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-rw-r--r--lib/kernel/src/ram_file.erl33
1 files changed, 32 insertions, 1 deletions
diff --git a/lib/kernel/src/ram_file.erl b/lib/kernel/src/ram_file.erl
index 0230cb4e0a..2bfb2cd021 100644
--- a/lib/kernel/src/ram_file.erl
+++ b/lib/kernel/src/ram_file.erl
@@ -28,7 +28,7 @@
%% Specialized file operations
-export([get_size/1, get_file/1, set_file/2, get_file_close/1]).
--export([compress/1, uncompress/1, uuencode/1, uudecode/1]).
+-export([compress/1, uncompress/1, uuencode/1, uudecode/1, advise/4]).
-export([open_mode/1]). %% used by ftp-file
@@ -71,6 +71,7 @@
-define(RAM_FILE_UUENCODE, 35).
-define(RAM_FILE_UUDECODE, 36).
-define(RAM_FILE_SIZE, 37).
+-define(RAM_FILE_ADVISE, 38).
%% Open modes for RAM_FILE_OPEN
-define(RAM_FILE_MODE_READ, 1).
@@ -91,6 +92,14 @@
-define(RAM_FILE_RESP_NUMBER, 3).
-define(RAM_FILE_RESP_INFO, 4).
+%% POSIX file advises
+-define(POSIX_FADV_NORMAL, 0).
+-define(POSIX_FADV_RANDOM, 1).
+-define(POSIX_FADV_SEQUENTIAL, 2).
+-define(POSIX_FADV_WILLNEED, 3).
+-define(POSIX_FADV_DONTNEED, 4).
+-define(POSIX_FADV_NOREUSE, 5).
+
%% --------------------------------------------------------------------------
%% Generic file contents operations.
%%
@@ -352,6 +361,28 @@ uudecode(#file_descriptor{module = ?MODULE, data = Port}) ->
uudecode(#file_descriptor{}) ->
{error, enotsup}.
+advise(#file_descriptor{module = ?MODULE, data = Port}, Offset,
+ Length, Advise) ->
+ Cmd0 = <<?RAM_FILE_ADVISE, Offset:64/signed, Length:64/signed>>,
+ case Advise of
+ normal ->
+ call_port(Port, <<Cmd0/binary, ?POSIX_FADV_NORMAL:32/signed>>);
+ random ->
+ call_port(Port, <<Cmd0/binary, ?POSIX_FADV_RANDOM:32/signed>>);
+ sequential ->
+ call_port(Port, <<Cmd0/binary, ?POSIX_FADV_SEQUENTIAL:32/signed>>);
+ will_need ->
+ call_port(Port, <<Cmd0/binary, ?POSIX_FADV_WILLNEED:32/signed>>);
+ dont_need ->
+ call_port(Port, <<Cmd0/binary, ?POSIX_FADV_DONTNEED:32/signed>>);
+ no_reuse ->
+ call_port(Port, <<Cmd0/binary, ?POSIX_FADV_NOREUSE:32/signed>>);
+ _ ->
+ {error, einval}
+ end;
+advise(#file_descriptor{}, _Offset, _Length, _Advise) ->
+ {error, enotsup}.
+
%%%-----------------------------------------------------------------