%% This module defines many callbacks relevant to range requests
%% and return something different depending on query string.
-module(provide_range_callback_h).
-export([init/2]).
-export([content_types_provided/2]).
-export([ranges_provided/2]).
-export([expires/2]).
-export([generate_etag/2]).
-export([last_modified/2]).
-export([get_text_plain/2]).
-export([get_text_plain_bytes/2]).
init(Req, State) ->
{cowboy_rest, Req, State}.
content_types_provided(Req, State) ->
{[
{{<<"text">>, <<"plain">>, []}, get_text_plain},
%% This one only exists so we generate a vary header.
{{<<"text">>, <<"html">>, []}, get_text_html}
], Req, State}.
ranges_provided(Req, State) ->
{[{<<"bytes">>, get_text_plain_bytes}], Req, State}.
generate_etag(Req=#{qs := <<"weak-etag">>}, State) ->
{{weak, <<"weak-no-match">>}, Req, State};
generate_etag(Req, State) ->
{{strong, <<"strong-and-match">>}, Req, State}.
last_modified(Req, State) ->
{{{2222, 2, 22}, {11, 11, 11}}, Req, State}.
expires(Req, State) ->
{{{3333, 3, 3}, {11, 11, 11}}, Req, State}.
get_text_plain(Req, State) ->
{<<"This is REST!">>, Req, State}.
%% Simulate the callback being missing, otherwise expect true/false.
get_text_plain_bytes(#{qs := <<"missing">>}, _) ->
ct_helper_error_h:ignore(cowboy_rest, set_ranged_body_callback, 3),
no_call;
get_text_plain_bytes(Req=#{qs := <<"sendfile">>, range := {_, [{From=0, infinity}]}}, State) ->
Path = code:lib_dir(cowboy) ++ "/ebin/cowboy.app",
Size = filelib:file_size(Path),
{[{{From, Size - 1, Size}, {sendfile, From, Size, Path}}], Req, State};
get_text_plain_bytes(Req=#{range := {_, [{From=0, infinity}]}}, State) ->
%% We send everything in one part.
Body = <<"This is ranged REST!">>,
Total = byte_size(Body),
{[{{From, Total - 1, Total}, Body}], Req, State};
get_text_plain_bytes(Req=#{qs := <<"sendfile">>, range := {_, Range}}, State) ->
%% We check the range header we get and send everything hardcoded.
[
{50, 99},
{150, 199},
{250, 299},
-99
] = Range,
Path = code:lib_dir(cowboy) ++ "/ebin/cowboy.app",
Size = filelib:file_size(Path),
{[
{{50, 99, Size}, {sendfile, 50, 50, Path}},
{{150, 199, Size}, {sendfile, 150, 50, Path}},
{{250, 299, Size}, {sendfile, 250, 50, Path}},
{{Size - 99, Size - 1, Size}, {sendfile, Size - 99, 99, Path}}
], Req, State};
get_text_plain_bytes(Req=#{range := {_, Range}}, State) ->
%% We check the range header we get and send everything hardcoded.
[
{0, 3},
{5, 6},
{8, 13},
{15, infinity}
] = Range,
Body = <<"This is ranged REST!">>,
Total = byte_size(Body),
{[
{{0, 3, Total}, <<"This">>},
{{5, 6, Total}, <<"is">>},
{{8, 13, Total}, <<"ranged">>},
{{15, 19, Total}, <<"REST!">>}
], Req, State}.
