refactor(api): refactor more api functions to use arena return

Currently having two separate memory strategies for API return values is
a bit unnecessary, and mostly a consequence of converting the hot spot
cases which needed it first. But there is really no downside to using
arena everywhere (which implies also directly using strings which are
allocated earlier or even statically, without copy).

There only restriction is we need to know the size of arrays in advance,
but this info can often be passed on from some earlier stage if it is
missing.

This collects some "small" cases. The more complex stuff will get a PR
each.

1 files changed, 10 insertions, 11 deletions

diff --git a/src/nvim/api/buffer.c b/src/nvim/api/buffer.c
index 7af2b7241c..751fc1c32d 100644
--- a/src/nvim/api/buffer.c
+++ b/src/nvim/api/buffer.c
@@ -1262,28 +1262,27 @@ Object nvim_buf_call(Buffer buffer, LuaRef fun, Error *err)
   return res;
 }
 
-Dictionary nvim__buf_stats(Buffer buffer, Error *err)
+Dictionary nvim__buf_stats(Buffer buffer, Arena *arena, Error *err)
 {
-  Dictionary rv = ARRAY_DICT_INIT;
-
   buf_T *buf = find_buffer_by_handle(buffer, err);
   if (!buf) {
-    return rv;
+    return (Dictionary)ARRAY_DICT_INIT;
   }
 
+  Dictionary rv = arena_dict(arena, 7);
   // Number of times the cached line was flushed.
   // This should generally not increase while editing the same
   // line in the same mode.
-  PUT(rv, "flush_count", INTEGER_OBJ(buf->flush_count));
+  PUT_C(rv, "flush_count", INTEGER_OBJ(buf->flush_count));
   // lnum of current line
-  PUT(rv, "current_lnum", INTEGER_OBJ(buf->b_ml.ml_line_lnum));
+  PUT_C(rv, "current_lnum", INTEGER_OBJ(buf->b_ml.ml_line_lnum));
   // whether the line has unflushed changes.
-  PUT(rv, "line_dirty", BOOLEAN_OBJ(buf->b_ml.ml_flags & ML_LINE_DIRTY));
+  PUT_C(rv, "line_dirty", BOOLEAN_OBJ(buf->b_ml.ml_flags & ML_LINE_DIRTY));
   // NB: this should be zero at any time API functions are called,
   // this exists to debug issues
-  PUT(rv, "dirty_bytes", INTEGER_OBJ((Integer)buf->deleted_bytes));
-  PUT(rv, "dirty_bytes2", INTEGER_OBJ((Integer)buf->deleted_bytes2));
-  PUT(rv, "virt_blocks", INTEGER_OBJ((Integer)buf_meta_total(buf, kMTMetaLines)));
+  PUT_C(rv, "dirty_bytes", INTEGER_OBJ((Integer)buf->deleted_bytes));
+  PUT_C(rv, "dirty_bytes2", INTEGER_OBJ((Integer)buf->deleted_bytes2));
+  PUT_C(rv, "virt_blocks", INTEGER_OBJ((Integer)buf_meta_total(buf, kMTMetaLines)));
 
   u_header_T *uhp = NULL;
   if (buf->b_u_curhead != NULL) {
@@ -1292,7 +1291,7 @@ Dictionary nvim__buf_stats(Buffer buffer, Error *err)
     uhp = buf->b_u_newhead;
   }
   if (uhp) {
-    PUT(rv, "uhp_extmark_size", INTEGER_OBJ((Integer)kv_size(uhp->uh_extmark)));
+    PUT_C(rv, "uhp_extmark_size", INTEGER_OBJ((Integer)kv_size(uhp->uh_extmark)));
   }
 
   return rv;