Add validate/1,2 call

c_src/decoder.c

@@ -65,8 +65,8 @@ typedef struct {
     int             st_size;
     int             st_top;
 
-    unsigned int    current_depth;
-    unsigned int    max_levels;
+    int             current_depth;
+    int             max_levels;
     unsigned int    level_start;
     unsigned int    empty_element;
 } Decoder;
@@ -105,7 +105,7 @@ dec_new(ErlNifEnv* env)
     }
 
     d->current_depth = 0;
-    d->max_levels = 0;
+    d->max_levels = -1;
     d->level_start = 0;
     d->empty_element = 1;
 
@@ -199,14 +199,14 @@ dec_pop_assert(Decoder* d, char val)
 
 static void inline
 level_increase(Decoder* d) {
-    if(d->max_levels && (d->max_levels == d->current_depth++)) {
+    if(d->max_levels >= 0 && (d->max_levels == d->current_depth++)) {
         d->level_start = d->i;
     }
 }
 
 static int inline
 level_decrease(Decoder* d, ERL_NIF_TERM* value) {
-    if (d->max_levels && d->max_levels == --d->current_depth) {
+    if (d->max_levels >= 0 && d->max_levels == --d->current_depth) {
         // Only builds term in threshold
         unsigned ulen = d->i - d->level_start + 1;
         if(!d->copy_strings) {
@@ -222,7 +222,7 @@ level_decrease(Decoder* d, ERL_NIF_TERM* value) {
 
 static int inline
 level_allows_terms(Decoder* d) {
-    return (!d->max_levels) || (d->max_levels >= d->current_depth);
+    return (d->max_levels < 0) || (d->max_levels >= d->current_depth);
 }
 
 int
@@ -689,12 +689,12 @@ make_array(ErlNifEnv* env, ERL_NIF_TERM list)
 }
 
 int
-get_max_levels(ErlNifEnv* env, ERL_NIF_TERM val, unsigned int* max_levels_p)
+get_max_levels(ErlNifEnv* env, ERL_NIF_TERM val, int* max_levels_p)
 {
     jiffy_st* st = (jiffy_st*) enif_priv_data(env);
     const ERL_NIF_TERM* tuple;
     int arity;
-    unsigned int max_levels;
+    int max_levels;
 
     if(!enif_get_tuple(env, val, &arity, &tuple)) {
         return 0;
@@ -708,11 +708,11 @@ get_max_levels(ErlNifEnv* env, ERL_NIF_TERM val, unsigned int* max_levels_p)
         return 0;
     }
 
-    if(!enif_get_uint(env, tuple[1], &max_levels)) {
+    if(!enif_get_int(env, tuple[1], &max_levels)) {
         return 0;
     }
 
-    if(max_levels == 0) {
+    if(max_levels < 0) {
         return 0;
     }
 
@@ -1168,6 +1168,7 @@ decode_iter(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     }
 
 decode_done:
+    level_decrease(d, &val);
 
     if(d->i < bin.size && d->return_trailer) {
         trailer = enif_make_sub_binary(env, argv[0], d->i, bin.size - d->i);

src/jiffy.erl

@@ -2,7 +2,7 @@
 % See the LICENSE file for more information.
 
 -module(jiffy).
--export([decode/1, decode/2, encode/1, encode/2]).
+-export([decode/1, decode/2, encode/1, encode/2, validate/1, validate/2]).
 -define(NOT_LOADED, not_loaded(?LINE)).
 
 -compile([no_native]).
@@ -115,6 +115,22 @@ encode(Data, Options) ->
     end.
 
 
+-spec validate(iolist() | binary()) -> boolean() | {has_trailer, true, binary()}.
+validate(Data) ->
+    validate(Data, []).
+
+
+-spec validate(iolist() | binary(), decode_options()) -> boolean() | {has_trailer, true, binary()}.
+validate(Data, Opts) when is_binary(Data), is_list(Opts) ->
+    try decode(Data, lists:keystore(max_levels, 1, Opts, {max_levels, 0})) of
+        {has_trailer, _FlatEJson, Trailer} -> {has_trailer, true, Trailer};
+        _FlatEJson -> true
+    catch _:_ -> false
+    end;
+validate(Data, Opts) when is_list(Data) ->
+    validate(iolist_to_binary(Data), Opts).
+
+
 finish_decode({bignum, Value}) ->
     list_to_integer(binary_to_list(Value));
 finish_decode({bignum_e, Value}) ->

test/jiffy_01_yajl_tests.erl

@@ -14,9 +14,9 @@ yajl_test_() ->
 
 
 gen({Name, Json, {error, Erl}}) ->
-    {Name, ?_assertError(Erl, jiffy:decode(Json))};
+    {Name, [?_assertEqual(false, jiffy:validate(Json)), ?_assertError(Erl, jiffy:decode(Json))]};
 gen({Name, Json, Erl}) ->
-    {Name, ?_assertEqual(Erl, jiffy:decode(Json))}.
+    {Name, [?_assertEqual(true, jiffy:validate(Json)), ?_assertEqual(Erl, jiffy:decode(Json))]}.
 
 
 read_cases() ->

test/jiffy_15_return_trailer_tests.erl

@@ -15,5 +15,9 @@ trailer_test_() ->
         {<<"1 2 3">>, {has_trailer, 1, <<"2 3">>}}
     ],
     {"Test return_trailer", lists:map(fun({Data, Result}) ->
-        ?_assertEqual(Result, jiffy:decode(Data, Opts))
-    end, Cases)}.
+        ValidateResult = if is_tuple(Result) -> setelement(2, Result, true);
+                            true -> Result
+                         end,
+        [?_assertEqual(ValidateResult, jiffy:validate(Data, Opts)),
+         ?_assertEqual(Result, jiffy:decode(Data, Opts))]
+    end, Cases)}.

test/jiffy_18_partials_tests.erl

@@ -12,7 +12,7 @@ decode_levels_test_() ->
             EJson = jiffy:decode(Json, [{max_levels, MaxLevels} | Opts]),
             FullEJson = to_full_json(EJson, MaxLevels, Opts),
             ?_assertEqual(jiffy:decode(Json, Opts), FullEJson)
-         end || MaxLevels <- lists:seq(1, MaxOptMaxLevels), Opts <- generate_options_groups()]
+         end || MaxLevels <- lists:seq(0, MaxOptMaxLevels), Opts <- generate_options_groups()]
     end, jsons())}.
 
 encode_resources_test_() ->