/// <summary>
/// The actual internal folder scan implementation.
/// </summary>
private void InternalScan()
{
if (isDisposed)
{
return;
}
try
{
if (Interlocked.Increment(ref scanning) > 1)
{
return; // Don't allow multiple parallel scans
}
Dictionary <AppRef, AppPackageInfo> newPackages = new Dictionary <AppRef, AppPackageInfo>();
string[] files;
files = Helper.GetFilesByPattern(packageFolder + "*.zip", SearchOption.TopDirectoryOnly);
foreach (string file in files)
{
bool isRetry = false;
retry:
try
{
int size;
using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))
size = (int)fs.Length;
using (AppPackage package = AppPackage.Open(file))
newPackages.Add(package.AppRef, new AppPackageInfo(package.AppRef,
Path.GetFileName(file),
file,
package.MD5,
size,
File.GetLastWriteTimeUtc(file)));
}
catch (FileNotFoundException e)
{
SysLog.LogErrorStackDump("{0}", e.Message);
}
catch (DirectoryNotFoundException e)
{
SysLog.LogErrorStackDump("{0}", e.Message);
}
catch (IOException e)
{
// I've run into trouble where we've gotten notifications from the
// file watcher while a new file is still locked for writing. In
// this situation, I'm going to wait a bit and then retry the
// operation once.
if (!isRetry)
{
Thread.Sleep(RetryTime);
isRetry = true;
goto retry;
}
SysLog.LogErrorStackDump("{0}", e.Message);
}
catch (Exception e)
{
SysLog.LogErrorStackDump("Error [{0}] loading application package [{1}].", e.Message, file);
}
}
// Determine if there have been any changes to the set of
// application packages and then update the cached package set
// and then raise the change event if there were any changes.
bool changed = false;
using (TimedLock.Lock(syncLock))
{
foreach (var info in newPackages.Values)
{
if (!packages.ContainsKey(info.AppRef))
{
changed = true;
break;
}
else
{
var orgInfo = packages[info.AppRef];
if (info.FileName != orgInfo.FileName ||
!Helper.ArrayEquals(info.MD5, orgInfo.MD5))
{
changed = true;
break;
}
}
}
if (!changed)
{
foreach (AppPackageInfo info in packages.Values)
{
if (!newPackages.ContainsKey(info.AppRef))
{
changed = true;
break;
}
}
}
if (changed)
{
packages = newPackages;
}
}
if (changed)
{
RaiseChangeEvent();
}
}
finally
{
Interlocked.Decrement(ref scanning);
}
}
