jsondiffpatch.net/Src/JsonDiffPatchDotNet/Formatters/JsonPatch/JsonDeltaFormatter.cs

132 lines
3.7 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using Newtonsoft.Json.Linq;
namespace JsonDiffPatchDotNet.Formatters.JsonPatch
{
public class JsonDeltaFormatter : BaseDeltaFormatter<JsonFormatContext, IList<Operation>>
{
protected override bool IncludeMoveDestinations => true;
public override IList<Operation> Format(JToken delta)
{
var result = base.Format(delta);
return ReorderOps(result);
}
protected override void Format(DeltaType type, JsonFormatContext context, JToken delta, JToken leftValue, string key, string leftKey, MoveDestination movedFrom)
{
switch (type)
{
case DeltaType.Added:
FormatAdded(context, delta);
break;
case DeltaType.Node:
FormatNode(context, delta, leftValue);
break;
case DeltaType.Modified:
FormatModified(context, delta);
break;
case DeltaType.Deleted:
FormatDeleted(context);
break;
case DeltaType.Moved:
FormatMoved(context, delta);
break;
case DeltaType.Unknown:
case DeltaType.Unchanged:
case DeltaType.MoveDestination:
break;
case DeltaType.TextDiff:
throw new InvalidOperationException("JSON RFC 6902 does not support TextDiff.");
}
}
protected override void NodeBegin(JsonFormatContext context, string key, string leftKey, DeltaType type, NodeType nodeType, bool isLast)
{
context.Path.Add(leftKey);
}
protected override void NodeEnd(JsonFormatContext context, string key, string leftKey, DeltaType type, NodeType nodeType, bool isLast)
{
if (context.Path.Count > 0)
context.Path.RemoveAt(context.Path.Count - 1);
}
protected override void RootBegin(JsonFormatContext context, DeltaType type, NodeType nodeType) { }
protected override void RootEnd(JsonFormatContext context, DeltaType type, NodeType nodeType) { }
private void FormatNode(JsonFormatContext context, JToken delta, JToken left)
{
FormatDeltaChildren(context, delta, left);
}
private void FormatAdded(JsonFormatContext context, JToken delta)
{
context.PushCurrentOp(OperationTypes.Add, delta[0]);
}
private void FormatModified(JsonFormatContext context, JToken delta)
{
context.PushCurrentOp(OperationTypes.Replace, delta[1]);
}
private void FormatDeleted(JsonFormatContext context)
{
context.PushCurrentOp(OperationTypes.Remove);
}
private void FormatMoved(JsonFormatContext context, JToken delta)
{
context.PushMoveOp(delta[1].ToString());
}
private IList<Operation> ReorderOps(IList<Operation> result)
{
var removeOpsOtherOps = PartitionRemoveOps(result);
var removeOps = removeOpsOtherOps[0];
var otherOps = removeOpsOtherOps[1];
Array.Sort(removeOps, new RemoveOperationComparer());
return removeOps.Concat(otherOps).ToList();
}
private IList<Operation[]> PartitionRemoveOps(IList<Operation> result)
{
var left = new List<Operation>();
var right = new List<Operation>();
foreach (var op in result)
(op.Op.Equals("remove", StringComparison.Ordinal) ? left : right).Add(op);
return new List<Operation[]> {left.ToArray(), right.ToArray()};
}
private class RemoveOperationComparer : IComparer<Operation>
{
public int Compare(Operation a, Operation b)
{
if (a == null) throw new ArgumentNullException(nameof(a));
if (b == null) throw new ArgumentNullException(nameof(b));
var splitA = a.Path.Split('/');
var splitB = b.Path.Split('/');
return splitA.Length != splitB.Length
? splitA.Length - splitB.Length
: CompareByIndexDesc(splitA.Last(), splitB.Last());
}
private static int CompareByIndexDesc(string indexA, string indexB)
=> int.TryParse(indexA, out var a) && int.TryParse(indexB, out var b) ? b - a : 0;
}
}
}