//
// Actually computes the browser capabilities
//
internal HttpCapabilitiesBase Evaluate(HttpRequest request)
{
HttpCapabilitiesBase result;
CacheInternal cacheInternal = System.Web.HttpRuntime.CacheInternal;
//
// 1) grab UA and do optimistic cache lookup (if UA is in dependency list)
//
string userAgent = GetUserAgent(request);
string userAgentCacheKey = userAgent;
// Use the shorten userAgent as the cache key.
Debug.Assert(UserAgentCacheKeyLength != 0);
// Trim the useragent string based on <browserCaps> config
if (userAgentCacheKey != null && userAgentCacheKey.Length > UserAgentCacheKeyLength)
{
userAgentCacheKey = userAgentCacheKey.Substring(0, UserAgentCacheKeyLength);
}
bool doFullCacheKeyLookup = false;
string optimisticCacheKey = _cacheKeyPrefix + userAgentCacheKey;
object optimisticCacheResult = cacheInternal.Get(optimisticCacheKey);
// optimize for common case (desktop browser)
result = optimisticCacheResult as HttpCapabilitiesBase;
if (result != null)
{
return(result);
}
//
// 1.1) optimistic cache entry could tell us to do full cache lookup
//
if (optimisticCacheResult == _disableOptimisticCachingSingleton)
{
doFullCacheKeyLookup = true;
}
else
{
// cache it and respect _cachetime
result = EvaluateFinal(request, true);
// Optimized cache key is disabled if the request matches any headers defined within identifications.
if (result.UseOptimizedCacheKey)
{
// Use the same browserCap result if one with the same capabilities can be found in the cache.
// This is to reduce the number of identical browserCap instances being cached.
CacheBrowserCapResult(ref result);
// Cache the result using the optimisicCacheKey
cacheInternal.UtcInsert(optimisticCacheKey, result, null, Cache.NoAbsoluteExpiration, _cachetime);
return(result);
}
}
//
// 2) either:
//
// We've never seen the UA before (parse all headers to
// determine if the new UA also carries modile device
// httpheaders).
//
// It's a mobile UA (so parse all headers) and do full
// cache lookup
//
// UA isn't in dependency list (customer custom caps section)
//
IDictionaryEnumerator de = _variables.GetEnumerator();
StringBuilder sb = new StringBuilder(_cacheKeyPrefix);
InternalSecurityPermissions.AspNetHostingPermissionLevelLow.Assert();
while (de.MoveNext())
{
string key = (string)de.Key;
string value;
if (key.Length == 0)
{
value = userAgent;
}
else
{
value = request.ServerVariables[key];
}
if (value != null)
{
sb.Append(value);
}
}
CodeAccessPermission.RevertAssert();
sb.Append(BrowserCapabilitiesFactoryBase.GetBrowserCapKey(BrowserCapFactory.InternalGetMatchedHeaders(), request));
string fullCacheKey = sb.ToString();
//
// Only do full cache lookup if the optimistic cache
// result was _disableOptimisticCachingSingleton or
// if UserAgent wasn't in the cap var list.
//
if (userAgent == null || doFullCacheKeyLookup)
{
result = cacheInternal.Get(fullCacheKey) as HttpCapabilitiesBase;
if (result != null)
{
return(result);
}
}
result = EvaluateFinal(request, false);
// Use the same browserCap result if one with the same matched nodes can be found in the cache.
// This is to reduce the number of identical browserCap instances being cached.
CacheBrowserCapResult(ref result);
// cache it and respect _cachetime
cacheInternal.UtcInsert(fullCacheKey, result, null, Cache.NoAbsoluteExpiration, _cachetime);
if (optimisticCacheKey != null)
{
cacheInternal.UtcInsert(optimisticCacheKey, _disableOptimisticCachingSingleton, null, Cache.NoAbsoluteExpiration, _cachetime);
}
return(result);
}
internal HttpCapabilitiesBase Evaluate(HttpRequest request)
{
CacheInternal cacheInternal = HttpRuntime.CacheInternal;
string userAgent = GetUserAgent(request);
string str2 = userAgent;
if ((str2 != null) && (str2.Length > this.UserAgentCacheKeyLength))
{
str2 = str2.Substring(0, this.UserAgentCacheKeyLength);
}
bool flag = false;
string key = this._cacheKeyPrefix + str2;
object obj2 = cacheInternal.Get(key);
HttpCapabilitiesBase result = obj2 as HttpCapabilitiesBase;
if (result == null)
{
if (obj2 == _disableOptimisticCachingSingleton)
{
flag = true;
}
else
{
result = this.EvaluateFinal(request, true);
if (result.UseOptimizedCacheKey)
{
this.CacheBrowserCapResult(ref result);
cacheInternal.UtcInsert(key, result, null, Cache.NoAbsoluteExpiration, this._cachetime);
return(result);
}
}
IDictionaryEnumerator enumerator = this._variables.GetEnumerator();
StringBuilder builder = new StringBuilder(this._cacheKeyPrefix);
InternalSecurityPermissions.AspNetHostingPermissionLevelLow.Assert();
while (enumerator.MoveNext())
{
string str5;
string str4 = (string)enumerator.Key;
if (str4.Length == 0)
{
str5 = userAgent;
}
else
{
str5 = request.ServerVariables[str4];
}
if (str5 != null)
{
builder.Append(str5);
}
}
CodeAccessPermission.RevertAssert();
builder.Append(BrowserCapabilitiesFactoryBase.GetBrowserCapKey(this.BrowserCapFactory.InternalGetMatchedHeaders(), request));
string str6 = builder.ToString();
if ((userAgent == null) || flag)
{
result = cacheInternal.Get(str6) as HttpCapabilitiesBase;
if (result != null)
{
return(result);
}
}
result = this.EvaluateFinal(request, false);
this.CacheBrowserCapResult(ref result);
cacheInternal.UtcInsert(str6, result, null, Cache.NoAbsoluteExpiration, this._cachetime);
if (key != null)
{
cacheInternal.UtcInsert(key, _disableOptimisticCachingSingleton, null, Cache.NoAbsoluteExpiration, this._cachetime);
}
}
return(result);
}
