ namespace System.Management.Automation
object command;
IScriptExtent commandExtent;
var cpiCommand = commandElements[commandIndex++];
var cpiCommand = commandElements[commandIndex];
if (cpiCommand.ParameterNameSpecified)
{
command = cpiCommand.ParameterText;
@@ -156,16 +156,12 @@ namespace System.Management.Automation
}
}
// If possible, rewrite the 'ForEach-Object' command into a filter-like script block in the pipeline.
// e.g. 1..2 | ForEach-Object { $_ + 1 } => 1..2 | . { process { $_ + 1 } }
if (!TryRewriteForEachObjectCommand(context, commandSessionState, commandElements, ref commandProcessor, ref commandIndex))
{
InternalCommand cmd = commandProcessor.Command;
commandProcessor.UseLocalScope = !dotSource && (cmd is ScriptCommand || cmd is PSScriptCmdlet);
}
InternalCommand cmd = commandProcessor.Command;
commandProcessor.UseLocalScope = !dotSource &&
(cmd is ScriptCommand || cmd is PSScriptCmdlet);
bool isNativeCommand = commandProcessor is NativeCommandProcessor;
for (int i = commandIndex; i < commandElements.Length; ++i)
for (int i = commandIndex + 1; i < commandElements.Length; ++i)
{
var cpi = commandElements[i];
@@ -315,107 +311,6 @@ namespace System.Management.Automation
return commandProcessor;
}
private static ConditionalWeakTable<ScriptBlockAst, ScriptBlock> s_astRewriteCache = new ConditionalWeakTable<ScriptBlockAst, ScriptBlock>();
private static ConditionalWeakTable<ScriptBlockAst, ScriptBlock>.CreateValueCallback s_astRewriteCallback =
sbAst =>
{
ScriptBlockAst newScriptBlockAst = new ScriptBlockAst(
sbAst.Extent,
paramBlock: null,
beginBlock: null,
processBlock: (NamedBlockAst)sbAst.EndBlock.Copy(),
endBlock: null,
dynamicParamBlock: null);
newScriptBlockAst.PostParseChecksPerformed = sbAst.PostParseChecksPerformed;
sbAst.Parent?.SetParent(newScriptBlockAst);
return new ScriptBlock(newScriptBlockAst, isFilter: false);
};
private static bool TryRewriteForEachObjectCommand(
ExecutionContext context,
SessionStateInternal commandSessionState,
CommandParameterInternal[] commandElements,
ref CommandProcessorBase commandProcessor,
ref int commandIndex)
{
const string ForEachObject_ProcessParam = "Process";
// Skip optimization in the following cases
// 1. the debugger is enabled -- so a breakpoint set on the command 'ForEach-Object' works properly.
// 2. the 'ConstrainedLanguageMode' has been used for the current runspace -- the language mode transition is tricky,
// and it's better to use the same old code path for safety.
if (context._debuggingMode > 0 || context.HasRunspaceEverUsedConstrainedLanguageMode)
{
return false;
}
var cmdlet = commandProcessor.CommandInfo as CmdletInfo;
if (cmdlet == null || cmdlet.ImplementingType != typeof(ForEachObjectCommand))
{
return false;
}
int indexAdvanceOffset = 0;
int cmdElementsLength = commandElements.Length;
ScriptBlock processScriptBlock = null;
if (commandIndex == cmdElementsLength - 1)
{
// Target ForEach-Object syntax:
// * `... | ForEach-Object { ... } | ...`
// * `... | ForEach-Object -process:{ ... } | ...`
var currentElement = commandElements[commandIndex];
if (currentElement.ArgumentSpecified && !currentElement.ArgumentSplatted &&
(!currentElement.ParameterAndArgumentSpecified || ForEachObject_ProcessParam.Equals(currentElement.ParameterName, StringComparison.OrdinalIgnoreCase)))
{
processScriptBlock = currentElement.ArgumentValue as ScriptBlock;
indexAdvanceOffset = 1;
}
}
else if (commandIndex == cmdElementsLength - 2)
{
// Target ForEach-Object syntax:
// * `... | ForEach-Object -Process { ... } | ...`
var currentElement = commandElements[commandIndex];
var nextElement = commandElements[commandIndex + 1];
if (currentElement.ParameterNameSpecified && !currentElement.ArgumentSpecified &&
ForEachObject_ProcessParam.Equals(currentElement.ParameterName, StringComparison.OrdinalIgnoreCase) &&
nextElement.ArgumentSpecified && !nextElement.ArgumentSplatted && !nextElement.ParameterNameSpecified)
{
processScriptBlock = nextElement.ArgumentValue as ScriptBlock;
indexAdvanceOffset = 2;
}
}
if (processScriptBlock != null && processScriptBlock.Ast is ScriptBlockAst sbAst)
{
if (!sbAst.IsConfiguration && sbAst.ParamBlock == null && sbAst.BeginBlock == null &&
sbAst.ProcessBlock == null && sbAst.DynamicParamBlock == null && sbAst.EndBlock != null &&
sbAst.EndBlock.Unnamed)
{
ScriptBlock sbRewritten = s_astRewriteCache.GetValue(sbAst, s_astRewriteCallback);
ScriptBlock sbToUse = sbRewritten.Clone();
sbToUse.SessionStateInternal = processScriptBlock.SessionStateInternal;
sbToUse.LanguageMode = processScriptBlock.LanguageMode;
// We always clone the script block, so that the cached value doesn't hold on to any session state.
// Foreach-Object invokes the script block in the caller's scope, so do not use new scope.
commandProcessor = CommandDiscovery.CreateCommandProcessorForScript(
sbToUse,
context,
useNewScope: false,
commandSessionState);
commandIndex += indexAdvanceOffset;
return true;
}
}
return false;
}
internal static IEnumerable<CommandParameterInternal> Splat(object splattedValue, Ast splatAst)
{
splattedValue = PSObject.Base(splattedValue);
test/powershell/Modules/Microsoft.PowerShell.Core/ForEach-Object.Tests.ps1
+6
View File
@@ -41,4 +41,10 @@ Describe "ForEach-Object" -Tags "CI" {
$sbToUse = GetScriptBlock
1 | ForEach-Object $sbToUse | Should -BeExactly "ForEachObjectTest-Zoo"
}
It "ForEach-Object scriptblock should get the 'InvocationInfo' from the caller scope" {
$file = New-Item TestDrive:\test.ps1 -ItemType File -Force
Set-Content -Path $file -Value '1 | ForEach-Object { $MyInvocation.MyCommand.Name }'
TestDrive:\test.ps1 | Should -BeExactly "test.ps1"
}
}