public void WrongCorrelationId()
{
FileEnvelopeId fe0 = FileEnvelopeId.Create();
FileEnvelopeId fe1 = FileEnvelopeId.Create();
Assert.Throws <BuildXLException>(
() => { FileEnvelope.CheckCorrelationIds(fe0, fe1); });
}
/// <summary>
/// Creates and starts a task to deserialize an object
/// </summary>
/// <param name="file">This will become the filename</param>
/// <param name="deserializer">Deserialization function; its get a reader for the file stream, and a function that allows obtaining additional streams if needed</param>
/// <param name="skipHeader">If enabled, the correlation id is not checked for consistency</param>
/// <returns>task for deserialized value</returns>
internal Task <TObject> DeserializeFromFileAsync <TObject>(
GraphCacheFile file,
Func <BuildXLReader, Task <TObject> > deserializer,
bool skipHeader = false)
{
var task = Task.Run(
async() =>
{
var objectLabel = GetFileName(file);
string path = GetFullPath(objectLabel);
FileEnvelope fileEnvelope = GetFileEnvelope(file);
var result = default(TObject);
try
{
Stopwatch sw = Stopwatch.StartNew();
using (var fileStreamWrapper = m_readStreamProvider.OpenReadStream(path))
{
var fileStream = fileStreamWrapper.Value;
FileEnvelopeId persistedCorrelationId = fileEnvelope.ReadHeader(fileStream);
if (!skipHeader)
{
// We are going to check if all files that are going to be (concurrently) deserialized have matching correlation ids.
// The first discovered correlation id is going to be used to check all others.
if (m_correlationId == null)
{
Interlocked.CompareExchange(ref m_correlationId, persistedCorrelationId, null);
}
FileEnvelope.CheckCorrelationIds(persistedCorrelationId, (FileEnvelopeId)m_correlationId);
}
var isCompressed = fileStream.ReadByte() == 1;
using (Stream readStream = isCompressed ? new TrackedStream(new BufferedStream(new DeflateStream(fileStream, CompressionMode.Decompress), 64 << 10)) : fileStream)
using (BuildXLReader reader = new BuildXLReader(m_debug, readStream, leaveOpen: false))
{
result = await deserializer(reader);
}
}
Tracing.Logger.Log.DeserializedFile(LoggingContext, path, sw.ElapsedMilliseconds);
return(result);
}
catch (BuildXLException ex)
{
if (ex.InnerException is FileNotFoundException)
{
// Files might be deleted manually in the EngineCache directory. Log it as verbose.
Tracing.Logger.Log.FailedToDeserializeDueToFileNotFound(LoggingContext, path);
return(result);
}
Tracing.Logger.Log.FailedToDeserializePipGraph(LoggingContext, path, ex.LogEventMessage);
return(result);
}
catch (IOException ex)
{
Tracing.Logger.Log.FailedToDeserializePipGraph(LoggingContext, path, ex.Message);
return(result);
}
catch (TaskCanceledException)
{
throw;
}
catch (Exception ex)
{
// There are 2 reasons to be here.
// 1. A malformed file can cause ContractException, IndexOutOfRangeException, MemoryException or something else.
// 2. We may have a bug.
// Since the malformed file will always cause a crash until someone removes the file from the cache, allow BuildXL to recover
// by eating the exception. However remember to log it in order to keep track of bugs.
ExceptionRootCause rootCause = ExceptionUtilities.AnalyzeExceptionRootCause(ex);
BuildXL.Tracing.UnexpectedCondition.Log(LoggingContext, ex.ToStringDemystified() + Environment.NewLine + rootCause);
Tracing.Logger.Log.FailedToDeserializePipGraph(LoggingContext, path, ex.Message);
return(result);
}
});
lock (m_deserializationSyncObject)
{
m_deserializationTasks.Add(task);
}
return(task);
}