Merged mochiweb branch back into trunk.

git-svn-id: https://svn.apache.org/repos/asf/incubator/couchdb/trunk@648222 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 178 insertions, 0 deletions

diff --git a/src/mochiweb/mochiweb_headers.erl b/src/mochiweb/mochiweb_headers.erl
new file mode 100644
index 00000000..5b538aa7
--- /dev/null
+++ b/src/mochiweb/mochiweb_headers.erl
@@ -0,0 +1,178 @@
+%% @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([get_primary_value/2]).
+-export([default/3, enter_from_list/2, default_from_list/2]).
+-export([to_list/1, make/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),
+    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_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.
+
+%% 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).
+
+