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//------------------------------------------------------------------------------
// <copyright file="CapabilitiesPattern.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Web.Configuration {
using System.Collections;
using System.Collections.Specialized;
using System.Diagnostics;
using System.Globalization;
using System.Reflection;
using System.Security;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Web.Caching;
using System.Web.Compilation;
using System.Web.Hosting;
using System.Security.Permissions;
//
// Represents a single pattern to be expanded
//
internal class CapabilitiesPattern {
internal String[] _strings;
internal int[] _rules;
internal const int Literal = 0; // literal string
internal const int Reference = 1; // regex reference ${name} or $number
internal const int Variable = 2; // regex reference %{name}
internal static readonly Regex refPat = new Regex("\\G\\$(?:(?<name>\\d+)|\\{(?<name>\\w+)\\})");
internal static readonly Regex varPat = new Regex("\\G\\%\\{(?<name>\\w+)\\}");
internal static readonly Regex textPat = new Regex("\\G[^$%\\\\]*(?:\\.[^$%\\\\]*)*");
internal static readonly Regex errorPat = new Regex(".{0,8}");
internal static readonly CapabilitiesPattern Default = new CapabilitiesPattern();
internal CapabilitiesPattern() {
_strings = new String[1];
_strings[0] = String.Empty;
_rules = new int[1];
_rules[0] = Variable;
}
internal CapabilitiesPattern(String text) {
ArrayList strings = new ArrayList();
ArrayList rules = new ArrayList();
int textpos = 0;
for (;;) {
Match match = null;
// 1: scan text
if ((match = textPat.Match(text, textpos)).Success && match.Length > 0) {
rules.Add(Literal);
strings.Add(Regex.Unescape(match.ToString()));
textpos = match.Index + match.Length;
}
if (textpos == text.Length)
break;
// 2: look for regex references
if ((match = refPat.Match(text, textpos)).Success) {
rules.Add(Reference);
strings.Add(match.Groups["name"].Value);
}
// 3: look for variables
else if ((match = varPat.Match(text, textpos)).Success) {
rules.Add(Variable);
strings.Add(match.Groups["name"].Value);
}
// 4: encountered a syntax error (
else {
match = errorPat.Match(text, textpos);
throw new ArgumentException(
SR.GetString(SR.Unrecognized_construct_in_pattern, match.ToString(), text));
}
textpos = match.Index + match.Length;
}
_strings = (String[])strings.ToArray(typeof(String));
_rules = new int[rules.Count];
for (int i = 0; i < rules.Count; i++)
_rules[i] = (int)rules[i];
}
internal virtual String Expand(CapabilitiesState matchstate) {
StringBuilder sb = null;
String result = null;
for (int i = 0; i < _rules.Length; i++) {
if (sb == null && result != null)
sb = new StringBuilder(result);
switch (_rules[i]) {
case Literal:
result = _strings[i];
break;
case Reference:
result = matchstate.ResolveReference(_strings[i]);
break;
case Variable:
result = matchstate.ResolveVariable(_strings[i]);
break;
}
if (sb != null && result != null)
sb.Append(result);
}
if (sb != null)
return sb.ToString();
if (result != null)
return result;
return String.Empty;
}
#if DBG
internal virtual String Dump() {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < _rules.Length; i++) {
switch (_rules[i]) {
case Literal:
sb.Append("\"" + _strings[i] + "\"");
break;
case Reference:
sb.Append("${" + _strings[i] + "}");
break;
default:
sb.Append("??");
break;
}
if (i < _rules.Length - 1)
sb.Append(" ");
}
return sb.ToString();
}
internal virtual String Dump(String indent) {
return indent + Dump() + "\n";
}
#endif
}
}
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