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Diffstat (limited to 'apps/mochiweb/src/mochiweb_request.erl')
| -rw-r--r-- | apps/mochiweb/src/mochiweb_request.erl | 867 |
1 files changed, 867 insertions, 0 deletions
diff --git a/apps/mochiweb/src/mochiweb_request.erl b/apps/mochiweb/src/mochiweb_request.erl new file mode 100644 index 00000000..5d7af26b --- /dev/null +++ b/apps/mochiweb/src/mochiweb_request.erl @@ -0,0 +1,867 @@ +%% @author Bob Ippolito <bob@mochimedia.com> +%% @copyright 2007 Mochi Media, Inc. + +%% @doc MochiWeb HTTP Request abstraction. + +-module(mochiweb_request, [Socket, Method, RawPath, Version, Headers]). +-author('bob@mochimedia.com'). + +-include_lib("kernel/include/file.hrl"). + +-define(QUIP, "Any of you quaids got a smint?"). +-define(READ_SIZE, 8192). + +-export([get_header_value/1, get_primary_header_value/1, get/1, dump/0]). +-export([send/1, recv/1, recv/2, recv_body/0, recv_body/1, stream_body/3]). +-export([start_response/1, start_response_length/1, start_raw_response/1]). +-export([respond/1, ok/1]). +-export([not_found/0, not_found/1]). +-export([parse_post/0, parse_qs/0]). +-export([should_close/0, cleanup/0]). +-export([parse_cookie/0, get_cookie_value/1]). +-export([serve_file/2, serve_file/3]). +-export([accepted_encodings/1]). +-export([test/0]). + +-define(SAVE_QS, mochiweb_request_qs). +-define(SAVE_PATH, mochiweb_request_path). +-define(SAVE_RECV, mochiweb_request_recv). +-define(SAVE_BODY, mochiweb_request_body). +-define(SAVE_BODY_LENGTH, mochiweb_request_body_length). +-define(SAVE_POST, mochiweb_request_post). +-define(SAVE_COOKIE, mochiweb_request_cookie). +-define(SAVE_FORCE_CLOSE, mochiweb_request_force_close). + +%% @type iolist() = [iolist() | binary() | char()]. +%% @type iodata() = binary() | iolist(). +%% @type key() = atom() | string() | binary() +%% @type value() = atom() | string() | binary() | integer() +%% @type headers(). A mochiweb_headers structure. +%% @type response(). A mochiweb_response parameterized module instance. +%% @type ioheaders() = headers() | [{key(), value()}]. + +% 5 minute default idle timeout +-define(IDLE_TIMEOUT, 300000). + +% Maximum recv_body() length of 1MB +-define(MAX_RECV_BODY, (1024*1024)). + +%% @spec get_header_value(K) -> undefined | Value +%% @doc Get the value of a given request header. +get_header_value(K) -> + mochiweb_headers:get_value(K, Headers). + +get_primary_header_value(K) -> + mochiweb_headers:get_primary_value(K, Headers). + +%% @type field() = socket | method | raw_path | version | headers | peer | path | body_length | range + +%% @spec get(field()) -> term() +%% @doc Return the internal representation of the given field. +get(socket) -> + Socket; +get(method) -> + Method; +get(raw_path) -> + RawPath; +get(version) -> + Version; +get(headers) -> + Headers; +get(peer) -> + case inet:peername(Socket) of + {ok, {Addr={10, _, _, _}, _Port}} -> + case get_header_value("x-forwarded-for") of + undefined -> + inet_parse:ntoa(Addr); + Hosts -> + string:strip(lists:last(string:tokens(Hosts, ","))) + end; + {ok, {{127, 0, 0, 1}, _Port}} -> + case get_header_value("x-forwarded-for") of + undefined -> + "127.0.0.1"; + Hosts -> + string:strip(lists:last(string:tokens(Hosts, ","))) + end; + {ok, {Addr, _Port}} -> + inet_parse:ntoa(Addr) + end; +get(path) -> + case erlang:get(?SAVE_PATH) of + undefined -> + {Path0, _, _} = mochiweb_util:urlsplit_path(RawPath), + Path = mochiweb_util:unquote(Path0), + put(?SAVE_PATH, Path), + Path; + Cached -> + Cached + end; +get(body_length) -> + erlang:get(?SAVE_BODY_LENGTH); +get(range) -> + case get_header_value(range) of + undefined -> + undefined; + RawRange -> + parse_range_request(RawRange) + end. + +%% @spec dump() -> {mochiweb_request, [{atom(), term()}]} +%% @doc Dump the internal representation to a "human readable" set of terms +%% for debugging/inspection purposes. +dump() -> + {?MODULE, [{method, Method}, + {version, Version}, + {raw_path, RawPath}, + {headers, mochiweb_headers:to_list(Headers)}]}. + +%% @spec send(iodata()) -> ok +%% @doc Send data over the socket. +send(Data) -> + case gen_tcp:send(Socket, Data) of + ok -> + ok; + _ -> + exit(normal) + end. + +%% @spec recv(integer()) -> binary() +%% @doc Receive Length bytes from the client as a binary, with the default +%% idle timeout. +recv(Length) -> + recv(Length, ?IDLE_TIMEOUT). + +%% @spec recv(integer(), integer()) -> binary() +%% @doc Receive Length bytes from the client as a binary, with the given +%% Timeout in msec. +recv(Length, Timeout) -> + case gen_tcp:recv(Socket, Length, Timeout) of + {ok, Data} -> + put(?SAVE_RECV, true), + Data; + _ -> + exit(normal) + end. + +%% @spec body_length() -> undefined | chunked | unknown_transfer_encoding | integer() +%% @doc Infer body length from transfer-encoding and content-length headers. +body_length() -> + case get_header_value("transfer-encoding") of + undefined -> + case get_header_value("content-length") of + undefined -> + undefined; + Length -> + list_to_integer(Length) + end; + "chunked" -> + chunked; + Unknown -> + {unknown_transfer_encoding, Unknown} + end. + + +%% @spec recv_body() -> binary() +%% @doc Receive the body of the HTTP request (defined by Content-Length). +%% Will only receive up to the default max-body length of 1MB. +recv_body() -> + recv_body(?MAX_RECV_BODY). + +%% @spec recv_body(integer()) -> binary() +%% @doc Receive the body of the HTTP request (defined by Content-Length). +%% Will receive up to MaxBody bytes. +recv_body(MaxBody) -> + % we could use a sane constant for max chunk size + Body = stream_body(?MAX_RECV_BODY, fun + ({0, _ChunkedFooter}, {_LengthAcc, BinAcc}) -> + iolist_to_binary(lists:reverse(BinAcc)); + ({Length, Bin}, {LengthAcc, BinAcc}) -> + NewLength = Length + LengthAcc, + if NewLength > MaxBody -> + exit({body_too_large, chunked}); + true -> + {NewLength, [Bin | BinAcc]} + end + end, {0, []}, MaxBody), + put(?SAVE_BODY, Body), + Body. + +stream_body(MaxChunkSize, ChunkFun, FunState) -> + stream_body(MaxChunkSize, ChunkFun, FunState, undefined). + +stream_body(MaxChunkSize, ChunkFun, FunState, MaxBodyLength) -> + Expect = case get_header_value("expect") of + undefined -> + undefined; + Value when is_list(Value) -> + string:to_lower(Value) + end, + case Expect of + "100-continue" -> + start_raw_response({100, gb_trees:empty()}); + _Else -> + ok + end, + case body_length() of + undefined -> + undefined; + {unknown_transfer_encoding, Unknown} -> + exit({unknown_transfer_encoding, Unknown}); + chunked -> + % In this case the MaxBody is actually used to + % determine the maximum allowed size of a single + % chunk. + stream_chunked_body(MaxChunkSize, ChunkFun, FunState); + 0 -> + <<>>; + Length when is_integer(Length) -> + case MaxBodyLength of + MaxBodyLength when is_integer(MaxBodyLength), MaxBodyLength < Length -> + exit({body_too_large, content_length}); + _ -> + stream_unchunked_body(Length, ChunkFun, FunState) + end; + Length -> + exit({length_not_integer, Length}) + end. + + +%% @spec start_response({integer(), ioheaders()}) -> response() +%% @doc Start the HTTP response by sending the Code HTTP response and +%% ResponseHeaders. The server will set header defaults such as Server +%% and Date if not present in ResponseHeaders. +start_response({Code, ResponseHeaders}) -> + HResponse = mochiweb_headers:make(ResponseHeaders), + HResponse1 = mochiweb_headers:default_from_list(server_headers(), + HResponse), + start_raw_response({Code, HResponse1}). + +%% @spec start_raw_response({integer(), headers()}) -> response() +%% @doc Start the HTTP response by sending the Code HTTP response and +%% ResponseHeaders. +start_raw_response({Code, ResponseHeaders}) -> + F = fun ({K, V}, Acc) -> + [make_io(K), <<": ">>, V, <<"\r\n">> | Acc] + end, + End = lists:foldl(F, [<<"\r\n">>], + mochiweb_headers:to_list(ResponseHeaders)), + send([make_version(Version), make_code(Code), <<"\r\n">> | End]), + mochiweb:new_response({THIS, Code, ResponseHeaders}). + + +%% @spec start_response_length({integer(), ioheaders(), integer()}) -> response() +%% @doc Start the HTTP response by sending the Code HTTP response and +%% ResponseHeaders including a Content-Length of Length. The server +%% will set header defaults such as Server +%% and Date if not present in ResponseHeaders. +start_response_length({Code, ResponseHeaders, Length}) -> + HResponse = mochiweb_headers:make(ResponseHeaders), + HResponse1 = mochiweb_headers:enter("Content-Length", Length, HResponse), + start_response({Code, HResponse1}). + +%% @spec respond({integer(), ioheaders(), iodata() | chunked | {file, IoDevice}}) -> response() +%% @doc Start the HTTP response with start_response, and send Body to the +%% client (if the get(method) /= 'HEAD'). The Content-Length header +%% will be set by the Body length, and the server will insert header +%% defaults. +respond({Code, ResponseHeaders, {file, IoDevice}}) -> + Length = iodevice_size(IoDevice), + Response = start_response_length({Code, ResponseHeaders, Length}), + case Method of + 'HEAD' -> + ok; + _ -> + iodevice_stream(IoDevice) + end, + Response; +respond({Code, ResponseHeaders, chunked}) -> + HResponse = mochiweb_headers:make(ResponseHeaders), + HResponse1 = case Method of + 'HEAD' -> + %% This is what Google does, http://www.google.com/ + %% is chunked but HEAD gets Content-Length: 0. + %% The RFC is ambiguous so emulating Google is smart. + mochiweb_headers:enter("Content-Length", "0", + HResponse); + _ when Version >= {1, 1} -> + %% Only use chunked encoding for HTTP/1.1 + mochiweb_headers:enter("Transfer-Encoding", "chunked", + HResponse); + _ -> + %% For pre-1.1 clients we send the data as-is + %% without a Content-Length header and without + %% chunk delimiters. Since the end of the document + %% is now ambiguous we must force a close. + put(?SAVE_FORCE_CLOSE, true), + HResponse + end, + start_response({Code, HResponse1}); +respond({Code, ResponseHeaders, Body}) -> + Response = start_response_length({Code, ResponseHeaders, iolist_size(Body)}), + case Method of + 'HEAD' -> + ok; + _ -> + send(Body) + end, + Response. + +%% @spec not_found() -> response() +%% @doc Alias for <code>not_found([])</code>. +not_found() -> + not_found([]). + +%% @spec not_found(ExtraHeaders) -> response() +%% @doc Alias for <code>respond({404, [{"Content-Type", "text/plain"} +%% | ExtraHeaders], <<"Not found.">>})</code>. +not_found(ExtraHeaders) -> + respond({404, [{"Content-Type", "text/plain"} | ExtraHeaders], + <<"Not found.">>}). + +%% @spec ok({value(), iodata()} | {value(), ioheaders(), iodata() | {file, IoDevice}}) -> +%% response() +%% @doc respond({200, [{"Content-Type", ContentType} | Headers], Body}). +ok({ContentType, Body}) -> + ok({ContentType, [], Body}); +ok({ContentType, ResponseHeaders, Body}) -> + HResponse = mochiweb_headers:make(ResponseHeaders), + case THIS:get(range) of + X when X =:= undefined; X =:= fail -> + HResponse1 = mochiweb_headers:enter("Content-Type", ContentType, HResponse), + respond({200, HResponse1, Body}); + Ranges -> + {PartList, Size} = range_parts(Body, Ranges), + case PartList of + [] -> %% no valid ranges + HResponse1 = mochiweb_headers:enter("Content-Type", + ContentType, + HResponse), + %% could be 416, for now we'll just return 200 + respond({200, HResponse1, Body}); + PartList -> + {RangeHeaders, RangeBody} = + parts_to_body(PartList, ContentType, Size), + HResponse1 = mochiweb_headers:enter_from_list( + [{"Accept-Ranges", "bytes"} | + RangeHeaders], + HResponse), + respond({206, HResponse1, RangeBody}) + end + end. + +%% @spec should_close() -> bool() +%% @doc Return true if the connection must be closed. If false, using +%% Keep-Alive should be safe. +should_close() -> + ForceClose = erlang:get(mochiweb_request_force_close) =/= undefined, + DidNotRecv = erlang:get(mochiweb_request_recv) =:= undefined, + ForceClose orelse Version < {1, 0} + %% Connection: close + orelse get_header_value("connection") =:= "close" + %% HTTP 1.0 requires Connection: Keep-Alive + orelse (Version =:= {1, 0} + andalso get_header_value("connection") =/= "Keep-Alive") + %% unread data left on the socket, can't safely continue + orelse (DidNotRecv + andalso get_header_value("content-length") =/= undefined + andalso list_to_integer(get_header_value("content-length")) > 0) + orelse (DidNotRecv + andalso get_header_value("transfer-encoding") =:= "chunked"). + +%% @spec cleanup() -> ok +%% @doc Clean up any junk in the process dictionary, required before continuing +%% a Keep-Alive request. +cleanup() -> + [erase(K) || K <- [?SAVE_QS, + ?SAVE_PATH, + ?SAVE_RECV, + ?SAVE_BODY, + ?SAVE_POST, + ?SAVE_COOKIE, + ?SAVE_FORCE_CLOSE]], + ok. + +%% @spec parse_qs() -> [{Key::string(), Value::string()}] +%% @doc Parse the query string of the URL. +parse_qs() -> + case erlang:get(?SAVE_QS) of + undefined -> + {_, QueryString, _} = mochiweb_util:urlsplit_path(RawPath), + Parsed = mochiweb_util:parse_qs(QueryString), + put(?SAVE_QS, Parsed), + Parsed; + Cached -> + Cached + end. + +%% @spec get_cookie_value(Key::string) -> string() | undefined +%% @doc Get the value of the given cookie. +get_cookie_value(Key) -> + proplists:get_value(Key, parse_cookie()). + +%% @spec parse_cookie() -> [{Key::string(), Value::string()}] +%% @doc Parse the cookie header. +parse_cookie() -> + case erlang:get(?SAVE_COOKIE) of + undefined -> + Cookies = case get_header_value("cookie") of + undefined -> + []; + Value -> + mochiweb_cookies:parse_cookie(Value) + end, + put(?SAVE_COOKIE, Cookies), + Cookies; + Cached -> + Cached + end. + +%% @spec parse_post() -> [{Key::string(), Value::string()}] +%% @doc Parse an application/x-www-form-urlencoded form POST. This +%% has the side-effect of calling recv_body(). +parse_post() -> + case erlang:get(?SAVE_POST) of + undefined -> + Parsed = case recv_body() of + undefined -> + []; + Binary -> + case get_primary_header_value("content-type") of + "application/x-www-form-urlencoded" ++ _ -> + mochiweb_util:parse_qs(Binary); + _ -> + [] + end + end, + put(?SAVE_POST, Parsed), + Parsed; + Cached -> + Cached + end. + +%% @spec stream_chunked_body(integer(), fun(), term()) -> term() +%% @doc The function is called for each chunk. +%% Used internally by read_chunked_body. +stream_chunked_body(MaxChunkSize, Fun, FunState) -> + case read_chunk_length() of + 0 -> + Fun({0, read_chunk(0)}, FunState); + Length when Length > MaxChunkSize -> + NewState = read_sub_chunks(Length, MaxChunkSize, Fun, FunState), + stream_chunked_body(MaxChunkSize, Fun, NewState); + Length -> + NewState = Fun({Length, read_chunk(Length)}, FunState), + stream_chunked_body(MaxChunkSize, Fun, NewState) + end. + +stream_unchunked_body(0, Fun, FunState) -> + Fun({0, <<>>}, FunState); +stream_unchunked_body(Length, Fun, FunState) when Length > 0 -> + Bin = recv(0), + BinSize = byte_size(Bin), + if BinSize > Length -> + <<OurBody:Length/binary, Extra/binary>> = Bin, + gen_tcp:unrecv(Socket, Extra), + NewState = Fun({Length, OurBody}, FunState), + stream_unchunked_body(0, Fun, NewState); + true -> + NewState = Fun({BinSize, Bin}, FunState), + stream_unchunked_body(Length - BinSize, Fun, NewState) + end. + + +%% @spec read_chunk_length() -> integer() +%% @doc Read the length of the next HTTP chunk. +read_chunk_length() -> + inet:setopts(Socket, [{packet, line}]), + case gen_tcp:recv(Socket, 0, ?IDLE_TIMEOUT) of + {ok, Header} -> + inet:setopts(Socket, [{packet, raw}]), + Splitter = fun (C) -> + C =/= $\r andalso C =/= $\n andalso C =/= $ + end, + {Hex, _Rest} = lists:splitwith(Splitter, binary_to_list(Header)), + mochihex:to_int(Hex); + _ -> + exit(normal) + end. + +%% @spec read_chunk(integer()) -> Chunk::binary() | [Footer::binary()] +%% @doc Read in a HTTP chunk of the given length. If Length is 0, then read the +%% HTTP footers (as a list of binaries, since they're nominal). +read_chunk(0) -> + inet:setopts(Socket, [{packet, line}]), + F = fun (F1, Acc) -> + case gen_tcp:recv(Socket, 0, ?IDLE_TIMEOUT) of + {ok, <<"\r\n">>} -> + Acc; + {ok, Footer} -> + F1(F1, [Footer | Acc]); + _ -> + exit(normal) + end + end, + Footers = F(F, []), + inet:setopts(Socket, [{packet, raw}]), + Footers; +read_chunk(Length) -> + case gen_tcp:recv(Socket, 2 + Length, ?IDLE_TIMEOUT) of + {ok, <<Chunk:Length/binary, "\r\n">>} -> + Chunk; + _ -> + exit(normal) + end. + +read_sub_chunks(Length, MaxChunkSize, Fun, FunState) when Length > MaxChunkSize -> + Bin = recv(MaxChunkSize), + NewState = Fun({size(Bin), Bin}, FunState), + read_sub_chunks(Length - MaxChunkSize, MaxChunkSize, Fun, NewState); + +read_sub_chunks(Length, _MaxChunkSize, Fun, FunState) -> + Fun({Length, read_chunk(Length)}, FunState). + +%% @spec serve_file(Path, DocRoot) -> Response +%% @doc Serve a file relative to DocRoot. +serve_file(Path, DocRoot) -> + serve_file(Path, DocRoot, []). + +%% @spec serve_file(Path, DocRoot, ExtraHeaders) -> Response +%% @doc Serve a file relative to DocRoot. +serve_file(Path, DocRoot, ExtraHeaders) -> + case mochiweb_util:safe_relative_path(Path) of + undefined -> + not_found(ExtraHeaders); + RelPath -> + FullPath = filename:join([DocRoot, RelPath]), + case filelib:is_dir(FullPath) of + true -> + maybe_redirect(RelPath, FullPath, ExtraHeaders); + false -> + maybe_serve_file(FullPath, ExtraHeaders) + end + end. + +%% Internal API + +%% This has the same effect as the DirectoryIndex directive in httpd +directory_index(FullPath) -> + filename:join([FullPath, "index.html"]). + +maybe_redirect([], FullPath, ExtraHeaders) -> + maybe_serve_file(directory_index(FullPath), ExtraHeaders); + +maybe_redirect(RelPath, FullPath, ExtraHeaders) -> + case string:right(RelPath, 1) of + "/" -> + maybe_serve_file(directory_index(FullPath), ExtraHeaders); + _ -> + Host = mochiweb_headers:get_value("host", Headers), + Location = "http://" ++ Host ++ "/" ++ RelPath ++ "/", + LocationBin = list_to_binary(Location), + MoreHeaders = [{"Location", Location}, + {"Content-Type", "text/html"} | ExtraHeaders], + Top = <<"<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">" + "<html><head>" + "<title>301 Moved Permanently</title>" + "</head><body>" + "<h1>Moved Permanently</h1>" + "<p>The document has moved <a href=\"">>, + Bottom = <<">here</a>.</p></body></html>\n">>, + Body = <<Top/binary, LocationBin/binary, Bottom/binary>>, + respond({301, MoreHeaders, Body}) + end. + +maybe_serve_file(File, ExtraHeaders) -> + case file:read_file_info(File) of + {ok, FileInfo} -> + LastModified = httpd_util:rfc1123_date(FileInfo#file_info.mtime), + case get_header_value("if-modified-since") of + LastModified -> + respond({304, ExtraHeaders, ""}); + _ -> + case file:open(File, [raw, binary]) of + {ok, IoDevice} -> + ContentType = mochiweb_util:guess_mime(File), + Res = ok({ContentType, + [{"last-modified", LastModified} + | ExtraHeaders], + {file, IoDevice}}), + file:close(IoDevice), + Res; + _ -> + not_found(ExtraHeaders) + end + end; + {error, _} -> + not_found(ExtraHeaders) + end. + +server_headers() -> + [{"Server", "MochiWeb/1.0 (" ++ ?QUIP ++ ")"}, + {"Date", httpd_util:rfc1123_date()}]. + +make_io(Atom) when is_atom(Atom) -> + atom_to_list(Atom); +make_io(Integer) when is_integer(Integer) -> + integer_to_list(Integer); +make_io(Io) when is_list(Io); is_binary(Io) -> + Io. + +make_code(X) when is_integer(X) -> + [integer_to_list(X), [" " | httpd_util:reason_phrase(X)]]; +make_code(Io) when is_list(Io); is_binary(Io) -> + Io. + +make_version({1, 0}) -> + <<"HTTP/1.0 ">>; +make_version(_) -> + <<"HTTP/1.1 ">>. + +iodevice_stream(IoDevice) -> + case file:read(IoDevice, ?READ_SIZE) of + eof -> + ok; + {ok, Data} -> + ok = send(Data), + iodevice_stream(IoDevice) + end. + + +parts_to_body([{Start, End, Body}], ContentType, Size) -> + %% return body for a range reponse with a single body + HeaderList = [{"Content-Type", ContentType}, + {"Content-Range", + ["bytes ", + make_io(Start), "-", make_io(End), + "/", make_io(Size)]}], + {HeaderList, Body}; +parts_to_body(BodyList, ContentType, Size) when is_list(BodyList) -> + %% return + %% header Content-Type: multipart/byteranges; boundary=441934886133bdee4 + %% and multipart body + Boundary = mochihex:to_hex(crypto:rand_bytes(8)), + HeaderList = [{"Content-Type", + ["multipart/byteranges; ", + "boundary=", Boundary]}], + MultiPartBody = multipart_body(BodyList, ContentType, Boundary, Size), + + {HeaderList, MultiPartBody}. + +multipart_body([], _ContentType, Boundary, _Size) -> + ["--", Boundary, "--\r\n"]; +multipart_body([{Start, End, Body} | BodyList], ContentType, Boundary, Size) -> + ["--", Boundary, "\r\n", + "Content-Type: ", ContentType, "\r\n", + "Content-Range: ", + "bytes ", make_io(Start), "-", make_io(End), + "/", make_io(Size), "\r\n\r\n", + Body, "\r\n" + | multipart_body(BodyList, ContentType, Boundary, Size)]. + +iodevice_size(IoDevice) -> + {ok, Size} = file:position(IoDevice, eof), + {ok, 0} = file:position(IoDevice, bof), + Size. + +range_parts({file, IoDevice}, Ranges) -> + Size = iodevice_size(IoDevice), + F = fun (Spec, Acc) -> + case range_skip_length(Spec, Size) of + invalid_range -> + Acc; + V -> + [V | Acc] + end + end, + LocNums = lists:foldr(F, [], Ranges), + {ok, Data} = file:pread(IoDevice, LocNums), + Bodies = lists:zipwith(fun ({Skip, Length}, PartialBody) -> + {Skip, Skip + Length - 1, PartialBody} + end, + LocNums, Data), + {Bodies, Size}; +range_parts(Body0, Ranges) -> + Body = iolist_to_binary(Body0), + Size = size(Body), + F = fun(Spec, Acc) -> + case range_skip_length(Spec, Size) of + invalid_range -> + Acc; + {Skip, Length} -> + <<_:Skip/binary, PartialBody:Length/binary, _/binary>> = Body, + [{Skip, Skip + Length - 1, PartialBody} | Acc] + end + end, + {lists:foldr(F, [], Ranges), Size}. + +range_skip_length(Spec, Size) -> + case Spec of + {none, R} when R =< Size, R >= 0 -> + {Size - R, R}; + {none, _OutOfRange} -> + {0, Size}; + {R, none} when R >= 0, R < Size -> + {R, Size - R}; + {_OutOfRange, none} -> + invalid_range; + {Start, End} when 0 =< Start, Start =< End, End < Size -> + {Start, End - Start + 1}; + {_OutOfRange, _End} -> + invalid_range + end. + +parse_range_request(RawRange) when is_list(RawRange) -> + try + "bytes=" ++ RangeString = RawRange, + Ranges = string:tokens(RangeString, ","), + lists:map(fun ("-" ++ V) -> + {none, list_to_integer(V)}; + (R) -> + case string:tokens(R, "-") of + [S1, S2] -> + {list_to_integer(S1), list_to_integer(S2)}; + [S] -> + {list_to_integer(S), none} + end + end, + Ranges) + catch + _:_ -> + fail + end. + +%% @spec accepted_encodings([encoding()]) -> [encoding()] | error() +%% @type encoding() -> string() +%% @type error() -> bad_accept_encoding_value +%% +%% @doc Returns a list of encodings accepted by a request. Encodings that are +%% not supported by the server will not be included in the return list. +%% This list is computed from the "Accept-Encoding" header and +%% its elements are ordered, descendingly, according to their Q values. +%% +%% Section 14.3 of the RFC 2616 (HTTP 1.1) describes the "Accept-Encoding" +%% header and the process of determining which server supported encodings +%% can be used for encoding the body for the request's response. +%% +%% Examples +%% +%% 1) For a missing "Accept-Encoding" header: +%% accepted_encodings(["gzip", "identity"]) -> ["identity"] +%% +%% 2) For an "Accept-Encoding" header with value "gzip, deflate": +%% accepted_encodings(["gzip", "identity"]) -> ["gzip", "identity"] +%% +%% 3) For an "Accept-Encoding" header with value "gzip;q=0.5, deflate": +%% accepted_encodings(["gzip", "deflate", "identity"]) -> +%% ["deflate", "gzip", "identity"] +%% +accepted_encodings(SupportedEncodings) -> + AcceptEncodingHeader = case get_header_value("Accept-Encoding") of + undefined -> + ""; + Value -> + Value + end, + case mochiweb_util:parse_qvalues(AcceptEncodingHeader) of + invalid_qvalue_string -> + bad_accept_encoding_value; + QList -> + mochiweb_util:pick_accepted_encodings( + QList, SupportedEncodings, "identity" + ) + end. + +test() -> + ok = test_range(), + ok. + +test_range() -> + %% valid, single ranges + io:format("Testing parse_range_request with valid single ranges~n"), + io:format("1"), + [{20, 30}] = parse_range_request("bytes=20-30"), + io:format("2"), + [{20, none}] = parse_range_request("bytes=20-"), + io:format("3"), + [{none, 20}] = parse_range_request("bytes=-20"), + io:format(".. ok ~n"), + + %% invalid, single ranges + io:format("Testing parse_range_request with invalid ranges~n"), + io:format("1"), + fail = parse_range_request(""), + io:format("2"), + fail = parse_range_request("garbage"), + io:format("3"), + fail = parse_range_request("bytes=-20-30"), + io:format(".. ok ~n"), + + %% valid, multiple range + io:format("Testing parse_range_request with valid multiple ranges~n"), + io:format("1"), + [{20, 30}, {50, 100}, {110, 200}] = + parse_range_request("bytes=20-30,50-100,110-200"), + io:format("2"), + [{20, none}, {50, 100}, {none, 200}] = + parse_range_request("bytes=20-,50-100,-200"), + io:format(".. ok~n"), + + %% no ranges + io:format("Testing out parse_range_request with no ranges~n"), + io:format("1"), + [] = parse_range_request("bytes="), + io:format(".. ok~n"), + + Body = <<"012345678901234567890123456789012345678901234567890123456789">>, + BodySize = byte_size(Body), %% 60 + BodySize = 60, + + %% these values assume BodySize =:= 60 + io:format("Testing out range_skip_length on valid ranges~n"), + io:format("1"), + {1,9} = range_skip_length({1,9}, BodySize), %% 1-9 + io:format("2"), + {10,10} = range_skip_length({10,19}, BodySize), %% 10-19 + io:format("3"), + {40, 20} = range_skip_length({none, 20}, BodySize), %% -20 + io:format("4"), + {30, 30} = range_skip_length({30, none}, BodySize), %% 30- + io:format(".. ok ~n"), + + %% valid edge cases for range_skip_length + io:format("Testing out range_skip_length on valid edge case ranges~n"), + io:format("1"), + {BodySize, 0} = range_skip_length({none, 0}, BodySize), + io:format("2"), + {0, BodySize} = range_skip_length({none, BodySize}, BodySize), + io:format("3"), + {0, BodySize} = range_skip_length({0, none}, BodySize), + BodySizeLess1 = BodySize - 1, + io:format("4"), + {BodySizeLess1, 1} = range_skip_length({BodySize - 1, none}, BodySize), + + %% out of range, return whole thing + io:format("5"), + {0, BodySize} = range_skip_length({none, BodySize + 1}, BodySize), + io:format("6"), + {0, BodySize} = range_skip_length({none, -1}, BodySize), + io:format(".. ok ~n"), + + %% invalid ranges + io:format("Testing out range_skip_length on invalid ranges~n"), + io:format("1"), + invalid_range = range_skip_length({-1, 30}, BodySize), + io:format("2"), + invalid_range = range_skip_length({0, BodySize + 1}, BodySize), + io:format("3"), + invalid_range = range_skip_length({-1, BodySize + 1}, BodySize), + io:format("4"), + invalid_range = range_skip_length({BodySize, 40}, BodySize), + io:format("5"), + invalid_range = range_skip_length({-1, none}, BodySize), + io:format("6"), + invalid_range = range_skip_length({BodySize, none}, BodySize), + io:format(".. ok ~n"), + ok. + |