| %% @author Bob Ippolito <bob@mochimedia.com> |
| %% @copyright 2007 Mochi Media, Inc. |
| |
| %% @doc Case preserving (but case insensitive) HTTP Header dictionary. |
| |
| -module(mochiweb_headers). |
| -author('bob@mochimedia.com'). |
| -export([empty/0, from_list/1, insert/3, enter/3, get_value/2, lookup/2]). |
| -export([delete_any/2, get_primary_value/2]). |
| -export([default/3, enter_from_list/2, default_from_list/2]). |
| -export([to_list/1, make/1]). |
| -export([from_binary/1]). |
| -export([test/0]). |
| |
| %% @type headers(). |
| %% @type key() = atom() | binary() | string(). |
| %% @type value() = atom() | binary() | string() | integer(). |
| |
| %% @spec test() -> ok |
| %% @doc Run tests for this module. |
| test() -> |
| H = ?MODULE:make([{hdr, foo}, {"Hdr", "bar"}, {'Hdr', 2}]), |
| [{hdr, "foo, bar, 2"}] = ?MODULE:to_list(H), |
| H1 = ?MODULE:insert(taco, grande, H), |
| [{hdr, "foo, bar, 2"}, {taco, "grande"}] = ?MODULE:to_list(H1), |
| H2 = ?MODULE:make([{"Set-Cookie", "foo"}]), |
| [{"Set-Cookie", "foo"}] = ?MODULE:to_list(H2), |
| H3 = ?MODULE:insert("Set-Cookie", "bar", H2), |
| [{"Set-Cookie", "foo"}, {"Set-Cookie", "bar"}] = ?MODULE:to_list(H3), |
| "foo, bar" = ?MODULE:get_value("set-cookie", H3), |
| {value, {"Set-Cookie", "foo, bar"}} = ?MODULE:lookup("set-cookie", H3), |
| undefined = ?MODULE:get_value("shibby", H3), |
| none = ?MODULE:lookup("shibby", H3), |
| H4 = ?MODULE:insert("content-type", |
| "application/x-www-form-urlencoded; charset=utf8", |
| H3), |
| "application/x-www-form-urlencoded" = ?MODULE:get_primary_value( |
| "content-type", H4), |
| H4 = ?MODULE:delete_any("nonexistent-header", H4), |
| H3 = ?MODULE:delete_any("content-type", H4), |
| HB = <<"Content-Length: 47\r\nContent-Type: text/plain\r\n\r\n">>, |
| H_HB = ?MODULE:from_binary(HB), |
| H_HB = ?MODULE:from_binary(binary_to_list(HB)), |
| "47" = ?MODULE:get_value("Content-Length", H_HB), |
| "text/plain" = ?MODULE:get_value("Content-Type", H_HB), |
| L_H_HB = ?MODULE:to_list(H_HB), |
| 2 = length(L_H_HB), |
| true = lists:member({'Content-Length', "47"}, L_H_HB), |
| true = lists:member({'Content-Type', "text/plain"}, L_H_HB), |
| HL = [ <<"Content-Length: 47\r\n">>, <<"Content-Type: text/plain\r\n">> ], |
| HL2 = [ "Content-Length: 47\r\n", <<"Content-Type: text/plain\r\n">> ], |
| HL3 = [ <<"Content-Length: 47\r\n">>, "Content-Type: text/plain\r\n" ], |
| H_HL = ?MODULE:from_binary(HL), |
| H_HL = ?MODULE:from_binary(HL2), |
| H_HL = ?MODULE:from_binary(HL3), |
| "47" = ?MODULE:get_value("Content-Length", H_HL), |
| "text/plain" = ?MODULE:get_value("Content-Type", H_HL), |
| L_H_HL = ?MODULE:to_list(H_HL), |
| 2 = length(L_H_HL), |
| true = lists:member({'Content-Length', "47"}, L_H_HL), |
| true = lists:member({'Content-Type', "text/plain"}, L_H_HL), |
| [] = ?MODULE:to_list(?MODULE:from_binary(<<>>)), |
| [] = ?MODULE:to_list(?MODULE:from_binary(<<"">>)), |
| [] = ?MODULE:to_list(?MODULE:from_binary(<<"\r\n">>)), |
| [] = ?MODULE:to_list(?MODULE:from_binary(<<"\r\n\r\n">>)), |
| [] = ?MODULE:to_list(?MODULE:from_binary("")), |
| [] = ?MODULE:to_list(?MODULE:from_binary([<<>>])), |
| [] = ?MODULE:to_list(?MODULE:from_binary([<<"">>])), |
| [] = ?MODULE:to_list(?MODULE:from_binary([<<"\r\n">>])), |
| [] = ?MODULE:to_list(?MODULE:from_binary([<<"\r\n\r\n">>])), |
| ok. |
| |
| %% @spec empty() -> headers() |
| %% @doc Create an empty headers structure. |
| empty() -> |
| gb_trees:empty(). |
| |
| %% @spec make(headers() | [{key(), value()}]) -> headers() |
| %% @doc Construct a headers() from the given list. |
| make(L) when is_list(L) -> |
| from_list(L); |
| %% assume a tuple is already mochiweb_headers. |
| make(T) when is_tuple(T) -> |
| T. |
| |
| %% @spec from_binary(RawHttpHeader()) -> headers() |
| %% @type RawHttpHeader() -> string() | binary() | [ string() | binary() ] |
| %% |
| %% @doc Transforms a raw HTTP header into a mochiweb headers structure. |
| %% |
| %% The given raw HTTP header can be one of the following: |
| %% |
| %% 1) A string or a binary representing a full HTTP header ending with |
| %% double CRLF. |
| %% Examples: |
| %% "Content-Length: 47\r\nContent-Type: text/plain\r\n\r\n" |
| %% <<"Content-Length: 47\r\nContent-Type: text/plain\r\n\r\n">> |
| %% |
| %% 2) A list of binaries or strings where each element represents a raw |
| %% HTTP header line ending with a single CRLF. |
| %% Examples: |
| %% [ <<"Content-Length: 47\r\n">>, <<"Content-Type: text/plain\r\n">> ] |
| %% [ "Content-Length: 47\r\n", "Content-Type: text/plain\r\n" ] |
| %% [ "Content-Length: 47\r\n", <<"Content-Type: text/plain\r\n">> ] |
| %% |
| from_binary(RawHttpHeader) when is_binary(RawHttpHeader) -> |
| from_binary(RawHttpHeader, []); |
| |
| from_binary(RawHttpHeaderList) -> |
| from_binary(list_to_binary([RawHttpHeaderList, "\r\n"])). |
| |
| from_binary(RawHttpHeader, Acc) -> |
| case erlang:decode_packet(httph, RawHttpHeader, []) of |
| { ok, {http_header, _, H, _, V}, Rest } -> |
| from_binary(Rest, [{H, V} | Acc]); |
| _ -> |
| make(Acc) |
| end. |
| |
| %% @spec from_list([{key(), value()}]) -> headers() |
| %% @doc Construct a headers() from the given list. |
| from_list(List) -> |
| lists:foldl(fun ({K, V}, T) -> insert(K, V, T) end, empty(), List). |
| |
| %% @spec enter_from_list([{key(), value()}], headers()) -> headers() |
| %% @doc Insert pairs into the headers, replace any values for existing keys. |
| enter_from_list(List, T) -> |
| lists:foldl(fun ({K, V}, T1) -> enter(K, V, T1) end, T, List). |
| |
| %% @spec default_from_list([{key(), value()}], headers()) -> headers() |
| %% @doc Insert pairs into the headers for keys that do not already exist. |
| default_from_list(List, T) -> |
| lists:foldl(fun ({K, V}, T1) -> default(K, V, T1) end, T, List). |
| |
| %% @spec to_list(headers()) -> [{key(), string()}] |
| %% @doc Return the contents of the headers. The keys will be the exact key |
| %% that was first inserted (e.g. may be an atom or binary, case is |
| %% preserved). |
| to_list(T) -> |
| F = fun ({K, {array, L}}, Acc) -> |
| L1 = lists:reverse(L), |
| lists:foldl(fun (V, Acc1) -> [{K, V} | Acc1] end, Acc, L1); |
| (Pair, Acc) -> |
| [Pair | Acc] |
| end, |
| lists:reverse(lists:foldl(F, [], gb_trees:values(T))). |
| |
| %% @spec get_value(key(), headers()) -> string() | undefined |
| %% @doc Return the value of the given header using a case insensitive search. |
| %% undefined will be returned for keys that are not present. |
| get_value(K, T) -> |
| case lookup(K, T) of |
| {value, {_, V}} -> |
| expand(V); |
| none -> |
| undefined |
| end. |
| |
| %% @spec get_primary_value(key(), headers()) -> string() | undefined |
| %% @doc Return the value of the given header up to the first semicolon using |
| %% a case insensitive search. undefined will be returned for keys |
| %% that are not present. |
| get_primary_value(K, T) -> |
| case get_value(K, T) of |
| undefined -> |
| undefined; |
| V -> |
| lists:takewhile(fun (C) -> C =/= $; end, V) |
| end. |
| |
| %% @spec lookup(key(), headers()) -> {value, {key(), string()}} | none |
| %% @doc Return the case preserved key and value for the given header using |
| %% a case insensitive search. none will be returned for keys that are |
| %% not present. |
| lookup(K, T) -> |
| case gb_trees:lookup(normalize(K), T) of |
| {value, {K0, V}} -> |
| {value, {K0, expand(V)}}; |
| none -> |
| none |
| end. |
| |
| %% @spec default(key(), value(), headers()) -> headers() |
| %% @doc Insert the pair into the headers if it does not already exist. |
| default(K, V, T) -> |
| K1 = normalize(K), |
| V1 = any_to_list(V), |
| try gb_trees:insert(K1, {K, V1}, T) |
| catch |
| error:{key_exists, _} -> |
| T |
| end. |
| |
| %% @spec enter(key(), value(), headers()) -> headers() |
| %% @doc Insert the pair into the headers, replacing any pre-existing key. |
| enter(K, V, T) -> |
| K1 = normalize(K), |
| V1 = any_to_list(V), |
| gb_trees:enter(K1, {K, V1}, T). |
| |
| %% @spec insert(key(), value(), headers()) -> headers() |
| %% @doc Insert the pair into the headers, merging with any pre-existing key. |
| %% A merge is done with Value = V0 ++ ", " ++ V1. |
| insert(K, V, T) -> |
| K1 = normalize(K), |
| V1 = any_to_list(V), |
| try gb_trees:insert(K1, {K, V1}, T) |
| catch |
| error:{key_exists, _} -> |
| {K0, V0} = gb_trees:get(K1, T), |
| V2 = merge(K1, V1, V0), |
| gb_trees:update(K1, {K0, V2}, T) |
| end. |
| |
| %% @spec delete_any(key(), headers()) -> headers() |
| %% @doc Delete the header corresponding to key if it is present. |
| delete_any(K, T) -> |
| K1 = normalize(K), |
| gb_trees:delete_any(K1, T). |
| |
| %% Internal API |
| |
| expand({array, L}) -> |
| mochiweb_util:join(lists:reverse(L), ", "); |
| expand(V) -> |
| V. |
| |
| merge("set-cookie", V1, {array, L}) -> |
| {array, [V1 | L]}; |
| merge("set-cookie", V1, V0) -> |
| {array, [V1, V0]}; |
| merge(_, V1, V0) -> |
| V0 ++ ", " ++ V1. |
| |
| normalize(K) when is_list(K) -> |
| string:to_lower(K); |
| normalize(K) when is_atom(K) -> |
| normalize(atom_to_list(K)); |
| normalize(K) when is_binary(K) -> |
| normalize(binary_to_list(K)). |
| |
| any_to_list(V) when is_list(V) -> |
| V; |
| any_to_list(V) when is_atom(V) -> |
| atom_to_list(V); |
| any_to_list(V) when is_binary(V) -> |
| binary_to_list(V); |
| any_to_list(V) when is_integer(V) -> |
| integer_to_list(V). |
| |
| |