Skip to content

Optimize IEnumerable variant of replace operator #14221

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
rjmholt merged 13 commits into from
Dec 9, 2020
Merged

Optimize IEnumerable variant of replace operator #14221

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
13 commits
Select commit Hold shift + click to select a range
3855e45
Opimize IEnumerable variant of replace operator
iSazonov Nov 22, 2020
4b27244
Add test
iSazonov Dec 3, 2020
325a6db
Refactor with OperatorReplacer struct
iSazonov Dec 3, 2020
b2a17ff
Refactor with OperatorReplacer struct
iSazonov Dec 3, 2020
f017610
Address feedback 2 and add new test
iSazonov Dec 4, 2020
86ce89e
Fix comment
iSazonov Dec 4, 2020
be67a62
Address feedback 3
iSazonov Dec 4, 2020
686f25f
Replace comment with assert
iSazonov Dec 4, 2020
58016c1
Address feedback 4
iSazonov Dec 5, 2020
8560f11
Update test/powershell/Language/Operators/ReplaceOperator.Tests.ps1
iSazonov Dec 9, 2020
72a5a64
Update src/System.Management.Automation/engine/lang/parserutils.cs
iSazonov Dec 9, 2020
388a304
Rename ReplacerOperator
iSazonov Dec 9, 2020
028fd2f
Use ReplaceOperatorImpl name
iSazonov Dec 9, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
77 changes: 52 additions & 25 deletions src/System.Management.Automation/engine/lang/parserutils.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -965,6 +965,7 @@ internal static object ReplaceOperator(ExecutionContext context, IScriptExtent e
}
}

var replacer = ReplaceOperatorImpl.Create(context, rr, substitute);
IEnumerator list = LanguagePrimitives.GetEnumerator(lval);
if (list == null)
{
Expand All @@ -978,53 +979,63 @@ internal static object ReplaceOperator(ExecutionContext context, IScriptExtent e
lvalString = lval?.ToString() ?? string.Empty;
}

return ReplaceOperatorImpl(context, lvalString, rr, substitute);
return replacer.Replace(lvalString);
}
else
{
List<object> resultList = new List<object>();
while (ParserOps.MoveNext(context, errorPosition, list))
{
string lvalString = PSObject.ToStringParser(context, ParserOps.Current(errorPosition, list));
resultList.Add(ReplaceOperatorImpl(context, lvalString, rr, substitute));
resultList.Add(replacer.Replace(lvalString));
}

return resultList.ToArray();
}
}

/// <summary>
/// ReplaceOperator implementation.
/// Abstracts away conversion of the optional substitute parameter to either a string or a MatchEvaluator delegate
/// and finally returns the result of the final Regex.Replace operation.
/// </summary>
/// <param name="context">The execution context in which to evaluate the expression.</param>
/// <param name="input">The input string.</param>
/// <param name="regex">A Regex instance.</param>
/// <param name="substitute">The substitute value.</param>
/// <returns>The result of the regex.Replace operation.</returns>
private static object ReplaceOperatorImpl(ExecutionContext context, string input, Regex regex, object substitute)
private struct ReplaceOperatorImpl
{
switch (substitute)
public static ReplaceOperatorImpl Create(ExecutionContext context, Regex regex, object substitute)
{
return new ReplaceOperatorImpl(context, regex, substitute);
}

private readonly Regex _regex;
private readonly string _cachedReplacementString;
private readonly MatchEvaluator _cachedMatchEvaluator;

private ReplaceOperatorImpl(
ExecutionContext context,
Regex regex,
object substitute)
{
case string replacementString:
return regex.Replace(input, replacementString);
_regex = regex;
_cachedReplacementString = null;
_cachedMatchEvaluator = null;

switch (substitute)
{
case string replacement:
_cachedReplacementString = replacement;
break;

case ScriptBlock sb:
MatchEvaluator me = GetMatchEvaluator(context, sb);
return regex.Replace(input, me);
case ScriptBlock sb:
_cachedMatchEvaluator = GetMatchEvaluator(context, sb);
break;

case object val when LanguagePrimitives.TryConvertTo(val, out MatchEvaluator matchEvaluator):
return regex.Replace(input, matchEvaluator);
case object val when LanguagePrimitives.TryConvertTo(val, out _cachedMatchEvaluator):
break;

default:
string replacement = PSObject.ToStringParser(context, substitute);
return regex.Replace(input, replacement);
default:
_cachedReplacementString = PSObject.ToStringParser(context, substitute);
break;
}
}

// Local helper function to avoid creating an instance of the generated delegate helper class
// every time 'ReplaceOperatorImpl' is invoked.
static MatchEvaluator GetMatchEvaluator(ExecutionContext context, ScriptBlock sb)
private static MatchEvaluator GetMatchEvaluator(ExecutionContext context, ScriptBlock sb)
{
return match =>
{
Expand All @@ -1039,6 +1050,22 @@ static MatchEvaluator GetMatchEvaluator(ExecutionContext context, ScriptBlock sb
return PSObject.ToStringParser(context, result);
};
}

/// <summary>
/// ReplaceOperator implementation.
/// Abstracts away conversion of the optional substitute parameter to either a string or a MatchEvaluator delegate
/// and finally returns the result of the final Regex.Replace operation.
/// </summary>
public object Replace(string input)
{
if (_cachedReplacementString is not null)
{
return _regex.Replace(input, _cachedReplacementString);
}

Dbg.Assert(_cachedMatchEvaluator is not null, "_cachedMatchEvaluator should be not null when code reach here.");
return _regex.Replace(input, _cachedMatchEvaluator);
}
}

/// <summary>
Expand Down
18 changes: 18 additions & 0 deletions test/powershell/Language/Operators/ReplaceOperator.Tests.ps1
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,12 @@ Describe "Replace Operator" -Tags CI {
$res | Should -BeExactly "image.jpg"
}

It "Replace operator can convert an substitution object to string" {
$substitution = Get-Process -Id $pid
$res = "!3!" -replace "3",$substitution
$res | Should -BeExactly "!System.Diagnostics.Process (pwsh)!"
}

It "Replace operator can be case-insensitive and case-sensitive" {
$res = "book" -replace "B","C"
$res | Should -BeExactly "Cook"
Expand All @@ -29,6 +35,18 @@ Describe "Replace Operator" -Tags CI {
$res = "PowerPoint" -replace "Point"
$res | Should -BeExactly "Power"
}

It "Replace operator can take an enumerable as first argument, a mandatory pattern, and an optional substitution" {
$res = "PowerPoint1","PowerPoint2" -replace "Point","Shell"
$res.Count | Should -Be 2
$res[0] | Should -BeExactly "PowerShell1"
$res[1] | Should -BeExactly "PowerShell2"

$res = "PowerPoint1","PowerPoint2" -replace "Point"
$res.Count | Should -Be 2
$res[0] | Should -BeExactly "Power1"
$res[1] | Should -BeExactly "Power2"
}
}

Context "Replace operator substitutions" {
Expand Down