diff options
Diffstat (limited to 'lib/kernel/src')
| -rw-r--r-- | lib/kernel/src/file.erl | 16 | ||||
| -rw-r--r-- | lib/kernel/src/file_io_server.erl | 8 | ||||
| -rw-r--r-- | lib/kernel/src/ram_file.erl | 33 |
3 files changed, 55 insertions, 2 deletions
diff --git a/lib/kernel/src/file.erl b/lib/kernel/src/file.erl index 5da359fdf1..a694ed0708 100644 --- a/lib/kernel/src/file.erl +++ b/lib/kernel/src/file.erl @@ -36,7 +36,7 @@ %% Specialized -export([ipread_s32bu_p32bu/3]). %% Generic file contents. --export([open/2, close/1, +-export([open/2, close/1, advise/4, read/2, write/2, pread/2, pread/3, pwrite/2, pwrite/3, read_line/1, @@ -89,6 +89,8 @@ -type date() :: {pos_integer(), pos_integer(), pos_integer()}. -type time() :: {non_neg_integer(), non_neg_integer(), non_neg_integer()}. -type date_time() :: {date(), time()}. +-type posix_file_advise() :: 'normal' | 'sequential' | 'random' | 'no_reuse' | + 'will_need' | 'dont_need'. %%%----------------------------------------------------------------- %%% General functions @@ -352,6 +354,18 @@ close(#file_descriptor{module = Module} = Handle) -> close(_) -> {error, badarg}. +-spec advise(File :: io_device(), Offset :: integer(), + Length :: integer(), Advise :: posix_file_advise()) -> + 'ok' | {'error', posix()}. + +advise(File, Offset, Length, Advise) when is_pid(File) -> + R = file_request(File, {advise, Offset, Length, Advise}), + wait_file_reply(File, R); +advise(#file_descriptor{module = Module} = Handle, Offset, Length, Advise) -> + Module:advise(Handle, Offset, Length, Advise); +advise(_, _, _, _) -> + {error, badarg}. + -spec read(File :: io_device(), Size :: non_neg_integer()) -> 'eof' | {'ok', [char()] | binary()} | {'error', posix()}. diff --git a/lib/kernel/src/file_io_server.erl b/lib/kernel/src/file_io_server.erl index d0b30192b3..39dc32bb79 100644 --- a/lib/kernel/src/file_io_server.erl +++ b/lib/kernel/src/file_io_server.erl @@ -198,6 +198,14 @@ io_reply(From, ReplyAs, Reply) -> %%%----------------------------------------------------------------- %%% file requests +file_request({advise,Offset,Length,Advise}, + #state{handle=Handle}=State) -> + case ?PRIM_FILE:advise(Handle, Offset, Length, Advise) of + {error,_}=Reply -> + {stop,normal,Reply,State}; + Reply -> + {reply,Reply,State} + end; file_request({pread,At,Sz}, #state{handle=Handle,buf=Buf,read_mode=ReadMode}=State) -> case position(Handle, At, Buf) of 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}. + %%%----------------------------------------------------------------- |