/// <summary> /// (Recursive) Recursive function that inspects an object and its properties/fields and clones it /// </summary> /// <param name="sourceObject">The object to clone</param> /// <param name="currentDepth">The current tree depth</param> /// <param name="maxDepth">The max tree depth</param> /// <param name="configuration">The cloning options</param> /// <param name="objectTree">The object tree to prevent cyclical references</param> /// <param name="path">The current path being traversed</param> /// <returns></returns> private object InspectAndCopy(object sourceObject, int currentDepth, int maxDepth, CloneConfiguration configuration, ObjectTreeReferenceTracker objectTree, string path) => InspectAndCopy(sourceObject, null, null, currentDepth, maxDepth, configuration, objectTree, path, null);
/// <summary>
/// Recursive function that inspects an object and its properties/fields and clones it to a new or existing type
/// </summary>
/// <param name="sourceObject">The object to clone</param>
/// <param name="destinationObject">An existing object to clone values to</param>
/// <param name="destinationObjectType">The type of the destination object to clone to</param>
/// <param name="currentDepth">The current tree depth</param>
/// <param name="maxDepth">The max tree depth</param>
/// <param name="configuration">Configure custom cloning options</param>
/// <param name="objectTree">The object tree to prevent cyclical references</param>
/// <param name="path">The current path being traversed</param>
/// <param name="ignorePropertiesOrPaths">A list of properties or paths to ignore</param>
/// <returns></returns>
private object InspectAndCopy(object sourceObject, object destinationObject, Type destinationObjectType, int currentDepth, int maxDepth, CloneConfiguration configuration, ObjectTreeReferenceTracker objectTree, string path, ICollection <string> ignorePropertiesOrPaths)
{
if (_hasIgnoreConfiguration == null)
{
_hasIgnoreConfiguration = HasIgnoreConfiguration(configuration, ignorePropertiesOrPaths);
}
if (_hasIgnoreConfiguration.Value && IgnoreObjectName(null, path, configuration, ignorePropertiesOrPaths))
{
return(null);
}
if (sourceObject == null)
{
return(null);
}
// ensure we don't go too deep if specified
if (maxDepth > 0 && currentDepth >= maxDepth)
{
throw new CloneException($"The maximum clone recursion depth has exceeded maxDepth of '{maxDepth}'. Try setting the configuration option {nameof(CloneConfiguration.AllowUseCustomHashCodes)} to true or increase the {nameof(CloneConfiguration.MaxDepth)}. The last path traversed was '{path}'.", path);
}
var type = sourceObject.GetType();
ExtendedType typeSupport;
try
{
typeSupport = type.GetExtendedType(DefaultExtendedTypeOptions);
}
// certain attributes such as .net remoting SoapTypeAttribute can cause issues trying to inspect. Possibly a framework bug with reflection
catch (CustomAttributeFormatException)
{
return(sourceObject);
}
ExtendedType destinationTypeSupport;
if (destinationObjectType == null || destinationObjectType == type)
{
destinationTypeSupport = typeSupport;
}
else
{
destinationTypeSupport = destinationObjectType.GetExtendedType(DefaultExtendedTypeOptions);
}
// always return the original value on value types
if (typeSupport.IsValueType)
{
return(sourceObject);
}
// drop any objects we are ignoring by attribute
if (_hasIgnoreConfiguration.Value && typeSupport.Attributes.Any(x => configuration.IgnorePropertiesWithAttributes.Contains(x.Name)))
{
return(null);
}
// for delegate types, copy them by reference rather than returning null
if (typeSupport.IsDelegate)
{
return(sourceObject);
}
object newObject = null;
// create a new empty object of the desired type
if (typeSupport.IsArray)
{
if (!(sourceObject is Array sourceArray))
{
throw new NullReferenceException($"{nameof(sourceArray)} cannot be null!");
}
// calculate the dimensions of the array
var arrayRank = sourceArray.Rank;
// get the length of each dimension
var arrayDimensions = new List <int>();
for (var dimension = 0; dimension < arrayRank; dimension++)
{
arrayDimensions.Add(sourceArray.GetLength(dimension));
}
newObject = _objectFactory.CreateEmptyObject(destinationTypeSupport, default(TypeRegistry), arrayDimensions.ToArray());
}
else if (typeSupport.Type == typeof(string))
{
// copy the item directly
newObject = string.Copy((string)sourceObject);
return(newObject);
}
else
{
newObject = destinationObject ?? _objectFactory.CreateEmptyObject(destinationTypeSupport);
}
if (newObject == null)
{
return(null);
}
// increment the current recursion depth
currentDepth++;
// construct a hashtable of objects we have already inspected (recursion loop preventer)
if (!typeSupport.IsValueType)
{
if (!objectTree.Contains(sourceObject))
{
objectTree.Add(sourceObject);
}
else
{
// object has already been traversed
return(sourceObject);
}
}
// clone using IClonable interface if exists
if (configuration.AllowIClonableImplementations && typeSupport.Interfaces.Contains(typeof(ICloneable)))
{
var iClonable = sourceObject as ICloneable;
return(iClonable?.Clone());
}
// clone a dictionary's key/values
else if (typeSupport.IsDictionary && typeSupport.IsGeneric)
{
var genericType = typeSupport.Type.GetGenericArguments().ToList();
Type[] typeArgs = { genericType[0], genericType[1] };
var listType = typeof(Dictionary <,>).MakeGenericType(typeArgs);
var newDictionary = Activator.CreateInstance(listType) as IDictionary;
newObject = newDictionary ?? throw new NullReferenceException($"{nameof(newDictionary)} cannot be null");
var iDictionary = sourceObject as IDictionary;
var success = false;
var retryCount = 0;
while (!success && retryCount < 10)
{
try
{
foreach (DictionaryEntry item in iDictionary)
{
var key = InspectAndCopy(item.Key, null, null, currentDepth, maxDepth, configuration, objectTree, path, ignorePropertiesOrPaths);
var value = InspectAndCopy(item.Value, null, null, currentDepth, maxDepth, configuration, objectTree, path, ignorePropertiesOrPaths);
newDictionary.Add(key, value);
}
success = true;
}
catch (InvalidOperationException)
{
// if the collection was modified during enumeration, stop re-initialize and retry
success = false;
retryCount++;
newDictionary.Clear();
}
}
if (!success)
{
throw new CloneException($"Error cloning Dictionary<,> at path '{path}'. Ensure the object is not modified while cloning data utilizing thread-safe access.");
}
return(newObject);
}
else if (typeSupport.IsHashtable && !typeSupport.IsGeneric)
{
var newHashtable = new Hashtable();
newObject = newHashtable ?? throw new NullReferenceException($"{nameof(newHashtable)} cannot be null");
var hashtable = (Hashtable)sourceObject;
var success = false;
var retryCount = 0;
while (!success && retryCount < 10)
{
try
{
foreach (DictionaryEntry item in hashtable)
{
var key = InspectAndCopy(item.Key, null, null, currentDepth, maxDepth, configuration, objectTree, path, ignorePropertiesOrPaths);
var value = InspectAndCopy(item.Value, null, null, currentDepth, maxDepth, configuration, objectTree, path, ignorePropertiesOrPaths);
newHashtable.Add(key, value);
}
success = true;
}
catch (InvalidOperationException)
{
// if the collection was modified during enumeration, stop re-initialize and retry
success = false;
retryCount++;
newHashtable.Clear();
}
}
if (!success)
{
throw new CloneException($"Error cloning Hashtable at path '{path}'. Ensure the object is not modified while cloning data utilizing thread-safe access.");
}
return(newObject);
}
else if (typeSupport.IsEnumerable && !typeSupport.IsArray)
{
// clone enumerable elements
var enumerable = (IEnumerable)sourceObject;
bool hasEntries;
if (typeSupport.IsCollection)
{
hasEntries = ((ICollection)sourceObject).Count > 0;
}
else
{
hasEntries = enumerable.Cast <object>().Any();
}
if (hasEntries)
{
#if NET45_OR_GREATER || NETSTANDARD1_0_OR_GREATER
var readOnlyCollectionTypes = new[] { typeof(ReadOnlyCollection <>), typeof(ReadOnlyDictionary <,>) };
if (type.IsGenericType && readOnlyCollectionTypes.Contains(type.GetGenericTypeDefinition()))
{
// return as-is, since they can't be modified anyways
return(sourceObject);
}
#endif
var addMethod = typeSupport.Type.GetMethod("Add");
if (addMethod == null)
{
addMethod = typeSupport.Type.GetMethod("Enqueue");
if (addMethod == null)
{
addMethod = typeSupport.Type.GetMethod("Push");
if (addMethod == null)
{
addMethod = typeSupport.Methods.FirstOrDefault(x => x.Name.StartsWith("Add"));
if (addMethod == null)
{
// as a backup, try utilizing memberwise clone
return(_memberwiseCloneMethod.Invoke(sourceObject, null));
}
}
}
}
var success = false;
var retryCount = 0;
while (!success && retryCount < 10)
{
try
{
foreach (var item in enumerable)
{
var element = InspectAndCopy(item, null, null, currentDepth, maxDepth, configuration,
objectTree, path, ignorePropertiesOrPaths);
addMethod.Invoke(newObject, new[] { element });
}
success = true;
}
catch (InvalidOperationException)
{
// if the collection was modified during enumeration, stop re-initialize and retry
success = false;
retryCount++;
var clearMethod = typeSupport.Type.GetMethod("Clear");
clearMethod?.Invoke(newObject, null);
}
}
if (!success)
{
throw new CloneException($"Error cloning IEnumerable at path '{path}'. Ensure the object is not modified while cloning data utilizing thread-safe access.");
}
}
return(newObject);
}
// clone an arrays' elements
if (typeSupport.IsArray)
{
var sourceArray = sourceObject as Array;
var newArray = newObject as Array;
// performance optimization, value typed primitive arrays can be block copied
if (typeSupport.ElementType.IsPrimitive)
{
var bytesPerValue = GetBytesPerValue(typeSupport.ElementType);
try
{
Buffer.BlockCopy(sourceArray, 0, newArray, 0, sourceArray.Length * bytesPerValue);
}
catch (Exception ex)
{
throw new CloneException($"Error block copying array at path '{path}'", ex);
}
}
else
{
// copy each array element and clone the value
var arrayRank = newArray.Rank;
var arrayDimensions = new List <int>();
for (var dimension = 0; dimension < arrayRank; dimension++)
{
arrayDimensions.Add(newArray.GetLength(dimension));
}
var flatRowIndex = 0;
foreach (var row in sourceArray)
{
var newElement = InspectAndCopy(row, null, null, currentDepth, maxDepth, configuration, objectTree, path, ignorePropertiesOrPaths);
// performance optimization, skip dimensional processing if it's a 1d array
if (arrayRank > 1)
{
// this is an optimized multi-dimensional array reconstruction
// based on the formula: indices.Add((i / (arrayDimensions[arrayRank - 1] * arrayDimensions[arrayRank - 2] * arrayDimensions[arrayRank - 3] * arrayDimensions[arrayRank - 4] * arrayDimensions[arrayRank - 5])) % arrayDimensions[arrayRank - 6]);
var indices = new List <int>();
for (var r = 1; r <= arrayRank; r++)
{
var multi = 1;
for (var p = 1; p < r; p++)
{
multi *= arrayDimensions[arrayRank - p];
}
var b = (flatRowIndex / multi) % arrayDimensions[arrayRank - r];
indices.Add(b);
}
indices.Reverse();
// set element of multi-dimensional array
newArray.SetValue(newElement, indices.ToArray());
}
else
{
// set element of 1d array
newArray.SetValue(newElement, flatRowIndex);
}
flatRowIndex++;
}
}
return(newArray);
}
if (typeSupport.IsExpression)
{
// utilize MemberwiseClone for expressions
try
{
var newExpression = _memberwiseCloneMethod.Invoke(sourceObject, null);
return(newExpression);
}
catch (Exception ex)
{
throw new CloneException($"Error cloning expression with type '{typeSupport.FullName}' at path '{path}'", ex);
}
}
var fields = typeSupport.Fields.Where(x => !x.IsConstant && !x.IsStatic);
var rootPath = path;
var localPath = string.Empty;
// clone and recurse fields
foreach (var field in fields)
{
localPath = $"{rootPath}.{field.Name}";
// optimization to disable ignores by attribute if configured
//System.Diagnostics.Debug.WriteLine($"Copying {localPath}");
if (_hasIgnoreConfiguration.Value)
{
if (IgnoreObjectName(field.Name, localPath, configuration, ignorePropertiesOrPaths, configuration.IgnorePropertiesWithAttributes.Count > 0 ? field.CustomAttributes : null))
{
continue;
}
// also check the property for ignore, if this is a auto-backing property
if (field.BackedProperty != null && IgnoreObjectName(field.BackedProperty.Name, $"{rootPath}.{field.BackedPropertyName}", configuration, ignorePropertiesOrPaths, configuration.IgnorePropertiesWithAttributes.Count > 0 ? field.BackedProperty.CustomAttributes : null))
{
continue;
}
}
#if FEATURE_DISABLE_SET_INITONLY
// we can't duplicate init-only fields since .net core 3.0+
// make use of IL to get around this limitation
if (field.FieldInfo.IsInitOnly && configuration.AllowCloningOfReadOnlyEntities)
{
try
{
var updateFieldValue = sourceObject.GetFieldValue(field);
var updater = GetWriterForField(field);
updater(ref newObject, updateFieldValue);
}
catch (Exception ex)
{
throw new CloneException($"Failed to set field value named '{field.Name}' at path '{path}' using IL DynamicMethod", ex);
}
continue;
}
#endif
// only copy readonly fields if we allow as such
if (field.FieldInfo.IsInitOnly && !configuration.AllowCloningOfReadOnlyEntities)
{
continue;
}
// utilize reflection
var fieldTypeSupport = field.Type;
var fieldValue = sourceObject.GetFieldValue(field);
var destinationField = newObject.GetField(field.Name, true);
// does this field exist on the destination object with the same type?
if (destinationField != null && destinationField.FieldType == field.FieldInfo.FieldType)
{
if (fieldTypeSupport.IsValueType || fieldTypeSupport.IsImmutable)
{
SetFieldValue(newObject, destinationField, fieldValue, localPath);
}
else if (fieldValue != null)
{
var clonedFieldValue = InspectAndCopy(fieldValue, null, null, currentDepth, maxDepth,
configuration, objectTree, localPath, ignorePropertiesOrPaths);
SetFieldValue(newObject, destinationField, clonedFieldValue, localPath);
}
}
}
return(newObject);
}
