[Lldb-commits] [lldb] [lldb-dap] Adding support for cancelling a request. (PR #130169)

[Jonas Devlieghere via lldb-commits]

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@@ -0,0 +1,55 @@
+//===-- CancelRequestHandler.cpp ------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Handler/RequestHandler.h"
+#include "Protocol/ProtocolRequests.h"
+#include "llvm/Support/Error.h"
+
+using namespace lldb_dap;
+using namespace lldb_dap::protocol;
+
+namespace lldb_dap {
+
+/// The `cancel` request is used by the client in two situations:
+///
+/// - to indicate that it is no longer interested in the result produced by a
+/// specific request issued earlier
+/// - to cancel a progress sequence.
+///
+/// Clients should only call this request if the corresponding capability
+/// `supportsCancelRequest` is true.
+///
+/// This request has a hint characteristic: a debug adapter can only be
+/// expected to make a 'best effort' in honoring this request but there are no
+/// guarantees.
+///
+/// The `cancel` request may return an error if it could not cancel
+/// an operation but a client should refrain from presenting this error to end
+/// users.
+///
+/// The request that got cancelled still needs to send a response back.
+/// This can either be a normal result (`success` attribute true) or an error
+/// response (`success` attribute false and the `message` set to `cancelled`).
+///
+/// Returning partial results from a cancelled request is possible but please
+/// note that a client has no generic way for detecting that a response is
+/// partial or not.
+///
+/// The progress that got cancelled still needs to send a `progressEnd` event
+/// back.
+///
+/// A client should not assume that progress just got cancelled after sending
+/// the `cancel` request.
----------------
JDevlieghere wrote:

For example, could this be written as follows?
```suggestion
/// A client cannot assume that progress just got cancelled after sending
/// the `cancel` request.
```

https://github.com/llvm/llvm-project/pull/130169