/// <summary>
/// Returns a stream over the update XML metadata
/// </summary>
/// <param name="updateId">The update ID to get XML metadata for</param>
/// <returns>Stream of the XML metadata</returns>
public Stream GetUpdateMetadataStream(Metadata.Identity updateId)
{
if (InputFile == null)
{
throw new Exception("Query result is not in read mode");
}
if (IsDeltaSource && BaselineIdentities.Contains(updateId))
{
return(BaselineSource.GetUpdateMetadataStream(updateId));
}
else
{
var entryIndex = InputFile.FindEntry(GetUpdateXmlPath(updateId), true);
if (entryIndex < 0)
{
throw new KeyNotFoundException();
}
return(InputFile.GetInputStream(entryIndex));
}
}
/// <summary>
/// Returns an index for an update (number between 0 and 255) based on the update\s ID.
/// </summary>
/// <param name="updateId">The update to get the index for</param>
/// <returns>String representation of the index</returns>
private static string GetUpdateIndex(Metadata.Identity updateId)
{
// The index is the last 8 bits of the update ID.
return(updateId.Raw.UpdateID.ToByteArray().Last().ToString());
}
/// <summary>
/// Returns the path to the update XML in query result ZIP archive
/// </summary>
/// <param name="updateId">The update to get the path for.</param>
/// <returns>A fully qualified path to the XML file belonging to the specified update</returns>
private string GetUpdateXmlPath(Metadata.Identity updateId)
{
return($"{GetUpdateIndex(updateId)}/{updateId.ToString()}.xml");
}