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| author | Tuncer Ayaz <[email protected]> | 2011-01-13 12:36:14 +0100 |
|---|---|---|
| committer | Lukas Larsson <[email protected]> | 2011-11-29 14:30:35 +0100 |
| commit | 195e1f19b06095f39a4fb0da46dfab2ec5b10e9a (patch) | |
| tree | 8f4a8c587b72c3a20d18b4cb6ccd7d1d52eb6286 /erts/preloaded/src/prim_file.erl | |
| parent | 7292c3d9f5285592aa4de996f6f106cd365d7895 (diff) | |
| download | otp-195e1f19b06095f39a4fb0da46dfab2ec5b10e9a.tar.gz otp-195e1f19b06095f39a4fb0da46dfab2ec5b10e9a.tar.bz2 otp-195e1f19b06095f39a4fb0da46dfab2ec5b10e9a.zip | |
Implement file:sendfile
Allow Erlang code to use sendfile() where available by wrapping it as
file:sendfile/4 and file:sendfile/2.
sendfile(2) - Linux man page:
"sendfile() copies data between one file descriptor and another.
Because this copying is done within the kernel, sendfile() is more
efficient than the combination of read(2) and write(2), which would
require transferring data to and from user space."
Diffstat (limited to 'erts/preloaded/src/prim_file.erl')
| -rw-r--r-- | erts/preloaded/src/prim_file.erl | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/erts/preloaded/src/prim_file.erl b/erts/preloaded/src/prim_file.erl index 30b7a5246a..f3f977a30b 100644 --- a/erts/preloaded/src/prim_file.erl +++ b/erts/preloaded/src/prim_file.erl @@ -26,7 +26,8 @@ %% Generic file contents operations -export([open/2, close/1, datasync/1, sync/1, advise/4, position/2, truncate/1, - write/2, pwrite/2, pwrite/3, read/2, read_line/1, pread/2, pread/3, copy/3]). + write/2, pwrite/2, pwrite/3, read/2, read_line/1, pread/2, pread/3, + copy/3, sendfile/5]). %% Specialized file operations -export([open/1, open/3]). @@ -98,6 +99,7 @@ -define(FILE_READ_LINE, 29). -define(FILE_FDATASYNC, 30). -define(FILE_ADVISE, 31). +-define(FILE_SENDFILE, 32). %% Driver responses -define(FILE_RESP_OK, 0). @@ -539,6 +541,21 @@ write_file(_, _) -> {error, badarg}. +%% Returns {error, Reason} | {ok, BytesCopied} +sendfile(#file_descriptor{module = ?MODULE, data = {Port, _}}, + DestFD, Offset, Bytes, ChunkSize) -> + ok = drv_command(Port, <<?FILE_SENDFILE, DestFD:32, Offset:64, Bytes:64, + ChunkSize:64>>), + Self = self(), + %% Should we use a ref()? + receive + {efile_reply, Self, Port, {ok, _Written}=OKRes}-> + OKRes; + {efile_reply, Self, Port, {error, _PosixError}=Error}-> + Error; + Unexpected -> + Unexpected + end. %%%----------------------------------------------------------------- %%% Functions operating on files without handle to the file. ?DRV. |