private object ProcessResourceSafely(Assembly callingAssembly, string name, string resourceUrl, string contentType, int requiredFreshnessDays, int timeoutMs, ResourceFileProcessor processor)
{
if (contentType == MimeHelper.TEXT_XML)
{
processor = new ResourceFileProcessor(new XPPResourceFileProcessor(processor).ProcessXmlResource);
}
// attempt to load and process the resource (potentially loading new data from the network)
try
{
using (Stream stream = GetResource(callingAssembly, name, resourceUrl, contentType, requiredFreshnessDays, timeoutMs))
{
return(processor(stream));
}
// verify content type of responding url
}
catch (Exception ex)
{
// report failure
Trace.WriteLine(String.Format(CultureInfo.InvariantCulture, "Unexpected exception occurred while processing resource {0}: {1}", name, ex.ToString()));
// NOTE: we should save the last successfully download/used file and
// "restore" from this rather than the embedded copy in the case of
// an error or failure reading from the downloaded file.
// safely delete the locally cached file (it contains bad data)
SafeDeleteLocalCacheFile(callingAssembly, name);
// try again on local data
using (Stream stream = GetResourceLocal(callingAssembly, name))
return(processor(stream));
}
}
/// <summary>
/// Trims the working set after a given delay
/// </summary>
/// <param name="delayMs">The delay prior to trimming the working set</param>
/// <returns></returns>
public DelayUpdateHelper(Assembly callingAssembly, string name, string url, string contentType, ResourceFileDownloader downloader, ResourceFileProcessor processor, int delayMs)
{
_callingAssembly = callingAssembly;
_name = name;
_url = url;
_contentType = contentType;
_processor = processor;
_downloader = downloader;
_delayMs = delayMs;
}
/// <summary>
/// Trims the working set after a given delay
/// </summary>
/// <param name="delayMs">The delay prior to trimming the working set</param>
/// <returns></returns>
public DelayUpdateHelper(Assembly callingAssembly, string name, string url, string contentType, ResourceFileDownloader downloader, ResourceFileProcessor processor, int delayMs)
{
_callingAssembly = callingAssembly;
_name = name;
_url = url;
_contentType = contentType;
_processor = processor;
_downloader = downloader;
_delayMs = delayMs;
}
public object ProcessLocalResourceSafelyAndRefresh(string name, string url, string contentType, ResourceFileProcessor processor, int delayMs)
{
Assembly assembly = Assembly.GetCallingAssembly();
lock (_downloadedResources.SyncRoot)
{
if (!_downloadedResources.Contains(url))
{
_downloadedResources.Add(url);
new DelayUpdateHelper(assembly, name, url, contentType, this, processor, delayMs).StartBackgroundUpdate();
}
}
return ProcessResourceSafely(assembly, name, string.Empty, contentType, REQUIREDFRESHNESSDAYS, TIMEOUTMS, processor);
}
public XPPResourceFileProcessor(ResourceFileProcessor processor)
{
_processor = processor;
}
private object ProcessResourceSafely(Assembly callingAssembly, string name, string resourceUrl, string contentType, int requiredFreshnessDays, int timeoutMs, ResourceFileProcessor processor)
{
if (contentType == MimeHelper.TEXT_XML)
processor = new ResourceFileProcessor(new XPPResourceFileProcessor(processor).ProcessXmlResource);
// attempt to load and process the resource (potentially loading new data from the network)
try
{
using (Stream stream = GetResource(callingAssembly, name, resourceUrl, contentType, requiredFreshnessDays, timeoutMs))
{
return processor(stream);
}
// verify content type of responding url
}
catch (Exception ex)
{
// report failure
Trace.WriteLine(String.Format(CultureInfo.InvariantCulture, "Unexpected exception occurred while processing resource {0}: {1}", name, ex.ToString()));
// NOTE: we should save the last successfully download/used file and
// "restore" from this rather than the embedded copy in the case of
// an error or failure reading from the downloaded file.
// safely delete the locally cached file (it contains bad data)
SafeDeleteLocalCacheFile(callingAssembly, name);
// try again on local data
using (Stream stream = GetResourceLocal(callingAssembly, name))
return processor(stream);
}
}
/// <summary>
/// Get and process a resource (see comment on GetResource for more info on resources)
/// This method attempts to load the resource normally (i.e. from the network). If
/// an exception of any kind happens during processing we revert back to processing
/// the version built into the assembly.
/// </summary>
/// <param name="name">resource name</param>
/// <param name="requiredFreshnessDays">number of days for which we can use cached copies</param>
/// <param name="timeoutMs">timeout in ms for request to web server</param>
/// <param name="processor">callback used for processing the resource</param>
/// <returns>result of processing</returns>
public object ProcessResourceSafely(string name, string resourceUrl, string contentType, int requiredFreshnessDays, int timeoutMs, ResourceFileProcessor processor)
{
// record calling assembly
return ProcessResourceSafely(Assembly.GetCallingAssembly(), name, resourceUrl, contentType, requiredFreshnessDays, timeoutMs, processor);
}
public object ProcessLocalResourceSafelyAndRefresh(string name, string url, string contentType, ResourceFileProcessor processor, int delayMs)
{
Assembly assembly = Assembly.GetCallingAssembly();
lock (_downloadedResources.SyncRoot)
{
if (!_downloadedResources.Contains(url))
{
_downloadedResources.Add(url);
new DelayUpdateHelper(assembly, name, url, contentType, this, processor, delayMs).StartBackgroundUpdate();
}
}
return(ProcessResourceSafely(assembly, name, string.Empty, contentType, REQUIREDFRESHNESSDAYS, TIMEOUTMS, processor));
}
public XPPResourceFileProcessor(ResourceFileProcessor processor)
{
_processor = processor;
}
/// <summary>
/// Get and process a resource (see comment on GetResource for more info on resources)
/// This method attempts to load the resource normally (i.e. from the network). If
/// an exception of any kind happens during processing we revert back to processing
/// the version built into the assembly.
/// </summary>
/// <param name="name">resource name</param>
/// <param name="requiredFreshnessDays">number of days for which we can use cached copies</param>
/// <param name="timeoutMs">timeout in ms for request to web server</param>
/// <param name="processor">callback used for processing the resource</param>
/// <returns>result of processing</returns>
public object ProcessResourceSafely(string name, string resourceUrl, string contentType, int requiredFreshnessDays, int timeoutMs, ResourceFileProcessor processor)
{
// record calling assembly
return(ProcessResourceSafely(Assembly.GetCallingAssembly(), name, resourceUrl, contentType, requiredFreshnessDays, timeoutMs, processor));
}
