Skip to content

Speed up WildcardPattern.IsMatch if an pattern ends with asterisk #10054

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
daxian-dbw merged 7 commits into from
Jul 10, 2019
Merged

Speed up WildcardPattern.IsMatch if an pattern ends with asterisk #10054

Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
8b33494
Speed up WildcardPattern.IsMatch if an pattern ends with asterisk
iSazonov Jul 3, 2019
17688b7
Speed up WindcardPattern.IsMatch()
iSazonov Jul 3, 2019
ff594e4
Move local function
iSazonov Jul 4, 2019
49e07d0
Remove unneeded setter
iSazonov Jul 4, 2019
c27314b
Update Init() method
iSazonov Jul 4, 2019
24d1367
Use index
iSazonov Jul 6, 2019
28ecf30
Exclude string allocation
iSazonov Jul 9, 2019
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
42 changes: 28 additions & 14 deletions src/System.Management.Automation/engine/regex.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -143,20 +143,8 @@ public static WildcardPattern Get(string pattern, WildcardOptions options)
/// <returns>True on success, false otherwise.</returns>
private void Init()
{
if (_isMatch != null)
{
return;
}

if (Pattern.Length == 1 && Pattern[0] == '*')
{
_isMatch = s_matchAll;
return;
}

if (Pattern.IndexOfAny(s_specialChars) == -1)
StringComparison GetStringComparison()
{
// No special characters present in the pattern, so we can just do a string comparison.
StringComparison stringComparison;
if (Options.HasFlag(WildcardOptions.IgnoreCase))
{
Expand All @@ -171,7 +159,33 @@ private void Init()
: StringComparison.CurrentCulture;
}

_isMatch = str => string.Equals(str, Pattern, stringComparison);
return stringComparison;
}

if (_isMatch != null)
{
return;
}

if (Pattern.Length == 1 && Pattern[0] == '*')
{
_isMatch = s_matchAll;
return;
}

int index = Pattern.IndexOfAny(s_specialChars);
if (index == -1)
{
// No special characters present in the pattern, so we can just do a string comparison.
_isMatch = str => string.Equals(str, Pattern, GetStringComparison());
return;
}

if (index == Pattern.Length - 1 && Pattern[index] == '*')
{
// No special characters present in the pattern before last position and last character is asterisk.
var patternWithoutAsterisk = Pattern.AsMemory().Slice(0, index);
_isMatch = str => str.AsSpan().StartsWith(patternWithoutAsterisk.Span, GetStringComparison());
return;
}

Expand Down