refactor(api): deprecate nvim_call_atomic #28433

TODO:
FUNC_API_REMOTE_ONLY APIs such as `nvim_ui_*` cannot (yet) be used in
`nvim_exec_lua`. We can change FUNC_API_REMOTE_ONLY to allow
Vimscript/Lua to pass an explicit `channel_id`. #28437

5 files changed, 91 insertions, 111 deletions

diff --git a/runtime/doc/api.txt b/runtime/doc/api.txt
index 91b80601da..cc5f228920 100644
--- a/runtime/doc/api.txt
+++ b/runtime/doc/api.txt
@@ -655,33 +655,6 @@ nvim__stats()                                                  *nvim__stats()*
     Return: ~
         Map of various internal stats.
 
-nvim_call_atomic({calls})                                 *nvim_call_atomic()*
-    Calls many API methods atomically.
-
-    This has two main usages:
-    1. To perform several requests from an async context atomically, i.e.
-       without interleaving redraws, RPC requests from other clients, or user
-       interactions (however API methods may trigger autocommands or event
-       processing which have such side effects, e.g. |:sleep| may wake
-       timers).
-    2. To minimize RPC overhead (roundtrips) of a sequence of many requests.
-
-    Attributes: ~
-        |RPC| only
-
-    Parameters: ~
-      • {calls}  an array of calls, where each call is described by an array
-                 with two elements: the request name, and an array of
-                 arguments.
-
-    Return: ~
-        Array of two elements. The first is an array of return values. The
-        second is NIL if all calls succeeded. If a call resulted in an error,
-        it is a three-element array with the zero-based index of the call
-        which resulted in an error, the error type and the error message. If
-        an error occurred, the values from all preceding calls will still be
-        returned.
-
 nvim_chan_send({chan}, {data})                              *nvim_chan_send()*
     Send data to channel `id`. For a job, it writes it to the stdin of the
     process. For the stdio channel |channel-stdio|, it writes to Nvim's
diff --git a/runtime/doc/deprecated.txt b/runtime/doc/deprecated.txt
index 834366f8ec..602b033ecc 100644
--- a/runtime/doc/deprecated.txt
+++ b/runtime/doc/deprecated.txt
@@ -16,6 +16,7 @@ API
 - *nvim_buf_clear_highlight()*	Use |nvim_buf_clear_namespace()| instead.
 - *nvim_buf_set_virtual_text()*	Use |nvim_buf_set_extmark()| instead.
 - *nvim_command_output()*	Use |nvim_exec2()| instead.
+- *nvim_call_atomic()*		Use |nvim_exec_lua()| instead.
 - *nvim_execute_lua()*		Use |nvim_exec_lua()| instead.
 - *nvim_get_hl_by_name()*	Use |nvim_get_hl()| instead.
 - *nvim_get_hl_by_id()*		Use |nvim_get_hl()| instead.
diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index 1247e56fb5..39a99a61d1 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -533,6 +533,7 @@ release.
 • |API| functions:
   - |nvim_buf_get_option()|	Use |nvim_get_option_value()| instead.
   - |nvim_buf_set_option()|	Use |nvim_set_option_value()| instead.
+  - nvim_call_atomic()		Use |nvim_exec_lua()| instead.
   - |nvim_get_option()|		Use |nvim_get_option_value()| instead.
   - |nvim_set_option()|		Use |nvim_set_option_value()| instead.
   - |nvim_win_get_option()|	Use |nvim_get_option_value()| instead.
diff --git a/src/nvim/api/deprecated.c b/src/nvim/api/deprecated.c
index 6254e9fbd8..d63b8411e8 100644
--- a/src/nvim/api/deprecated.c
+++ b/src/nvim/api/deprecated.c
@@ -20,6 +20,9 @@
 #include "nvim/lua/executor.h"
 #include "nvim/memory.h"
 #include "nvim/memory_defs.h"
+#include "nvim/msgpack_rpc/channel.h"
+#include "nvim/msgpack_rpc/channel_defs.h"
+#include "nvim/msgpack_rpc/unpacker.h"
 #include "nvim/option.h"
 #include "nvim/option_defs.h"
 #include "nvim/pos_defs.h"
@@ -697,3 +700,89 @@ static void set_option_to(uint64_t channel_id, void *to, OptReqScope req_scope,
     set_option_value_for(name.data, opt_idx, optval, opt_flags, req_scope, to, err);
   });
 }
+
+/// @deprecated Use nvim_exec_lua() instead.
+///
+/// Calls many API methods atomically.
+///
+/// This has two main usages:
+/// 1. To perform several requests from an async context atomically, i.e.
+///    without interleaving redraws, RPC requests from other clients, or user
+///    interactions (however API methods may trigger autocommands or event
+///    processing which have such side effects, e.g. |:sleep| may wake timers).
+/// 2. To minimize RPC overhead (roundtrips) of a sequence of many requests.
+///
+/// @param channel_id
+/// @param calls an array of calls, where each call is described by an array
+///              with two elements: the request name, and an array of arguments.
+/// @param[out] err Validation error details (malformed `calls` parameter),
+///             if any. Errors from batched calls are given in the return value.
+///
+/// @return Array of two elements. The first is an array of return
+/// values. The second is NIL if all calls succeeded. If a call resulted in
+/// an error, it is a three-element array with the zero-based index of the call
+/// which resulted in an error, the error type and the error message. If an
+/// error occurred, the values from all preceding calls will still be returned.
+Array nvim_call_atomic(uint64_t channel_id, Array calls, Arena *arena, Error *err)
+  FUNC_API_SINCE(1) FUNC_API_DEPRECATED_SINCE(12) FUNC_API_REMOTE_ONLY
+{
+  Array rv = arena_array(arena, 2);
+  Array results = arena_array(arena, calls.size);
+  Error nested_error = ERROR_INIT;
+
+  size_t i;  // also used for freeing the variables
+  for (i = 0; i < calls.size; i++) {
+    VALIDATE_T("'calls' item", kObjectTypeArray, calls.items[i].type, {
+      goto theend;
+    });
+    Array call = calls.items[i].data.array;
+    VALIDATE_EXP((call.size == 2), "'calls' item", "2-item Array", NULL, {
+      goto theend;
+    });
+    VALIDATE_T("name", kObjectTypeString, call.items[0].type, {
+      goto theend;
+    });
+    String name = call.items[0].data.string;
+    VALIDATE_T("call args", kObjectTypeArray, call.items[1].type, {
+      goto theend;
+    });
+    Array args = call.items[1].data.array;
+
+    MsgpackRpcRequestHandler handler =
+      msgpack_rpc_get_handler_for(name.data,
+                                  name.size,
+                                  &nested_error);
+
+    if (ERROR_SET(&nested_error)) {
+      break;
+    }
+
+    Object result = handler.fn(channel_id, args, arena, &nested_error);
+    if (ERROR_SET(&nested_error)) {
+      // error handled after loop
+      break;
+    }
+    // TODO(bfredl): wasteful copy. It could be avoided to encoding to msgpack
+    // directly here. But `result` might become invalid when next api function
+    // is called in the loop.
+    ADD_C(results, copy_object(result, arena));
+    if (handler.ret_alloc) {
+      api_free_object(result);
+    }
+  }
+
+  ADD_C(rv, ARRAY_OBJ(results));
+  if (ERROR_SET(&nested_error)) {
+    Array errval = arena_array(arena, 3);
+    ADD_C(errval, INTEGER_OBJ((Integer)i));
+    ADD_C(errval, INTEGER_OBJ(nested_error.type));
+    ADD_C(errval, STRING_OBJ(copy_string(cstr_as_string(nested_error.msg), arena)));
+    ADD_C(rv, ARRAY_OBJ(errval));
+  } else {
+    ADD_C(rv, NIL);
+  }
+
+theend:
+  api_clear_error(&nested_error);
+  return rv;
+}
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index 82e9ddff2d..d62ea46e1b 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -1698,90 +1698,6 @@ Array nvim_list_chans(Arena *arena)
   return channel_all_info(arena);
 }
 
-/// Calls many API methods atomically.
-///
-/// This has two main usages:
-/// 1. To perform several requests from an async context atomically, i.e.
-///    without interleaving redraws, RPC requests from other clients, or user
-///    interactions (however API methods may trigger autocommands or event
-///    processing which have such side effects, e.g. |:sleep| may wake timers).
-/// 2. To minimize RPC overhead (roundtrips) of a sequence of many requests.
-///
-/// @param channel_id
-/// @param calls an array of calls, where each call is described by an array
-///              with two elements: the request name, and an array of arguments.
-/// @param[out] err Validation error details (malformed `calls` parameter),
-///             if any. Errors from batched calls are given in the return value.
-///
-/// @return Array of two elements. The first is an array of return
-/// values. The second is NIL if all calls succeeded. If a call resulted in
-/// an error, it is a three-element array with the zero-based index of the call
-/// which resulted in an error, the error type and the error message. If an
-/// error occurred, the values from all preceding calls will still be returned.
-Array nvim_call_atomic(uint64_t channel_id, Array calls, Arena *arena, Error *err)
-  FUNC_API_SINCE(1) FUNC_API_REMOTE_ONLY
-{
-  Array rv = arena_array(arena, 2);
-  Array results = arena_array(arena, calls.size);
-  Error nested_error = ERROR_INIT;
-
-  size_t i;  // also used for freeing the variables
-  for (i = 0; i < calls.size; i++) {
-    VALIDATE_T("'calls' item", kObjectTypeArray, calls.items[i].type, {
-      goto theend;
-    });
-    Array call = calls.items[i].data.array;
-    VALIDATE_EXP((call.size == 2), "'calls' item", "2-item Array", NULL, {
-      goto theend;
-    });
-    VALIDATE_T("name", kObjectTypeString, call.items[0].type, {
-      goto theend;
-    });
-    String name = call.items[0].data.string;
-    VALIDATE_T("call args", kObjectTypeArray, call.items[1].type, {
-      goto theend;
-    });
-    Array args = call.items[1].data.array;
-
-    MsgpackRpcRequestHandler handler =
-      msgpack_rpc_get_handler_for(name.data,
-                                  name.size,
-                                  &nested_error);
-
-    if (ERROR_SET(&nested_error)) {
-      break;
-    }
-
-    Object result = handler.fn(channel_id, args, arena, &nested_error);
-    if (ERROR_SET(&nested_error)) {
-      // error handled after loop
-      break;
-    }
-    // TODO(bfredl): wasteful copy. It could be avoided to encoding to msgpack
-    // directly here. But `result` might become invalid when next api function
-    // is called in the loop.
-    ADD_C(results, copy_object(result, arena));
-    if (handler.ret_alloc) {
-      api_free_object(result);
-    }
-  }
-
-  ADD_C(rv, ARRAY_OBJ(results));
-  if (ERROR_SET(&nested_error)) {
-    Array errval = arena_array(arena, 3);
-    ADD_C(errval, INTEGER_OBJ((Integer)i));
-    ADD_C(errval, INTEGER_OBJ(nested_error.type));
-    ADD_C(errval, STRING_OBJ(copy_string(cstr_as_string(nested_error.msg), arena)));
-    ADD_C(rv, ARRAY_OBJ(errval));
-  } else {
-    ADD_C(rv, NIL);
-  }
-
-theend:
-  api_clear_error(&nested_error);
-  return rv;
-}
-
 /// Writes a message to vim output or error buffer. The string is split
 /// and flushed after each newline. Incomplete lines are kept for writing
 /// later.