Code:
/ Dotnetfx_Win7_3.5.1 / Dotnetfx_Win7_3.5.1 / 3.5.1 / DEVDIV / depot / DevDiv / releases / whidbey / NetFXspW7 / ndp / fx / src / Regex / System / Text / RegularExpressions / Regex.cs / 1 / Regex.cs
//------------------------------------------------------------------------------
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
//-----------------------------------------------------------------------------
// The Regex class represents a single compiled instance of a regular
// expression.
namespace System.Text.RegularExpressions {
using System;
using System.Threading;
using System.Collections;
using System.Runtime.Serialization;
using System.Reflection;
using System.Reflection.Emit;
using System.Globalization;
using System.Security.Policy;
using System.Security.Permissions;
using System.Runtime.CompilerServices;
using System.Collections.Generic;
using System.Runtime.Versioning;
///
///
/// Represents an immutable, compiled regular expression. Also
/// contains static methods that allow use of regular expressions without instantiating
/// a Regex explicitly.
///
///
[ Serializable() ]
public class Regex : ISerializable {
// Fields used by precompiled regexes
protected internal string pattern;
protected internal RegexRunnerFactory factory; // if compiled, this is the RegexRunner subclass
protected internal RegexOptions roptions; // the top-level options from the options string
protected internal Hashtable caps; // if captures are sparse, this is the hashtable capnum->index
protected internal Hashtable capnames; // if named captures are used, this maps names->index
protected internal String[] capslist; // if captures are sparse or named captures are used, this is the sorted list of names
protected internal int capsize; // the size of the capture array
internal ExclusiveReference runnerref; // cached runner
internal SharedReference replref; // cached parsed replacement pattern
internal RegexCode code; // if interpreted, this is the code for RegexIntepreter
internal bool refsInitialized = false;
internal static LinkedList livecode = new LinkedList();// the cached of code and factories that are currently loaded
internal static int cacheSize = 15;
internal const int MaxOptionShift = 10;
protected Regex() {
}
/*
* Compiles and returns a Regex object corresponding to the given pattern
*/
///
///
/// Creates and compiles a regular expression object for the specified regular
/// expression.
///
///
public Regex(String pattern) : this(pattern, RegexOptions.None, false) {
}
/*
* Returns a Regex object corresponding to the given pattern, compiled with
* the specified options.
*/
///
///
/// Creates and compiles a regular expression object for the
/// specified regular expression
/// with options that modify the pattern.
///
///
public Regex(String pattern, RegexOptions options) : this(pattern, options, false){
}
private Regex(String pattern, RegexOptions options, bool useCache) {
RegexTree tree;
CachedCodeEntry cached = null;
string cultureKey = null;
if (pattern == null)
throw new ArgumentNullException("pattern");
if (options < RegexOptions.None || ( ((int) options) >> MaxOptionShift) != 0)
throw new ArgumentOutOfRangeException("options");
if ((options & RegexOptions.ECMAScript) != 0
&& (options & ~(RegexOptions.ECMAScript |
RegexOptions.IgnoreCase |
RegexOptions.Multiline |
RegexOptions.Compiled |
RegexOptions.CultureInvariant
#if DBG
| RegexOptions.Debug
#endif
)) != 0)
throw new ArgumentOutOfRangeException("options");
// Try to look up this regex in the cache. We do this regardless of whether useCache is true since there's
// really no reason not to.
if ((options & RegexOptions.CultureInvariant) != 0)
cultureKey = CultureInfo.InvariantCulture.ThreeLetterWindowsLanguageName;
else
cultureKey = CultureInfo.CurrentCulture.ThreeLetterWindowsLanguageName;
String key = ((int) options).ToString(NumberFormatInfo.InvariantInfo) + ":" + cultureKey + ":" + pattern;
cached = LookupCachedAndUpdate(key);
this.pattern = pattern;
this.roptions = options;
if (cached == null) {
// Parse the input
tree = RegexParser.Parse(pattern, roptions);
// Extract the relevant information
capnames = tree._capnames;
capslist = tree._capslist;
code = RegexWriter.Write(tree);
caps = code._caps;
capsize = code._capsize;
InitializeReferences();
tree = null;
if (useCache)
cached = CacheCode(key);
}
else {
caps = cached._caps;
capnames = cached._capnames;
capslist = cached._capslist;
capsize = cached._capsize;
code = cached._code;
factory = cached._factory;
runnerref = cached._runnerref;
replref = cached._replref;
refsInitialized = true;
}
// if the compile option is set, then compile the code if it's not already
if (UseOptionC() && factory == null) {
factory = Compile(code, roptions);
if (useCache && cached != null)
cached.AddCompiled(factory);
code = null;
}
}
/*
* ISerializable constructor
*/
protected Regex(SerializationInfo info, StreamingContext context) : this(info.GetString("pattern"), (RegexOptions) info.GetInt32("options")) {
}
/*
* ISerializable method
*/
///
///
/// Escapes
/// a minimal set of metacharacters (\, *, +, ?, |, {, [, (, ), ^, $, ., #, and
/// whitespace) by replacing them with their \ codes. This converts a string so that
/// it can be used as a constant within a regular expression safely. (Note that the
/// reason # and whitespace must be escaped is so the string can be used safely
/// within an expression parsed with x mode. If future Regex features add
/// additional metacharacters, developers should depend on Escape to escape those
/// characters as well.)
///
///
public static String Escape(String str) {
if (str==null)
throw new ArgumentNullException("str");
return RegexParser.Escape(str);
}
/*
* Unescape character codes within the string
*/
///
///
/// Unescapes any escaped characters in the input string.
///
///
public static String Unescape(String str) {
if (str==null)
throw new ArgumentNullException("str");
return RegexParser.Unescape(str);
}
public static int CacheSize {
get {
return cacheSize;
}
set {
if (value < 0)
throw new ArgumentOutOfRangeException("value");
cacheSize = value;
if (livecode.Count > cacheSize) {
lock (livecode) {
while (livecode.Count > cacheSize)
livecode.RemoveLast();
}
}
}
}
///
///
/// Returns the options passed into the constructor
///
///
public RegexOptions Options {
get { return roptions;}
}
/*
* True if the regex is leftward
*/
///
///
/// Indicates whether the regular expression matches from right to
/// left.
///
///
public bool RightToLeft {
get {
return UseOptionR();
}
}
///
///
/// Returns the regular expression pattern passed into the constructor
///
///
public override string ToString() {
return pattern;
}
/*
* Returns an array of the group names that are used to capture groups
* in the regular expression. Only needed if the regex is not known until
* runtime, and one wants to extract captured groups. (Probably unusual,
* but supplied for completeness.)
*/
///
/// Returns
/// the GroupNameCollection for the regular expression. This collection contains the
/// set of strings used to name capturing groups in the expression.
///
public String[] GetGroupNames() {
String[] result;
if (capslist == null) {
int max = capsize;
result = new String[max];
for (int i = 0; i < max; i++) {
result[i] = Convert.ToString(i, CultureInfo.InvariantCulture);
}
}
else {
result = new String[capslist.Length];
System.Array.Copy(capslist, 0, result, 0, capslist.Length);
}
return result;
}
/*
* Returns an array of the group numbers that are used to capture groups
* in the regular expression. Only needed if the regex is not known until
* runtime, and one wants to extract captured groups. (Probably unusual,
* but supplied for completeness.)
*/
///
/// returns
/// the integer group number corresponding to a group name.
///
public int[] GetGroupNumbers() {
int[] result;
if (caps == null) {
int max = capsize;
result = new int[max];
for (int i = 0; i < max; i++) {
result[i] = i;
}
}
else {
result = new int[caps.Count];
IDictionaryEnumerator de = caps.GetEnumerator();
while (de.MoveNext()) {
result[(int)de.Value] = (int)de.Key;
}
}
return result;
}
/*
* Given a group number, maps it to a group name. Note that nubmered
* groups automatically get a group name that is the decimal string
* equivalent of its number.
*
* Returns null if the number is not a recognized group number.
*/
///
///
/// Retrieves a group name that corresponds to a group number.
///
///
public String GroupNameFromNumber(int i) {
if (capslist == null) {
if (i >= 0 && i < capsize)
return i.ToString(CultureInfo.InvariantCulture);
return String.Empty;
}
else {
if (caps != null) {
Object obj = caps[i];
if (obj == null)
return String.Empty;
i = (int)obj;
}
if (i >= 0 && i < capslist.Length)
return capslist[i];
return String.Empty;
}
}
/*
* Given a group name, maps it to a group number. Note that nubmered
* groups automatically get a group name that is the decimal string
* equivalent of its number.
*
* Returns -1 if the name is not a recognized group name.
*/
///
///
/// Returns a group number that corresponds to a group name.
///
///
public int GroupNumberFromName(String name) {
int result = -1;
if (name == null)
throw new ArgumentNullException("name");
// look up name if we have a hashtable of names
if (capnames != null) {
Object ret = capnames[name];
if (ret == null)
return -1;
return(int)ret;
}
// convert to an int if it looks like a number
result = 0;
for (int i = 0; i < name.Length; i++) {
char ch = name[i];
if (ch > '9' || ch < '0')
return -1;
result *= 10;
result += (ch - '0');
}
// return int if it's in range
if (result >= 0 && result < capsize)
return result;
return -1;
}
/*
* Static version of simple IsMatch call
*/
///
///
/// Searches the input
/// string for one or more occurrences of the text supplied in the pattern
/// parameter.
///
///
public static bool IsMatch(String input, String pattern) {
return new Regex(pattern, RegexOptions.None, true).IsMatch(input);
}
/*
* Static version of simple IsMatch call
*/
///
///
/// Searches the input string for one or more occurrences of the text
/// supplied in the pattern parameter with matching options supplied in the options
/// parameter.
///
///
public static bool IsMatch(String input, String pattern, RegexOptions options) {
return new Regex(pattern, options, true).IsMatch(input);
}
/*
* Returns true if the regex finds a match within the specified string
*/
///
///
/// Searches the input string for one or
/// more matches using the previous pattern, options, and starting
/// position.
///
///
public bool IsMatch(String input) {
if (input == null)
throw new ArgumentNullException("input");
return(null == Run(true, -1, input, 0, input.Length, UseOptionR() ? input.Length : 0));
}
/*
* Returns true if the regex finds a match after the specified position
* (proceeding leftward if the regex is leftward and rightward otherwise)
*/
///
///
/// Searches the input
/// string for one or more matches using the previous pattern and options, with
/// a new starting position.
///
///
public bool IsMatch(String input, int startat) {
if (input == null)
throw new ArgumentNullException("input");
return(null == Run(true, -1, input, 0, input.Length, startat));
}
/*
* Static version of simple Match call
*/
///
///
/// Searches the input string for one or more occurrences of the text
/// supplied in the pattern parameter.
///
///
public static Match Match(String input, String pattern) {
return new Regex(pattern, RegexOptions.None, true).Match(input);
}
/*
* Static version of simple Match call
*/
///
///
/// Searches the input string for one or more occurrences of the text
/// supplied in the pattern parameter. Matching is modified with an option
/// string.
///
///
public static Match Match(String input, String pattern, RegexOptions options) {
return new Regex(pattern, options, true).Match(input);
}
/*
* Finds the first match for the regular expression starting at the beginning
* of the string (or at the end of the string if the regex is leftward)
*/
///
///
/// Matches a regular expression with a string and returns
/// the precise result as a RegexMatch object.
///
///
public Match Match(String input) {
if (input == null)
throw new ArgumentNullException("input");
return Run(false, -1, input, 0, input.Length, UseOptionR() ? input.Length : 0);
}
/*
* Finds the first match, starting at the specified position
*/
///
/// Matches a regular expression with a string and returns
/// the precise result as a RegexMatch object.
///
public Match Match(String input, int startat) {
if (input == null)
throw new ArgumentNullException("input");
return Run(false, -1, input, 0, input.Length, startat);
}
/*
* Finds the first match, restricting the search to the specified interval of
* the char array.
*/
///
///
/// Matches a
/// regular expression with a string and returns the precise result as a
/// RegexMatch object.
///
///
public Match Match(String input, int beginning, int length) {
if (input == null)
throw new ArgumentNullException("input");
return Run(false, -1, input, beginning, length, UseOptionR() ? beginning + length : beginning);
}
/*
* Static version of simple Matches call
*/
///
///
/// Returns all the successful matches as if Match were
/// called iteratively numerous times.
///
///
public static MatchCollection Matches(String input, String pattern) {
return new Regex(pattern, RegexOptions.None, true).Matches(input);
}
/*
* Static version of simple Matches call
*/
///
///
/// Returns all the successful matches as if Match were called iteratively
/// numerous times.
///
///
public static MatchCollection Matches(String input, String pattern, RegexOptions options) {
return new Regex(pattern, options, true).Matches(input);
}
/*
* Finds the first match for the regular expression starting at the beginning
* of the string Enumerator(or at the end of the string if the regex is leftward)
*/
///
///
/// Returns
/// all the successful matches as if Match was called iteratively numerous
/// times.
///
///
public MatchCollection Matches(String input) {
if (input == null)
throw new ArgumentNullException("input");
return new MatchCollection(this, input, 0, input.Length, UseOptionR() ? input.Length : 0);
}
/*
* Finds the first match, starting at the specified position
*/
///
///
/// Returns
/// all the successful matches as if Match was called iteratively numerous
/// times.
///
///
public MatchCollection Matches(String input, int startat) {
if (input == null)
throw new ArgumentNullException("input");
return new MatchCollection(this, input, 0, input.Length, startat);
}
/*
* Static version of simple Replace call
*/
///
///
/// Replaces
/// all occurrences of the pattern with the
///
public static String Replace(String input, String pattern, String replacement) {
return new Regex(pattern, RegexOptions.None, true).Replace(input, replacement);
}
/*
* Static version of simple Replace call
*/
///
///
/// Replaces all occurrences of
/// the
///
public static String Replace(String input, String pattern, String replacement, RegexOptions options) {
return new Regex(pattern, options, true).Replace(input, replacement);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of
/// the
///
public String Replace(String input, String replacement) {
if (input == null)
throw new ArgumentNullException("input");
return Replace(input, replacement, -1, UseOptionR() ? input.Length : 0);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of the (previously defined)
///
public String Replace(String input, String replacement, int count) {
if (input == null)
throw new ArgumentNullException("input");
return Replace(input, replacement, count, UseOptionR() ? input.Length : 0);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of the
///
public String Replace(String input, String replacement, int count, int startat) {
RegexReplacement repl;
if (input == null)
throw new ArgumentNullException("input");
if (replacement == null)
throw new ArgumentNullException("replacement");
// a little code to grab a cached parsed replacement object
repl = (RegexReplacement)replref.Get();
if (repl == null || !repl.Pattern.Equals(replacement)) {
repl = RegexParser.ParseReplacement(replacement, caps, capsize, capnames, this.roptions);
replref.Cache(repl);
}
return repl.Replace(this, input, count, startat);
}
/*
* Static version of simple Replace call
*/
///
///
/// Replaces all occurrences of the
///
public static String Replace(String input, String pattern, MatchEvaluator evaluator) {
return new Regex(pattern, RegexOptions.None, true).Replace(input, evaluator);
}
/*
* Static version of simple Replace call
*/
///
///
/// Replaces all occurrences of the
///
public static String Replace(String input, String pattern, MatchEvaluator evaluator, RegexOptions options) {
return new Regex(pattern, options, true).Replace(input, evaluator);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of the
///
public String Replace(String input, MatchEvaluator evaluator) {
if (input==null)
throw new ArgumentNullException("input");
return Replace(input, evaluator, -1, UseOptionR() ? input.Length : 0);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of the
///
public String Replace(String input, MatchEvaluator evaluator, int count) {
if (input==null)
throw new ArgumentNullException("input");
return Replace(input, evaluator, count, UseOptionR() ? input.Length : 0);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of the (previouly defined)
///
public String Replace(String input, MatchEvaluator evaluator, int count, int startat) {
if (input==null)
throw new ArgumentNullException("input");
return RegexReplacement.Replace(evaluator, this, input, count, startat);
}
/*
* Static version of simple Split call
*/
///
///
/// Splits the
///
public static String[] Split(String input, String pattern) {
return new Regex(pattern, RegexOptions.None, true).Split(input);
}
/*
* Static version of simple Split call
*/
///
///
/// Splits the
///
public static String[] Split(String input, String pattern, RegexOptions options) {
return new Regex(pattern, options, true).Split(input);
}
/*
* Does a split
*/
///
///
/// Splits the
///
public String[] Split(String input) {
if (input==null)
throw new ArgumentNullException("input");
return Split(input, 0, UseOptionR() ? input.Length : 0);
}
/*
* Does a split
*/
///
///
/// Splits the
///
public String[] Split(String input, int count) {
if (input==null)
throw new ArgumentNullException("input");
return RegexReplacement.Split(this, input, count, UseOptionR() ? input.Length : 0);
}
/*
* Does a split
*/
///
///
/// Splits the
///
public String[] Split(String input, int count, int startat) {
if (input==null)
throw new ArgumentNullException("input");
return RegexReplacement.Split(this, input, count, startat);
}
///
///
[HostProtection(MayLeakOnAbort=true)]
[ResourceExposure(ResourceScope.Machine)] // The AssemblyName is interesting.
[ResourceConsumption(ResourceScope.Machine)]
public static void CompileToAssembly(RegexCompilationInfo[] regexinfos, AssemblyName assemblyname) {
CompileToAssemblyInternal(regexinfos, assemblyname, null, null, Assembly.GetCallingAssembly().Evidence);
}
///
///
[HostProtection(MayLeakOnAbort=true)]
[ResourceExposure(ResourceScope.Machine)] // The AssemblyName is interesting.
[ResourceConsumption(ResourceScope.Machine)]
public static void CompileToAssembly(RegexCompilationInfo[] regexinfos, AssemblyName assemblyname, CustomAttributeBuilder[] attributes) {
CompileToAssemblyInternal(regexinfos, assemblyname, attributes, null, Assembly.GetCallingAssembly().Evidence);
}
[HostProtection(MayLeakOnAbort=true)]
[ResourceExposure(ResourceScope.Machine)]
[ResourceConsumption(ResourceScope.Machine)]
public static void CompileToAssembly(RegexCompilationInfo[] regexinfos, AssemblyName assemblyname, CustomAttributeBuilder[] attributes, String resourceFile) {
CompileToAssemblyInternal(regexinfos, assemblyname, attributes, resourceFile, Assembly.GetCallingAssembly().Evidence);
}
[ResourceExposure(ResourceScope.Machine)] // AssemblyName & resourceFile
[ResourceConsumption(ResourceScope.Machine)]
private static void CompileToAssemblyInternal (RegexCompilationInfo[] regexinfos, AssemblyName assemblyname, CustomAttributeBuilder[] attributes, String resourceFile, Evidence evidence) {
if (assemblyname == null)
throw new ArgumentNullException("assemblyname");
if (regexinfos == null)
throw new ArgumentNullException("regexinfos");
RegexCompiler.CompileToAssembly(regexinfos, assemblyname, attributes, resourceFile, evidence);
}
///
///
protected void InitializeReferences() {
if (refsInitialized)
throw new NotSupportedException(SR.GetString(SR.OnlyAllowedOnce));
refsInitialized = true;
runnerref = new ExclusiveReference();
replref = new SharedReference();
}
/*
* Internal worker called by all the public APIs
*/
internal Match Run(bool quick, int prevlen, String input, int beginning, int length, int startat) {
Match match;
RegexRunner runner = null;
if (startat < 0 || startat > input.Length)
throw new ArgumentOutOfRangeException("start", SR.GetString(SR.BeginIndexNotNegative));
if (length < 0 || length > input.Length)
throw new ArgumentOutOfRangeException("length", SR.GetString(SR.LengthNotNegative));
// There may be a cached runner; grab ownership of it if we can.
runner = (RegexRunner)runnerref.Get();
// Create a RegexRunner instance if we need to
if (runner == null) {
// Use the compiled RegexRunner factory if the code was compiled to MSIL
if (factory != null)
runner = factory.CreateInstance();
else
runner = new RegexInterpreter(code, UseOptionInvariant() ? CultureInfo.InvariantCulture : CultureInfo.CurrentCulture);
}
// Do the scan starting at the requested position
match = runner.Scan(this, input, beginning, beginning + length, startat, prevlen, quick);
// Release or fill the cache slot
runnerref.Release(runner);
#if DBG
if (Debug && match != null)
match.Dump();
#endif
return match;
}
/*
* Find code cache based on options+pattern
*/
private static CachedCodeEntry LookupCachedAndUpdate(String key) {
lock (livecode) {
for (LinkedListNode current = livecode.First; current != null; current = current.Next) {
if (current.Value._key == key) {
// If we find an entry in the cache, move it to the head at the same time.
livecode.Remove(current);
livecode.AddFirst(current);
return current.Value;
}
}
}
return null;
}
/*
* Add current code to the cache
*/
private CachedCodeEntry CacheCode(String key) {
CachedCodeEntry newcached = null;
lock (livecode) {
// first look for it in the cache and move it to the head
for (LinkedListNode current = livecode.First; current != null; current = current.Next) {
if (current.Value._key == key) {
livecode.Remove(current);
livecode.AddFirst(current);
return current.Value;
}
}
// it wasn't in the cache, so we'll add a new one. Shortcut out for the case where cacheSize is zero.
if (cacheSize != 0) {
newcached = new CachedCodeEntry(key, capnames, capslist, code, caps, capsize, runnerref, replref);
livecode.AddFirst(newcached);
if (livecode.Count > cacheSize)
livecode.RemoveLast();
}
}
return newcached;
}
/*
* True if the O option was set
*/
///
///
protected bool UseOptionC() {
return(roptions & RegexOptions.Compiled) != 0;
}
/*
* True if the L option was set
*/
///
///
protected bool UseOptionR() {
return(roptions & RegexOptions.RightToLeft) != 0;
}
internal bool UseOptionInvariant() {
return(roptions & RegexOptions.CultureInvariant) != 0;
}
#if DBG
/*
* True if the regex has debugging enabled
*/
///
///
internal bool Debug {
get {
return(roptions & RegexOptions.Debug) != 0;
}
}
#endif
}
/*
* Callback class
*/
///
///
[ Serializable() ]
public delegate String MatchEvaluator(Match match);
/*
* Used to cache byte codes or compiled factories
*/
internal sealed class CachedCodeEntry {
internal string _key;
internal RegexCode _code;
internal Hashtable _caps;
internal Hashtable _capnames;
internal String[] _capslist;
internal int _capsize;
internal RegexRunnerFactory _factory;
internal ExclusiveReference _runnerref;
internal SharedReference _replref;
internal CachedCodeEntry(string key, Hashtable capnames, String[] capslist, RegexCode code, Hashtable caps, int capsize, ExclusiveReference runner, SharedReference repl) {
_key = key;
_capnames = capnames;
_capslist = capslist;
_code = code;
_caps = caps;
_capsize = capsize;
_runnerref = runner;
_replref = repl;
}
internal void AddCompiled(RegexRunnerFactory factory) {
_factory = factory;
_code = null;
}
}
/*
* Used to cache one exclusive runner reference
*/
internal sealed class ExclusiveReference {
RegexRunner _ref;
Object _obj;
int _locked;
/*
* Return an object and grab an exclusive lock.
*
* If the exclusive lock can't be obtained, null is returned;
* if the object can't be returned, the lock is released.
*
*/
internal Object Get() {
// try to obtain the lock
if (0 == Interlocked.Exchange(ref _locked, 1)) {
// grab reference
Object obj = _ref;
// release the lock and return null if no reference
if (obj == null) {
_locked = 0;
return null;
}
// remember the reference and keep the lock
_obj = obj;
return obj;
}
return null;
}
/*
* Release an object back to the cache
*
* If the object is the one that's under lock, the lock
* is released.
*
* If there is no cached object, then the lock is obtained
* and the object is placed in the cache.
*
*/
internal void Release(Object obj) {
if (obj == null)
throw new ArgumentNullException("obj");
// if this reference owns the lock, release it
if (_obj == obj) {
_obj = null;
_locked = 0;
return;
}
// if no reference owns the lock, try to cache this reference
if (_obj == null) {
// try to obtain the lock
if (0 == Interlocked.Exchange(ref _locked, 1)) {
// if there's really no reference, cache this reference
if (_ref == null)
_ref = (RegexRunner) obj;
// release the lock
_locked = 0;
return;
}
}
}
}
/*
* Used to cache a weak reference in a threadsafe way
*/
internal sealed class SharedReference {
WeakReference _ref = new WeakReference(null);
int _locked;
/*
* Return an object from a weakref, protected by a lock.
*
* If the exclusive lock can't be obtained, null is returned;
*
* Note that _ref.Target is referenced only under the protection
* of the lock. (Is this necessary?)
*/
internal Object Get() {
if (0 == Interlocked.Exchange(ref _locked, 1)) {
Object obj = _ref.Target;
_locked = 0;
return obj;
}
return null;
}
/*
* Suggest an object into a weakref, protected by a lock.
*
* Note that _ref.Target is referenced only under the protection
* of the lock. (Is this necessary?)
*/
internal void Cache(Object obj) {
if (0 == Interlocked.Exchange(ref _locked, 1)) {
_ref.Target = obj;
_locked = 0;
}
}
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//------------------------------------------------------------------------------
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
//-----------------------------------------------------------------------------
// The Regex class represents a single compiled instance of a regular
// expression.
namespace System.Text.RegularExpressions {
using System;
using System.Threading;
using System.Collections;
using System.Runtime.Serialization;
using System.Reflection;
using System.Reflection.Emit;
using System.Globalization;
using System.Security.Policy;
using System.Security.Permissions;
using System.Runtime.CompilerServices;
using System.Collections.Generic;
using System.Runtime.Versioning;
///
///
/// Represents an immutable, compiled regular expression. Also
/// contains static methods that allow use of regular expressions without instantiating
/// a Regex explicitly.
///
///
[ Serializable() ]
public class Regex : ISerializable {
// Fields used by precompiled regexes
protected internal string pattern;
protected internal RegexRunnerFactory factory; // if compiled, this is the RegexRunner subclass
protected internal RegexOptions roptions; // the top-level options from the options string
protected internal Hashtable caps; // if captures are sparse, this is the hashtable capnum->index
protected internal Hashtable capnames; // if named captures are used, this maps names->index
protected internal String[] capslist; // if captures are sparse or named captures are used, this is the sorted list of names
protected internal int capsize; // the size of the capture array
internal ExclusiveReference runnerref; // cached runner
internal SharedReference replref; // cached parsed replacement pattern
internal RegexCode code; // if interpreted, this is the code for RegexIntepreter
internal bool refsInitialized = false;
internal static LinkedList livecode = new LinkedList();// the cached of code and factories that are currently loaded
internal static int cacheSize = 15;
internal const int MaxOptionShift = 10;
protected Regex() {
}
/*
* Compiles and returns a Regex object corresponding to the given pattern
*/
///
///
/// Creates and compiles a regular expression object for the specified regular
/// expression.
///
///
public Regex(String pattern) : this(pattern, RegexOptions.None, false) {
}
/*
* Returns a Regex object corresponding to the given pattern, compiled with
* the specified options.
*/
///
///
/// Creates and compiles a regular expression object for the
/// specified regular expression
/// with options that modify the pattern.
///
///
public Regex(String pattern, RegexOptions options) : this(pattern, options, false){
}
private Regex(String pattern, RegexOptions options, bool useCache) {
RegexTree tree;
CachedCodeEntry cached = null;
string cultureKey = null;
if (pattern == null)
throw new ArgumentNullException("pattern");
if (options < RegexOptions.None || ( ((int) options) >> MaxOptionShift) != 0)
throw new ArgumentOutOfRangeException("options");
if ((options & RegexOptions.ECMAScript) != 0
&& (options & ~(RegexOptions.ECMAScript |
RegexOptions.IgnoreCase |
RegexOptions.Multiline |
RegexOptions.Compiled |
RegexOptions.CultureInvariant
#if DBG
| RegexOptions.Debug
#endif
)) != 0)
throw new ArgumentOutOfRangeException("options");
// Try to look up this regex in the cache. We do this regardless of whether useCache is true since there's
// really no reason not to.
if ((options & RegexOptions.CultureInvariant) != 0)
cultureKey = CultureInfo.InvariantCulture.ThreeLetterWindowsLanguageName;
else
cultureKey = CultureInfo.CurrentCulture.ThreeLetterWindowsLanguageName;
String key = ((int) options).ToString(NumberFormatInfo.InvariantInfo) + ":" + cultureKey + ":" + pattern;
cached = LookupCachedAndUpdate(key);
this.pattern = pattern;
this.roptions = options;
if (cached == null) {
// Parse the input
tree = RegexParser.Parse(pattern, roptions);
// Extract the relevant information
capnames = tree._capnames;
capslist = tree._capslist;
code = RegexWriter.Write(tree);
caps = code._caps;
capsize = code._capsize;
InitializeReferences();
tree = null;
if (useCache)
cached = CacheCode(key);
}
else {
caps = cached._caps;
capnames = cached._capnames;
capslist = cached._capslist;
capsize = cached._capsize;
code = cached._code;
factory = cached._factory;
runnerref = cached._runnerref;
replref = cached._replref;
refsInitialized = true;
}
// if the compile option is set, then compile the code if it's not already
if (UseOptionC() && factory == null) {
factory = Compile(code, roptions);
if (useCache && cached != null)
cached.AddCompiled(factory);
code = null;
}
}
/*
* ISerializable constructor
*/
protected Regex(SerializationInfo info, StreamingContext context) : this(info.GetString("pattern"), (RegexOptions) info.GetInt32("options")) {
}
/*
* ISerializable method
*/
///
///
/// Escapes
/// a minimal set of metacharacters (\, *, +, ?, |, {, [, (, ), ^, $, ., #, and
/// whitespace) by replacing them with their \ codes. This converts a string so that
/// it can be used as a constant within a regular expression safely. (Note that the
/// reason # and whitespace must be escaped is so the string can be used safely
/// within an expression parsed with x mode. If future Regex features add
/// additional metacharacters, developers should depend on Escape to escape those
/// characters as well.)
///
///
public static String Escape(String str) {
if (str==null)
throw new ArgumentNullException("str");
return RegexParser.Escape(str);
}
/*
* Unescape character codes within the string
*/
///
///
/// Unescapes any escaped characters in the input string.
///
///
public static String Unescape(String str) {
if (str==null)
throw new ArgumentNullException("str");
return RegexParser.Unescape(str);
}
public static int CacheSize {
get {
return cacheSize;
}
set {
if (value < 0)
throw new ArgumentOutOfRangeException("value");
cacheSize = value;
if (livecode.Count > cacheSize) {
lock (livecode) {
while (livecode.Count > cacheSize)
livecode.RemoveLast();
}
}
}
}
///
///
/// Returns the options passed into the constructor
///
///
public RegexOptions Options {
get { return roptions;}
}
/*
* True if the regex is leftward
*/
///
///
/// Indicates whether the regular expression matches from right to
/// left.
///
///
public bool RightToLeft {
get {
return UseOptionR();
}
}
///
///
/// Returns the regular expression pattern passed into the constructor
///
///
public override string ToString() {
return pattern;
}
/*
* Returns an array of the group names that are used to capture groups
* in the regular expression. Only needed if the regex is not known until
* runtime, and one wants to extract captured groups. (Probably unusual,
* but supplied for completeness.)
*/
///
/// Returns
/// the GroupNameCollection for the regular expression. This collection contains the
/// set of strings used to name capturing groups in the expression.
///
public String[] GetGroupNames() {
String[] result;
if (capslist == null) {
int max = capsize;
result = new String[max];
for (int i = 0; i < max; i++) {
result[i] = Convert.ToString(i, CultureInfo.InvariantCulture);
}
}
else {
result = new String[capslist.Length];
System.Array.Copy(capslist, 0, result, 0, capslist.Length);
}
return result;
}
/*
* Returns an array of the group numbers that are used to capture groups
* in the regular expression. Only needed if the regex is not known until
* runtime, and one wants to extract captured groups. (Probably unusual,
* but supplied for completeness.)
*/
///
/// returns
/// the integer group number corresponding to a group name.
///
public int[] GetGroupNumbers() {
int[] result;
if (caps == null) {
int max = capsize;
result = new int[max];
for (int i = 0; i < max; i++) {
result[i] = i;
}
}
else {
result = new int[caps.Count];
IDictionaryEnumerator de = caps.GetEnumerator();
while (de.MoveNext()) {
result[(int)de.Value] = (int)de.Key;
}
}
return result;
}
/*
* Given a group number, maps it to a group name. Note that nubmered
* groups automatically get a group name that is the decimal string
* equivalent of its number.
*
* Returns null if the number is not a recognized group number.
*/
///
///
/// Retrieves a group name that corresponds to a group number.
///
///
public String GroupNameFromNumber(int i) {
if (capslist == null) {
if (i >= 0 && i < capsize)
return i.ToString(CultureInfo.InvariantCulture);
return String.Empty;
}
else {
if (caps != null) {
Object obj = caps[i];
if (obj == null)
return String.Empty;
i = (int)obj;
}
if (i >= 0 && i < capslist.Length)
return capslist[i];
return String.Empty;
}
}
/*
* Given a group name, maps it to a group number. Note that nubmered
* groups automatically get a group name that is the decimal string
* equivalent of its number.
*
* Returns -1 if the name is not a recognized group name.
*/
///
///
/// Returns a group number that corresponds to a group name.
///
///
public int GroupNumberFromName(String name) {
int result = -1;
if (name == null)
throw new ArgumentNullException("name");
// look up name if we have a hashtable of names
if (capnames != null) {
Object ret = capnames[name];
if (ret == null)
return -1;
return(int)ret;
}
// convert to an int if it looks like a number
result = 0;
for (int i = 0; i < name.Length; i++) {
char ch = name[i];
if (ch > '9' || ch < '0')
return -1;
result *= 10;
result += (ch - '0');
}
// return int if it's in range
if (result >= 0 && result < capsize)
return result;
return -1;
}
/*
* Static version of simple IsMatch call
*/
///
///
/// Searches the input
/// string for one or more occurrences of the text supplied in the pattern
/// parameter.
///
///
public static bool IsMatch(String input, String pattern) {
return new Regex(pattern, RegexOptions.None, true).IsMatch(input);
}
/*
* Static version of simple IsMatch call
*/
///
///
/// Searches the input string for one or more occurrences of the text
/// supplied in the pattern parameter with matching options supplied in the options
/// parameter.
///
///
public static bool IsMatch(String input, String pattern, RegexOptions options) {
return new Regex(pattern, options, true).IsMatch(input);
}
/*
* Returns true if the regex finds a match within the specified string
*/
///
///
/// Searches the input string for one or
/// more matches using the previous pattern, options, and starting
/// position.
///
///
public bool IsMatch(String input) {
if (input == null)
throw new ArgumentNullException("input");
return(null == Run(true, -1, input, 0, input.Length, UseOptionR() ? input.Length : 0));
}
/*
* Returns true if the regex finds a match after the specified position
* (proceeding leftward if the regex is leftward and rightward otherwise)
*/
///
///
/// Searches the input
/// string for one or more matches using the previous pattern and options, with
/// a new starting position.
///
///
public bool IsMatch(String input, int startat) {
if (input == null)
throw new ArgumentNullException("input");
return(null == Run(true, -1, input, 0, input.Length, startat));
}
/*
* Static version of simple Match call
*/
///
///
/// Searches the input string for one or more occurrences of the text
/// supplied in the pattern parameter.
///
///
public static Match Match(String input, String pattern) {
return new Regex(pattern, RegexOptions.None, true).Match(input);
}
/*
* Static version of simple Match call
*/
///
///
/// Searches the input string for one or more occurrences of the text
/// supplied in the pattern parameter. Matching is modified with an option
/// string.
///
///
public static Match Match(String input, String pattern, RegexOptions options) {
return new Regex(pattern, options, true).Match(input);
}
/*
* Finds the first match for the regular expression starting at the beginning
* of the string (or at the end of the string if the regex is leftward)
*/
///
///
/// Matches a regular expression with a string and returns
/// the precise result as a RegexMatch object.
///
///
public Match Match(String input) {
if (input == null)
throw new ArgumentNullException("input");
return Run(false, -1, input, 0, input.Length, UseOptionR() ? input.Length : 0);
}
/*
* Finds the first match, starting at the specified position
*/
///
/// Matches a regular expression with a string and returns
/// the precise result as a RegexMatch object.
///
public Match Match(String input, int startat) {
if (input == null)
throw new ArgumentNullException("input");
return Run(false, -1, input, 0, input.Length, startat);
}
/*
* Finds the first match, restricting the search to the specified interval of
* the char array.
*/
///
///
/// Matches a
/// regular expression with a string and returns the precise result as a
/// RegexMatch object.
///
///
public Match Match(String input, int beginning, int length) {
if (input == null)
throw new ArgumentNullException("input");
return Run(false, -1, input, beginning, length, UseOptionR() ? beginning + length : beginning);
}
/*
* Static version of simple Matches call
*/
///
///
/// Returns all the successful matches as if Match were
/// called iteratively numerous times.
///
///
public static MatchCollection Matches(String input, String pattern) {
return new Regex(pattern, RegexOptions.None, true).Matches(input);
}
/*
* Static version of simple Matches call
*/
///
///
/// Returns all the successful matches as if Match were called iteratively
/// numerous times.
///
///
public static MatchCollection Matches(String input, String pattern, RegexOptions options) {
return new Regex(pattern, options, true).Matches(input);
}
/*
* Finds the first match for the regular expression starting at the beginning
* of the string Enumerator(or at the end of the string if the regex is leftward)
*/
///
///
/// Returns
/// all the successful matches as if Match was called iteratively numerous
/// times.
///
///
public MatchCollection Matches(String input) {
if (input == null)
throw new ArgumentNullException("input");
return new MatchCollection(this, input, 0, input.Length, UseOptionR() ? input.Length : 0);
}
/*
* Finds the first match, starting at the specified position
*/
///
///
/// Returns
/// all the successful matches as if Match was called iteratively numerous
/// times.
///
///
public MatchCollection Matches(String input, int startat) {
if (input == null)
throw new ArgumentNullException("input");
return new MatchCollection(this, input, 0, input.Length, startat);
}
/*
* Static version of simple Replace call
*/
///
///
/// Replaces
/// all occurrences of the pattern with the
///
public static String Replace(String input, String pattern, String replacement) {
return new Regex(pattern, RegexOptions.None, true).Replace(input, replacement);
}
/*
* Static version of simple Replace call
*/
///
///
/// Replaces all occurrences of
/// the
///
public static String Replace(String input, String pattern, String replacement, RegexOptions options) {
return new Regex(pattern, options, true).Replace(input, replacement);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of
/// the
///
public String Replace(String input, String replacement) {
if (input == null)
throw new ArgumentNullException("input");
return Replace(input, replacement, -1, UseOptionR() ? input.Length : 0);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of the (previously defined)
///
public String Replace(String input, String replacement, int count) {
if (input == null)
throw new ArgumentNullException("input");
return Replace(input, replacement, count, UseOptionR() ? input.Length : 0);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of the
///
public String Replace(String input, String replacement, int count, int startat) {
RegexReplacement repl;
if (input == null)
throw new ArgumentNullException("input");
if (replacement == null)
throw new ArgumentNullException("replacement");
// a little code to grab a cached parsed replacement object
repl = (RegexReplacement)replref.Get();
if (repl == null || !repl.Pattern.Equals(replacement)) {
repl = RegexParser.ParseReplacement(replacement, caps, capsize, capnames, this.roptions);
replref.Cache(repl);
}
return repl.Replace(this, input, count, startat);
}
/*
* Static version of simple Replace call
*/
///
///
/// Replaces all occurrences of the
///
public static String Replace(String input, String pattern, MatchEvaluator evaluator) {
return new Regex(pattern, RegexOptions.None, true).Replace(input, evaluator);
}
/*
* Static version of simple Replace call
*/
///
///
/// Replaces all occurrences of the
///
public static String Replace(String input, String pattern, MatchEvaluator evaluator, RegexOptions options) {
return new Regex(pattern, options, true).Replace(input, evaluator);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of the
///
public String Replace(String input, MatchEvaluator evaluator) {
if (input==null)
throw new ArgumentNullException("input");
return Replace(input, evaluator, -1, UseOptionR() ? input.Length : 0);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of the
///
public String Replace(String input, MatchEvaluator evaluator, int count) {
if (input==null)
throw new ArgumentNullException("input");
return Replace(input, evaluator, count, UseOptionR() ? input.Length : 0);
}
/*
* Does the replacement
*/
///
///
/// Replaces all occurrences of the (previouly defined)
///
public String Replace(String input, MatchEvaluator evaluator, int count, int startat) {
if (input==null)
throw new ArgumentNullException("input");
return RegexReplacement.Replace(evaluator, this, input, count, startat);
}
/*
* Static version of simple Split call
*/
///
///
/// Splits the
///
public static String[] Split(String input, String pattern) {
return new Regex(pattern, RegexOptions.None, true).Split(input);
}
/*
* Static version of simple Split call
*/
///
///
/// Splits the
///
public static String[] Split(String input, String pattern, RegexOptions options) {
return new Regex(pattern, options, true).Split(input);
}
/*
* Does a split
*/
///
///
/// Splits the
///
public String[] Split(String input) {
if (input==null)
throw new ArgumentNullException("input");
return Split(input, 0, UseOptionR() ? input.Length : 0);
}
/*
* Does a split
*/
///
///
/// Splits the
///
public String[] Split(String input, int count) {
if (input==null)
throw new ArgumentNullException("input");
return RegexReplacement.Split(this, input, count, UseOptionR() ? input.Length : 0);
}
/*
* Does a split
*/
///
///
/// Splits the
///
public String[] Split(String input, int count, int startat) {
if (input==null)
throw new ArgumentNullException("input");
return RegexReplacement.Split(this, input, count, startat);
}
///
///
[HostProtection(MayLeakOnAbort=true)]
[ResourceExposure(ResourceScope.Machine)] // The AssemblyName is interesting.
[ResourceConsumption(ResourceScope.Machine)]
public static void CompileToAssembly(RegexCompilationInfo[] regexinfos, AssemblyName assemblyname) {
CompileToAssemblyInternal(regexinfos, assemblyname, null, null, Assembly.GetCallingAssembly().Evidence);
}
///
///
[HostProtection(MayLeakOnAbort=true)]
[ResourceExposure(ResourceScope.Machine)] // The AssemblyName is interesting.
[ResourceConsumption(ResourceScope.Machine)]
public static void CompileToAssembly(RegexCompilationInfo[] regexinfos, AssemblyName assemblyname, CustomAttributeBuilder[] attributes) {
CompileToAssemblyInternal(regexinfos, assemblyname, attributes, null, Assembly.GetCallingAssembly().Evidence);
}
[HostProtection(MayLeakOnAbort=true)]
[ResourceExposure(ResourceScope.Machine)]
[ResourceConsumption(ResourceScope.Machine)]
public static void CompileToAssembly(RegexCompilationInfo[] regexinfos, AssemblyName assemblyname, CustomAttributeBuilder[] attributes, String resourceFile) {
CompileToAssemblyInternal(regexinfos, assemblyname, attributes, resourceFile, Assembly.GetCallingAssembly().Evidence);
}
[ResourceExposure(ResourceScope.Machine)] // AssemblyName & resourceFile
[ResourceConsumption(ResourceScope.Machine)]
private static void CompileToAssemblyInternal (RegexCompilationInfo[] regexinfos, AssemblyName assemblyname, CustomAttributeBuilder[] attributes, String resourceFile, Evidence evidence) {
if (assemblyname == null)
throw new ArgumentNullException("assemblyname");
if (regexinfos == null)
throw new ArgumentNullException("regexinfos");
RegexCompiler.CompileToAssembly(regexinfos, assemblyname, attributes, resourceFile, evidence);
}
///
///
protected void InitializeReferences() {
if (refsInitialized)
throw new NotSupportedException(SR.GetString(SR.OnlyAllowedOnce));
refsInitialized = true;
runnerref = new ExclusiveReference();
replref = new SharedReference();
}
/*
* Internal worker called by all the public APIs
*/
internal Match Run(bool quick, int prevlen, String input, int beginning, int length, int startat) {
Match match;
RegexRunner runner = null;
if (startat < 0 || startat > input.Length)
throw new ArgumentOutOfRangeException("start", SR.GetString(SR.BeginIndexNotNegative));
if (length < 0 || length > input.Length)
throw new ArgumentOutOfRangeException("length", SR.GetString(SR.LengthNotNegative));
// There may be a cached runner; grab ownership of it if we can.
runner = (RegexRunner)runnerref.Get();
// Create a RegexRunner instance if we need to
if (runner == null) {
// Use the compiled RegexRunner factory if the code was compiled to MSIL
if (factory != null)
runner = factory.CreateInstance();
else
runner = new RegexInterpreter(code, UseOptionInvariant() ? CultureInfo.InvariantCulture : CultureInfo.CurrentCulture);
}
// Do the scan starting at the requested position
match = runner.Scan(this, input, beginning, beginning + length, startat, prevlen, quick);
// Release or fill the cache slot
runnerref.Release(runner);
#if DBG
if (Debug && match != null)
match.Dump();
#endif
return match;
}
/*
* Find code cache based on options+pattern
*/
private static CachedCodeEntry LookupCachedAndUpdate(String key) {
lock (livecode) {
for (LinkedListNode current = livecode.First; current != null; current = current.Next) {
if (current.Value._key == key) {
// If we find an entry in the cache, move it to the head at the same time.
livecode.Remove(current);
livecode.AddFirst(current);
return current.Value;
}
}
}
return null;
}
/*
* Add current code to the cache
*/
private CachedCodeEntry CacheCode(String key) {
CachedCodeEntry newcached = null;
lock (livecode) {
// first look for it in the cache and move it to the head
for (LinkedListNode current = livecode.First; current != null; current = current.Next) {
if (current.Value._key == key) {
livecode.Remove(current);
livecode.AddFirst(current);
return current.Value;
}
}
// it wasn't in the cache, so we'll add a new one. Shortcut out for the case where cacheSize is zero.
if (cacheSize != 0) {
newcached = new CachedCodeEntry(key, capnames, capslist, code, caps, capsize, runnerref, replref);
livecode.AddFirst(newcached);
if (livecode.Count > cacheSize)
livecode.RemoveLast();
}
}
return newcached;
}
/*
* True if the O option was set
*/
///
///
protected bool UseOptionC() {
return(roptions & RegexOptions.Compiled) != 0;
}
/*
* True if the L option was set
*/
///
///
protected bool UseOptionR() {
return(roptions & RegexOptions.RightToLeft) != 0;
}
internal bool UseOptionInvariant() {
return(roptions & RegexOptions.CultureInvariant) != 0;
}
#if DBG
/*
* True if the regex has debugging enabled
*/
///
///
internal bool Debug {
get {
return(roptions & RegexOptions.Debug) != 0;
}
}
#endif
}
/*
* Callback class
*/
///
///
[ Serializable() ]
public delegate String MatchEvaluator(Match match);
/*
* Used to cache byte codes or compiled factories
*/
internal sealed class CachedCodeEntry {
internal string _key;
internal RegexCode _code;
internal Hashtable _caps;
internal Hashtable _capnames;
internal String[] _capslist;
internal int _capsize;
internal RegexRunnerFactory _factory;
internal ExclusiveReference _runnerref;
internal SharedReference _replref;
internal CachedCodeEntry(string key, Hashtable capnames, String[] capslist, RegexCode code, Hashtable caps, int capsize, ExclusiveReference runner, SharedReference repl) {
_key = key;
_capnames = capnames;
_capslist = capslist;
_code = code;
_caps = caps;
_capsize = capsize;
_runnerref = runner;
_replref = repl;
}
internal void AddCompiled(RegexRunnerFactory factory) {
_factory = factory;
_code = null;
}
}
/*
* Used to cache one exclusive runner reference
*/
internal sealed class ExclusiveReference {
RegexRunner _ref;
Object _obj;
int _locked;
/*
* Return an object and grab an exclusive lock.
*
* If the exclusive lock can't be obtained, null is returned;
* if the object can't be returned, the lock is released.
*
*/
internal Object Get() {
// try to obtain the lock
if (0 == Interlocked.Exchange(ref _locked, 1)) {
// grab reference
Object obj = _ref;
// release the lock and return null if no reference
if (obj == null) {
_locked = 0;
return null;
}
// remember the reference and keep the lock
_obj = obj;
return obj;
}
return null;
}
/*
* Release an object back to the cache
*
* If the object is the one that's under lock, the lock
* is released.
*
* If there is no cached object, then the lock is obtained
* and the object is placed in the cache.
*
*/
internal void Release(Object obj) {
if (obj == null)
throw new ArgumentNullException("obj");
// if this reference owns the lock, release it
if (_obj == obj) {
_obj = null;
_locked = 0;
return;
}
// if no reference owns the lock, try to cache this reference
if (_obj == null) {
// try to obtain the lock
if (0 == Interlocked.Exchange(ref _locked, 1)) {
// if there's really no reference, cache this reference
if (_ref == null)
_ref = (RegexRunner) obj;
// release the lock
_locked = 0;
return;
}
}
}
}
/*
* Used to cache a weak reference in a threadsafe way
*/
internal sealed class SharedReference {
WeakReference _ref = new WeakReference(null);
int _locked;
/*
* Return an object from a weakref, protected by a lock.
*
* If the exclusive lock can't be obtained, null is returned;
*
* Note that _ref.Target is referenced only under the protection
* of the lock. (Is this necessary?)
*/
internal Object Get() {
if (0 == Interlocked.Exchange(ref _locked, 1)) {
Object obj = _ref.Target;
_locked = 0;
return obj;
}
return null;
}
/*
* Suggest an object into a weakref, protected by a lock.
*
* Note that _ref.Target is referenced only under the protection
* of the lock. (Is this necessary?)
*/
internal void Cache(Object obj) {
if (0 == Interlocked.Exchange(ref _locked, 1)) {
_ref.Target = obj;
_locked = 0;
}
}
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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- RowUpdatingEventArgs.cs
- StyleSheetComponentEditor.cs
- IisTraceWebEventProvider.cs
- MatrixConverter.cs
- SystemWebExtensionsSectionGroup.cs
- ProfileEventArgs.cs
- HeaderedContentControl.cs
- PerformanceCounterPermissionEntry.cs
- LogicalExpr.cs
- XmlCustomFormatter.cs
- DllNotFoundException.cs
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- AnnotationResource.cs
- DataServiceRequest.cs
- DocumentApplicationJournalEntryEventArgs.cs
- CodeEntryPointMethod.cs
- SerializationFieldInfo.cs
- DigestComparer.cs
- DragSelectionMessageFilter.cs
- CodeTypeMemberCollection.cs
- XmlSignatureManifest.cs
- RouteData.cs
- SqlDelegatedTransaction.cs
- HtmlShim.cs
- HtmlMeta.cs
- AssemblyAttributesGoHere.cs
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- DataControlButton.cs
- MethodBuilder.cs
- XamlFigureLengthSerializer.cs
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- TreeViewItemAutomationPeer.cs
- Cloud.cs
- HostedHttpContext.cs
- CompositeTypefaceMetrics.cs
- ProtocolsConfiguration.cs
- XmlArrayAttribute.cs
- StaticResourceExtension.cs
- MaterialCollection.cs
- AccessDataSourceWizardForm.cs
- RegexGroupCollection.cs
- MeasurementDCInfo.cs
- XmlToDatasetMap.cs
- XmlSchemaAppInfo.cs
- ProxyAttribute.cs
- RelatedPropertyManager.cs
- ToolboxItemFilterAttribute.cs
- SerialErrors.cs
- ExtensibleClassFactory.cs
- NamedPipeActivation.cs
- ProtectedConfigurationSection.cs
- XmlAutoDetectWriter.cs
- _ScatterGatherBuffers.cs
- TextParaClient.cs
- SerializationException.cs
- GCHandleCookieTable.cs
- TablePattern.cs
- NCryptSafeHandles.cs
- MatrixTransform.cs
- Rect3DConverter.cs
- XPathItem.cs
- SecurityState.cs
- Visual.cs
- AutomationProperty.cs
- XMLSchema.cs
- ResetableIterator.cs
- GenericXmlSecurityToken.cs
- ImageSource.cs
- MobileControlBuilder.cs
- PeerNameResolver.cs
- IntMinMaxAggregationOperator.cs
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- WindowInteropHelper.cs
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