public async Task <SumType <LSP.SemanticTokens, LSP.SemanticTokensDelta> > HandleRequestAsync(
LSP.SemanticTokensDeltaParams request,
RequestContext context,
CancellationToken cancellationToken)
{
Contract.ThrowIfNull(request.TextDocument, "TextDocument is null.");
Contract.ThrowIfNull(request.PreviousResultId, "previousResultId is null.");
Contract.ThrowIfNull(context.Document, "Document is null.");
// Even though we want to ultimately pass edits back to LSP, we still need to compute all semantic tokens,
// both for caching purposes and in order to have a baseline comparison when computing the edits.
var newSemanticTokensData = await SemanticTokensHelpers.ComputeSemanticTokensDataAsync(
context.Document, SemanticTokensCache.TokenTypeToIndex,
range : null, cancellationToken).ConfigureAwait(false);
Contract.ThrowIfNull(newSemanticTokensData, "newSemanticTokensData is null.");
// Getting the cached tokens for the document. If we don't have an applicable cached token set,
// we can't calculate edits, so we must return all semantic tokens instead.
var oldSemanticTokensData = await _tokensCache.GetCachedTokensDataAsync(
request.TextDocument.Uri, request.PreviousResultId, cancellationToken).ConfigureAwait(false);
if (oldSemanticTokensData == null)
{
var newResultId = _tokensCache.GetNextResultId();
return(new LSP.SemanticTokens {
ResultId = newResultId, Data = newSemanticTokensData
});
}
var resultId = request.PreviousResultId;
var editArray = ComputeSemanticTokensEdits(oldSemanticTokensData, newSemanticTokensData);
// If we have edits, generate a new ResultId. Otherwise, re-use the previous one.
if (editArray.Length != 0)
{
resultId = _tokensCache.GetNextResultId();
var updatedTokens = new LSP.SemanticTokens {
ResultId = resultId, Data = newSemanticTokensData
};
await _tokensCache.UpdateCacheAsync(
request.TextDocument.Uri, updatedTokens, cancellationToken).ConfigureAwait(false);
}
var edits = new SemanticTokensDelta
{
Edits = editArray,
ResultId = resultId
};
return(edits);
}
public TextDocumentIdentifier?GetTextDocumentIdentifier(LSP.SemanticTokensDeltaParams request)
{
Contract.ThrowIfNull(request.TextDocument);
return(request.TextDocument);
}