From 39de3072bcf9fdeec6d3faeb125924c401242205 Mon Sep 17 00:00:00 2001 From: Christopher Lenz Date: Tue, 15 Apr 2008 12:21:00 +0000 Subject: Merged mochiweb branch back into trunk. git-svn-id: https://svn.apache.org/repos/asf/incubator/couchdb/trunk@648222 13f79535-47bb-0310-9956-ffa450edef68 --- src/mochiweb/mochijson2.erl | 509 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 509 insertions(+) create mode 100644 src/mochiweb/mochijson2.erl (limited to 'src/mochiweb/mochijson2.erl') diff --git a/src/mochiweb/mochijson2.erl b/src/mochiweb/mochijson2.erl new file mode 100644 index 00000000..dfaffbab --- /dev/null +++ b/src/mochiweb/mochijson2.erl @@ -0,0 +1,509 @@ +%% @author Bob Ippolito +%% @copyright 2007 Mochi Media, Inc. + +%% @doc Yet another JSON (RFC 4627) library for Erlang. mochijson2 works +%% with binaries as strings, arrays as lists (without an {array, _}) +%% wrapper and it only knows how to decode UTF-8 (and ASCII). + +-module(mochijson2). +-author('bob@mochimedia.com'). +-export([encoder/1, encode/1]). +-export([decoder/1, decode/1]). +-export([test/0]). + +% This is a macro to placate syntax highlighters.. +-define(Q, $\"). +-define(ADV_COL(S, N), S#decoder{offset=N+S#decoder.offset, + column=N+S#decoder.column}). +-define(INC_COL(S), S#decoder{offset=1+S#decoder.offset, + column=1+S#decoder.column}). +-define(INC_LINE(S), S#decoder{offset=1+S#decoder.offset, + column=1, + line=1+S#decoder.line}). +-define(INC_CHAR(S, C), + case C of + $\n -> + S#decoder{column=1, + line=1+S#decoder.line, + offset=1+S#decoder.offset}; + _ -> + S#decoder{column=1+S#decoder.column, + offset=1+S#decoder.offset} + end). +-define(IS_WHITESPACE(C), + (C =:= $\s orelse C =:= $\t orelse C =:= $\r orelse C =:= $\n)). + +%% @type iolist() = [char() | binary() | iolist()] +%% @type iodata() = iolist() | binary() +%% @type json_string() = atom | binary() +%% @type json_number() = integer() | float() +%% @type json_array() = [json_term()] +%% @type json_object() = {struct, [{json_string(), json_term()}]} +%% @type json_term() = json_string() | json_number() | json_array() | +%% json_object() + +-record(encoder, {handler=null}). + +-record(decoder, {object_hook=null, + offset=0, + line=1, + column=1, + state=null}). + +%% @spec encoder([encoder_option()]) -> function() +%% @doc Create an encoder/1 with the given options. +encoder(Options) -> + State = parse_encoder_options(Options, #encoder{}), + fun (O) -> json_encode(O, State) end. + +%% @spec encode(json_term()) -> iolist() +%% @doc Encode the given as JSON to an iolist. +encode(Any) -> + json_encode(Any, #encoder{}). + +%% @spec decoder([decoder_option()]) -> function() +%% @doc Create a decoder/1 with the given options. +decoder(Options) -> + State = parse_decoder_options(Options, #decoder{}), + fun (O) -> json_decode(O, State) end. + +%% @spec decode(iolist()) -> json_term() +%% @doc Decode the given iolist to Erlang terms. +decode(S) -> + json_decode(S, #decoder{}). + +test() -> + test_all(). + +%% Internal API + +parse_encoder_options([], State) -> + State; +parse_encoder_options([{handler, Handler} | Rest], State) -> + parse_encoder_options(Rest, State#encoder{handler=Handler}). + +parse_decoder_options([], State) -> + State; +parse_decoder_options([{object_hook, Hook} | Rest], State) -> + parse_decoder_options(Rest, State#decoder{object_hook=Hook}). + +json_encode(true, _State) -> + <<"true">>; +json_encode(false, _State) -> + <<"false">>; +json_encode(null, _State) -> + <<"null">>; +json_encode(I, _State) when is_integer(I) andalso I >= -2147483648 andalso I =< 2147483647 -> + %% Anything outside of 32-bit integers should be encoded as a float + integer_to_list(I); +json_encode(I, _State) when is_integer(I) -> + mochinum:digits(float(I)); +json_encode(F, _State) when is_float(F) -> + mochinum:digits(F); +json_encode(S, State) when is_binary(S); is_atom(S) -> + json_encode_string(S, State); +json_encode(Array, State) when is_list(Array) -> + json_encode_array(Array, State); +json_encode({struct, Props}, State) when is_list(Props) -> + json_encode_proplist(Props, State); +json_encode(Bad, #encoder{handler=null}) -> + exit({json_encode, {bad_term, Bad}}); +json_encode(Bad, State=#encoder{handler=Handler}) -> + json_encode(Handler(Bad), State). + +json_encode_array([], _State) -> + <<"[]">>; +json_encode_array(L, State) -> + F = fun (O, Acc) -> + [$,, json_encode(O, State) | Acc] + end, + [$, | Acc1] = lists:foldl(F, "[", L), + lists:reverse([$\] | Acc1]). + +json_encode_proplist([], _State) -> + <<"{}">>; +json_encode_proplist(Props, State) -> + F = fun ({K, V}, Acc) -> + KS = json_encode_string(K, State), + VS = json_encode(V, State), + [$,, VS, $:, KS | Acc] + end, + [$, | Acc1] = lists:foldl(F, "{", Props), + lists:reverse([$\} | Acc1]). + +json_encode_string(A, _State) when is_atom(A) -> + json_encode_string_unicode(xmerl_ucs:from_utf8(atom_to_list(A)), [?Q]); +json_encode_string(B, _State) when is_binary(B) -> + json_encode_string_unicode(xmerl_ucs:from_utf8(B), [?Q]); +json_encode_string(I, _State) when is_integer(I) -> + json_encode_string_unicode(integer_to_list(I), [?Q]); +json_encode_string(L, _State) when is_list(L) -> + json_encode_string_unicode(L, [?Q]). + +json_encode_string_unicode([], Acc) -> + lists:reverse([$\" | Acc]); +json_encode_string_unicode([C | Cs], Acc) -> + Acc1 = case C of + ?Q -> + [?Q, $\\ | Acc]; + %% Escaping solidus is only useful when trying to protect + %% against "" injection attacks which are only + %% possible when JSON is inserted into a HTML document + %% in-line. mochijson2 does not protect you from this, so + %% if you do insert directly into HTML then you need to + %% uncomment the following case or escape the output of encode. + %% + %% $/ -> + %% [$/, $\\ | Acc]; + %% + $\\ -> + [$\\, $\\ | Acc]; + $\b -> + [$b, $\\ | Acc]; + $\f -> + [$f, $\\ | Acc]; + $\n -> + [$n, $\\ | Acc]; + $\r -> + [$r, $\\ | Acc]; + $\t -> + [$t, $\\ | Acc]; + C when C >= 0, C < $\s; C >= 16#7f, C =< 16#10FFFF -> + [unihex(C) | Acc]; + C when C < 16#7f -> + [C | Acc]; + _ -> + exit({json_encode, {bad_char, C}}) + end, + json_encode_string_unicode(Cs, Acc1). + +hexdigit(C) when C >= 0, C =< 9 -> + C + $0; +hexdigit(C) when C =< 15 -> + C + $a - 10. + +unihex(C) when C < 16#10000 -> + <> = <>, + Digits = [hexdigit(D) || D <- [D3, D2, D1, D0]], + [$\\, $u | Digits]; +unihex(C) when C =< 16#10FFFF -> + N = C - 16#10000, + S1 = 16#d800 bor ((N bsr 10) band 16#3ff), + S2 = 16#dc00 bor (N band 16#3ff), + [unihex(S1), unihex(S2)]. + +json_decode(L, S) when is_list(L) -> + json_decode(iolist_to_binary(L), S); +json_decode(B, S) -> + {Res, S1} = decode1(B, S), + {eof, _} = tokenize(B, S1#decoder{state=trim}), + Res. + +decode1(B, S=#decoder{state=null}) -> + case tokenize(B, S#decoder{state=any}) of + {{const, C}, S1} -> + {C, S1}; + {start_array, S1} -> + decode_array(B, S1); + {start_object, S1} -> + decode_object(B, S1) + end. + +make_object(V, #decoder{object_hook=null}) -> + V; +make_object(V, #decoder{object_hook=Hook}) -> + Hook(V). + +decode_object(B, S) -> + decode_object(B, S#decoder{state=key}, []). + +decode_object(B, S=#decoder{state=key}, Acc) -> + case tokenize(B, S) of + {end_object, S1} -> + V = make_object({struct, lists:reverse(Acc)}, S1), + {V, S1#decoder{state=null}}; + {{const, K}, S1} -> + {colon, S2} = tokenize(B, S1), + {V, S3} = decode1(B, S2#decoder{state=null}), + decode_object(B, S3#decoder{state=comma}, [{K, V} | Acc]) + end; +decode_object(B, S=#decoder{state=comma}, Acc) -> + case tokenize(B, S) of + {end_object, S1} -> + V = make_object({struct, lists:reverse(Acc)}, S1), + {V, S1#decoder{state=null}}; + {comma, S1} -> + decode_object(B, S1#decoder{state=key}, Acc) + end. + +decode_array(B, S) -> + decode_array(B, S#decoder{state=any}, []). + +decode_array(B, S=#decoder{state=any}, Acc) -> + case tokenize(B, S) of + {end_array, S1} -> + {lists:reverse(Acc), S1#decoder{state=null}}; + {start_array, S1} -> + {Array, S2} = decode_array(B, S1), + decode_array(B, S2#decoder{state=comma}, [Array | Acc]); + {start_object, S1} -> + {Array, S2} = decode_object(B, S1), + decode_array(B, S2#decoder{state=comma}, [Array | Acc]); + {{const, Const}, S1} -> + decode_array(B, S1#decoder{state=comma}, [Const | Acc]) + end; +decode_array(B, S=#decoder{state=comma}, Acc) -> + case tokenize(B, S) of + {end_array, S1} -> + {lists:reverse(Acc), S1#decoder{state=null}}; + {comma, S1} -> + decode_array(B, S1#decoder{state=any}, Acc) + end. + +tokenize_string(B, S) -> + tokenize_string(B, S, []). + +tokenize_string(B, S=#decoder{offset=O}, Acc) -> + case B of + <<_:O/binary, ?Q, _/binary>> -> + {{const, iolist_to_binary(lists:reverse(Acc))}, ?INC_COL(S)}; + <<_:O/binary, "\\\"", _/binary>> -> + tokenize_string(B, ?ADV_COL(S, 2), [$\" | Acc]); + <<_:O/binary, "\\\\", _/binary>> -> + tokenize_string(B, ?ADV_COL(S, 2), [$\\ | Acc]); + <<_:O/binary, "\\/", _/binary>> -> + tokenize_string(B, ?ADV_COL(S, 2), [$/ | Acc]); + <<_:O/binary, "\\b", _/binary>> -> + tokenize_string(B, ?ADV_COL(S, 2), [$\b | Acc]); + <<_:O/binary, "\\f", _/binary>> -> + tokenize_string(B, ?ADV_COL(S, 2), [$\f | Acc]); + <<_:O/binary, "\\n", _/binary>> -> + tokenize_string(B, ?ADV_COL(S, 2), [$\n | Acc]); + <<_:O/binary, "\\r", _/binary>> -> + tokenize_string(B, ?ADV_COL(S, 2), [$\r | Acc]); + <<_:O/binary, "\\t", _/binary>> -> + tokenize_string(B, ?ADV_COL(S, 2), [$\t | Acc]); + <<_:O/binary, "\\u", C3, C2, C1, C0, _/binary>> -> + %% coalesce UTF-16 surrogate pair? + C = erlang:list_to_integer([C3, C2, C1, C0], 16), + Acc1 = lists:reverse(xmerl_ucs:to_utf8(C), Acc), + tokenize_string(B, ?ADV_COL(S, 6), Acc1); + <<_:O/binary, C, _/binary>> -> + tokenize_string(B, ?INC_CHAR(S, C), [C | Acc]) + end. + +tokenize_number(B, S) -> + case tokenize_number(B, sign, S, []) of + {{int, Int}, S1} -> + {{const, list_to_integer(Int)}, S1}; + {{float, Float}, S1} -> + {{const, list_to_float(Float)}, S1} + end. + +tokenize_number(B, sign, S=#decoder{offset=O}, []) -> + case B of + <<_:O/binary, $-, _/binary>> -> + tokenize_number(B, int, ?INC_COL(S), [$-]); + _ -> + tokenize_number(B, int, S, []) + end; +tokenize_number(B, int, S=#decoder{offset=O}, Acc) -> + case B of + <<_:O/binary, $0, _/binary>> -> + tokenize_number(B, frac, ?INC_COL(S), [$0 | Acc]); + <<_:O/binary, C, _/binary>> when C >= $1 andalso C =< $9 -> + tokenize_number(B, int1, ?INC_COL(S), [C | Acc]) + end; +tokenize_number(B, int1, S=#decoder{offset=O}, Acc) -> + case B of + <<_:O/binary, C, _/binary>> when C >= $0 andalso C =< $9 -> + tokenize_number(B, int1, ?INC_COL(S), [C | Acc]); + _ -> + tokenize_number(B, frac, S, Acc) + end; +tokenize_number(B, frac, S=#decoder{offset=O}, Acc) -> + case B of + <<_:O/binary, $., C, _/binary>> when C >= $0, C =< $9 -> + tokenize_number(B, frac1, ?ADV_COL(S, 2), [C, $. | Acc]); + <<_:O/binary, E, _/binary>> when E =:= $e orelse E =:= $E -> + tokenize_number(B, esign, ?INC_COL(S), [$e, $0, $. | Acc]); + _ -> + {{int, lists:reverse(Acc)}, S} + end; +tokenize_number(B, frac1, S=#decoder{offset=O}, Acc) -> + case B of + <<_:O/binary, C, _/binary>> when C >= $0 andalso C =< $9 -> + tokenize_number(B, frac1, ?INC_COL(S), [C | Acc]); + <<_:O/binary, E, _/binary>> when E =:= $e orelse E =:= $E -> + tokenize_number(B, esign, ?INC_COL(S), [$e | Acc]); + _ -> + {{float, lists:reverse(Acc)}, S} + end; +tokenize_number(B, esign, S=#decoder{offset=O}, Acc) -> + case B of + <<_:O/binary, C, _/binary>> when C =:= $- orelse C=:= $+ -> + tokenize_number(B, eint, ?INC_COL(S), [C | Acc]); + _ -> + tokenize_number(B, eint, S, Acc) + end; +tokenize_number(B, eint, S=#decoder{offset=O}, Acc) -> + case B of + <<_:O/binary, C, _/binary>> when C >= $0 andalso C =< $9 -> + tokenize_number(B, eint1, ?INC_COL(S), [C | Acc]) + end; +tokenize_number(B, eint1, S=#decoder{offset=O}, Acc) -> + case B of + <<_:O/binary, C, _/binary>> when C >= $0 andalso C =< $9 -> + tokenize_number(B, eint1, ?INC_COL(S), [C | Acc]); + _ -> + {{float, lists:reverse(Acc)}, S} + end. + +tokenize(B, S=#decoder{offset=O}) -> + case B of + <<_:O/binary, C, _/binary>> when ?IS_WHITESPACE(C) -> + tokenize(B, ?INC_CHAR(S, C)); + <<_:O/binary, "{", _/binary>> -> + {start_object, ?INC_COL(S)}; + <<_:O/binary, "}", _/binary>> -> + {end_object, ?INC_COL(S)}; + <<_:O/binary, "[", _/binary>> -> + {start_array, ?INC_COL(S)}; + <<_:O/binary, "]", _/binary>> -> + {end_array, ?INC_COL(S)}; + <<_:O/binary, ",", _/binary>> -> + {comma, ?INC_COL(S)}; + <<_:O/binary, ":", _/binary>> -> + {colon, ?INC_COL(S)}; + <<_:O/binary, "null", _/binary>> -> + {{const, null}, ?ADV_COL(S, 4)}; + <<_:O/binary, "true", _/binary>> -> + {{const, true}, ?ADV_COL(S, 4)}; + <<_:O/binary, "false", _/binary>> -> + {{const, false}, ?ADV_COL(S, 5)}; + <<_:O/binary, "\"", _/binary>> -> + tokenize_string(B, ?INC_COL(S)); + <<_:O/binary, C, _/binary>> when (C >= $0 andalso C =< $9) + orelse C =:= $- -> + tokenize_number(B, S); + <<_:O/binary>> -> + trim = S#decoder.state, + {eof, S} + end. + +%% testing constructs borrowed from the Yaws JSON implementation. + +%% Create an object from a list of Key/Value pairs. + +obj_new() -> + {struct, []}. + +is_obj({struct, Props}) -> + F = fun ({K, _}) when is_binary(K) -> + true; + (_) -> + false + end, + lists:all(F, Props). + +obj_from_list(Props) -> + Obj = {struct, Props}, + case is_obj(Obj) of + true -> Obj; + false -> exit({json_bad_object, Obj}) + end. + +%% Test for equivalence of Erlang terms. +%% Due to arbitrary order of construction, equivalent objects might +%% compare unequal as erlang terms, so we need to carefully recurse +%% through aggregates (tuples and objects). + +equiv({struct, Props1}, {struct, Props2}) -> + equiv_object(Props1, Props2); +equiv(L1, L2) when is_list(L1), is_list(L2) -> + equiv_list(L1, L2); +equiv(N1, N2) when is_number(N1), is_number(N2) -> N1 == N2; +equiv(B1, B2) when is_binary(B1), is_binary(B2) -> B1 == B2; +equiv(true, true) -> true; +equiv(false, false) -> true; +equiv(null, null) -> true. + +%% Object representation and traversal order is unknown. +%% Use the sledgehammer and sort property lists. + +equiv_object(Props1, Props2) -> + L1 = lists:keysort(1, Props1), + L2 = lists:keysort(1, Props2), + Pairs = lists:zip(L1, L2), + true = lists:all(fun({{K1, V1}, {K2, V2}}) -> + equiv(K1, K2) and equiv(V1, V2) + end, Pairs). + +%% Recursively compare tuple elements for equivalence. + +equiv_list([], []) -> + true; +equiv_list([V1 | L1], [V2 | L2]) -> + case equiv(V1, V2) of + true -> + equiv_list(L1, L2); + false -> + false + end. + +test_all() -> + [1199344435545.0, 1] = decode(<<"[1199344435545.0,1]">>), + test_one(e2j_test_vec(utf8), 1). + +test_one([], _N) -> + %% io:format("~p tests passed~n", [N-1]), + ok; +test_one([{E, J} | Rest], N) -> + %% io:format("[~p] ~p ~p~n", [N, E, J]), + true = equiv(E, decode(J)), + true = equiv(E, decode(encode(E))), + test_one(Rest, 1+N). + +e2j_test_vec(utf8) -> + [ + {1, "1"}, + {3.1416, "3.14160"}, %% text representation may truncate, trail zeroes + {-1, "-1"}, + {-3.1416, "-3.14160"}, + {12.0e10, "1.20000e+11"}, + {1.234E+10, "1.23400e+10"}, + {-1.234E-10, "-1.23400e-10"}, + {10.0, "1.0e+01"}, + {123.456, "1.23456E+2"}, + {10.0, "1e1"}, + {<<"foo">>, "\"foo\""}, + {<<"foo", 5, "bar">>, "\"foo\\u0005bar\""}, + {<<"">>, "\"\""}, + {<<"\n\n\n">>, "\"\\n\\n\\n\""}, + {<<"\" \b\f\r\n\t\"">>, "\"\\\" \\b\\f\\r\\n\\t\\\"\""}, + {obj_new(), "{}"}, + {obj_from_list([{<<"foo">>, <<"bar">>}]), "{\"foo\":\"bar\"}"}, + {obj_from_list([{<<"foo">>, <<"bar">>}, {<<"baz">>, 123}]), + "{\"foo\":\"bar\",\"baz\":123}"}, + {[], "[]"}, + {[[]], "[[]]"}, + {[1, <<"foo">>], "[1,\"foo\"]"}, + + %% json array in a json object + {obj_from_list([{<<"foo">>, [123]}]), + "{\"foo\":[123]}"}, + + %% json object in a json object + {obj_from_list([{<<"foo">>, obj_from_list([{<<"bar">>, true}])}]), + "{\"foo\":{\"bar\":true}}"}, + + %% fold evaluation order + {obj_from_list([{<<"foo">>, []}, + {<<"bar">>, obj_from_list([{<<"baz">>, true}])}, + {<<"alice">>, <<"bob">>}]), + "{\"foo\":[],\"bar\":{\"baz\":true},\"alice\":\"bob\"}"}, + + %% json object in a json array + {[-123, <<"foo">>, obj_from_list([{<<"bar">>, []}]), null], + "[-123,\"foo\",{\"bar\":[]},null]"} + ]. -- cgit v1.2.3