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/cvs/JSON-XS/XS.xs
Revision: 1.52
Committed: Mon Jul 2 02:57:11 2007 UTC (16 years, 10 months ago) by root
Branch: MAIN
CVS Tags: rel-1_4
Changes since 1.51: +55 -31 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 #include "EXTERN.h"
2 #include "perl.h"
3 #include "XSUB.h"
4
5 #include "assert.h"
6 #include "string.h"
7 #include "stdlib.h"
8 #include "stdio.h"
9
10 #if defined(__BORLANDC__) || defined(_MSC_VER)
11 # define snprintf _snprintf // C compilers have this in stdio.h
12 #endif
13
14 // some old perls do not have this, try to make it work, no
15 // guarentees, though. if it breaks, you get to keep the pieces.
16 #ifndef UTF8_MAXBYTES
17 # define UTF8_MAXBYTES 13
18 #endif
19
20 #define F_ASCII 0x00000001UL
21 #define F_LATIN1 0x00000002UL
22 #define F_UTF8 0x00000004UL
23 #define F_INDENT 0x00000008UL
24 #define F_CANONICAL 0x00000010UL
25 #define F_SPACE_BEFORE 0x00000020UL
26 #define F_SPACE_AFTER 0x00000040UL
27 #define F_ALLOW_NONREF 0x00000100UL
28 #define F_SHRINK 0x00000200UL
29 #define F_ALLOW_BLESSED 0x00000400UL
30 #define F_CONV_BLESSED 0x00000800UL
31 #define F_MAXDEPTH 0xf8000000UL
32 #define S_MAXDEPTH 27
33 #define F_MAXSIZE 0x01f00000UL
34 #define S_MAXSIZE 20
35 #define F_HOOK 0x00080000UL // some hooks exist, so slow-path processing
36
37 #define DEC_DEPTH(flags) (1UL << ((flags & F_MAXDEPTH) >> S_MAXDEPTH))
38 #define DEC_SIZE(flags) (1UL << ((flags & F_MAXSIZE ) >> S_MAXSIZE ))
39
40 #define F_PRETTY F_INDENT | F_SPACE_BEFORE | F_SPACE_AFTER
41 #define F_DEFAULT (9UL << S_MAXDEPTH)
42
43 #define INIT_SIZE 32 // initial scalar size to be allocated
44 #define INDENT_STEP 3 // spaces per indentation level
45
46 #define SHORT_STRING_LEN 16384 // special-case strings of up to this size
47
48 #define SB do {
49 #define SE } while (0)
50
51 #if __GNUC__ >= 3
52 # define expect(expr,value) __builtin_expect ((expr),(value))
53 # define inline inline
54 #else
55 # define expect(expr,value) (expr)
56 # define inline static
57 #endif
58
59 #define expect_false(expr) expect ((expr) != 0, 0)
60 #define expect_true(expr) expect ((expr) != 0, 1)
61
62 static HV *json_stash, *json_boolean_stash; // JSON::XS::
63 static SV *json_true, *json_false;
64
65 typedef struct {
66 U32 flags;
67 SV *cb_object;
68 HV *cb_sk_object;
69 } JSON;
70
71 /////////////////////////////////////////////////////////////////////////////
72 // utility functions
73
74 inline void
75 shrink (SV *sv)
76 {
77 sv_utf8_downgrade (sv, 1);
78 if (SvLEN (sv) > SvCUR (sv) + 1)
79 {
80 #ifdef SvPV_shrink_to_cur
81 SvPV_shrink_to_cur (sv);
82 #elif defined (SvPV_renew)
83 SvPV_renew (sv, SvCUR (sv) + 1);
84 #endif
85 }
86 }
87
88 // decode an utf-8 character and return it, or (UV)-1 in
89 // case of an error.
90 // we special-case "safe" characters from U+80 .. U+7FF,
91 // but use the very good perl function to parse anything else.
92 // note that we never call this function for a ascii codepoints
93 inline UV
94 decode_utf8 (unsigned char *s, STRLEN len, STRLEN *clen)
95 {
96 if (expect_false (s[0] > 0xdf || s[0] < 0xc2))
97 return utf8n_to_uvuni (s, len, clen, UTF8_CHECK_ONLY);
98 else if (len > 1 && s[1] >= 0x80 && s[1] <= 0xbf)
99 {
100 *clen = 2;
101 return ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
102 }
103 else
104 {
105 *clen = (STRLEN)-1;
106 return (UV)-1;
107 }
108 }
109
110 /////////////////////////////////////////////////////////////////////////////
111 // encoder
112
113 // structure used for encoding JSON
114 typedef struct
115 {
116 char *cur; // SvPVX (sv) + current output position
117 char *end; // SvEND (sv)
118 SV *sv; // result scalar
119 JSON json;
120 U32 indent; // indentation level
121 U32 maxdepth; // max. indentation/recursion level
122 } enc_t;
123
124 inline void
125 need (enc_t *enc, STRLEN len)
126 {
127 if (expect_false (enc->cur + len >= enc->end))
128 {
129 STRLEN cur = enc->cur - SvPVX (enc->sv);
130 SvGROW (enc->sv, cur + len + 1);
131 enc->cur = SvPVX (enc->sv) + cur;
132 enc->end = SvPVX (enc->sv) + SvLEN (enc->sv) - 1;
133 }
134 }
135
136 inline void
137 encode_ch (enc_t *enc, char ch)
138 {
139 need (enc, 1);
140 *enc->cur++ = ch;
141 }
142
143 static void
144 encode_str (enc_t *enc, char *str, STRLEN len, int is_utf8)
145 {
146 char *end = str + len;
147
148 need (enc, len);
149
150 while (str < end)
151 {
152 unsigned char ch = *(unsigned char *)str;
153
154 if (expect_true (ch >= 0x20 && ch < 0x80)) // most common case
155 {
156 if (expect_false (ch == '"')) // but with slow exceptions
157 {
158 need (enc, len += 1);
159 *enc->cur++ = '\\';
160 *enc->cur++ = '"';
161 }
162 else if (expect_false (ch == '\\'))
163 {
164 need (enc, len += 1);
165 *enc->cur++ = '\\';
166 *enc->cur++ = '\\';
167 }
168 else
169 *enc->cur++ = ch;
170
171 ++str;
172 }
173 else
174 {
175 switch (ch)
176 {
177 case '\010': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'b'; ++str; break;
178 case '\011': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 't'; ++str; break;
179 case '\012': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'n'; ++str; break;
180 case '\014': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'f'; ++str; break;
181 case '\015': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'r'; ++str; break;
182
183 default:
184 {
185 STRLEN clen;
186 UV uch;
187
188 if (is_utf8)
189 {
190 uch = decode_utf8 (str, end - str, &clen);
191 if (clen == (STRLEN)-1)
192 croak ("malformed or illegal unicode character in string [%.11s], cannot convert to JSON", str);
193 }
194 else
195 {
196 uch = ch;
197 clen = 1;
198 }
199
200 if (uch > 0x10FFFFUL)
201 croak ("out of range codepoint (0x%lx) encountered, unrepresentable in JSON", (unsigned long)uch);
202
203 if (uch < 0x80 || enc->json.flags & F_ASCII || (enc->json.flags & F_LATIN1 && uch > 0xFF))
204 {
205 if (uch > 0xFFFFUL)
206 {
207 need (enc, len += 11);
208 sprintf (enc->cur, "\\u%04x\\u%04x",
209 (int)((uch - 0x10000) / 0x400 + 0xD800),
210 (int)((uch - 0x10000) % 0x400 + 0xDC00));
211 enc->cur += 12;
212 }
213 else
214 {
215 static char hexdigit [16] = "0123456789abcdef";
216 need (enc, len += 5);
217 *enc->cur++ = '\\';
218 *enc->cur++ = 'u';
219 *enc->cur++ = hexdigit [ uch >> 12 ];
220 *enc->cur++ = hexdigit [(uch >> 8) & 15];
221 *enc->cur++ = hexdigit [(uch >> 4) & 15];
222 *enc->cur++ = hexdigit [(uch >> 0) & 15];
223 }
224
225 str += clen;
226 }
227 else if (enc->json.flags & F_LATIN1)
228 {
229 *enc->cur++ = uch;
230 str += clen;
231 }
232 else if (is_utf8)
233 {
234 need (enc, len += clen);
235 do
236 {
237 *enc->cur++ = *str++;
238 }
239 while (--clen);
240 }
241 else
242 {
243 need (enc, len += UTF8_MAXBYTES - 1); // never more than 11 bytes needed
244 enc->cur = uvuni_to_utf8_flags (enc->cur, uch, 0);
245 ++str;
246 }
247 }
248 }
249 }
250
251 --len;
252 }
253 }
254
255 inline void
256 encode_indent (enc_t *enc)
257 {
258 if (enc->json.flags & F_INDENT)
259 {
260 int spaces = enc->indent * INDENT_STEP;
261
262 need (enc, spaces);
263 memset (enc->cur, ' ', spaces);
264 enc->cur += spaces;
265 }
266 }
267
268 inline void
269 encode_space (enc_t *enc)
270 {
271 need (enc, 1);
272 encode_ch (enc, ' ');
273 }
274
275 inline void
276 encode_nl (enc_t *enc)
277 {
278 if (enc->json.flags & F_INDENT)
279 {
280 need (enc, 1);
281 encode_ch (enc, '\n');
282 }
283 }
284
285 inline void
286 encode_comma (enc_t *enc)
287 {
288 encode_ch (enc, ',');
289
290 if (enc->json.flags & F_INDENT)
291 encode_nl (enc);
292 else if (enc->json.flags & F_SPACE_AFTER)
293 encode_space (enc);
294 }
295
296 static void encode_sv (enc_t *enc, SV *sv);
297
298 static void
299 encode_av (enc_t *enc, AV *av)
300 {
301 int i, len = av_len (av);
302
303 if (enc->indent >= enc->maxdepth)
304 croak ("data structure too deep (hit recursion limit)");
305
306 encode_ch (enc, '['); encode_nl (enc);
307 ++enc->indent;
308
309 for (i = 0; i <= len; ++i)
310 {
311 encode_indent (enc);
312 encode_sv (enc, *av_fetch (av, i, 0));
313
314 if (i < len)
315 encode_comma (enc);
316 }
317
318 encode_nl (enc);
319
320 --enc->indent;
321 encode_indent (enc); encode_ch (enc, ']');
322 }
323
324 static void
325 encode_he (enc_t *enc, HE *he)
326 {
327 encode_ch (enc, '"');
328
329 if (HeKLEN (he) == HEf_SVKEY)
330 {
331 SV *sv = HeSVKEY (he);
332 STRLEN len;
333 char *str;
334
335 SvGETMAGIC (sv);
336 str = SvPV (sv, len);
337
338 encode_str (enc, str, len, SvUTF8 (sv));
339 }
340 else
341 encode_str (enc, HeKEY (he), HeKLEN (he), HeKUTF8 (he));
342
343 encode_ch (enc, '"');
344
345 if (enc->json.flags & F_SPACE_BEFORE) encode_space (enc);
346 encode_ch (enc, ':');
347 if (enc->json.flags & F_SPACE_AFTER ) encode_space (enc);
348 encode_sv (enc, HeVAL (he));
349 }
350
351 // compare hash entries, used when all keys are bytestrings
352 static int
353 he_cmp_fast (const void *a_, const void *b_)
354 {
355 int cmp;
356
357 HE *a = *(HE **)a_;
358 HE *b = *(HE **)b_;
359
360 STRLEN la = HeKLEN (a);
361 STRLEN lb = HeKLEN (b);
362
363 if (!(cmp = memcmp (HeKEY (a), HeKEY (b), la < lb ? la : lb)))
364 cmp = la - lb;
365
366 return cmp;
367 }
368
369 // compare hash entries, used when some keys are sv's or utf-x
370 static int
371 he_cmp_slow (const void *a, const void *b)
372 {
373 return sv_cmp (HeSVKEY_force (*(HE **)a), HeSVKEY_force (*(HE **)b));
374 }
375
376 static void
377 encode_hv (enc_t *enc, HV *hv)
378 {
379 int count, i;
380
381 if (enc->indent >= enc->maxdepth)
382 croak ("data structure too deep (hit recursion limit)");
383
384 encode_ch (enc, '{'); encode_nl (enc); ++enc->indent;
385
386 if ((count = hv_iterinit (hv)))
387 {
388 // for canonical output we have to sort by keys first
389 // actually, this is mostly due to the stupid so-called
390 // security workaround added somewhere in 5.8.x.
391 // that randomises hash orderings
392 if (enc->json.flags & F_CANONICAL)
393 {
394 int fast = 1;
395 HE *he;
396 #if defined(__BORLANDC__) || defined(_MSC_VER)
397 HE **hes = _alloca (count * sizeof (HE));
398 #else
399 HE *hes [count]; // if your compiler dies here, you need to enable C99 mode
400 #endif
401
402 i = 0;
403 while ((he = hv_iternext (hv)))
404 {
405 hes [i++] = he;
406 if (HeKLEN (he) < 0 || HeKUTF8 (he))
407 fast = 0;
408 }
409
410 assert (i == count);
411
412 if (fast)
413 qsort (hes, count, sizeof (HE *), he_cmp_fast);
414 else
415 {
416 // hack to forcefully disable "use bytes"
417 COP cop = *PL_curcop;
418 cop.op_private = 0;
419
420 ENTER;
421 SAVETMPS;
422
423 SAVEVPTR (PL_curcop);
424 PL_curcop = &cop;
425
426 qsort (hes, count, sizeof (HE *), he_cmp_slow);
427
428 FREETMPS;
429 LEAVE;
430 }
431
432 for (i = 0; i < count; ++i)
433 {
434 encode_indent (enc);
435 encode_he (enc, hes [i]);
436
437 if (i < count - 1)
438 encode_comma (enc);
439 }
440
441 encode_nl (enc);
442 }
443 else
444 {
445 HE *he = hv_iternext (hv);
446
447 for (;;)
448 {
449 encode_indent (enc);
450 encode_he (enc, he);
451
452 if (!(he = hv_iternext (hv)))
453 break;
454
455 encode_comma (enc);
456 }
457
458 encode_nl (enc);
459 }
460 }
461
462 --enc->indent; encode_indent (enc); encode_ch (enc, '}');
463 }
464
465 // encode objects, arrays and special \0=false and \1=true values.
466 static void
467 encode_rv (enc_t *enc, SV *sv)
468 {
469 svtype svt;
470
471 SvGETMAGIC (sv);
472 svt = SvTYPE (sv);
473
474 if (expect_false (SvOBJECT (sv)))
475 {
476 if (SvSTASH (sv) == json_boolean_stash)
477 {
478 if (SvIV (sv))
479 encode_str (enc, "true", 4, 0);
480 else
481 encode_str (enc, "false", 5, 0);
482 }
483 else
484 {
485 #if 0
486 if (0 && sv_derived_from (rv, "JSON::Literal"))
487 {
488 // not yet
489 }
490 #endif
491 if (enc->json.flags & F_CONV_BLESSED)
492 {
493 // we re-bless the reference to get overload and other niceties right
494 GV *to_json = gv_fetchmethod_autoload (SvSTASH (sv), "TO_JSON", 1);
495
496 if (to_json)
497 {
498 dSP; ENTER; SAVETMPS; PUSHMARK (SP);
499 XPUSHs (sv_bless (sv_2mortal (newRV_inc (sv)), SvSTASH (sv)));
500
501 // calling with G_SCALAR ensures that we always get a 1 reutrn value
502 // check anyways.
503 PUTBACK;
504 assert (1 == call_sv ((SV *)GvCV (to_json), G_SCALAR));
505 SPAGAIN;
506
507 encode_sv (enc, POPs);
508
509 FREETMPS; LEAVE;
510 }
511 else if (enc->json.flags & F_ALLOW_BLESSED)
512 encode_str (enc, "null", 4, 0);
513 else
514 croak ("encountered object '%s', but neither allow_blessed enabled nor TO_JSON method available on it",
515 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
516 }
517 else if (enc->json.flags & F_ALLOW_BLESSED)
518 encode_str (enc, "null", 4, 0);
519 else
520 croak ("encountered object '%s', but neither allow_blessed nor convert_blessed settings are enabled",
521 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
522 }
523 }
524 else if (svt == SVt_PVHV)
525 encode_hv (enc, (HV *)sv);
526 else if (svt == SVt_PVAV)
527 encode_av (enc, (AV *)sv);
528 else if (svt < SVt_PVAV)
529 {
530 STRLEN len = 0;
531 char *pv = svt ? SvPV (sv, len) : 0;
532
533 if (len == 1 && *pv == '1')
534 encode_str (enc, "true", 4, 0);
535 else if (len == 1 && *pv == '0')
536 encode_str (enc, "false", 5, 0);
537 else
538 croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
539 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
540 }
541 else
542 croak ("encountered %s, but JSON can only represent references to arrays or hashes",
543 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
544 }
545
546 static void
547 encode_sv (enc_t *enc, SV *sv)
548 {
549 SvGETMAGIC (sv);
550
551 if (SvPOKp (sv))
552 {
553 STRLEN len;
554 char *str = SvPV (sv, len);
555 encode_ch (enc, '"');
556 encode_str (enc, str, len, SvUTF8 (sv));
557 encode_ch (enc, '"');
558 }
559 else if (SvNOKp (sv))
560 {
561 // trust that perl will do the right thing w.r.t. JSON syntax.
562 need (enc, NV_DIG + 32);
563 Gconvert (SvNVX (sv), NV_DIG, 0, enc->cur);
564 enc->cur += strlen (enc->cur);
565 }
566 else if (SvIOKp (sv))
567 {
568 // we assume we can always read an IV as a UV
569 if (SvUV (sv) & ~(UV)0x7fff)
570 {
571 // large integer, use the (rather slow) snprintf way.
572 need (enc, sizeof (UV) * 3);
573 enc->cur +=
574 SvIsUV(sv)
575 ? snprintf (enc->cur, sizeof (UV) * 3, "%"UVuf, (UV)SvUVX (sv))
576 : snprintf (enc->cur, sizeof (UV) * 3, "%"IVdf, (IV)SvIVX (sv));
577 }
578 else
579 {
580 // optimise the "small number case"
581 // code will likely be branchless and use only a single multiplication
582 I32 i = SvIV (sv);
583 U32 u;
584 char digit, nz = 0;
585
586 need (enc, 6);
587
588 *enc->cur = '-'; enc->cur += i < 0 ? 1 : 0;
589 u = i < 0 ? -i : i;
590
591 // convert to 4.28 fixed-point representation
592 u = u * ((0xfffffff + 10000) / 10000); // 10**5, 5 fractional digits
593
594 // now output digit by digit, each time masking out the integer part
595 // and multiplying by 5 while moving the decimal point one to the right,
596 // resulting in a net multiplication by 10.
597 // we always write the digit to memory but conditionally increment
598 // the pointer, to ease the usage of conditional move instructions.
599 digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffff) * 5;
600 digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffff) * 5;
601 digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffff) * 5;
602 digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffff) * 5;
603 digit = u >> 24; *enc->cur = digit + '0'; enc->cur += 1; // correctly generate '0'
604 }
605 }
606 else if (SvROK (sv))
607 encode_rv (enc, SvRV (sv));
608 else if (!SvOK (sv))
609 encode_str (enc, "null", 4, 0);
610 else
611 croak ("encountered perl type (%s,0x%x) that JSON cannot handle, you might want to report this",
612 SvPV_nolen (sv), SvFLAGS (sv));
613 }
614
615 static SV *
616 encode_json (SV *scalar, JSON *json)
617 {
618 enc_t enc;
619
620 if (!(json->flags & F_ALLOW_NONREF) && !SvROK (scalar))
621 croak ("hash- or arrayref expected (not a simple scalar, use allow_nonref to allow this)");
622
623 enc.json = *json;
624 enc.sv = sv_2mortal (NEWSV (0, INIT_SIZE));
625 enc.cur = SvPVX (enc.sv);
626 enc.end = SvEND (enc.sv);
627 enc.indent = 0;
628 enc.maxdepth = DEC_DEPTH (enc.json.flags);
629
630 SvPOK_only (enc.sv);
631 encode_sv (&enc, scalar);
632
633 SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
634 *SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings
635
636 if (!(enc.json.flags & (F_ASCII | F_LATIN1 | F_UTF8)))
637 SvUTF8_on (enc.sv);
638
639 if (enc.json.flags & F_SHRINK)
640 shrink (enc.sv);
641
642 return enc.sv;
643 }
644
645 /////////////////////////////////////////////////////////////////////////////
646 // decoder
647
648 // structure used for decoding JSON
649 typedef struct
650 {
651 char *cur; // current parser pointer
652 char *end; // end of input string
653 const char *err; // parse error, if != 0
654 JSON json;
655 U32 depth; // recursion depth
656 U32 maxdepth; // recursion depth limit
657 } dec_t;
658
659 inline void
660 decode_ws (dec_t *dec)
661 {
662 for (;;)
663 {
664 char ch = *dec->cur;
665
666 if (ch > 0x20
667 || (ch != 0x20 && ch != 0x0a && ch != 0x0d && ch != 0x09))
668 break;
669
670 ++dec->cur;
671 }
672 }
673
674 #define ERR(reason) SB dec->err = reason; goto fail; SE
675
676 #define EXPECT_CH(ch) SB \
677 if (*dec->cur != ch) \
678 ERR (# ch " expected"); \
679 ++dec->cur; \
680 SE
681
682 #define DEC_INC_DEPTH if (++dec->depth > dec->maxdepth) ERR ("json datastructure exceeds maximum nesting level (set a higher max_depth)")
683 #define DEC_DEC_DEPTH --dec->depth
684
685 static SV *decode_sv (dec_t *dec);
686
687 static signed char decode_hexdigit[256];
688
689 static UV
690 decode_4hex (dec_t *dec)
691 {
692 signed char d1, d2, d3, d4;
693 unsigned char *cur = (unsigned char *)dec->cur;
694
695 d1 = decode_hexdigit [cur [0]]; if (expect_false (d1 < 0)) ERR ("exactly four hexadecimal digits expected");
696 d2 = decode_hexdigit [cur [1]]; if (expect_false (d2 < 0)) ERR ("exactly four hexadecimal digits expected");
697 d3 = decode_hexdigit [cur [2]]; if (expect_false (d3 < 0)) ERR ("exactly four hexadecimal digits expected");
698 d4 = decode_hexdigit [cur [3]]; if (expect_false (d4 < 0)) ERR ("exactly four hexadecimal digits expected");
699
700 dec->cur += 4;
701
702 return ((UV)d1) << 12
703 | ((UV)d2) << 8
704 | ((UV)d3) << 4
705 | ((UV)d4);
706
707 fail:
708 return (UV)-1;
709 }
710
711 static SV *
712 decode_str (dec_t *dec)
713 {
714 SV *sv = 0;
715 int utf8 = 0;
716 char *dec_cur = dec->cur;
717
718 do
719 {
720 char buf [SHORT_STRING_LEN + UTF8_MAXBYTES];
721 char *cur = buf;
722
723 do
724 {
725 unsigned char ch = *(unsigned char *)dec_cur++;
726
727 if (expect_false (ch == '"'))
728 {
729 --dec_cur;
730 break;
731 }
732 else if (expect_false (ch == '\\'))
733 {
734 switch (*dec_cur)
735 {
736 case '\\':
737 case '/':
738 case '"': *cur++ = *dec_cur++; break;
739
740 case 'b': ++dec_cur; *cur++ = '\010'; break;
741 case 't': ++dec_cur; *cur++ = '\011'; break;
742 case 'n': ++dec_cur; *cur++ = '\012'; break;
743 case 'f': ++dec_cur; *cur++ = '\014'; break;
744 case 'r': ++dec_cur; *cur++ = '\015'; break;
745
746 case 'u':
747 {
748 UV lo, hi;
749 ++dec_cur;
750
751 dec->cur = dec_cur;
752 hi = decode_4hex (dec);
753 dec_cur = dec->cur;
754 if (hi == (UV)-1)
755 goto fail;
756
757 // possibly a surrogate pair
758 if (hi >= 0xd800)
759 if (hi < 0xdc00)
760 {
761 if (dec_cur [0] != '\\' || dec_cur [1] != 'u')
762 ERR ("missing low surrogate character in surrogate pair");
763
764 dec_cur += 2;
765
766 dec->cur = dec_cur;
767 lo = decode_4hex (dec);
768 dec_cur = dec->cur;
769 if (lo == (UV)-1)
770 goto fail;
771
772 if (lo < 0xdc00 || lo >= 0xe000)
773 ERR ("surrogate pair expected");
774
775 hi = (hi - 0xD800) * 0x400 + (lo - 0xDC00) + 0x10000;
776 }
777 else if (hi < 0xe000)
778 ERR ("missing high surrogate character in surrogate pair");
779
780 if (hi >= 0x80)
781 {
782 utf8 = 1;
783
784 cur = (char *)uvuni_to_utf8_flags (cur, hi, 0);
785 }
786 else
787 *cur++ = hi;
788 }
789 break;
790
791 default:
792 --dec_cur;
793 ERR ("illegal backslash escape sequence in string");
794 }
795 }
796 else if (expect_true (ch >= 0x20 && ch <= 0x7f))
797 *cur++ = ch;
798 else if (ch >= 0x80)
799 {
800 STRLEN clen;
801 UV uch;
802
803 --dec_cur;
804
805 uch = decode_utf8 (dec_cur, dec->end - dec_cur, &clen);
806 if (clen == (STRLEN)-1)
807 ERR ("malformed UTF-8 character in JSON string");
808
809 do
810 *cur++ = *dec_cur++;
811 while (--clen);
812
813 utf8 = 1;
814 }
815 else
816 {
817 --dec_cur;
818
819 if (!ch)
820 ERR ("unexpected end of string while parsing JSON string");
821 else
822 ERR ("invalid character encountered while parsing JSON string");
823 }
824 }
825 while (cur < buf + SHORT_STRING_LEN);
826
827 {
828 STRLEN len = cur - buf;
829
830 if (sv)
831 {
832 SvGROW (sv, SvCUR (sv) + len + 1);
833 memcpy (SvPVX (sv) + SvCUR (sv), buf, len);
834 SvCUR_set (sv, SvCUR (sv) + len);
835 }
836 else
837 sv = newSVpvn (buf, len);
838 }
839 }
840 while (*dec_cur != '"');
841
842 ++dec_cur;
843
844 if (sv)
845 {
846 SvPOK_only (sv);
847 *SvEND (sv) = 0;
848
849 if (utf8)
850 SvUTF8_on (sv);
851 }
852 else
853 sv = newSVpvn ("", 0);
854
855 dec->cur = dec_cur;
856 return sv;
857
858 fail:
859 dec->cur = dec_cur;
860 return 0;
861 }
862
863 static SV *
864 decode_num (dec_t *dec)
865 {
866 int is_nv = 0;
867 char *start = dec->cur;
868
869 // [minus]
870 if (*dec->cur == '-')
871 ++dec->cur;
872
873 if (*dec->cur == '0')
874 {
875 ++dec->cur;
876 if (*dec->cur >= '0' && *dec->cur <= '9')
877 ERR ("malformed number (leading zero must not be followed by another digit)");
878 }
879 else if (*dec->cur < '0' || *dec->cur > '9')
880 ERR ("malformed number (no digits after initial minus)");
881 else
882 do
883 {
884 ++dec->cur;
885 }
886 while (*dec->cur >= '0' && *dec->cur <= '9');
887
888 // [frac]
889 if (*dec->cur == '.')
890 {
891 ++dec->cur;
892
893 if (*dec->cur < '0' || *dec->cur > '9')
894 ERR ("malformed number (no digits after decimal point)");
895
896 do
897 {
898 ++dec->cur;
899 }
900 while (*dec->cur >= '0' && *dec->cur <= '9');
901
902 is_nv = 1;
903 }
904
905 // [exp]
906 if (*dec->cur == 'e' || *dec->cur == 'E')
907 {
908 ++dec->cur;
909
910 if (*dec->cur == '-' || *dec->cur == '+')
911 ++dec->cur;
912
913 if (*dec->cur < '0' || *dec->cur > '9')
914 ERR ("malformed number (no digits after exp sign)");
915
916 do
917 {
918 ++dec->cur;
919 }
920 while (*dec->cur >= '0' && *dec->cur <= '9');
921
922 is_nv = 1;
923 }
924
925 if (!is_nv)
926 {
927 // special case the rather common 1..4-digit-int case, assumes 32 bit ints or so
928 if (*start == '-')
929 switch (dec->cur - start)
930 {
931 case 2: return newSViv (-( start [1] - '0' * 1));
932 case 3: return newSViv (-( start [1] * 10 + start [2] - '0' * 11));
933 case 4: return newSViv (-( start [1] * 100 + start [2] * 10 + start [3] - '0' * 111));
934 case 5: return newSViv (-(start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 1111));
935 }
936 else
937 switch (dec->cur - start)
938 {
939 case 1: return newSViv ( start [0] - '0' * 1);
940 case 2: return newSViv ( start [0] * 10 + start [1] - '0' * 11);
941 case 3: return newSViv ( start [0] * 100 + start [1] * 10 + start [2] - '0' * 111);
942 case 4: return newSViv ( start [0] * 1000 + start [1] * 100 + start [2] * 10 + start [3] - '0' * 1111);
943 }
944
945 {
946 UV uv;
947 int numtype = grok_number (start, dec->cur - start, &uv);
948 if (numtype & IS_NUMBER_IN_UV)
949 if (numtype & IS_NUMBER_NEG)
950 {
951 if (uv < (UV)IV_MIN)
952 return newSViv (-(IV)uv);
953 }
954 else
955 return newSVuv (uv);
956
957 // here would likely be the place for bigint support
958 }
959 }
960
961 // if we ever support bigint or bigfloat, this is the place for bigfloat
962 return newSVnv (Atof (start));
963
964 fail:
965 return 0;
966 }
967
968 static SV *
969 decode_av (dec_t *dec)
970 {
971 AV *av = newAV ();
972
973 DEC_INC_DEPTH;
974 decode_ws (dec);
975
976 if (*dec->cur == ']')
977 ++dec->cur;
978 else
979 for (;;)
980 {
981 SV *value;
982
983 value = decode_sv (dec);
984 if (!value)
985 goto fail;
986
987 av_push (av, value);
988
989 decode_ws (dec);
990
991 if (*dec->cur == ']')
992 {
993 ++dec->cur;
994 break;
995 }
996
997 if (*dec->cur != ',')
998 ERR (", or ] expected while parsing array");
999
1000 ++dec->cur;
1001 }
1002
1003 DEC_DEC_DEPTH;
1004 return newRV_noinc ((SV *)av);
1005
1006 fail:
1007 SvREFCNT_dec (av);
1008 DEC_DEC_DEPTH;
1009 return 0;
1010 }
1011
1012 static SV *
1013 decode_hv (dec_t *dec)
1014 {
1015 SV *sv;
1016 HV *hv = newHV ();
1017
1018 DEC_INC_DEPTH;
1019 decode_ws (dec);
1020
1021 if (*dec->cur == '}')
1022 ++dec->cur;
1023 else
1024 for (;;)
1025 {
1026 decode_ws (dec); EXPECT_CH ('"');
1027
1028 // heuristic: assume that
1029 // a) decode_str + hv_store_ent are abysmally slow.
1030 // b) most hash keys are short, simple ascii text.
1031 // => try to "fast-match" such strings to avoid
1032 // the overhead of decode_str + hv_store_ent.
1033 {
1034 SV *value;
1035 char *p = dec->cur;
1036 char *e = p + 24; // only try up to 24 bytes
1037
1038 for (;;)
1039 {
1040 // the >= 0x80 is true on most architectures
1041 if (p == e || *p < 0x20 || *p >= 0x80 || *p == '\\')
1042 {
1043 // slow path, back up and use decode_str
1044 SV *key = decode_str (dec);
1045 if (!key)
1046 goto fail;
1047
1048 decode_ws (dec); EXPECT_CH (':');
1049
1050 value = decode_sv (dec);
1051 if (!value)
1052 {
1053 SvREFCNT_dec (key);
1054 goto fail;
1055 }
1056
1057 hv_store_ent (hv, key, value, 0);
1058 SvREFCNT_dec (key);
1059
1060 break;
1061 }
1062 else if (*p == '"')
1063 {
1064 // fast path, got a simple key
1065 char *key = dec->cur;
1066 int len = p - key;
1067 dec->cur = p + 1;
1068
1069 decode_ws (dec); EXPECT_CH (':');
1070
1071 value = decode_sv (dec);
1072 if (!value)
1073 goto fail;
1074
1075 hv_store (hv, key, len, value, 0);
1076
1077 break;
1078 }
1079
1080 ++p;
1081 }
1082 }
1083
1084 decode_ws (dec);
1085
1086 if (*dec->cur == '}')
1087 {
1088 ++dec->cur;
1089 break;
1090 }
1091
1092 if (*dec->cur != ',')
1093 ERR (", or } expected while parsing object/hash");
1094
1095 ++dec->cur;
1096 }
1097
1098 DEC_DEC_DEPTH;
1099 sv = newRV_noinc ((SV *)hv);
1100
1101 // check filter callbacks
1102 if (dec->json.flags & F_HOOK)
1103 {
1104 if (dec->json.cb_sk_object && HvKEYS (hv) == 1)
1105 {
1106 HE *cb, *he;
1107
1108 hv_iterinit (hv);
1109 he = hv_iternext (hv);
1110 hv_iterinit (hv);
1111
1112 // the next line creates a mortal sv each time its called.
1113 // might want to optimise this for common cases.
1114 cb = hv_fetch_ent (dec->json.cb_sk_object, hv_iterkeysv (he), 0, 0);
1115
1116 if (cb)
1117 {
1118 int count;
1119 ENTER; SAVETMPS;
1120
1121 dSP; PUSHMARK (SP);
1122 XPUSHs (HeVAL (he));
1123
1124 PUTBACK; count = call_sv (HeVAL (cb), G_ARRAY); SPAGAIN;
1125
1126 if (count == 1)
1127 {
1128 sv = newSVsv (POPs);
1129 FREETMPS; LEAVE;
1130 return sv;
1131 }
1132
1133 FREETMPS; LEAVE;
1134 }
1135 }
1136
1137 if (dec->json.cb_object)
1138 {
1139 int count;
1140 ENTER; SAVETMPS;
1141
1142 dSP; ENTER; SAVETMPS; PUSHMARK (SP);
1143 XPUSHs (sv_2mortal (sv));
1144
1145 PUTBACK; count = call_sv (dec->json.cb_object, G_ARRAY); SPAGAIN;
1146
1147 if (count == 1)
1148 {
1149 sv = newSVsv (POPs);
1150 FREETMPS; LEAVE;
1151 return sv;
1152 }
1153
1154 SvREFCNT_inc (sv);
1155 FREETMPS; LEAVE;
1156 }
1157 }
1158
1159 return sv;
1160
1161 fail:
1162 SvREFCNT_dec (hv);
1163 DEC_DEC_DEPTH;
1164 return 0;
1165 }
1166
1167 static SV *
1168 decode_sv (dec_t *dec)
1169 {
1170 decode_ws (dec);
1171
1172 // the beauty of JSON: you need exactly one character lookahead
1173 // to parse anything.
1174 switch (*dec->cur)
1175 {
1176 case '"': ++dec->cur; return decode_str (dec);
1177 case '[': ++dec->cur; return decode_av (dec);
1178 case '{': ++dec->cur; return decode_hv (dec);
1179
1180 case '-':
1181 case '0': case '1': case '2': case '3': case '4':
1182 case '5': case '6': case '7': case '8': case '9':
1183 return decode_num (dec);
1184
1185 case 't':
1186 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "true", 4))
1187 {
1188 dec->cur += 4;
1189 return SvREFCNT_inc (json_true);
1190 }
1191 else
1192 ERR ("'true' expected");
1193
1194 break;
1195
1196 case 'f':
1197 if (dec->end - dec->cur >= 5 && !memcmp (dec->cur, "false", 5))
1198 {
1199 dec->cur += 5;
1200 return SvREFCNT_inc (json_false);
1201 }
1202 else
1203 ERR ("'false' expected");
1204
1205 break;
1206
1207 case 'n':
1208 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "null", 4))
1209 {
1210 dec->cur += 4;
1211 return newSVsv (&PL_sv_undef);
1212 }
1213 else
1214 ERR ("'null' expected");
1215
1216 break;
1217
1218 default:
1219 ERR ("malformed JSON string, neither array, object, number, string or atom");
1220 break;
1221 }
1222
1223 fail:
1224 return 0;
1225 }
1226
1227 static SV *
1228 decode_json (SV *string, JSON *json, UV *offset_return)
1229 {
1230 dec_t dec;
1231 UV offset;
1232 SV *sv;
1233
1234 SvGETMAGIC (string);
1235 SvUPGRADE (string, SVt_PV);
1236
1237 if (json->flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (json->flags))
1238 croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu",
1239 (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (json->flags));
1240
1241 if (json->flags & F_UTF8)
1242 sv_utf8_downgrade (string, 0);
1243 else
1244 sv_utf8_upgrade (string);
1245
1246 SvGROW (string, SvCUR (string) + 1); // should basically be a NOP
1247
1248 dec.json = *json;
1249 dec.cur = SvPVX (string);
1250 dec.end = SvEND (string);
1251 dec.err = 0;
1252 dec.depth = 0;
1253 dec.maxdepth = DEC_DEPTH (dec.json.flags);
1254
1255 if (dec.json.cb_object || dec.json.cb_sk_object)
1256 dec.json.flags |= F_HOOK;
1257
1258 *dec.end = 0; // this should basically be a nop, too, but make sure it's there
1259 sv = decode_sv (&dec);
1260
1261 if (!(offset_return || !sv))
1262 {
1263 // check for trailing garbage
1264 decode_ws (&dec);
1265
1266 if (*dec.cur)
1267 {
1268 dec.err = "garbage after JSON object";
1269 SvREFCNT_dec (sv);
1270 sv = 0;
1271 }
1272 }
1273
1274 if (offset_return || !sv)
1275 {
1276 offset = dec.json.flags & F_UTF8
1277 ? dec.cur - SvPVX (string)
1278 : utf8_distance (dec.cur, SvPVX (string));
1279
1280 if (offset_return)
1281 *offset_return = offset;
1282 }
1283
1284 if (!sv)
1285 {
1286 SV *uni = sv_newmortal ();
1287
1288 // horrible hack to silence warning inside pv_uni_display
1289 COP cop = *PL_curcop;
1290 cop.cop_warnings = pWARN_NONE;
1291 ENTER;
1292 SAVEVPTR (PL_curcop);
1293 PL_curcop = &cop;
1294 pv_uni_display (uni, dec.cur, dec.end - dec.cur, 20, UNI_DISPLAY_QQ);
1295 LEAVE;
1296
1297 croak ("%s, at character offset %d [\"%s\"]",
1298 dec.err,
1299 (int)offset,
1300 dec.cur != dec.end ? SvPV_nolen (uni) : "(end of string)");
1301 }
1302
1303 sv = sv_2mortal (sv);
1304
1305 if (!(dec.json.flags & F_ALLOW_NONREF) && !SvROK (sv))
1306 croak ("JSON text must be an object or array (but found number, string, true, false or null, use allow_nonref to allow this)");
1307
1308 return sv;
1309 }
1310
1311 /////////////////////////////////////////////////////////////////////////////
1312 // XS interface functions
1313
1314 MODULE = JSON::XS PACKAGE = JSON::XS
1315
1316 BOOT:
1317 {
1318 int i;
1319
1320 for (i = 0; i < 256; ++i)
1321 decode_hexdigit [i] =
1322 i >= '0' && i <= '9' ? i - '0'
1323 : i >= 'a' && i <= 'f' ? i - 'a' + 10
1324 : i >= 'A' && i <= 'F' ? i - 'A' + 10
1325 : -1;
1326
1327 json_stash = gv_stashpv ("JSON::XS" , 1);
1328 json_boolean_stash = gv_stashpv ("JSON::XS::Boolean", 1);
1329
1330 json_true = get_sv ("JSON::XS::true" , 1); SvREADONLY_on (json_true );
1331 json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false);
1332 }
1333
1334 PROTOTYPES: DISABLE
1335
1336 void new (char *klass)
1337 PPCODE:
1338 {
1339 SV *pv = NEWSV (0, sizeof (JSON));
1340 SvPOK_only (pv);
1341 Zero (SvPVX (pv), 1, JSON);
1342 ((JSON *)SvPVX (pv))->flags = F_DEFAULT;
1343 XPUSHs (sv_2mortal (sv_bless (newRV_noinc (pv), json_stash)));
1344 }
1345
1346 void ascii (JSON *self, int enable = 1)
1347 ALIAS:
1348 ascii = F_ASCII
1349 latin1 = F_LATIN1
1350 utf8 = F_UTF8
1351 indent = F_INDENT
1352 canonical = F_CANONICAL
1353 space_before = F_SPACE_BEFORE
1354 space_after = F_SPACE_AFTER
1355 pretty = F_PRETTY
1356 allow_nonref = F_ALLOW_NONREF
1357 shrink = F_SHRINK
1358 allow_blessed = F_ALLOW_BLESSED
1359 convert_blessed = F_CONV_BLESSED
1360 PPCODE:
1361 {
1362 if (enable)
1363 self->flags |= ix;
1364 else
1365 self->flags &= ~ix;
1366
1367 XPUSHs (ST (0));
1368 }
1369
1370 void max_depth (JSON *self, UV max_depth = 0x80000000UL)
1371 PPCODE:
1372 {
1373 UV log2 = 0;
1374
1375 if (max_depth > 0x80000000UL) max_depth = 0x80000000UL;
1376
1377 while ((1UL << log2) < max_depth)
1378 ++log2;
1379
1380 self->flags = self->flags & ~F_MAXDEPTH | (log2 << S_MAXDEPTH);
1381
1382 XPUSHs (ST (0));
1383 }
1384
1385 void max_size (JSON *self, UV max_size = 0)
1386 PPCODE:
1387 {
1388 UV log2 = 0;
1389
1390 if (max_size > 0x80000000UL) max_size = 0x80000000UL;
1391 if (max_size == 1) max_size = 2;
1392
1393 while ((1UL << log2) < max_size)
1394 ++log2;
1395
1396 self->flags = self->flags & ~F_MAXSIZE | (log2 << S_MAXSIZE);
1397
1398 XPUSHs (ST (0));
1399 }
1400
1401 void filter_json_object (JSON *self, SV *cb = &PL_sv_undef)
1402 PPCODE:
1403 {
1404 SvREFCNT_dec (self->cb_object);
1405 self->cb_object = SvOK (cb) ? newSVsv (cb) : 0;
1406
1407 XPUSHs (ST (0));
1408 }
1409
1410 void filter_json_single_key_object (JSON *self, SV *key, SV *cb = &PL_sv_undef)
1411 PPCODE:
1412 {
1413 if (!self->cb_sk_object)
1414 self->cb_sk_object = newHV ();
1415
1416 if (SvOK (cb))
1417 hv_store_ent (self->cb_sk_object, key, newSVsv (cb), 0);
1418 else
1419 {
1420 hv_delete_ent (self->cb_sk_object, key, G_DISCARD, 0);
1421
1422 if (!HvKEYS (self->cb_sk_object))
1423 {
1424 SvREFCNT_dec (self->cb_sk_object);
1425 self->cb_sk_object = 0;
1426 }
1427 }
1428
1429 XPUSHs (ST (0));
1430 }
1431
1432 void encode (JSON *self, SV *scalar)
1433 PPCODE:
1434 XPUSHs (encode_json (scalar, self));
1435
1436 void decode (JSON *self, SV *jsonstr)
1437 PPCODE:
1438 XPUSHs (decode_json (jsonstr, self, 0));
1439
1440 void decode_prefix (JSON *self, SV *jsonstr)
1441 PPCODE:
1442 {
1443 UV offset;
1444 EXTEND (SP, 2);
1445 PUSHs (decode_json (jsonstr, self, &offset));
1446 PUSHs (sv_2mortal (newSVuv (offset)));
1447 }
1448
1449 void DESTROY (JSON *self)
1450 CODE:
1451 SvREFCNT_dec (self->cb_sk_object);
1452 SvREFCNT_dec (self->cb_object);
1453
1454 PROTOTYPES: ENABLE
1455
1456 void to_json (SV *scalar)
1457 PPCODE:
1458 {
1459 JSON json = { F_DEFAULT | F_UTF8 };
1460 XPUSHs (encode_json (scalar, &json));
1461 }
1462
1463 void from_json (SV *jsonstr)
1464 PPCODE:
1465 {
1466 JSON json = { F_DEFAULT | F_UTF8 };
1467 XPUSHs (decode_json (jsonstr, &json, 0));
1468 }
1469