// Example of configPath = "machine/webroot/1/fxtest/sub/foo.aspx"
// The configPath parameter must be lower case.
static private CachedPathData GetConfigPathData(string configPath)
{
Debug.Assert(ConfigPathUtility.IsValid(configPath), "ConfigPathUtility.IsValid(configPath)");
Debug.Assert(configPath == configPath.ToLower(CultureInfo.InvariantCulture), "configPath == configPath.ToLower(CultureInfo.InvariantCulture)");
bool exists = false;
bool isDirectory = false;
bool isRemovable = IsCachedPathDataRemovable(configPath);
// if the sliding expiration is zero, we won't cache it unless it is a configPath for root web.config or above
if (isRemovable && DoNotCacheUrlMetadata)
{
string pathSiteID = null;
VirtualPath virtualFilePath = null;
string physicalFilePath = null;
WebConfigurationHost.GetSiteIDAndVPathFromConfigPath(configPath, out pathSiteID, out virtualFilePath);
physicalFilePath = GetPhysicalPath(virtualFilePath);
string parentConfigPath = ConfigPathUtility.GetParent(configPath);
CachedPathData pathParentData = GetConfigPathData(parentConfigPath);
if (!String.IsNullOrEmpty(physicalFilePath))
{
FileUtil.PhysicalPathStatus(physicalFilePath, false, false, out exists, out isDirectory);
}
CachedPathData pathData = new CachedPathData(configPath, virtualFilePath, physicalFilePath, exists);
pathData.Init(pathParentData);
return(pathData);
}
//
// First, see if the CachedPathData is in the cache.
// we don't use Add for this lookup, as doing so requires
// creating a CacheDependency, which can be slow as it may hit
// the filesystem.
//
string key = CreateKey(configPath);
CacheStoreProvider cacheInternal = HttpRuntime.Cache.InternalCache;
CachedPathData data = (CachedPathData)cacheInternal.Get(key);
// if found, return the data
if (data != null)
{
data.WaitForInit();
return(data);
}
// WOS
bool cacheEntryIsNotRemovable = false;
// if not found, try to add it
string siteID = null;
VirtualPath virtualPath = null;
CachedPathData parentData = null;
CacheDependency dependency = null;
string physicalPath = null;
string[] fileDependencies = null;
string[] cacheItemDependencies = null;
if (WebConfigurationHost.IsMachineConfigPath(configPath))
{
cacheEntryIsNotRemovable = true;
}
else
{
// Make sure we have the parent data so we can create a dependency on the parent.
// The parent dependency will ensure that configuration data in the parent
// will be referenced by a cache hit on the child. (see UtcUpdateUsageRecursive in Cache.cs)
string parentConfigPath = ConfigPathUtility.GetParent(configPath);
parentData = GetConfigPathData(parentConfigPath);
string parentKey = CreateKey(parentConfigPath);
cacheItemDependencies = new string[1] {
parentKey
};
if (!WebConfigurationHost.IsVirtualPathConfigPath(configPath))
{
// assume hardcoded levels above the path, such as root web.config, exist
cacheEntryIsNotRemovable = true;
}
else
{
cacheEntryIsNotRemovable = !isRemovable;
WebConfigurationHost.GetSiteIDAndVPathFromConfigPath(configPath, out siteID, out virtualPath);
physicalPath = GetPhysicalPath(virtualPath);
// Add a dependency on the path itself, if it is a file,
// to handle the case where a file is deleted and replaced
// with a directory of the same name.
if (!String.IsNullOrEmpty(physicalPath))
{
FileUtil.PhysicalPathStatus(physicalPath, false, false, out exists, out isDirectory);
if (exists && !isDirectory)
{
fileDependencies = new string[1] {
physicalPath
};
}
}
}
try {
dependency = new CacheDependency(0, fileDependencies, cacheItemDependencies);
}
catch {
// CacheDependency ctor could fail because of bogus file path
// and it is ok not to watch those
}
}
// Try to add the CachedPathData to the cache.
CachedPathData dataAdd = null;
bool isDataCreator = false;
bool initCompleted = false;
CacheItemPriority priority = cacheEntryIsNotRemovable ? CacheItemPriority.NotRemovable : CacheItemPriority.Normal;
TimeSpan slidingExpiration = cacheEntryIsNotRemovable ? Cache.NoSlidingExpiration : UrlMetadataSlidingExpiration;
try {
using (dependency) {
dataAdd = new CachedPathData(configPath, virtualPath, physicalPath, exists);
try {
}
finally {
data = (CachedPathData)cacheInternal.Add(key, dataAdd, new CacheInsertOptions()
{
Dependencies = dependency,
SlidingExpiration = slidingExpiration,
Priority = priority,
OnRemovedCallback = s_callback
});
if (data == null)
{
isDataCreator = true;
}
}
}
// If another thread added it first, return the data
if (!isDataCreator)
{
data.WaitForInit();
return(data);
}
// This thread is the creator of the CachedPathData, initialize it
lock (dataAdd) {
try {
dataAdd.Init(parentData);
initCompleted = true;
}
finally {
// free waiters
dataAdd._flags[FInited] = true;
// Wake up waiters.
Monitor.PulseAll(dataAdd);
if (dataAdd._flags[FCloseNeeded])
{
// If we have received a call back to close, then lets
// make sure that our config object is cleaned up
dataAdd.Close();
}
}
}
}
finally {
// All the work in this finally block is for the case where we're the
// creator of the CachedPathData.
if (isDataCreator)
{
//
if (!dataAdd._flags[FInited])
{
lock (dataAdd) {
// free waiters
dataAdd._flags[FInited] = true;
// Wake up waiters.
Monitor.PulseAll(dataAdd);
if (dataAdd._flags[FCloseNeeded])
{
// If we have received a call back to close, then lets
// make sure that our config object is cleaned up
dataAdd.Close();
}
}
}
//
// Even though there is a try/catch handler surrounding the call to Init,
// a ThreadAbortException can still cause the handler to be bypassed.
//
// If there is an error, either a thread abort or an error in the config
// file itself, we do want to leave the item cached for a short period
// so that we do not revisit the error and potentially reparse the config file
// on every request.
//
// The reason we simply do not leave the item in the cache forever is that the
// problem that caused the configuration exception may be fixed without touching
// the config file in a way that causes a file change notification (for example, an
// acl change in a parent directory, or a change of path mapping in the metabase).
//
// NOTE: It is important to reinsert the item into the cache AFTER dropping
// the lock on dataAdd, in order to prevent the possibility of deadlock.
//
Debug.Assert(dataAdd._flags[FInited], "_flags[FInited]");
if (!initCompleted || (dataAdd.ConfigRecord != null && dataAdd.ConfigRecord.HasInitErrors))
{
//
// Create a new dependency object as the old one cannot be reused.
// Do not include a file dependency if initialization could not be completed,
// as invoking the file system could lead to further errors during a thread abort.
//
if (dependency != null)
{
if (!initCompleted)
{
dependency = new CacheDependency(0, null, cacheItemDependencies);
}
else
{
dependency = new CacheDependency(0, fileDependencies, cacheItemDependencies);
}
}
using (dependency) {
cacheInternal.Insert(key, dataAdd, new CacheInsertOptions()
{
Dependencies = dependency,
AbsoluteExpiration = DateTime.UtcNow.AddSeconds(5),
OnRemovedCallback = s_callback
});
}
}
}
}
return(dataAdd);
}