Add Transport:sendfile/4,/5

Adds offset based sendfile to transports. Same behaviour as
file:sendfile/4,/5 except socket and file arguments are reversed and
either a raw file or a filename can be used.

sendfile/2,/4,/5 now compulsory callbacks in ranch_transport.

ranch_tcp:sendfile/2 now defaults to a chunk_size of 8191 - the default
for ranch_ssl:sendfile/2. The same default is used for both
ranch_tcp:sendfile/4,5 and ranch_ssl:sendfile/4,5.

1 files changed, 42 insertions, 9 deletions

diff --git a/src/ranch_tcp.erl b/src/ranch_tcp.erl
index 11a0843..6bdcdd0 100644
--- a/src/ranch_tcp.erl
+++ b/src/ranch_tcp.erl
@@ -28,6 +28,8 @@
 -export([recv/3]).
 -export([send/2]).
 -export([sendfile/2]).
+-export([sendfile/4]).
+-export([sendfile/5]).
 -export([setopts/2]).
 -export([controlling_process/2]).
 -export([peername/1]).
@@ -110,21 +112,52 @@ recv(Socket, Length, Timeout) ->
 send(Socket, Packet) ->
 	gen_tcp:send(Socket, Packet).
 
-%% @doc Send a file on a socket.
+%% @equiv sendfile(Socket, File, Offset, Bytes, [])
+-spec sendfile(inet:socket(), file:name_all())
+	-> {ok, non_neg_integer()} | {error, atom()}.
+sendfile(Socket, Filename) ->
+	sendfile(Socket, Filename, 0, 0, []).
+
+%% @equiv sendfile(Socket, File, Offset, Bytes, [])
+-spec sendfile(inet:socket(), file:name_all() | file:fd(), non_neg_integer(),
+		non_neg_integer())
+	-> {ok, non_neg_integer()} | {error, atom()}.
+sendfile(Socket, File, Offset, Bytes) ->
+	sendfile(Socket, File, Offset, Bytes, []).
+
+%% @doc Send part of a file on a socket.
 %%
-%% This is the optimal way to send files using TCP. It uses a syscall
-%% which means there is no context switch between opening the file
-%% and writing its contents on the socket.
+%% As with sendfile/2 this is the optimal way to send (parts) of files using
+%% TCP. Note that unlike file:sendfile/5 this function accepts either a raw file
+%% or a file name and the ordering of arguments is different.
 %%
-%% @see file:sendfile/2
--spec sendfile(inet:socket(), file:name())
+%% @see file:sendfile/5
+-spec sendfile(inet:socket(), file:name_all() | file:fd(), non_neg_integer(),
+		non_neg_integer(), [{chunk_size, non_neg_integer()}])
 	-> {ok, non_neg_integer()} | {error, atom()}.
-sendfile(Socket, Filename) ->
-	try file:sendfile(Filename, Socket) of
+sendfile(Socket, Filename, Offset, Bytes, Opts)
+		when is_list(Filename) orelse is_atom(Filename)
+		orelse is_binary(Filename) ->
+	case file:open(Filename, [read, raw, binary]) of
+		{ok, RawFile} ->
+			try sendfile(Socket, RawFile, Offset, Bytes, Opts) of
+				Result -> Result
+			after
+				ok = file:close(RawFile)
+			end;
+		{error, _} = Error ->
+			Error
+	end;
+sendfile(Socket, RawFile, Offset, Bytes, Opts) ->
+	Opts2 = case Opts of
+		[] -> [{chunk_size, 16#1FFF}];
+		_ -> Opts
+	end,
+	try file:sendfile(RawFile, Socket, Offset, Bytes, Opts2) of
 		Result -> Result
 	catch
 		error:{badmatch, {error, enotconn}} ->
-			%% file:sendfile/2 might fail by throwing a {badmatch, {error, enotconn}}
+			%% file:sendfile/5 might fail by throwing a {badmatch, {error, enotconn}}
 			%% this is because its internal implementation fails with a badmatch in
 			%% prim_file:sendfile/10 if the socket is not connected.
 			{error, closed}