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Merged
merged 3 commits into from
Aug 14, 2022
Merged

System.Net.WebProxy Bypass regex list optimization #73803

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f27b711
System.Net.WebProxy Bypass regex list optimization
Aug 11, 2022
02b0c7a
Cosmetic changes.
Aug 11, 2022
c635195
Address PR feedback
stephentoub Aug 14, 2022
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129 changes: 105 additions & 24 deletions src/libraries/System.Net.WebProxy/src/System/Net/WebProxy.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,7 @@ namespace System.Net
{
public partial class WebProxy : IWebProxy, ISerializable
{
private ArrayList? _bypassList;
private ChangeTrackingArrayList? _bypassList;
private Regex[]? _regexBypassList;

public WebProxy() : this((Uri?)null, false, null, null) { }
Expand All @@ -31,8 +31,8 @@ public WebProxy(Uri? Address, bool BypassOnLocal, [StringSyntax(StringSyntaxAttr
this.BypassProxyOnLocal = BypassOnLocal;
if (BypassList != null)
{
_bypassList = new ArrayList(BypassList);
UpdateRegexList(true);
_bypassList = new ChangeTrackingArrayList(BypassList);
UpdateRegexList(); // prompt creation of the Regex instances so that any exceptions are propagated
}
}

Expand Down Expand Up @@ -71,20 +71,22 @@ public string[] BypassList
get
{
if (_bypassList == null)
{
return Array.Empty<string>();
}

var bypassList = new string[_bypassList.Count];
_bypassList.CopyTo(bypassList);
return bypassList;
}
set
{
_bypassList = value != null ? new ArrayList(value) : null;
UpdateRegexList(true);
_bypassList = value != null ? new ChangeTrackingArrayList(value) : null;
UpdateRegexList(); // prompt creation of the Regex instances so that any exceptions are propagated
}
}

public ArrayList BypassArrayList => _bypassList ??= new ArrayList();
public ArrayList BypassArrayList => _bypassList ??= new ChangeTrackingArrayList();

public ICredentials? Credentials { get; set; }

Expand Down Expand Up @@ -123,40 +125,41 @@ public bool UseDefaultCredentials
return proxyUri;
}

private void UpdateRegexList(bool canThrow)
private void UpdateRegexList()
{
Regex[]? regexBypassList = null;
ArrayList? bypassList = _bypassList;
try
if (_bypassList is ChangeTrackingArrayList bypassList)
{
if (bypassList != null && bypassList.Count > 0)
bypassList.IsChanged = false;
if (bypassList.Count > 0)
{
regexBypassList = new Regex[bypassList.Count];
for (int i = 0; i < bypassList.Count; i++)
for (int i = 0; i < regexBypassList.Length; i++)
{
regexBypassList[i] = new Regex((string)bypassList[i]!, RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
}
}
}
catch
{
if (!canThrow)
{
_regexBypassList = null;
return;
}
throw;
}

// Update field here, as it could throw earlier in the loop
_regexBypassList = regexBypassList;
}

private bool IsMatchInBypassList(Uri input)
{
UpdateRegexList(canThrow: false);
// Update our list of Regex instances if the ArrayList has changed.
if (_bypassList is ChangeTrackingArrayList bypassList && bypassList.IsChanged)
{
try
{
UpdateRegexList();
}
catch
{
_regexBypassList = null;
}
}

if (_regexBypassList is Regex[] bypassList)
if (_regexBypassList is Regex[] regexBypassList)
{
bool isDefaultPort = input.IsDefaultPort;
int lengthRequired = input.Scheme.Length + 3 + input.Host.Length;
Expand All @@ -173,7 +176,7 @@ private bool IsMatchInBypassList(Uri input)
Debug.Assert(formatted);
url = url.Slice(0, charsWritten);

foreach (Regex r in bypassList)
foreach (Regex r in regexBypassList)
{
if (r.IsMatch(url))
{
Expand Down Expand Up @@ -209,5 +212,83 @@ public static WebProxy GetDefaultProxy() =>
// The .NET Framework here returns a proxy that fetches IE settings and
// executes JavaScript to determine the correct proxy.
throw new PlatformNotSupportedException();

private sealed class ChangeTrackingArrayList : ArrayList
{
public ChangeTrackingArrayList() { }

public ChangeTrackingArrayList(ICollection c) : base(c) { }

public bool IsChanged { get; set; }

// Override the methods that can add, remove, or change the regexes in the bypass list.
// Methods that only read (like CopyTo, BinarySearch, etc.) and methods that reorder
// the collection but that don't change the overall list of regexes (e.g. Sort) do not
// need to be overridden.

public override object? this[int index]
{
get => base[index];
set
{
IsChanged = true;
base[index] = value;
}
}

public override int Add(object? value)
{
IsChanged = true;
return base.Add(value);
}

public override void AddRange(ICollection c)
{
IsChanged = true;
base.AddRange(c);
}

public override void Insert(int index, object? value)
{
IsChanged = true;
base.Insert(index, value);
}

public override void InsertRange(int index, ICollection c)
{
IsChanged = true;
base.InsertRange(index, c);
}

public override void SetRange(int index, ICollection c)
{
IsChanged = true;
base.SetRange(index, c);
}

public override void Remove(object? obj)
{
IsChanged = true;
base.Remove(obj);
}

public override void RemoveAt(int index)
{
IsChanged = true;
base.RemoveAt(index);
}

public override void RemoveRange(int index, int count)
{
IsChanged = true;
base.RemoveRange(index, count);
}

public override void Clear()
{
IsChanged = true;
base.Clear();
}
}
}
}
41 changes: 41 additions & 0 deletions src/libraries/System.Net.WebProxy/tests/WebProxyTest.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -132,6 +132,47 @@ public static void WebProxy_InvalidBypassUrl_AddedDirectlyToList_SilentlyEaten()
p.IsBypassed(new Uri("http://microsoft.com")); // exception should be silently eaten
}

[Fact]
public static void WebProxy_BypassUrl_BypassArrayListChangedDirectly_IsBypassedAsExpected()
{
var p = new WebProxy("http://microsoft.com", BypassOnLocal: false);
Assert.False(p.IsBypassed(new Uri("http://bing.com")));

p.BypassArrayList.Add("bing");
Assert.True(p.IsBypassed(new Uri("http://bing.com")));

p.BypassArrayList.Remove("bing");
Assert.False(p.IsBypassed(new Uri("http://bing.com")));

p.BypassArrayList.AddRange(new[] { "dot.net" });
Assert.True(p.IsBypassed(new Uri("http://dot.net")));

p.BypassArrayList.InsertRange(0, new[] { "bing" });
Assert.True(p.IsBypassed(new Uri("http://bing.com")));

p.BypassArrayList.SetRange(0, new[] { "example", "microsoft" });
Assert.True(p.IsBypassed(new Uri("http://example.com")));
Assert.True(p.IsBypassed(new Uri("http://microsoft.com")));
Assert.False(p.IsBypassed(new Uri("http://bing.com")));
Assert.False(p.IsBypassed(new Uri("http://dot.net")));

p.BypassArrayList.Clear();
Assert.False(p.IsBypassed(new Uri("http://example.com")));
Assert.False(p.IsBypassed(new Uri("http://microsoft.com")));

p.BypassArrayList.Insert(0, "bing");
p.BypassArrayList.Insert(1, "example");
Assert.True(p.IsBypassed(new Uri("http://bing.com")));
Assert.True(p.IsBypassed(new Uri("http://example.com")));

p.BypassArrayList.RemoveAt(0);
Assert.False(p.IsBypassed(new Uri("http://bing.com")));
Assert.True(p.IsBypassed(new Uri("http://example.com")));

p.BypassArrayList.RemoveRange(0, 1);
Assert.False(p.IsBypassed(new Uri("http://example.com")));
}

[Fact]
public static void WebProxy_BypassList_DoesntContainUrl_NotBypassed()
{
Expand Down