//
// System.Web.Caching.CachedDependency
//
// Author(s):
// Lluis Sanchez (lluis@ximian.com)
//
// (C) 2005 Novell, Inc (http://www.novell.com)
//
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System.Collections;
using System.ComponentModel;
using System.IO;
using System.Security.Permissions;
using System.Text;
namespace System.Web.Caching{
// CAS
[AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
[AspNetHostingPermission (SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
public class CacheDependency: IDisposable
{
static readonly object dependencyChangedEvent = new object ();
string[] cachekeys;
CacheDependency dependency;
DateTime start;
Cache cache;
FileSystemWatcher[] watchers;
bool hasChanged;
bool used;
DateTime utcLastModified;
object locker = new object ();
EventHandlerList events = new EventHandlerList ();
internal event EventHandler DependencyChanged {
add { events.AddHandler (dependencyChangedEvent, value); }
remove { events.RemoveHandler (dependencyChangedEvent, value); }
}
#if NET_4_0
protected
#else
public
#endif
CacheDependency (): this (null, null, null, DateTime.Now)
{
}
public CacheDependency (string filename): this (new string[] { filename }, null, null, DateTime.Now)
{
}
public CacheDependency (string[] filenames): this (filenames, null, null, DateTime.Now)
{
}
public CacheDependency (string filename, DateTime start): this (new string[] { filename }, null, null, start)
{
}
public CacheDependency (string [] filenames, DateTime start)
: this (filenames, null, null, start)
{
}
public CacheDependency (string[] filenames, string[] cachekeys): this (filenames, cachekeys, null, DateTime.Now)
{
}
public CacheDependency (string[] filenames, string[] cachekeys, CacheDependency dependency): this (filenames, cachekeys, dependency, DateTime.Now)
{
}
public CacheDependency (string[] filenames, string[] cachekeys, DateTime start): this (filenames, cachekeys, null, start)
{
}
public CacheDependency (string[] filenames, string[] cachekeys, CacheDependency dependency, DateTime start)
{
int flen = filenames != null ? filenames.Length : 0;
if (flen > 0) {
watchers = new FileSystemWatcher [flen];
string filename;
for (int n = 0; n < flen; n++) {
filename = filenames [n];
if (String.IsNullOrEmpty (filename))
continue;
FileSystemWatcher watcher = new FileSystemWatcher ();
if (Directory.Exists (filename))
watcher.Path = filename;
else {
string parentPath = Path.GetDirectoryName (filename);
if (parentPath != null && Directory.Exists (parentPath)) {
watcher.Path = parentPath;
watcher.Filter = Path.GetFileName (filename);
} else
continue;
}
watcher.NotifyFilter |= NotifyFilters.Size;
watcher.Created += new FileSystemEventHandler (OnChanged);
watcher.Changed += new FileSystemEventHandler (OnChanged);
watcher.Deleted += new FileSystemEventHandler (OnChanged);
watcher.Renamed += new RenamedEventHandler (OnChanged);
watcher.EnableRaisingEvents = true;
watchers [n] = watcher;
}
}
this.cachekeys = cachekeys;
this.dependency = dependency;
if (dependency != null)
dependency.DependencyChanged += new EventHandler (OnChildDependencyChanged);
this.start = start;
FinishInit ();
}
public virtual string GetUniqueID ()
{
var sb = new StringBuilder ();
lock (locker) {
if (watchers != null)
foreach (FileSystemWatcher fsw in watchers)
if (fsw != null && fsw.Path != null && fsw.Path.Length != 0)
sb.Append ("_" + fsw.Path);
}
if (cachekeys != null)
foreach (string key in cachekeys)
sb.AppendFormat ("_" + key);
return sb.ToString ();
}
void OnChanged (object sender, FileSystemEventArgs args)
{
OnDependencyChanged (sender, args);
}
bool DoOnChanged ()
{
DateTime now = DateTime.Now;
if (now < start)
return false;
hasChanged = true;
utcLastModified = now.ToUniversalTime ();
DisposeWatchers ();
if (cache != null)
cache.CheckDependencies ();
return true;
}
void DisposeWatchers ()
{
lock (locker) {
if (watchers != null) {
foreach (FileSystemWatcher w in watchers)
if (w != null)
w.Dispose ();
}
watchers = null;
}
}
public void Dispose ()
{
DependencyDispose ();
}
internal virtual void DependencyDisposeInternal ()
{
}
protected virtual void DependencyDispose ()
{
DependencyDisposeInternal ();
DisposeWatchers ();
if (dependency != null) {
dependency.DependencyChanged -= new EventHandler (OnChildDependencyChanged);
dependency.Dispose ();
}
cache = null;
}
internal void SetCache (Cache c)
{
cache = c;
used = c != null;
}
protected internal void FinishInit ()
{
utcLastModified = DateTime.UtcNow;
}
internal bool IsUsed {
get { return used; }
}
internal DateTime Start {
get { return start; }
set { start = value; }
}
public DateTime UtcLastModified {
get {
return utcLastModified;
}
}
protected void SetUtcLastModified (DateTime utcLastModified)
{
this.utcLastModified = utcLastModified;
}
public bool HasChanged {
get {
if (hasChanged)
return true;
if (DateTime.Now < start)
return false;
if (cache != null && cachekeys != null) {
foreach (string key in cachekeys) {
if (cache.GetKeyLastChange (key) > start) {
hasChanged = true;
break;
}
}
}
if (hasChanged)
DisposeWatchers ();
return hasChanged;
}
}
void OnChildDependencyChanged (object o, EventArgs e)
{
hasChanged = true;
OnDependencyChanged (o, e);
}
void OnDependencyChanged (object sender, EventArgs e)
{
if (!DoOnChanged ())
return;
EventHandler eh = events [dependencyChangedEvent] as EventHandler;
if (eh != null)
eh (sender, e);
}
protected void NotifyDependencyChanged (object sender, EventArgs e)
{
OnDependencyChanged (sender, e);
}
}
}
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