Merge branch 'fm/file-operations' into dev

* fm/file-operations:
  Update preloaded modules
  Add file:advise/4 - a wrapper to the POSIX syscall posix_fadvise
  Add file:datasync/1 for syncing file contents only
  sys.h: Correct the get_int64() macro

OTP-8637 fm/file-operations

The functions file:advise/4 and file:datasync/1 have been added. (Thanks to
Filipe David Manana.)

1 files changed, 41 insertions, 7 deletions

diff --git a/lib/kernel/src/ram_file.erl b/lib/kernel/src/ram_file.erl
index d996650948..48ea871433 100644
--- a/lib/kernel/src/ram_file.erl
+++ b/lib/kernel/src/ram_file.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 1997-2010. All Rights Reserved.
+%%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 %%
 -module(ram_file).
@@ -24,11 +24,11 @@
 -export([open/2, close/1]).
 -export([write/2, read/2, copy/3,
 	 pread/2, pread/3, pwrite/2, pwrite/3, 
-	 position/2, truncate/1, sync/1]).
+	 position/2, truncate/1, datasync/1, sync/1]).
 
 %% 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
 
@@ -60,6 +60,7 @@
 -define(RAM_FILE_TRUNCATE,       14).
 -define(RAM_FILE_PREAD,          17).
 -define(RAM_FILE_PWRITE,         18).
+-define(RAM_FILE_FDATASYNC,      19).
 
 %% Other operations
 -define(RAM_FILE_GET,            30).
@@ -70,6 +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).
@@ -90,6 +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.
 %%
@@ -167,6 +177,8 @@ copy(#file_descriptor{module = ?MODULE} = Source,
     %% XXX Should be moved down to the driver for optimization.
     file:copy_opened(Source, Dest, Length).
 
+datasync(#file_descriptor{module = ?MODULE, data = Port}) ->
+    call_port(Port, <<?RAM_FILE_FDATASYNC>>).
 
 sync(#file_descriptor{module = ?MODULE, data = Port}) -> 
     call_port(Port, <<?RAM_FILE_FSYNC>>).
@@ -349,6 +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}.
+
 
 
 %%%-----------------------------------------------------------------