Make with_handle/{1,2} into part of the fhc API, and thus hide the extra obtain/release/transfer variants.bug26180

2 files changed, 37 insertions, 39 deletions

diff --git a/src/file_handle_cache.erl b/src/file_handle_cache.erl
index 7005a929..3a7a692c 100644
--- a/src/file_handle_cache.erl
+++ b/src/file_handle_cache.erl
@@ -146,9 +146,8 @@
 -export([open/3, close/1, read/2, append/2, needs_sync/1, sync/1, position/2,
          truncate/1, current_virtual_offset/1, current_raw_offset/1, flush/1,
          copy/3, set_maximum_since_use/1, delete/1, clear/1]).
--export([obtain/0, obtain/1, obtain/2,
-         release/0, release/1, release/2, transfer/1, transfer/2, transfer/3,
-         set_limit/1, get_limit/0, info_keys/0,
+-export([obtain/0, obtain/1, release/0, release/1, transfer/1, transfer/2,
+         set_limit/1, get_limit/0, info_keys/0, with_handle/1, with_handle/2,
          info/0, info/1]).
 -export([ulimit/0]).
 
@@ -234,7 +233,6 @@
                      {('bof' |'eof'), non_neg_integer()} |
                      {'cur', integer()})).
 -type(offset() :: non_neg_integer()).
--type(obtain_type() :: 'file' | 'socket').
 
 -spec(register_callback/3 :: (atom(), atom(), [any()]) -> 'ok').
 -spec(open/3 ::
@@ -258,13 +256,12 @@
 -spec(set_maximum_since_use/1 :: (non_neg_integer()) -> 'ok').
 -spec(obtain/0 :: () -> 'ok').
 -spec(obtain/1 :: (non_neg_integer()) -> 'ok').
--spec(obtain/2 :: (non_neg_integer(), obtain_type()) -> 'ok').
 -spec(release/0 :: () -> 'ok').
 -spec(release/1 :: (non_neg_integer()) -> 'ok').
--spec(release/2 :: (non_neg_integer(), obtain_type()) -> 'ok').
 -spec(transfer/1 :: (pid()) -> 'ok').
 -spec(transfer/2 :: (pid(), non_neg_integer()) -> 'ok').
--spec(transfer/3 :: (pid(), non_neg_integer(), obtain_type()) -> 'ok').
+-spec(with_handle/1 :: (fun(() -> A)) -> A).
+-spec(with_handle/2 :: (non_neg_integer(), fun(() -> A)) -> A).
 -spec(set_limit/1 :: (non_neg_integer()) -> 'ok').
 -spec(get_limit/0 :: () -> non_neg_integer()).
 -spec(info_keys/0 :: () -> rabbit_types:info_keys()).
@@ -503,7 +500,15 @@ transfer(Pid) -> transfer(Pid, 1).
 
 obtain(Count)        -> obtain(Count, socket).
 release(Count)       -> release(Count, socket).
-transfer(Pid, Count) -> transfer(Pid, Count, socket).
+
+with_handle(Fun) ->
+    with_handle(1, Fun).
+
+with_handle(N, Fun) ->
+    ok = obtain(N, file),
+    try Fun()
+    after ok = release(N, file)
+    end.
 
 obtain(Count, Type) when Count > 0 ->
     %% If the FHC isn't running, obtains succeed immediately.
@@ -516,8 +521,8 @@ obtain(Count, Type) when Count > 0 ->
 release(Count, Type) when Count > 0 ->
     gen_server2:cast(?SERVER, {release, Count, Type, self()}).
 
-transfer(Pid, Count, Type) when Count > 0 ->
-    gen_server2:cast(?SERVER, {transfer, Count, Type, self(), Pid}).
+transfer(Pid, Count) when Count > 0 ->
+    gen_server2:cast(?SERVER, {transfer, Count, self(), Pid}).
 
 set_limit(Limit) ->
     gen_server2:call(?SERVER, {set_limit, Limit}, infinity).
@@ -968,11 +973,11 @@ handle_cast({close, Pid, EldestUnusedSince},
     {noreply, adjust_alarm(State, process_pending(
                 update_counts(open, Pid, -1, State)))};
 
-handle_cast({transfer, N, Type, FromPid, ToPid}, State) ->
+handle_cast({transfer, N, FromPid, ToPid}, State) ->
     ok = track_client(ToPid, State#fhc_state.clients),
     {noreply, process_pending(
-                update_counts({obtain, Type}, ToPid, +N,
-                              update_counts({obtain, Type}, FromPid, -N,
+                update_counts({obtain, socket}, ToPid, +N,
+                              update_counts({obtain, socket}, FromPid, -N,
                                             State)))}.
 
 handle_info(check_counts, State) ->
diff --git a/src/rabbit_file.erl b/src/rabbit_file.erl
index d6f0f632..81a617a8 100644
--- a/src/rabbit_file.erl
+++ b/src/rabbit_file.erl
@@ -24,6 +24,8 @@
 -export([rename/2, delete/1, recursive_delete/1, recursive_copy/2]).
 -export([lock_file/1]).
 
+-import(file_handle_cache, [with_handle/1, with_handle/2]).
+
 -define(TMP_EXT, ".tmp").
 
 %%----------------------------------------------------------------------------
@@ -81,7 +83,7 @@ file_size(File) ->
         _                           -> 0
     end.
 
-ensure_dir(File) -> with_fhc_handle(fun () -> ensure_dir_internal(File) end).
+ensure_dir(File) -> with_handle(fun () -> ensure_dir_internal(File) end).
 
 ensure_dir_internal("/")  ->
     ok;
@@ -101,23 +103,14 @@ wildcard(Pattern, Dir) ->
         {error, _}  -> []
     end.
 
-list_dir(Dir) -> with_fhc_handle(fun () -> prim_file:list_dir(Dir) end).
+list_dir(Dir) -> with_handle(fun () -> prim_file:list_dir(Dir) end).
 
 read_file_info(File) ->
-    with_fhc_handle(fun () -> prim_file:read_file_info(File) end).
-
-with_fhc_handle(Fun) ->
-    with_fhc_handle(1, Fun).
-
-with_fhc_handle(N, Fun) ->
-    ok = file_handle_cache:obtain(N, file),
-    try Fun()
-    after ok = file_handle_cache:release(N, file)
-    end.
+    with_handle(fun () -> prim_file:read_file_info(File) end).
 
 read_term_file(File) ->
     try
-        {ok, Data} = with_fhc_handle(fun () -> prim_file:read_file(File) end),
+        {ok, Data} = with_handle(fun () -> prim_file:read_file(File) end),
         {ok, Tokens, _} = erl_scan:string(binary_to_list(Data)),
         TokenGroups = group_tokens(Tokens),
         {ok, [begin
@@ -177,7 +170,7 @@ with_synced_copy(Path, Modes, Fun) ->
         true ->
             {error, append_not_supported, Path};
         false ->
-            with_fhc_handle(
+            with_handle(
               fun () ->
                       Bak = Path ++ ?TMP_EXT,
                       case prim_file:open(Bak, Modes) of
@@ -206,16 +199,16 @@ append_file(File, Suffix) ->
 append_file(_, _, "") ->
     ok;
 append_file(File, 0, Suffix) ->
-    with_fhc_handle(fun () ->
-                            case prim_file:open([File, Suffix], [append]) of
-                                {ok, Fd} -> prim_file:close(Fd);
-                                Error    -> Error
-                            end
-                    end);
+    with_handle(fun () ->
+                        case prim_file:open([File, Suffix], [append]) of
+                            {ok, Fd} -> prim_file:close(Fd);
+                            Error    -> Error
+                        end
+                end);
 append_file(File, _, Suffix) ->
-    case with_fhc_handle(2, fun () ->
+    case with_handle(2, fun () ->
                                 file:copy(File, {[File, Suffix], [append]})
-                            end) of
+                        end) of
         {ok, _BytesCopied} -> ok;
         Error              -> Error
     end.
@@ -227,12 +220,12 @@ ensure_parent_dirs_exist(Filename) ->
             throw({error, {cannot_create_parent_dirs, Filename, Reason}})
     end.
 
-rename(Old, New) -> with_fhc_handle(fun () -> prim_file:rename(Old, New) end).
+rename(Old, New) -> with_handle(fun () -> prim_file:rename(Old, New) end).
 
-delete(File) -> with_fhc_handle(fun () -> prim_file:delete(File) end).
+delete(File) -> with_handle(fun () -> prim_file:delete(File) end).
 
 recursive_delete(Files) ->
-    with_fhc_handle(
+    with_handle(
       fun () -> lists:foldl(fun (Path,  ok) -> recursive_delete1(Path);
                                 (_Path, {error, _Err} = Error) -> Error
                             end, ok, Files)
@@ -307,7 +300,7 @@ recursive_copy(Src, Dest) ->
 lock_file(Path) ->
     case is_file(Path) of
         true  -> {error, eexist};
-        false -> with_fhc_handle(
+        false -> with_handle(
                    fun () -> {ok, Lock} = prim_file:open(Path, [write]),
                              ok = prim_file:close(Lock)
                    end)