// finds and matches a tracker (this a or sub-tracker in varyby cases) for a HttpRequest
public Tracker FindTrackerForRequest(HttpRequest request)
{
// path
if (String.Compare(_path, request.FilePath, StringComparison.OrdinalIgnoreCase) != 0)
{
return null;
}
// verbs
bool verbMatchFound = String.Compare(_verbs[0], request.HttpMethod, StringComparison.OrdinalIgnoreCase) == 0;
if (!verbMatchFound && _verbs.Length > 1)
{
for (int i = 1; i < _verbs.Length; i++)
{
if (String.Compare(_verbs[i], request.HttpMethod, StringComparison.OrdinalIgnoreCase) == 0)
{
verbMatchFound = true;
break;
}
}
}
if (!verbMatchFound)
{
return null;
}
// path info
if (_emptyPathInfoOnly && !string.IsNullOrEmpty(request.PathInfo))
{
return null;
}
// query string
if (_emptyQueryStringOnly && request.QueryString.Count > 0)
{
return null;
}
// in non-vary-by case return this tracker
if (_varyBy == null || _varyBy.Length == 0)
{
return this;
}
// get the child tracker corresponding to vary-by key for this request
Tracker childTracker = null;
string varyByKey = CalculateVaryByKey(_varyBy, request);
lock (_varyByTrackers)
{
if (!_varyByTrackers.TryGetValue(varyByKey, out childTracker))
{
// create a new child tracker if not exceeding the limit already
if (_varyByTrackers.Count < HttpModule.OutputCache.VaryByLimit)
{
childTracker = new Tracker(this, varyByKey);
_varyByTrackers.Add(varyByKey, childTracker);
}
}
}
return childTracker;
}
// private ctor to create a child tracker for a specific vary-by value
Tracker(Tracker parent, string varyById)
{
_parent = parent;
_path = parent._path;
_duration = parent._duration;
_verbs = parent._verbs;
_varyBy = parent._varyBy;
_serveFromMemory = parent._serveFromMemory;
_varyById = varyById;
_filenamePrefix = string.Format("{0}_q_{1:x8}", parent._filenamePrefix, varyById.GetHashCode());
_capturingEvent = new ManualResetEvent(true);
_varyByTrackers = null; // no need for sub-sub-trackers
}
void OnResolveRequestCache(object sender, EventArgs e)
{
// start clean
_trackerCapturingResponse = null;
Tracker tracker = HttpModule.OutputCache.Lookup(_app.Context);
if (tracker == null)
{
// this request is not subject to cache
return;
}
// try to send response or start capture
// (use 'finally' because starting capture would lock)
try { }
finally
{
if (tracker.TrySendResponseOrStartResponseCapture(_app.Response))
{
// successfully sent current response
_app.CompleteRequest();
}
else
{
// started capturing
_trackerCapturingResponse = tracker;
}
}
}
void OnEndRequest(object sender, EventArgs e)
{
if (_trackerCapturingResponse != null)
{
// if still capturing, abandon the process
try
{
_trackerCapturingResponse.CancelCapture(_app.Response);
}
finally
{
_trackerCapturingResponse = null;
}
}
}
void OnUpdateRequestCache(object sender, EventArgs e)
{
if (_trackerCapturingResponse != null)
{
// if capturing, finish the capture and save the file
_trackerCapturingResponse.FinishCaptureAndSaveResponse(_app.Response);
_trackerCapturingResponse = null;
}
}
bool Startup()
{
DiskOutputCacheSettingsSection config = (DiskOutputCacheSettingsSection)
WebConfigurationManager.GetWebApplicationSection("diskOutputCacheSettings");
if (config == null)
{
// no config - the list of URLs is empty
return false;
}
if (string.IsNullOrEmpty(config.Location))
{
// the default location is in temporary asp.net files
_location = Path.Combine(HttpRuntime.CodegenDir, "DiskOutputCache");
if (!Directory.Exists(_location))
{
Directory.CreateDirectory(_location);
}
}
else
{
_location = config.Location;
if (!Directory.Exists(_location))
{
throw new InvalidDataException(string.Format("Invalid location '{0}'", _location));
}
}
_varyByLimit = config.VaryByLimitPerUrl;
_fileValidationDelay = config.FileValidationDelay;
foreach (CachedUrlsElement e in config.CachedUrls)
{
string path = e.Path;
if (!VirtualPathUtility.IsAppRelative(path) && !VirtualPathUtility.IsAbsolute(path))
{
throw new InvalidDataException(string.Format("Invalid path '{0}', absolute or app-relative path expected", path));
}
path = VirtualPathUtility.ToAbsolute(path);
// create file path prefix for this path
string relPathPrefix = VirtualPathUtility.ToAppRelative(path);
if (relPathPrefix.StartsWith("~/"))
{
relPathPrefix = relPathPrefix.Substring(2);
}
relPathPrefix = relPathPrefix.Replace('.', '_');
relPathPrefix = relPathPrefix.Replace('/', '_');
// list of verbs
string[] verbs = ParseStringList(e.Verbs);
if (verbs.Length == 0)
{
throw new InvalidDataException(string.Format("Invalid list of verbs '{0}'", e.Verbs));
}
// vary-by
string[] varyBy = ParseStringList(e.VaryBy);
// remember the tracker object
_trackers[path] = new Tracker(path, Path.Combine(_location, relPathPrefix), e.Duration,
verbs, varyBy, e.EmptyQueryStringOnly, e.EmptyPathInfoOnly, e.ServeFromMemory);
}
return true;
}
