Merge pull request #27511 from bfredl/maparena

refactor(api): use arena for mappings, autocmd, channel info

8 files changed, 129 insertions, 132 deletions

diff --git a/src/nvim/api/autocmd.c b/src/nvim/api/autocmd.c
index 90b7f3a5c6..7e33a77d24 100644
--- a/src/nvim/api/autocmd.c
+++ b/src/nvim/api/autocmd.c
@@ -23,6 +23,7 @@
 #include "nvim/globals.h"
 #include "nvim/lua/executor.h"
 #include "nvim/memory.h"
+#include "nvim/strings.h"
 #include "nvim/types_defs.h"
 #include "nvim/vim_defs.h"
 
@@ -33,12 +34,12 @@
 #define AUCMD_MAX_PATTERNS 256
 
 // Copy string or array of strings into an empty array.
-// Get the event number, unless it is an error. Then goto `goto_name`.
-#define GET_ONE_EVENT(event_nr, event_str, goto_name) \
+// Get the event number, unless it is an error. Then do `or_else`.
+#define GET_ONE_EVENT(event_nr, event_str, or_else) \
   event_T event_nr = \
     event_name2nr_str(event_str.data.string); \
   VALIDATE_S((event_nr < NUM_EVENTS), "event", event_str.data.string.data, { \
-    goto goto_name; \
+    or_else; \
   });
 
 // ID for associating autocmds created via nvim_create_autocmd
@@ -88,14 +89,14 @@ static int64_t next_autocmd_id = 1;
 ///             If the autocommand is buffer local |autocmd-buffer-local|:
 ///             - buflocal (boolean): true if the autocommand is buffer local.
 ///             - buffer (number): the buffer number.
-Array nvim_get_autocmds(Dict(get_autocmds) *opts, Error *err)
+Array nvim_get_autocmds(Dict(get_autocmds) *opts, Arena *arena, Error *err)
   FUNC_API_SINCE(9)
 {
   // TODO(tjdevries): Would be cool to add nvim_get_autocmds({ id = ... })
 
-  Array autocmd_list = ARRAY_DICT_INIT;
+  ArrayBuilder autocmd_list = KV_INITIAL_VALUE;
+  kvi_init(autocmd_list);
   char *pattern_filters[AUCMD_MAX_PATTERNS];
-  char pattern_buflocal[BUFLOCAL_PAT_LEN];
 
   Array buffers = ARRAY_DICT_INIT;
 
@@ -131,7 +132,7 @@ Array nvim_get_autocmds(Dict(get_autocmds) *opts, Error *err)
 
     Object v = opts->event;
     if (v.type == kObjectTypeString) {
-      GET_ONE_EVENT(event_nr, v, cleanup);
+      GET_ONE_EVENT(event_nr, v, goto cleanup);
       event_set[event_nr] = true;
     } else if (v.type == kObjectTypeArray) {
       FOREACH_ITEM(v.data.array, event_v, {
@@ -139,7 +140,7 @@ Array nvim_get_autocmds(Dict(get_autocmds) *opts, Error *err)
           goto cleanup;
         });
 
-        GET_ONE_EVENT(event_nr, event_v, cleanup);
+        GET_ONE_EVENT(event_nr, event_v, goto cleanup);
         event_set[event_nr] = true;
       })
     } else {
@@ -187,8 +188,9 @@ Array nvim_get_autocmds(Dict(get_autocmds) *opts, Error *err)
       goto cleanup;
     }
 
-    snprintf(pattern_buflocal, BUFLOCAL_PAT_LEN, "<buffer=%d>", (int)buf->handle);
-    ADD(buffers, CSTR_TO_OBJ(pattern_buflocal));
+    String pat = arena_printf(arena, "<buffer=%d>", (int)buf->handle);
+    buffers = arena_array(arena, 1);
+    ADD_C(buffers, STRING_OBJ(pat));
   } else if (opts->buffer.type == kObjectTypeArray) {
     if (opts->buffer.data.array.size > AUCMD_MAX_PATTERNS) {
       api_set_error(err, kErrorTypeValidation, "Too many buffers (maximum of %d)",
@@ -196,6 +198,7 @@ Array nvim_get_autocmds(Dict(get_autocmds) *opts, Error *err)
       goto cleanup;
     }
 
+    buffers = arena_array(arena, kv_size(opts->buffer.data.array));
     FOREACH_ITEM(opts->buffer.data.array, bufnr, {
       VALIDATE_EXP((bufnr.type == kObjectTypeInteger || bufnr.type == kObjectTypeBuffer),
                    "buffer", "Integer", api_typename(bufnr.type), {
@@ -207,8 +210,7 @@ Array nvim_get_autocmds(Dict(get_autocmds) *opts, Error *err)
         goto cleanup;
       }
 
-      snprintf(pattern_buflocal, BUFLOCAL_PAT_LEN, "<buffer=%d>", (int)buf->handle);
-      ADD(buffers, CSTR_TO_OBJ(pattern_buflocal));
+      ADD_C(buffers, STRING_OBJ(arena_printf(arena, "<buffer=%d>", (int)buf->handle)));
     });
   } else if (HAS_KEY(opts, get_autocmds, buffer)) {
     VALIDATE_EXP(false, "buffer", "Integer or Array", api_typename(opts->buffer.type), {
@@ -250,6 +252,7 @@ Array nvim_get_autocmds(Dict(get_autocmds) *opts, Error *err)
           char *pat = pattern_filters[j];
           int patlen = (int)strlen(pat);
 
+          char pattern_buflocal[BUFLOCAL_PAT_LEN];
           if (aupat_is_buflocal(pat, patlen)) {
             aupat_normalize_buflocal_pat(pattern_buflocal, pat, patlen,
                                          aupat_get_buflocal_nr(pat, patlen));
@@ -267,51 +270,51 @@ Array nvim_get_autocmds(Dict(get_autocmds) *opts, Error *err)
         }
       }
 
-      Dictionary autocmd_info = ARRAY_DICT_INIT;
+      Dictionary autocmd_info = arena_dict(arena, 11);
 
       if (ap->group != AUGROUP_DEFAULT) {
-        PUT(autocmd_info, "group", INTEGER_OBJ(ap->group));
-        PUT(autocmd_info, "group_name", CSTR_TO_OBJ(augroup_name(ap->group)));
+        PUT_C(autocmd_info, "group", INTEGER_OBJ(ap->group));
+        PUT_C(autocmd_info, "group_name", CSTR_AS_OBJ(augroup_name(ap->group)));
       }
 
       if (ac->id > 0) {
-        PUT(autocmd_info, "id", INTEGER_OBJ(ac->id));
+        PUT_C(autocmd_info, "id", INTEGER_OBJ(ac->id));
       }
 
       if (ac->desc != NULL) {
-        PUT(autocmd_info, "desc", CSTR_TO_OBJ(ac->desc));
+        PUT_C(autocmd_info, "desc", CSTR_AS_OBJ(ac->desc));
       }
 
       if (ac->exec.type == CALLABLE_CB) {
-        PUT(autocmd_info, "command", STRING_OBJ(STRING_INIT));
+        PUT_C(autocmd_info, "command", STRING_OBJ(STRING_INIT));
 
         Callback *cb = &ac->exec.callable.cb;
         switch (cb->type) {
         case kCallbackLua:
           if (nlua_ref_is_function(cb->data.luaref)) {
-            PUT(autocmd_info, "callback", LUAREF_OBJ(api_new_luaref(cb->data.luaref)));
+            PUT_C(autocmd_info, "callback", LUAREF_OBJ(api_new_luaref(cb->data.luaref)));
           }
           break;
         case kCallbackFuncref:
         case kCallbackPartial:
-          PUT(autocmd_info, "callback", CSTR_AS_OBJ(callback_to_string(cb)));
+          PUT_C(autocmd_info, "callback", CSTR_AS_OBJ(callback_to_string(cb, arena)));
           break;
         case kCallbackNone:
           abort();
         }
       } else {
-        PUT(autocmd_info, "command", CSTR_TO_OBJ(ac->exec.callable.cmd));
+        PUT_C(autocmd_info, "command", CSTR_AS_OBJ(ac->exec.callable.cmd));
       }
 
-      PUT(autocmd_info, "pattern", CSTR_TO_OBJ(ap->pat));
-      PUT(autocmd_info, "event", CSTR_TO_OBJ(event_nr2name(event)));
-      PUT(autocmd_info, "once", BOOLEAN_OBJ(ac->once));
+      PUT_C(autocmd_info, "pattern", CSTR_AS_OBJ(ap->pat));
+      PUT_C(autocmd_info, "event", CSTR_AS_OBJ(event_nr2name(event)));
+      PUT_C(autocmd_info, "once", BOOLEAN_OBJ(ac->once));
 
       if (ap->buflocal_nr) {
-        PUT(autocmd_info, "buflocal", BOOLEAN_OBJ(true));
-        PUT(autocmd_info, "buffer", INTEGER_OBJ(ap->buflocal_nr));
+        PUT_C(autocmd_info, "buflocal", BOOLEAN_OBJ(true));
+        PUT_C(autocmd_info, "buffer", INTEGER_OBJ(ap->buflocal_nr));
       } else {
-        PUT(autocmd_info, "buflocal", BOOLEAN_OBJ(false));
+        PUT_C(autocmd_info, "buflocal", BOOLEAN_OBJ(false));
       }
 
       // TODO(sctx): It would be good to unify script_ctx to actually work with lua
@@ -328,16 +331,15 @@ Array nvim_get_autocmds(Dict(get_autocmds) *opts, Error *err)
       //  Once we do that, we can put these into the autocmd_info, but I don't think it's
       //  useful to do that at this time.
       //
-      // PUT(autocmd_info, "sid", INTEGER_OBJ(ac->script_ctx.sc_sid));
-      // PUT(autocmd_info, "lnum", INTEGER_OBJ(ac->script_ctx.sc_lnum));
+      // PUT_C(autocmd_info, "sid", INTEGER_OBJ(ac->script_ctx.sc_sid));
+      // PUT_C(autocmd_info, "lnum", INTEGER_OBJ(ac->script_ctx.sc_lnum));
 
-      ADD(autocmd_list, DICTIONARY_OBJ(autocmd_info));
+      kvi_push(autocmd_list, DICTIONARY_OBJ(autocmd_info));
     }
   }
 
 cleanup:
-  api_free_array(buffers);
-  return autocmd_list;
+  return arena_take_arraybuilder(arena, &autocmd_list);
 }
 
 /// Creates an |autocommand| event handler, defined by `callback` (Lua function or Vimscript
@@ -399,17 +401,16 @@ cleanup:
 /// @see |autocommand|
 /// @see |nvim_del_autocmd()|
 Integer nvim_create_autocmd(uint64_t channel_id, Object event, Dict(create_autocmd) *opts,
-                            Error *err)
+                            Arena *arena, Error *err)
   FUNC_API_SINCE(9)
 {
   int64_t autocmd_id = -1;
   char *desc = NULL;
-  Array patterns = ARRAY_DICT_INIT;
-  Array event_array = ARRAY_DICT_INIT;
   AucmdExecutable aucmd = AUCMD_EXECUTABLE_INIT;
   Callback cb = CALLBACK_NONE;
 
-  if (!unpack_string_or_array(&event_array, &event, "event", true, err)) {
+  Array event_array = unpack_string_or_array(event, "event", true, arena, err);
+  if (ERROR_SET(err)) {
     goto cleanup;
   }
 
@@ -469,7 +470,9 @@ Integer nvim_create_autocmd(uint64_t channel_id, Object event, Dict(create_autoc
     goto cleanup;
   });
 
-  if (!get_patterns_from_pattern_or_buf(&patterns, opts->pattern, has_buffer, opts->buffer, err)) {
+  Array patterns = get_patterns_from_pattern_or_buf(opts->pattern, has_buffer, opts->buffer, "*",
+                                                    arena, err);
+  if (ERROR_SET(err)) {
     goto cleanup;
   }
 
@@ -477,17 +480,13 @@ Integer nvim_create_autocmd(uint64_t channel_id, Object event, Dict(create_autoc
     desc = opts->desc.data;
   }
 
-  if (patterns.size == 0) {
-    ADD(patterns, STATIC_CSTR_TO_OBJ("*"));
-  }
-
   VALIDATE_R((event_array.size > 0), "event", {
     goto cleanup;
   });
 
   autocmd_id = next_autocmd_id++;
   FOREACH_ITEM(event_array, event_str, {
-    GET_ONE_EVENT(event_nr, event_str, cleanup);
+    GET_ONE_EVENT(event_nr, event_str, goto cleanup);
 
     int retval;
 
@@ -514,8 +513,6 @@ Integer nvim_create_autocmd(uint64_t channel_id, Object event, Dict(create_autoc
 
 cleanup:
   aucmd_exec_free(&aucmd);
-  api_free_array(event_array);
-  api_free_array(patterns);
 
   return autocmd_id;
 }
@@ -555,7 +552,7 @@ void nvim_del_autocmd(Integer id, Error *err)
 ///         - group: (string|int) The augroup name or id.
 ///             - NOTE: If not passed, will only delete autocmds *not* in any group.
 ///
-void nvim_clear_autocmds(Dict(clear_autocmds) *opts, Error *err)
+void nvim_clear_autocmds(Dict(clear_autocmds) *opts, Arena *arena, Error *err)
   FUNC_API_SINCE(9)
 {
   // TODO(tjdevries): Future improvements:
@@ -564,33 +561,29 @@ void nvim_clear_autocmds(Dict(clear_autocmds) *opts, Error *err)
   //        - group: Allow passing "*" or true or something like that to force doing all
   //        autocmds, regardless of their group.
 
-  Array patterns = ARRAY_DICT_INIT;
-  Array event_array = ARRAY_DICT_INIT;
-
-  if (!unpack_string_or_array(&event_array, &opts->event, "event", false, err)) {
-    goto cleanup;
+  Array event_array = unpack_string_or_array(opts->event, "event", false, arena, err);
+  if (ERROR_SET(err)) {
+    return;
   }
 
   bool has_buffer = HAS_KEY(opts, clear_autocmds, buffer);
 
   VALIDATE((!HAS_KEY(opts, clear_autocmds, pattern) || !has_buffer),
            "%s", "Cannot use both 'pattern' and 'buffer'", {
-    goto cleanup;
+    return;
   });
 
   int au_group = get_augroup_from_object(opts->group, err);
   if (au_group == AUGROUP_ERROR) {
-    goto cleanup;
-  }
-
-  if (!get_patterns_from_pattern_or_buf(&patterns, opts->pattern, has_buffer, opts->buffer, err)) {
-    goto cleanup;
+    return;
   }
 
   // When we create the autocmds, we want to say that they are all matched, so that's *
   // but when we clear them, we want to say that we didn't pass a pattern, so that's NUL
-  if (patterns.size == 0) {
-    ADD(patterns, STATIC_CSTR_TO_OBJ(""));
+  Array patterns = get_patterns_from_pattern_or_buf(opts->pattern, has_buffer, opts->buffer, "",
+                                                    arena, err);
+  if (ERROR_SET(err)) {
+    return;
   }
 
   // If we didn't pass any events, that means clear all events.
@@ -599,26 +592,22 @@ void nvim_clear_autocmds(Dict(clear_autocmds) *opts, Error *err)
       FOREACH_ITEM(patterns, pat_object, {
         char *pat = pat_object.data.string.data;
         if (!clear_autocmd(event, pat, au_group, err)) {
-          goto cleanup;
+          return;
         }
       });
     }
   } else {
     FOREACH_ITEM(event_array, event_str, {
-      GET_ONE_EVENT(event_nr, event_str, cleanup);
+      GET_ONE_EVENT(event_nr, event_str, return );
 
       FOREACH_ITEM(patterns, pat_object, {
         char *pat = pat_object.data.string.data;
         if (!clear_autocmd(event_nr, pat, au_group, err)) {
-          goto cleanup;
+          return;
         }
       });
     });
   }
-
-cleanup:
-  api_free_array(event_array);
-  api_free_array(patterns);
 }
 
 /// Create or get an autocommand group |autocmd-groups|.
@@ -709,7 +698,7 @@ void nvim_del_augroup_by_name(String name, Error *err)
 ///             - data (any): arbitrary data to send to the autocommand callback. See
 ///             |nvim_create_autocmd()| for details.
 /// @see |:doautocmd|
-void nvim_exec_autocmds(Object event, Dict(exec_autocmds) *opts, Error *err)
+void nvim_exec_autocmds(Object event, Dict(exec_autocmds) *opts, Arena *arena, Error *err)
   FUNC_API_SINCE(9)
 {
   int au_group = AUGROUP_ALL;
@@ -717,13 +706,11 @@ void nvim_exec_autocmds(Object event, Dict(exec_autocmds) *opts, Error *err)
 
   buf_T *buf = curbuf;
 
-  Array patterns = ARRAY_DICT_INIT;
-  Array event_array = ARRAY_DICT_INIT;
-
   Object *data = NULL;
 
-  if (!unpack_string_or_array(&event_array, &event, "event", true, err)) {
-    goto cleanup;
+  Array event_array = unpack_string_or_array(event, "event", true, arena, err);
+  if (ERROR_SET(err)) {
+    return;
   }
 
   switch (opts->group.type) {
@@ -732,19 +719,19 @@ void nvim_exec_autocmds(Object event, Dict(exec_autocmds) *opts, Error *err)
   case kObjectTypeString:
     au_group = augroup_find(opts->group.data.string.data);
     VALIDATE_S((au_group != AUGROUP_ERROR), "group", opts->group.data.string.data, {
-      goto cleanup;
+      return;
     });
     break;
   case kObjectTypeInteger:
     au_group = (int)opts->group.data.integer;
     char *name = au_group == 0 ? NULL : augroup_name(au_group);
     VALIDATE_INT(augroup_exists(name), "group", (int64_t)au_group, {
-      goto cleanup;
+      return;
     });
     break;
   default:
     VALIDATE_EXP(false, "group", "String or Integer", api_typename(opts->group.type), {
-      goto cleanup;
+      return;
     });
   }
 
@@ -752,23 +739,21 @@ void nvim_exec_autocmds(Object event, Dict(exec_autocmds) *opts, Error *err)
   if (HAS_KEY(opts, exec_autocmds, buffer)) {
     VALIDATE((!HAS_KEY(opts, exec_autocmds, pattern)),
              "%s", "Cannot use both 'pattern' and 'buffer' for the same autocmd", {
-      goto cleanup;
+      return;
     });
 
     has_buffer = true;
     buf = find_buffer_by_handle(opts->buffer, err);
 
     if (ERROR_SET(err)) {
-      goto cleanup;
+      return;
     }
   }
 
-  if (!get_patterns_from_pattern_or_buf(&patterns, opts->pattern, has_buffer, opts->buffer, err)) {
-    goto cleanup;
-  }
-
-  if (patterns.size == 0) {
-    ADD(patterns, STATIC_CSTR_TO_OBJ(""));
+  Array patterns = get_patterns_from_pattern_or_buf(opts->pattern, has_buffer, opts->buffer, "",
+                                                    arena, err);
+  if (ERROR_SET(err)) {
+    return;
   }
 
   if (HAS_KEY(opts, exec_autocmds, data)) {
@@ -779,7 +764,7 @@ void nvim_exec_autocmds(Object event, Dict(exec_autocmds) *opts, Error *err)
 
   bool did_aucmd = false;
   FOREACH_ITEM(event_array, event_str, {
-    GET_ONE_EVENT(event_nr, event_str, cleanup)
+    GET_ONE_EVENT(event_nr, event_str, return )
 
     FOREACH_ITEM(patterns, pat, {
       char *fname = !has_buffer ? pat.data.string.data : NULL;
@@ -790,28 +775,26 @@ void nvim_exec_autocmds(Object event, Dict(exec_autocmds) *opts, Error *err)
   if (did_aucmd && modeline) {
     do_modelines(0);
   }
-
-cleanup:
-  api_free_array(event_array);
-  api_free_array(patterns);
 }
 
-static bool unpack_string_or_array(Array *array, Object *v, char *k, bool required, Error *err)
+static Array unpack_string_or_array(Object v, char *k, bool required, Arena *arena, Error *err)
 {
-  if (v->type == kObjectTypeString) {
-    ADD(*array, copy_object(*v, NULL));
-  } else if (v->type == kObjectTypeArray) {
-    if (!check_string_array(v->data.array, k, true, err)) {
-      return false;
+  if (v.type == kObjectTypeString) {
+    Array arr = arena_array(arena, 1);
+    ADD_C(arr, v);
+    return arr;
+  } else if (v.type == kObjectTypeArray) {
+    if (!check_string_array(v.data.array, k, true, err)) {
+      return (Array)ARRAY_DICT_INIT;
     }
-    *array = copy_array(v->data.array, NULL);
+    return v.data.array;
   } else {
-    VALIDATE_EXP(!required, k, "Array or String", api_typename(v->type), {
-      return false;
+    VALIDATE_EXP(!required, k, "Array or String", api_typename(v.type), {
+      return (Array)ARRAY_DICT_INIT;
     });
   }
 
-  return true;
+  return (Array)ARRAY_DICT_INIT;
 }
 
 // Returns AUGROUP_ERROR if there was a problem with {group}
@@ -843,55 +826,57 @@ static int get_augroup_from_object(Object group, Error *err)
   }
 }
 
-static bool get_patterns_from_pattern_or_buf(Array *patterns, Object pattern, bool has_buffer,
-                                             Buffer buffer, Error *err)
+static Array get_patterns_from_pattern_or_buf(Object pattern, bool has_buffer, Buffer buffer,
+                                              char *fallback, Arena *arena, Error *err)
 {
-  const char pattern_buflocal[BUFLOCAL_PAT_LEN];
+  ArrayBuilder patterns = ARRAY_DICT_INIT;
+  kvi_init(patterns);
 
   if (pattern.type != kObjectTypeNil) {
-    Object *v = &pattern;
-
-    if (v->type == kObjectTypeString) {
-      const char *pat = v->data.string.data;
+    if (pattern.type == kObjectTypeString) {
+      const char *pat = pattern.data.string.data;
       size_t patlen = aucmd_pattern_length(pat);
       while (patlen) {
-        ADD(*patterns, STRING_OBJ(cbuf_to_string(pat, patlen)));
+        kvi_push(patterns, CBUF_TO_ARENA_OBJ(arena, pat, patlen));
 
         pat = aucmd_next_pattern(pat, patlen);
         patlen = aucmd_pattern_length(pat);
       }
-    } else if (v->type == kObjectTypeArray) {
-      if (!check_string_array(v->data.array, "pattern", true, err)) {
-        return false;
+    } else if (pattern.type == kObjectTypeArray) {
+      if (!check_string_array(pattern.data.array, "pattern", true, err)) {
+        return (Array)ARRAY_DICT_INIT;
       }
 
-      Array array = v->data.array;
+      Array array = pattern.data.array;
       FOREACH_ITEM(array, entry, {
         const char *pat = entry.data.string.data;
         size_t patlen = aucmd_pattern_length(pat);
         while (patlen) {
-          ADD(*patterns, STRING_OBJ(cbuf_to_string(pat, patlen)));
+          kvi_push(patterns, CBUF_TO_ARENA_OBJ(arena, pat, patlen));
 
           pat = aucmd_next_pattern(pat, patlen);
           patlen = aucmd_pattern_length(pat);
         }
       })
     } else {
-      VALIDATE_EXP(false, "pattern", "String or Table", api_typename(v->type), {
-        return false;
+      VALIDATE_EXP(false, "pattern", "String or Table", api_typename(pattern.type), {
+        return (Array)ARRAY_DICT_INIT;
       });
     }
   } else if (has_buffer) {
     buf_T *buf = find_buffer_by_handle(buffer, err);
     if (ERROR_SET(err)) {
-      return false;
+      return (Array)ARRAY_DICT_INIT;
     }
 
-    snprintf((char *)pattern_buflocal, BUFLOCAL_PAT_LEN, "<buffer=%d>", (int)buf->handle);
-    ADD(*patterns, CSTR_TO_OBJ(pattern_buflocal));
+    kvi_push(patterns, STRING_OBJ(arena_printf(arena, "<buffer=%d>", (int)buf->handle)));
   }
 
-  return true;
+  if (kv_size(patterns) == 0 && fallback) {
+    kvi_push(patterns, CSTR_AS_OBJ(fallback));
+  }
+
+  return arena_take_arraybuilder(arena, &patterns);
 }
 
 static bool clear_autocmd(event_T event, char *pat, int au_group, Error *err)
diff --git a/src/nvim/api/buffer.c b/src/nvim/api/buffer.c
index 257e5e6b05..ddca85945a 100644
--- a/src/nvim/api/buffer.c
+++ b/src/nvim/api/buffer.c
@@ -905,7 +905,7 @@ Integer nvim_buf_get_changedtick(Buffer buffer, Error *err)
 /// @param[out]  err   Error details, if any
 /// @returns Array of |maparg()|-like dictionaries describing mappings.
 ///          The "buffer" key holds the associated buffer handle.
-ArrayOf(Dictionary) nvim_buf_get_keymap(Buffer buffer, String mode, Error *err)
+ArrayOf(Dictionary) nvim_buf_get_keymap(Buffer buffer, String mode, Arena *arena, Error *err)
   FUNC_API_SINCE(3)
 {
   buf_T *buf = find_buffer_by_handle(buffer, err);
@@ -914,7 +914,7 @@ ArrayOf(Dictionary) nvim_buf_get_keymap(Buffer buffer, String mode, Error *err)
     return (Array)ARRAY_DICT_INIT;
   }
 
-  return keymap_array(mode, buf);
+  return keymap_array(mode, buf, arena);
 }
 
 /// Sets a buffer-local |mapping| for the given mode.
diff --git a/src/nvim/api/extmark.c b/src/nvim/api/extmark.c
index 94f6059014..f6f7d332ec 100644
--- a/src/nvim/api/extmark.c
+++ b/src/nvim/api/extmark.c
@@ -346,7 +346,7 @@ Array nvim_buf_get_extmarks(Buffer buffer, Integer ns_id, Object start, Object e
 
   rv = arena_array(arena, kv_size(marks));
   for (size_t i = 0; i < kv_size(marks); i++) {
-    ADD(rv, ARRAY_OBJ(extmark_to_array(kv_A(marks, i), true, details, hl_name, arena)));
+    ADD_C(rv, ARRAY_OBJ(extmark_to_array(kv_A(marks, i), true, details, hl_name, arena)));
   }
 
   kv_destroy(marks);
diff --git a/src/nvim/api/private/helpers.c b/src/nvim/api/private/helpers.c
index 1446683b0c..983f1a4fed 100644
--- a/src/nvim/api/private/helpers.c
+++ b/src/nvim/api/private/helpers.c
@@ -581,6 +581,15 @@ String arena_string(Arena *arena, String str)
   }
 }
 
+Array arena_take_arraybuilder(Arena *arena, ArrayBuilder *arr)
+{
+  Array ret = arena_array(arena, kv_size(*arr));
+  ret.size = kv_size(*arr);
+  memcpy(ret.items, arr->items, sizeof(ret.items[0]) * ret.size);
+  kvi_destroy(*arr);
+  return ret;
+}
+
 void api_free_object(Object value)
 {
   switch (value.type) {
diff --git a/src/nvim/api/private/helpers.h b/src/nvim/api/private/helpers.h
index 395c5a9d1f..20bc889a0a 100644
--- a/src/nvim/api/private/helpers.h
+++ b/src/nvim/api/private/helpers.h
@@ -95,6 +95,8 @@
   name.capacity = maxsize; \
   name.items = name##__items; \
 
+typedef kvec_withinit_t(Object, 16) ArrayBuilder;
+
 #define cbuf_as_string(d, s) ((String) { .data = d, .size = s })
 
 #define STATIC_CSTR_AS_STRING(s) ((String) { .data = s, .size = sizeof("" s) - 1 })
diff --git a/src/nvim/api/ui.c b/src/nvim/api/ui.c
index 140b520cb5..d5843caa96 100644
--- a/src/nvim/api/ui.c
+++ b/src/nvim/api/ui.c
@@ -1046,7 +1046,7 @@ static Array translate_firstarg(UI *ui, Array args, Arena *arena)
 
   ADD_C(new_args, ARRAY_OBJ(translate_contents(ui, contents, arena)));
   for (size_t i = 1; i < args.size; i++) {
-    ADD(new_args, args.items[i]);
+    ADD_C(new_args, args.items[i]);
   }
   return new_args;
 }
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index 1184eb7441..7a19ccf295 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -1456,10 +1456,10 @@ Dictionary nvim_get_mode(Arena *arena)
 /// @param  mode       Mode short-name ("n", "i", "v", ...)
 /// @returns Array of |maparg()|-like dictionaries describing mappings.
 ///          The "buffer" key is always zero.
-ArrayOf(Dictionary) nvim_get_keymap(String mode)
+ArrayOf(Dictionary) nvim_get_keymap(String mode, Arena *arena)
   FUNC_API_SINCE(3)
 {
-  return keymap_array(mode, NULL);
+  return keymap_array(mode, NULL, arena);
 }
 
 /// Sets a global |mapping| for the given mode.
@@ -1633,7 +1633,7 @@ void nvim_set_client_info(uint64_t channel_id, String name, Dictionary version,
 ///                 the RPC channel), if provided by it via
 ///                 |nvim_set_client_info()|.
 ///
-Dictionary nvim_get_chan_info(uint64_t channel_id, Integer chan, Error *err)
+Dictionary nvim_get_chan_info(uint64_t channel_id, Integer chan, Arena *arena, Error *err)
   FUNC_API_SINCE(4)
 {
   if (chan < 0) {
@@ -1644,17 +1644,17 @@ Dictionary nvim_get_chan_info(uint64_t channel_id, Integer chan, Error *err)
     assert(channel_id <= INT64_MAX);
     chan = (Integer)channel_id;
   }
-  return channel_info((uint64_t)chan);
+  return channel_info((uint64_t)chan, arena);
 }
 
 /// Get information about all open channels.
 ///
 /// @returns Array of Dictionaries, each describing a channel with
 ///          the format specified at |nvim_get_chan_info()|.
-Array nvim_list_chans(void)
+Array nvim_list_chans(Arena *arena)
   FUNC_API_SINCE(4)
 {
-  return channel_all_info();
+  return channel_all_info(arena);
 }
 
 /// Calls many API methods atomically.
@@ -1891,7 +1891,7 @@ Array nvim_get_proc_children(Integer pid, Arena *arena, Error *err)
     // syscall failed (possibly because of kernel options), try shelling out.
     DLOG("fallback to vim._os_proc_children()");
     MAXSIZE_TEMP_ARRAY(a, 1);
-    ADD(a, INTEGER_OBJ(pid));
+    ADD_C(a, INTEGER_OBJ(pid));
     Object o = NLUA_EXEC_STATIC("return vim._os_proc_children(...)", a, kRetObject, arena, err);
     if (o.type == kObjectTypeArray) {
       rvobj = o.data.array;
@@ -1903,7 +1903,7 @@ Array nvim_get_proc_children(Integer pid, Arena *arena, Error *err)
   } else {
     rvobj = arena_array(arena, proc_count);
     for (size_t i = 0; i < proc_count; i++) {
-      ADD(rvobj, INTEGER_OBJ(proc_list[i]));
+      ADD_C(rvobj, INTEGER_OBJ(proc_list[i]));
     }
   }
 
@@ -1925,7 +1925,7 @@ Object nvim_get_proc(Integer pid, Arena *arena, Error *err)
   });
 
 #ifdef MSWIN
-  rvobj = DICTIONARY_OBJ(os_proc_info((int)pid));
+  rvobj = DICTIONARY_OBJ(os_proc_info((int)pid, arena));
   if (rvobj.data.dictionary.size == 0) {  // Process not found.
     return NIL;
   }
diff --git a/src/nvim/api/window.c b/src/nvim/api/window.c
index ed1ad5b583..c41c5d4b07 100644
--- a/src/nvim/api/window.c
+++ b/src/nvim/api/window.c
@@ -77,15 +77,16 @@ void nvim_win_set_buf(Window window, Buffer buffer, Error *err)
 /// @param window   Window handle, or 0 for current window
 /// @param[out] err Error details, if any
 /// @return (row, col) tuple
-ArrayOf(Integer, 2) nvim_win_get_cursor(Window window, Error *err)
+ArrayOf(Integer, 2) nvim_win_get_cursor(Window window, Arena *arena, Error *err)
   FUNC_API_SINCE(1)
 {
   Array rv = ARRAY_DICT_INIT;
   win_T *win = find_window_by_handle(window, err);
 
   if (win) {
-    ADD(rv, INTEGER_OBJ(win->w_cursor.lnum));
-    ADD(rv, INTEGER_OBJ(win->w_cursor.col));
+    rv = arena_array(arena, 2);
+    ADD_C(rv, INTEGER_OBJ(win->w_cursor.lnum));
+    ADD_C(rv, INTEGER_OBJ(win->w_cursor.col));
   }
 
   return rv;