/// <summary>
/// Performs a deep copy operation on <paramref name="jsonElement"/> returning corresponding modifiable tree structure of JSON nodes.
/// Operations performed on returned <see cref="JsonNode"/> does not modify <paramref name="jsonElement"/>.
/// </summary>
/// <param name="jsonElement"><see cref="JsonElement"/> to copy.</param>
/// <returns><see cref="JsonNode"/> representing <paramref name="jsonElement"/>.</returns>
public static JsonNode DeepCopy(JsonElement jsonElement)
{
if (!jsonElement.IsImmutable)
{
return(GetNode(jsonElement).Clone());
}
// Iterative DFS:
var currentNodes = new Stack <KeyValuePair <string, JsonNode> >(); // objects/arrays currently being created
var recursionStack = new Stack <KeyValuePair <string, JsonElement?> >(); // null JsonElement represents end of current object/array
JsonNode toReturn = null;
recursionStack.Push(new KeyValuePair <string, JsonElement?>(null, jsonElement));
while (recursionStack.TryPop(out KeyValuePair <string, JsonElement?> currentPair))
{
JsonElement?currentJsonElement = currentPair.Value;
if (!currentJsonElement.HasValue)
{
// Current object/array is finished and can be added to its parent:
KeyValuePair <string, JsonNode> nodePair = currentNodes.Pop();
Debug.Assert(nodePair.Value is JsonArray || nodePair.Value is JsonObject);
AddToParent(nodePair, ref currentNodes, ref toReturn);
continue;
}
switch (currentJsonElement.Value.ValueKind)
{
case JsonValueKind.Object:
var jsonObject = new JsonObject();
// Add jsonObject to current nodes:
currentNodes.Push(new KeyValuePair <string, JsonNode>(currentPair.Key, jsonObject));
// Add end of object marker:
recursionStack.Push(new KeyValuePair <string, JsonElement?>(null, null));
// Add properties to recursion stack. Reverse enumerate to keep properties order:
foreach (JsonProperty property in currentJsonElement.Value.EnumerateObject().Reverse())
{
recursionStack.Push(new KeyValuePair <string, JsonElement?>(property.Name, property.Value));
}
break;
case JsonValueKind.Array:
var jsonArray = new JsonArray();
// Add jsonArray to current nodes:
currentNodes.Push(new KeyValuePair <string, JsonNode>(currentPair.Key, jsonArray));
// Add end of array marker:
recursionStack.Push(new KeyValuePair <string, JsonElement?>(null, null));
// Add elements to recursion stack. Reverse enumerate to keep items order:
foreach (JsonElement element in currentJsonElement.Value.EnumerateArray().Reverse())
{
recursionStack.Push(new KeyValuePair <string, JsonElement?>(null, element));
}
break;
case JsonValueKind.Number:
var jsonNumber = new JsonNumber(currentJsonElement.Value.GetRawText());
AddToParent(new KeyValuePair <string, JsonNode>(currentPair.Key, jsonNumber), ref currentNodes, ref toReturn);
break;
case JsonValueKind.String:
var jsonString = new JsonString(currentJsonElement.Value.GetString());
AddToParent(new KeyValuePair <string, JsonNode>(currentPair.Key, jsonString), ref currentNodes, ref toReturn);
break;
case JsonValueKind.True:
var jsonBooleanTrue = new JsonBoolean(true);
AddToParent(new KeyValuePair <string, JsonNode>(currentPair.Key, jsonBooleanTrue), ref currentNodes, ref toReturn);
break;
case JsonValueKind.False:
var jsonBooleanFalse = new JsonBoolean(false);
AddToParent(new KeyValuePair <string, JsonNode>(currentPair.Key, jsonBooleanFalse), ref currentNodes, ref toReturn);
break;
case JsonValueKind.Null:
var jsonNull = new JsonNull();
AddToParent(new KeyValuePair <string, JsonNode>(currentPair.Key, jsonNull), ref currentNodes, ref toReturn);
break;
default:
Debug.Assert(jsonElement.ValueKind == JsonValueKind.Undefined, "No handler for JsonValueKind.{jsonElement.ValueKind}");
throw ThrowHelper.GetJsonElementWrongTypeException(JsonValueKind.Undefined, jsonElement.ValueKind);
}
}
Debug.Assert(toReturn != null);
return(toReturn);
}
public RecursionStackFrame(string propertyName, JsonNode propertyValue) : this(propertyName, propertyValue, propertyValue.ValueKind)
{
}
/// <summary>
/// Parses a string representing JSON document into <see cref="JsonNode"/>.
/// </summary>
/// <param name="json">JSON to parse.</param>
/// <param name="options">Options to control the parsing behavior.</param>
/// <returns><see cref="JsonNode"/> representation of <paramref name="json"/>.</returns>
public static JsonNode Parse(string json, JsonNodeOptions options = default)
{
Utf8JsonReader reader = new Utf8JsonReader(Encoding.UTF8.GetBytes(json), options.GetReaderOptions());
var currentNodes = new Stack <KeyValuePair <string, JsonNode> >(); // nodes currently being created
JsonNode toReturn = null;
while (reader.Read())
{
JsonTokenType tokenType = reader.TokenType;
currentNodes.TryPeek(out KeyValuePair <string, JsonNode> currentPair);
void AddNewPair(JsonNode jsonNode, bool keepInCurrentNodes = false)
{
KeyValuePair <string, JsonNode> newProperty;
if (currentPair.Value == null)
{
// If previous token was property name,
// it was added to stack with not null name and null value,
// otherwise, this is first JsonNode added
if (currentPair.Key != null)
{
// Create as property, keep name, replace null with new JsonNode:
currentNodes.Pop();
newProperty = new KeyValuePair <string, JsonNode>(currentPair.Key, jsonNode);
}
else
{
// Add first JsonNode:
newProperty = new KeyValuePair <string, JsonNode>(null, jsonNode);
}
}
else
{
// Create as value:
newProperty = new KeyValuePair <string, JsonNode>(null, jsonNode);
}
if (keepInCurrentNodes)
{
// If after adding property, it should be kept in currentNodes, it must be JsonObject or JsonArray
Debug.Assert(jsonNode.ValueKind == JsonValueKind.Object || jsonNode.ValueKind == JsonValueKind.Array);
currentNodes.Push(newProperty);
}
else
{
AddToParent(newProperty, ref currentNodes, ref toReturn, options.DuplicatePropertyNameHandling);
}
}
switch (tokenType)
{
case JsonTokenType.StartObject:
AddNewPair(new JsonObject(), true);
break;
case JsonTokenType.EndObject:
Debug.Assert(currentPair.Value is JsonObject);
currentNodes.Pop();
AddToParent(currentPair, ref currentNodes, ref toReturn, options.DuplicatePropertyNameHandling);
break;
case JsonTokenType.StartArray:
AddNewPair(new JsonArray(), true);
break;
case JsonTokenType.EndArray:
Debug.Assert(currentPair.Value is JsonArray);
currentNodes.Pop();
AddToParent(currentPair, ref currentNodes, ref toReturn, options.DuplicatePropertyNameHandling);
break;
case JsonTokenType.PropertyName:
currentNodes.Push(new KeyValuePair <string, JsonNode>(reader.GetString(), null));
break;
case JsonTokenType.Number:
AddNewPair(new JsonNumber(JsonHelpers.Utf8GetString(reader.ValueSpan)));
break;
case JsonTokenType.String:
AddNewPair(new JsonString(reader.GetString()));
break;
case JsonTokenType.True:
AddNewPair(new JsonBoolean(true));
break;
case JsonTokenType.False:
AddNewPair(new JsonBoolean(false));
break;
case JsonTokenType.Null:
AddNewPair(new JsonNull());
break;
}
}
Debug.Assert(toReturn != null);
return(toReturn);
}
} // to retrieve ValueKind when PropertyValue is null
public RecursionStackFrame(string propertyName, JsonNode propertyValue, JsonValueKind valueKind)
{
PropertyName = propertyName;
PropertyValue = propertyValue;
ValueKind = valueKind;
}
