private static Lcs Backtrack(int[,] matrix, List <JToken> left, List <JToken> right, int li, int ri)
{
var result = new Lcs();
for (int i = li, j = ri; i > 0 && j > 0;)
{
// If the JSON tokens at the same position are both Objects or both Arrays, we just say they
// are the same even if they are not, because we can package smaller deltas than an entire
// object or array replacement by doing object to object or array to array diff.
if (left[i - 1].Equals(right[j - 1]) ||
(left[i - 1].Type == JTokenType.Object && right[j - 1].Type == JTokenType.Object) ||
(left[i - 1].Type == JTokenType.Array && right[j - 1].Type == JTokenType.Array))
{
result.Sequence.Insert(0, left[i - 1]);
result.Indices1.Insert(0, i - 1);
result.Indices2.Insert(0, j - 1);
i--;
j--;
continue;
}
if (matrix[i, j - 1] > matrix[i - 1, j])
{
j--;
}
else
{
i--;
}
}
return(result);
}
private static Lcs Backtrack(int[,] matrix, List <JToken> left, List <JToken> right, int li, int ri, ItemMatch match)
{
var result = new Lcs();
for (int i = 1, j = 1; i <= li && j <= ri;)
{
// If the JSON tokens at the same position are both Objects or both Arrays, we just say they
// are the same even if they are not, because we can package smaller deltas than an entire
// object or array replacement by doing object to object or array to array diff.
if (match.Match(left[i - 1], right[j - 1]))
{
result.Sequence.Add(left[i - 1]);
result.Indices1.Add(i - 1);
result.Indices2.Add(j - 1);
i++;
j++;
continue;
}
if (matrix[i, j - 1] > matrix[i - 1, j])
{
i++;
}
else
{
j++;
}
}
return(result);
}
private JObject ArrayDiff(JArray left, JArray right)
{
var objectHash = this._options.ObjectHash;
var itemMatch = new DefaultItemMatch(objectHash);
var result = JObject.Parse(@"{ ""_t"": ""a"" }");
int commonHead = 0;
int commonTail = 0;
if (itemMatch.Match(left, right))
{
return(null);
}
var childContext = new List <JToken>();
// Find common head
while (commonHead < left.Count &&
commonHead < right.Count &&
itemMatch.Match(left[commonHead], right[commonHead]))
{
var index = commonHead;
var child = Diff(left[index], right[index]);
if (child != null)
{
result[$"{index}"] = child;
}
commonHead++;
}
// Find common tail
while (commonTail + commonHead < left.Count &&
commonTail + commonHead < right.Count &&
itemMatch.Match(left[left.Count - 1 - commonTail], right[right.Count - 1 - commonTail]))
{
var index1 = left.Count - 1 - commonTail;
var index2 = right.Count - 1 - commonTail;
var child = Diff(left[index1], right[index2]);
if (child != null)
{
result[$"{index2}"] = child;
}
commonTail++;
}
if (commonHead + commonTail == left.Count)
{
// Trivial case, a block (1 or more consecutive items) was added
for (int index = commonHead; index < right.Count - commonTail; ++index)
{
result[$"{index}"] = new JArray(right[index]);
}
return(result);
}
if (commonHead + commonTail == right.Count)
{
// Trivial case, a block (1 or more consecutive items) was removed
for (int index = commonHead; index < left.Count - commonTail; ++index)
{
if (result.ContainsKey(index.ToString()))
{
result.Remove(index.ToString());
}
result[$"_{index}"] = new JArray(left[index], 0, (int)DiffOperation.Deleted);
}
return(result);
}
// Complex Diff, find the LCS (Longest Common Subsequence)
List <JToken> trimmedLeft = left.ToList().GetRange(commonHead, left.Count - commonTail - commonHead);
List <JToken> trimmedRight = right.ToList().GetRange(commonHead, right.Count - commonTail - commonHead);
Lcs lcs = Lcs.Get(trimmedLeft, trimmedRight, itemMatch);
for (int index = commonHead; index < left.Count - commonTail; ++index)
{
if (lcs.Indices1.IndexOf(index - commonHead) < 0)
{
// Removed
if (result.ContainsKey(index.ToString()))
{
result.Remove(index.ToString());
}
result[$"_{index}"] = new JArray(left[index], 0, (int)DiffOperation.Deleted);
}
}
for (int index = commonHead; index < right.Count - commonTail; index++)
{
int indexRight = lcs.Indices2.IndexOf(index - commonHead);
if (indexRight < 0)
{
// Added
result[$"{index}"] = new JArray(right[index]);
}
else
{
int li = lcs.Indices1[indexRight] + commonHead;
int ri = lcs.Indices2[indexRight] + commonHead;
JToken diff = Diff(left[li], right[ri]);
if (diff != null)
{
result[$"{index}"] = diff;
}
}
}
return(result);
}
private JObject ArrayDiff(JArray left, JArray right)
{
var result = JObject.Parse(@"{ ""_t"": ""a"" }");
int commonHead = 0;
int commonTail = 0;
if (JToken.DeepEquals(left, right))
{
return(null);
}
// Find common head
while (commonHead < left.Count &&
commonHead < right.Count &&
JToken.DeepEquals(left[commonHead], right[commonHead]))
{
commonHead++;
}
// Find common tail
while (commonTail + commonHead < left.Count &&
commonTail + commonHead < right.Count &&
JToken.DeepEquals(left[left.Count - 1 - commonTail], right[right.Count - 1 - commonTail]))
{
commonTail++;
}
if (commonHead + commonTail == left.Count)
{
// Trivial case, a block (1 or more consecutive items) was added
for (int index = commonHead; index < right.Count - commonTail; ++index)
{
result[$"{index}"] = new JArray(right[index]);
}
return(result);
}
if (commonHead + commonTail == right.Count)
{
// Trivial case, a block (1 or more consecutive items) was removed
for (int index = commonHead; index < left.Count - commonTail; ++index)
{
result[$"_{index}"] = new JArray(left[index], 0, (int)DiffOperation.Deleted);
}
return(result);
}
// Complex Diff, find the LCS (Longest Common Subsequence)
List <JToken> trimmedLeft = left.ToList().GetRange(commonHead, left.Count - commonTail - commonHead);
List <JToken> trimmedRight = right.ToList().GetRange(commonHead, right.Count - commonTail - commonHead);
Lcs lcs = Lcs.Get(trimmedLeft, trimmedRight);
for (int index = commonHead; index < left.Count - commonTail; ++index)
{
if (lcs.Indices1.IndexOf(index - commonHead) < 0)
{
// Removed
result[$"_{index}"] = new JArray(left[index], 0, (int)DiffOperation.Deleted);
}
}
for (int index = commonHead; index < right.Count - commonTail; index++)
{
int indexRight = lcs.Indices2.IndexOf(index - commonHead);
if (indexRight < 0)
{
// Added
result[$"{index}"] = new JArray(right[index]);
}
else
{
int li = lcs.Indices1[indexRight] + commonHead;
int ri = lcs.Indices2[indexRight] + commonHead;
JToken diff = Diff(left[li], right[ri]);
if (diff != null)
{
result[$"{index}"] = diff;
}
}
}
return(result);
}
private List <Microsoft.AspNetCore.JsonPatch.Operations.Operation> ArrayDiff(JArray left, JArray right)
{
var result = new List <Microsoft.AspNetCore.JsonPatch.Operations.Operation>();
int commonHead = 0;
int commonTail = 0;
if (JToken.DeepEquals(left, right))
{
return(null);
}
// Find common head
while (commonHead < left.Count &&
commonHead < right.Count &&
JToken.DeepEquals(left[commonHead], right[commonHead]))
{
commonHead++;
}
// Find common tail
while (commonTail + commonHead < left.Count &&
commonTail + commonHead < right.Count &&
JToken.DeepEquals(left[left.Count - 1 - commonTail], right[right.Count - 1 - commonTail]))
{
commonTail++;
}
if (commonHead + commonTail == left.Count)
{
// Trivial case, a block (1 or more consecutive items) was added
for (int index = commonHead; index < right.Count - commonTail; ++index)
{
result.Add(new Microsoft.AspNetCore.JsonPatch.Operations.Operation("add", right.Path, null, right[index]));
//result[$"{index}"] = new JArray(right[index]);
}
return(result);
}
if (commonHead + commonTail == right.Count)
{
// Trivial case, a block (1 or more consecutive items) was removed
for (int index = commonHead; index < left.Count - commonTail; ++index)
{
result.Add(new Microsoft.AspNetCore.JsonPatch.Operations.Operation("remove", $"{right.Path}/{index}", null, null));
//result[$"_{index}"] = new JArray(left[index], 0, (int)DiffOperation.Deleted);
}
return(result);
}
// Complex Diff, find the LCS (Longest Common Subsequence)
List <JToken> trimmedLeft = left.ToList().GetRange(commonHead, left.Count - commonTail - commonHead);
List <JToken> trimmedRight = right.ToList().GetRange(commonHead, right.Count - commonTail - commonHead);
Lcs lcs = Lcs.Get(trimmedLeft, trimmedRight);
for (int index = commonHead; index < left.Count - commonTail; ++index)
{
if (lcs.Indices1.IndexOf(index - commonHead) < 0)
{
// Removed
result.Add(new Microsoft.AspNetCore.JsonPatch.Operations.Operation("remove", $"{right.Path}/{index}", null, null));
//result[$"_{index}"] = new JArray(left[index], 0, (int)DiffOperation.Deleted);
}
}
for (int index = commonHead; index < right.Count - commonTail; index++)
{
int indexRight = lcs.Indices2.IndexOf(index - commonHead);
if (indexRight < 0)
{
// Added
result.Add(new Microsoft.AspNetCore.JsonPatch.Operations.Operation("add", right.Path, null, right[index]));
//result[$"{index}"] = new JArray(right[index]);
}
else
{
int li = lcs.Indices1[indexRight] + commonHead;
int ri = lcs.Indices2[indexRight] + commonHead;
var diff = Diff(left[li], right[ri]);
if (diff != null)
{
foreach (var operation in diff)
{
result.Add(operation);
}
//result[$"{index}"] = diff;
}
}
}
return(result);
}
