static bool ValidateAssemblyCacheListIntegrity(HashSet <Assembly> assemblies, List <MefControlCacheAssemblyInfo> cachedAssemblyInfos, ICachingFaultInjector?cachingFaultInjector)
{
var currentAssemblies = new Dictionary <string, Guid> (assemblies.Count);
foreach (var asm in assemblies)
{
currentAssemblies.Add(asm.Location, asm.ManifestModule.ModuleVersionId);
}
foreach (var assemblyInfo in cachedAssemblyInfos)
{
cachingFaultInjector?.FaultAssemblyInfo(assemblyInfo);
if (!currentAssemblies.TryGetValue(assemblyInfo.Location, out var mvid))
{
return(false);
}
if (mvid != assemblyInfo.ModuleVersionId)
{
return(false);
}
}
return(true);
}
internal bool CanUse()
{
// If we don't have a control file, bail early
if (!File.Exists(MefCacheControlFile) || !File.Exists(MefCacheFile))
{
return(false);
}
using (var timer = Counters.CompositionCacheControl.BeginTiming()) {
// Read the cache from disk
var serializer = new JsonSerializer();
MefControlCache controlCache;
try {
using (var sr = File.OpenText(MefCacheControlFile)) {
controlCache = (MefControlCache)serializer.Deserialize(sr, typeof(MefControlCache));
}
} catch (Exception ex) {
LoggingService.LogError("Could not deserialize MEF cache control", ex);
DeleteFiles();
return(false);
}
//this can return null (if the cache format changed?). clean up and start over.
if (controlCache == null)
{
LoggingService.LogError("MEF cache control deserialized as null");
DeleteFiles();
return(false);
}
var currentAssemblies = new HashSet <string> (Assemblies.Select(asm => asm.Location));
// Short-circuit on number of assemblies change
if (controlCache.AssemblyInfos.Length != currentAssemblies.Count)
{
return(false);
}
// Validate that the assemblies match and we have the same time stamps on them.
foreach (var assemblyInfo in controlCache.AssemblyInfos)
{
cachingFaultInjector?.FaultAssemblyInfo(assemblyInfo);
if (!currentAssemblies.Contains(assemblyInfo.Location))
{
return(false);
}
if (File.GetLastWriteTimeUtc(assemblyInfo.Location) != assemblyInfo.LastWriteTimeUtc)
{
return(false);
}
}
}
return(true);
}