Remove the code path cache in the code server

In practice, it does not seem that code path cache can
improve performance. Looking for any file that is not found
will cause the cache to be rebuilt, which will negate any
gain of using the cache.

1 files changed, 25 insertions, 20 deletions

diff --git a/lib/kernel/src/code.erl b/lib/kernel/src/code.erl
index 352c02562b..ae28c97b47 100644
--- a/lib/kernel/src/code.erl
+++ b/lib/kernel/src/code.erl
@@ -68,6 +68,8 @@
 	 clash/0,
      get_mode/0]).
 
+-deprecated({rehash,0,next_major_release}).
+
 -export_type([load_error_rsn/0, load_ret/0]).
 
 -include_lib("kernel/include/file.hrl").
@@ -293,7 +295,9 @@ replace_path(Name, Dir) when (is_atom(Name) orelse is_list(Name)),
     call({replace_path,Name,Dir}).
 
 -spec rehash() -> 'ok'.
-rehash() -> call(rehash).
+rehash() ->
+    cache_warning(),
+    ok.
 
 -spec get_mode() -> 'embedded' | 'interactive'.
 get_mode() -> call(get_mode).
@@ -322,6 +326,7 @@ start_link(Flags) ->
 %%-----------------------------------------------------------------
 
 do_start(Flags) ->
+    maybe_warn_for_cache(),
     load_code_server_prerequisites(),
 
     Mode = get_mode(Flags),
@@ -452,30 +457,14 @@ which(File, Base, [Directory|Tail]) ->
       Filename :: file:filename(),
       Absname :: file:filename().
 where_is_file(File) when is_list(File) ->
-    case call({is_cached,File}) of
-	no ->
-	    Path = get_path(),
-	    which(File, ".", Path);
-	Dir ->
-	    filename:join(Dir, File)
-    end.
+    Path = get_path(),
+    which(File, ".", Path).
 
 -spec where_is_file(Path :: file:filename(), Filename :: file:filename()) ->
         file:filename() | 'non_existing'.
 
 where_is_file(Path, File) when is_list(Path), is_list(File) ->
-    CodePath = get_path(),
-    if
-	Path =:= CodePath ->
-	    case call({is_cached, File}) of
-		no ->
-		    which(File, ".", Path);
-		Dir ->
-		    filename:join(Dir, File)
-	    end;
-	true ->
-	    which(File, ".", Path)
-    end.
+    which(File, ".", Path).
 
 -spec set_primary_archive(ArchiveFile :: file:filename(),
 			  ArchiveBin :: binary(),
@@ -553,6 +542,22 @@ has_ext(Ext, Extlen, File) ->
     end.
 
 %%%
+%%% Warning for deprecated code path cache.
+%%%
+
+maybe_warn_for_cache() ->
+    case init:get_argument(code_path_cache) of
+	{ok, _} ->
+	    cache_warning();
+	error ->
+	    ok
+    end.
+
+cache_warning() ->
+    W = "The code path cache functionality has been removed",
+    error_logger:warning_report(W).
+
+%%%
 %%% Silently load native code for all modules loaded so far.
 %%%