public static Delta Diffing(Stream previousStream, Stream currentStream, bool enablePropertyDiff = true, List <string> exceptions = null, bool useDefaultExceptions = true)
{
// Take the Stream's objects
List <IBHoMObject> currentObjs = currentStream.Objects.ToList();
List <IBHoMObject> readObjs = previousStream.Objects.ToList();
// Make dictionary with object hashes to speed up the next lookups
Dictionary <string, IBHoMObject> readObjs_dict = readObjs.ToDictionary(obj => obj.GetHashFragment().Hash, obj => obj);
// Set exceptions
if (useDefaultExceptions)
{
Compute.SetDefaultExceptions(ref exceptions);
}
// Dispatch the objects: new, modified or old
List <IBHoMObject> toBeCreated = new List <IBHoMObject>();
List <IBHoMObject> toBeUpdated = new List <IBHoMObject>();
List <IBHoMObject> toBeDeleted = new List <IBHoMObject>();
var objModifiedProps = new Dictionary <string, Dictionary <string, Tuple <object, object> > >();
foreach (var obj in currentObjs)
{
var hashFragm = obj.GetHashFragment();
if (hashFragm?.PreviousHash == null)
{
toBeCreated.Add(obj); // It's a new object
}
else if (hashFragm.PreviousHash == hashFragm.Hash)
{
// It's NOT been modified
}
else if (hashFragm.PreviousHash != hashFragm.Hash)
{
toBeUpdated.Add(obj); // It's been modified
if (enablePropertyDiff)
{
// Determine changed properties
IBHoMObject oldObjState = null;
readObjs_dict.TryGetValue(hashFragm.PreviousHash, out oldObjState);
if (oldObjState == null)
{
continue;
}
IsEqualConfig config = new IsEqualConfig();
config.PropertiesToIgnore = exceptions;
var differentProps = BH.Engine.Testing.Query.DifferentProperties(obj, oldObjState, config);
objModifiedProps.Add(hashFragm.Hash, differentProps);
}
}
else
{
throw new Exception("Could not find hash information to perform Diffing on some objects.");
}
}
// If no modified property was found, set the field to null (otherwise will get empty list)
objModifiedProps = objModifiedProps.Count == 0 ? null : objModifiedProps;
// All ReadObjs that cannot be found by hash in the previousHash of the CurrentObjs are toBeDeleted
Dictionary <string, IBHoMObject> CurrentObjs_withPreviousHash_dict = currentObjs
.Where(obj => obj.GetHashFragment().PreviousHash != null)
.ToDictionary(obj => obj.GetHashFragment().PreviousHash, obj => obj);
toBeDeleted = readObjs_dict.Keys.Except(CurrentObjs_withPreviousHash_dict.Keys)
.Where(k => readObjs_dict.ContainsKey(k)).Select(k => readObjs_dict[k]).ToList();
return(new Delta(toBeCreated, toBeDeleted, toBeUpdated, objModifiedProps));
}
public static string DiffingHash(this IBHoMObject obj, DiffConfig diffConfig)
{
return(Compute.SHA256Hash(obj, diffConfig.PropertiesToIgnore));
}