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/cvs/JSON-XS/XS.xs
Revision: 1.48
Committed: Sun Jul 1 22:20:00 2007 UTC (16 years, 10 months ago) by root
Branch: MAIN
Changes since 1.47: +37 -58 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 // NYI
31 #define F_MAXDEPTH 0xf8000000UL
32 #define S_MAXDEPTH 27
33 #define F_MAXSIZE 0x01f00000UL
34 #define S_MAXSIZE 20
35
36 #define DEC_DEPTH(flags) (1UL << ((flags & F_MAXDEPTH) >> S_MAXDEPTH))
37 #define DEC_SIZE(flags) (1UL << ((flags & F_MAXSIZE ) >> S_MAXSIZE ))
38
39 #define F_PRETTY F_INDENT | F_SPACE_BEFORE | F_SPACE_AFTER
40 #define F_DEFAULT (9UL << S_MAXDEPTH)
41
42 #define INIT_SIZE 32 // initial scalar size to be allocated
43 #define INDENT_STEP 3 // spaces per indentation level
44
45 #define SHORT_STRING_LEN 16384 // special-case strings of up to this size
46
47 #define SB do {
48 #define SE } while (0)
49
50 #if __GNUC__ >= 3
51 # define expect(expr,value) __builtin_expect ((expr),(value))
52 # define inline inline
53 #else
54 # define expect(expr,value) (expr)
55 # define inline static
56 #endif
57
58 #define expect_false(expr) expect ((expr) != 0, 0)
59 #define expect_true(expr) expect ((expr) != 0, 1)
60
61 static HV *json_stash, *json_boolean_stash; // JSON::XS::
62 static SV *json_true, *json_false;
63
64 typedef struct {
65 U32 flags;
66 } JSON;
67
68 /////////////////////////////////////////////////////////////////////////////
69 // utility functions
70
71 inline void
72 shrink (SV *sv)
73 {
74 sv_utf8_downgrade (sv, 1);
75 if (SvLEN (sv) > SvCUR (sv) + 1)
76 {
77 #ifdef SvPV_shrink_to_cur
78 SvPV_shrink_to_cur (sv);
79 #elif defined (SvPV_renew)
80 SvPV_renew (sv, SvCUR (sv) + 1);
81 #endif
82 }
83 }
84
85 // decode an utf-8 character and return it, or (UV)-1 in
86 // case of an error.
87 // we special-case "safe" characters from U+80 .. U+7FF,
88 // but use the very good perl function to parse anything else.
89 // note that we never call this function for a ascii codepoints
90 inline UV
91 decode_utf8 (unsigned char *s, STRLEN len, STRLEN *clen)
92 {
93 if (expect_false (s[0] > 0xdf || s[0] < 0xc2))
94 return utf8n_to_uvuni (s, len, clen, UTF8_CHECK_ONLY);
95 else if (len > 1 && s[1] >= 0x80 && s[1] <= 0xbf)
96 {
97 *clen = 2;
98 return ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
99 }
100 else
101 {
102 *clen = (STRLEN)-1;
103 return (UV)-1;
104 }
105 }
106
107 /////////////////////////////////////////////////////////////////////////////
108 // encoder
109
110 // structure used for encoding JSON
111 typedef struct
112 {
113 char *cur; // SvPVX (sv) + current output position
114 char *end; // SvEND (sv)
115 SV *sv; // result scalar
116 JSON json;
117 U32 indent; // indentation level
118 U32 maxdepth; // max. indentation/recursion level
119 } enc_t;
120
121 inline void
122 need (enc_t *enc, STRLEN len)
123 {
124 if (expect_false (enc->cur + len >= enc->end))
125 {
126 STRLEN cur = enc->cur - SvPVX (enc->sv);
127 SvGROW (enc->sv, cur + len + 1);
128 enc->cur = SvPVX (enc->sv) + cur;
129 enc->end = SvPVX (enc->sv) + SvLEN (enc->sv) - 1;
130 }
131 }
132
133 inline void
134 encode_ch (enc_t *enc, char ch)
135 {
136 need (enc, 1);
137 *enc->cur++ = ch;
138 }
139
140 static void
141 encode_str (enc_t *enc, char *str, STRLEN len, int is_utf8)
142 {
143 char *end = str + len;
144
145 need (enc, len);
146
147 while (str < end)
148 {
149 unsigned char ch = *(unsigned char *)str;
150
151 if (expect_true (ch >= 0x20 && ch < 0x80)) // most common case
152 {
153 if (expect_false (ch == '"')) // but with slow exceptions
154 {
155 need (enc, len += 1);
156 *enc->cur++ = '\\';
157 *enc->cur++ = '"';
158 }
159 else if (expect_false (ch == '\\'))
160 {
161 need (enc, len += 1);
162 *enc->cur++ = '\\';
163 *enc->cur++ = '\\';
164 }
165 else
166 *enc->cur++ = ch;
167
168 ++str;
169 }
170 else
171 {
172 switch (ch)
173 {
174 case '\010': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'b'; ++str; break;
175 case '\011': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 't'; ++str; break;
176 case '\012': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'n'; ++str; break;
177 case '\014': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'f'; ++str; break;
178 case '\015': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'r'; ++str; break;
179
180 default:
181 {
182 STRLEN clen;
183 UV uch;
184
185 if (is_utf8)
186 {
187 uch = decode_utf8 (str, end - str, &clen);
188 if (clen == (STRLEN)-1)
189 croak ("malformed or illegal unicode character in string [%.11s], cannot convert to JSON", str);
190 }
191 else
192 {
193 uch = ch;
194 clen = 1;
195 }
196
197 if (uch > 0x10FFFFUL)
198 croak ("out of range codepoint (0x%lx) encountered, unrepresentable in JSON", (unsigned long)uch);
199
200 if (uch < 0x80 || enc->json.flags & F_ASCII || (enc->json.flags & F_LATIN1 && uch > 0xFF))
201 {
202 if (uch > 0xFFFFUL)
203 {
204 need (enc, len += 11);
205 sprintf (enc->cur, "\\u%04x\\u%04x",
206 (int)((uch - 0x10000) / 0x400 + 0xD800),
207 (int)((uch - 0x10000) % 0x400 + 0xDC00));
208 enc->cur += 12;
209 }
210 else
211 {
212 static char hexdigit [16] = "0123456789abcdef";
213 need (enc, len += 5);
214 *enc->cur++ = '\\';
215 *enc->cur++ = 'u';
216 *enc->cur++ = hexdigit [ uch >> 12 ];
217 *enc->cur++ = hexdigit [(uch >> 8) & 15];
218 *enc->cur++ = hexdigit [(uch >> 4) & 15];
219 *enc->cur++ = hexdigit [(uch >> 0) & 15];
220 }
221
222 str += clen;
223 }
224 else if (enc->json.flags & F_LATIN1)
225 {
226 *enc->cur++ = uch;
227 str += clen;
228 }
229 else if (is_utf8)
230 {
231 need (enc, len += clen);
232 do
233 {
234 *enc->cur++ = *str++;
235 }
236 while (--clen);
237 }
238 else
239 {
240 need (enc, len += UTF8_MAXBYTES - 1); // never more than 11 bytes needed
241 enc->cur = uvuni_to_utf8_flags (enc->cur, uch, 0);
242 ++str;
243 }
244 }
245 }
246 }
247
248 --len;
249 }
250 }
251
252 inline void
253 encode_indent (enc_t *enc)
254 {
255 if (enc->json.flags & F_INDENT)
256 {
257 int spaces = enc->indent * INDENT_STEP;
258
259 need (enc, spaces);
260 memset (enc->cur, ' ', spaces);
261 enc->cur += spaces;
262 }
263 }
264
265 inline void
266 encode_space (enc_t *enc)
267 {
268 need (enc, 1);
269 encode_ch (enc, ' ');
270 }
271
272 inline void
273 encode_nl (enc_t *enc)
274 {
275 if (enc->json.flags & F_INDENT)
276 {
277 need (enc, 1);
278 encode_ch (enc, '\n');
279 }
280 }
281
282 inline void
283 encode_comma (enc_t *enc)
284 {
285 encode_ch (enc, ',');
286
287 if (enc->json.flags & F_INDENT)
288 encode_nl (enc);
289 else if (enc->json.flags & F_SPACE_AFTER)
290 encode_space (enc);
291 }
292
293 static void encode_sv (enc_t *enc, SV *sv);
294
295 static void
296 encode_av (enc_t *enc, AV *av)
297 {
298 int i, len = av_len (av);
299
300 if (enc->indent >= enc->maxdepth)
301 croak ("data structure too deep (hit recursion limit)");
302
303 encode_ch (enc, '['); encode_nl (enc);
304 ++enc->indent;
305
306 for (i = 0; i <= len; ++i)
307 {
308 encode_indent (enc);
309 encode_sv (enc, *av_fetch (av, i, 0));
310
311 if (i < len)
312 encode_comma (enc);
313 }
314
315 encode_nl (enc);
316
317 --enc->indent;
318 encode_indent (enc); encode_ch (enc, ']');
319 }
320
321 static void
322 encode_he (enc_t *enc, HE *he)
323 {
324 encode_ch (enc, '"');
325
326 if (HeKLEN (he) == HEf_SVKEY)
327 {
328 SV *sv = HeSVKEY (he);
329 STRLEN len;
330 char *str;
331
332 SvGETMAGIC (sv);
333 str = SvPV (sv, len);
334
335 encode_str (enc, str, len, SvUTF8 (sv));
336 }
337 else
338 encode_str (enc, HeKEY (he), HeKLEN (he), HeKUTF8 (he));
339
340 encode_ch (enc, '"');
341
342 if (enc->json.flags & F_SPACE_BEFORE) encode_space (enc);
343 encode_ch (enc, ':');
344 if (enc->json.flags & F_SPACE_AFTER ) encode_space (enc);
345 encode_sv (enc, HeVAL (he));
346 }
347
348 // compare hash entries, used when all keys are bytestrings
349 static int
350 he_cmp_fast (const void *a_, const void *b_)
351 {
352 int cmp;
353
354 HE *a = *(HE **)a_;
355 HE *b = *(HE **)b_;
356
357 STRLEN la = HeKLEN (a);
358 STRLEN lb = HeKLEN (b);
359
360 if (!(cmp = memcmp (HeKEY (a), HeKEY (b), la < lb ? la : lb)))
361 cmp = la - lb;
362
363 return cmp;
364 }
365
366 // compare hash entries, used when some keys are sv's or utf-x
367 static int
368 he_cmp_slow (const void *a, const void *b)
369 {
370 return sv_cmp (HeSVKEY_force (*(HE **)a), HeSVKEY_force (*(HE **)b));
371 }
372
373 static void
374 encode_hv (enc_t *enc, HV *hv)
375 {
376 int count, i;
377
378 if (enc->indent >= enc->maxdepth)
379 croak ("data structure too deep (hit recursion limit)");
380
381 encode_ch (enc, '{'); encode_nl (enc); ++enc->indent;
382
383 if ((count = hv_iterinit (hv)))
384 {
385 // for canonical output we have to sort by keys first
386 // actually, this is mostly due to the stupid so-called
387 // security workaround added somewhere in 5.8.x.
388 // that randomises hash orderings
389 if (enc->json.flags & F_CANONICAL)
390 {
391 int fast = 1;
392 HE *he;
393 #if defined(__BORLANDC__) || defined(_MSC_VER)
394 HE **hes = _alloca (count * sizeof (HE));
395 #else
396 HE *hes [count]; // if your compiler dies here, you need to enable C99 mode
397 #endif
398
399 i = 0;
400 while ((he = hv_iternext (hv)))
401 {
402 hes [i++] = he;
403 if (HeKLEN (he) < 0 || HeKUTF8 (he))
404 fast = 0;
405 }
406
407 assert (i == count);
408
409 if (fast)
410 qsort (hes, count, sizeof (HE *), he_cmp_fast);
411 else
412 {
413 // hack to forcefully disable "use bytes"
414 COP cop = *PL_curcop;
415 cop.op_private = 0;
416
417 ENTER;
418 SAVETMPS;
419
420 SAVEVPTR (PL_curcop);
421 PL_curcop = &cop;
422
423 qsort (hes, count, sizeof (HE *), he_cmp_slow);
424
425 FREETMPS;
426 LEAVE;
427 }
428
429 for (i = 0; i < count; ++i)
430 {
431 encode_indent (enc);
432 encode_he (enc, hes [i]);
433
434 if (i < count - 1)
435 encode_comma (enc);
436 }
437
438 encode_nl (enc);
439 }
440 else
441 {
442 HE *he = hv_iternext (hv);
443
444 for (;;)
445 {
446 encode_indent (enc);
447 encode_he (enc, he);
448
449 if (!(he = hv_iternext (hv)))
450 break;
451
452 encode_comma (enc);
453 }
454
455 encode_nl (enc);
456 }
457 }
458
459 --enc->indent; encode_indent (enc); encode_ch (enc, '}');
460 }
461
462 // encode objects, arrays and special \0=false and \1=true values.
463 static void
464 encode_rv (enc_t *enc, SV *sv)
465 {
466 svtype svt;
467
468 SvGETMAGIC (sv);
469 svt = SvTYPE (sv);
470
471 if (expect_false (SvOBJECT (sv)))
472 {
473 if (SvSTASH (sv) == json_boolean_stash)
474 {
475 if (SvIV (sv) == 0)
476 encode_str (enc, "false", 5, 0);
477 else
478 encode_str (enc, "true", 4, 0);
479 }
480 else
481 {
482 #if 0
483 if (0 && sv_derived_from (rv, "JSON::Literal"))
484 {
485 // not yet
486 }
487 #endif
488 if (enc->json.flags & F_CONV_BLESSED)
489 {
490 // we re-bless the reference to get overload and other niceties right
491 GV *to_json = gv_fetchmethod_autoload (SvSTASH (sv), "TO_JSON", 1);
492
493 if (to_json)
494 {
495 dSP;
496 ENTER;
497 SAVETMPS;
498 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;
510 LEAVE;
511 }
512 else if (enc->json.flags & F_ALLOW_BLESSED)
513 encode_str (enc, "null", 4, 0);
514 else
515 croak ("encountered object '%s', but neither allow_blessed enabled nor TO_JSON method available on it",
516 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
517 }
518 else if (enc->json.flags & F_ALLOW_BLESSED)
519 encode_str (enc, "null", 4, 0);
520 else
521 croak ("encountered object '%s', but neither allow_blessed nor convert_blessed settings are enabled",
522 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
523 }
524 }
525 else if (svt == SVt_PVHV)
526 encode_hv (enc, (HV *)sv);
527 else if (svt == SVt_PVAV)
528 encode_av (enc, (AV *)sv);
529 else if (svt < SVt_PVAV)
530 {
531 if (SvNIOK (sv) && SvIV (sv) == 0)
532 encode_str (enc, "false", 5, 0);
533 else if (SvNIOK (sv) && SvIV (sv) == 1)
534 encode_str (enc, "true", 4, 0);
535 else
536 croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
537 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
538 }
539 else
540 croak ("encountered %s, but JSON can only represent references to arrays or hashes",
541 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
542 }
543
544 static void
545 encode_sv (enc_t *enc, SV *sv)
546 {
547 SvGETMAGIC (sv);
548
549 if (SvPOKp (sv))
550 {
551 STRLEN len;
552 char *str = SvPV (sv, len);
553 encode_ch (enc, '"');
554 encode_str (enc, str, len, SvUTF8 (sv));
555 encode_ch (enc, '"');
556 }
557 else if (SvNOKp (sv))
558 {
559 // trust that perl will do the right thing w.r.t. JSON syntax.
560 need (enc, NV_DIG + 32);
561 Gconvert (SvNVX (sv), NV_DIG, 0, enc->cur);
562 enc->cur += strlen (enc->cur);
563 }
564 else if (SvIOKp (sv))
565 {
566 // we assume we can always read an IV as a UV
567 if (SvUV (sv) & ~(UV)0x7fff)
568 {
569 // large integer, use the (rather slow) snprintf way.
570 need (enc, sizeof (UV) * 3);
571 enc->cur +=
572 SvIsUV(sv)
573 ? snprintf (enc->cur, sizeof (UV) * 3, "%"UVuf, (UV)SvUVX (sv))
574 : snprintf (enc->cur, sizeof (UV) * 3, "%"IVdf, (IV)SvIVX (sv));
575 }
576 else
577 {
578 // optimise the "small number case"
579 // code will likely be branchless and use only a single multiplication
580 I32 i = SvIV (sv);
581 U32 u;
582 char digit, nz = 0;
583
584 need (enc, 6);
585
586 *enc->cur = '-'; enc->cur += i < 0 ? 1 : 0;
587 u = i < 0 ? -i : i;
588
589 // convert to 4.28 fixed-point representation
590 u = u * ((0xfffffff + 10000) / 10000); // 10**5, 5 fractional digits
591
592 // now output digit by digit, each time masking out the integer part
593 // and multiplying by 5 while moving the decimal point one to the right,
594 // resulting in a net multiplication by 10.
595 // we always write the digit to memory but conditionally increment
596 // the pointer, to ease the usage of conditional move instructions.
597 digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffff) * 5;
598 digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffff) * 5;
599 digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffff) * 5;
600 digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffff) * 5;
601 digit = u >> 24; *enc->cur = digit + '0'; enc->cur += 1; // correctly generate '0'
602 }
603 }
604 else if (SvROK (sv))
605 encode_rv (enc, SvRV (sv));
606 else if (!SvOK (sv))
607 encode_str (enc, "null", 4, 0);
608 else
609 croak ("encountered perl type (%s,0x%x) that JSON cannot handle, you might want to report this",
610 SvPV_nolen (sv), SvFLAGS (sv));
611 }
612
613 static SV *
614 encode_json (SV *scalar, JSON *json)
615 {
616 enc_t enc;
617
618 if (!(json->flags & F_ALLOW_NONREF) && !SvROK (scalar))
619 croak ("hash- or arrayref expected (not a simple scalar, use allow_nonref to allow this)");
620
621 enc.json = *json;
622 enc.sv = sv_2mortal (NEWSV (0, INIT_SIZE));
623 enc.cur = SvPVX (enc.sv);
624 enc.end = SvEND (enc.sv);
625 enc.indent = 0;
626 enc.maxdepth = DEC_DEPTH (enc.json.flags);
627
628 SvPOK_only (enc.sv);
629 encode_sv (&enc, scalar);
630
631 SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
632 *SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings
633
634 if (!(enc.json.flags & (F_ASCII | F_LATIN1 | F_UTF8)))
635 SvUTF8_on (enc.sv);
636
637 if (enc.json.flags & F_SHRINK)
638 shrink (enc.sv);
639
640 return enc.sv;
641 }
642
643 /////////////////////////////////////////////////////////////////////////////
644 // decoder
645
646 // structure used for decoding JSON
647 typedef struct
648 {
649 char *cur; // current parser pointer
650 char *end; // end of input string
651 const char *err; // parse error, if != 0
652 JSON json;
653 U32 depth; // recursion depth
654 U32 maxdepth; // recursion depth limit
655 } dec_t;
656
657 inline void
658 decode_ws (dec_t *dec)
659 {
660 for (;;)
661 {
662 char ch = *dec->cur;
663
664 if (ch > 0x20
665 || (ch != 0x20 && ch != 0x0a && ch != 0x0d && ch != 0x09))
666 break;
667
668 ++dec->cur;
669 }
670 }
671
672 #define ERR(reason) SB dec->err = reason; goto fail; SE
673
674 #define EXPECT_CH(ch) SB \
675 if (*dec->cur != ch) \
676 ERR (# ch " expected"); \
677 ++dec->cur; \
678 SE
679
680 #define DEC_INC_DEPTH if (++dec->depth > dec->maxdepth) ERR ("json datastructure exceeds maximum nesting level (set a higher max_depth)")
681 #define DEC_DEC_DEPTH --dec->depth
682
683 static SV *decode_sv (dec_t *dec);
684
685 static signed char decode_hexdigit[256];
686
687 static UV
688 decode_4hex (dec_t *dec)
689 {
690 signed char d1, d2, d3, d4;
691 unsigned char *cur = (unsigned char *)dec->cur;
692
693 d1 = decode_hexdigit [cur [0]]; if (expect_false (d1 < 0)) ERR ("exactly four hexadecimal digits expected");
694 d2 = decode_hexdigit [cur [1]]; if (expect_false (d2 < 0)) ERR ("exactly four hexadecimal digits expected");
695 d3 = decode_hexdigit [cur [2]]; if (expect_false (d3 < 0)) ERR ("exactly four hexadecimal digits expected");
696 d4 = decode_hexdigit [cur [3]]; if (expect_false (d4 < 0)) ERR ("exactly four hexadecimal digits expected");
697
698 dec->cur += 4;
699
700 return ((UV)d1) << 12
701 | ((UV)d2) << 8
702 | ((UV)d3) << 4
703 | ((UV)d4);
704
705 fail:
706 return (UV)-1;
707 }
708
709 static SV *
710 decode_str (dec_t *dec)
711 {
712 SV *sv = 0;
713 int utf8 = 0;
714 char *dec_cur = dec->cur;
715
716 do
717 {
718 char buf [SHORT_STRING_LEN + UTF8_MAXBYTES];
719 char *cur = buf;
720
721 do
722 {
723 unsigned char ch = *(unsigned char *)dec_cur++;
724
725 if (expect_false (ch == '"'))
726 {
727 --dec_cur;
728 break;
729 }
730 else if (expect_false (ch == '\\'))
731 {
732 switch (*dec_cur)
733 {
734 case '\\':
735 case '/':
736 case '"': *cur++ = *dec_cur++; break;
737
738 case 'b': ++dec_cur; *cur++ = '\010'; break;
739 case 't': ++dec_cur; *cur++ = '\011'; break;
740 case 'n': ++dec_cur; *cur++ = '\012'; break;
741 case 'f': ++dec_cur; *cur++ = '\014'; break;
742 case 'r': ++dec_cur; *cur++ = '\015'; break;
743
744 case 'u':
745 {
746 UV lo, hi;
747 ++dec_cur;
748
749 dec->cur = dec_cur;
750 hi = decode_4hex (dec);
751 dec_cur = dec->cur;
752 if (hi == (UV)-1)
753 goto fail;
754
755 // possibly a surrogate pair
756 if (hi >= 0xd800)
757 if (hi < 0xdc00)
758 {
759 if (dec_cur [0] != '\\' || dec_cur [1] != 'u')
760 ERR ("missing low surrogate character in surrogate pair");
761
762 dec_cur += 2;
763
764 dec->cur = dec_cur;
765 lo = decode_4hex (dec);
766 dec_cur = dec->cur;
767 if (lo == (UV)-1)
768 goto fail;
769
770 if (lo < 0xdc00 || lo >= 0xe000)
771 ERR ("surrogate pair expected");
772
773 hi = (hi - 0xD800) * 0x400 + (lo - 0xDC00) + 0x10000;
774 }
775 else if (hi < 0xe000)
776 ERR ("missing high surrogate character in surrogate pair");
777
778 if (hi >= 0x80)
779 {
780 utf8 = 1;
781
782 cur = (char *)uvuni_to_utf8_flags (cur, hi, 0);
783 }
784 else
785 *cur++ = hi;
786 }
787 break;
788
789 default:
790 --dec_cur;
791 ERR ("illegal backslash escape sequence in string");
792 }
793 }
794 else if (expect_true (ch >= 0x20 && ch <= 0x7f))
795 *cur++ = ch;
796 else if (ch >= 0x80)
797 {
798 STRLEN clen;
799 UV uch;
800
801 --dec_cur;
802
803 uch = decode_utf8 (dec_cur, dec->end - dec_cur, &clen);
804 if (clen == (STRLEN)-1)
805 ERR ("malformed UTF-8 character in JSON string");
806
807 do
808 *cur++ = *dec_cur++;
809 while (--clen);
810
811 utf8 = 1;
812 }
813 else
814 {
815 --dec_cur;
816
817 if (!ch)
818 ERR ("unexpected end of string while parsing JSON string");
819 else
820 ERR ("invalid character encountered while parsing JSON string");
821 }
822 }
823 while (cur < buf + SHORT_STRING_LEN);
824
825 {
826 STRLEN len = cur - buf;
827
828 if (sv)
829 {
830 SvGROW (sv, SvCUR (sv) + len + 1);
831 memcpy (SvPVX (sv) + SvCUR (sv), buf, len);
832 SvCUR_set (sv, SvCUR (sv) + len);
833 }
834 else
835 sv = newSVpvn (buf, len);
836 }
837 }
838 while (*dec_cur != '"');
839
840 ++dec_cur;
841
842 if (sv)
843 {
844 SvPOK_only (sv);
845 *SvEND (sv) = 0;
846
847 if (utf8)
848 SvUTF8_on (sv);
849 }
850 else
851 sv = newSVpvn ("", 0);
852
853 dec->cur = dec_cur;
854 return sv;
855
856 fail:
857 dec->cur = dec_cur;
858 return 0;
859 }
860
861 static SV *
862 decode_num (dec_t *dec)
863 {
864 int is_nv = 0;
865 char *start = dec->cur;
866
867 // [minus]
868 if (*dec->cur == '-')
869 ++dec->cur;
870
871 if (*dec->cur == '0')
872 {
873 ++dec->cur;
874 if (*dec->cur >= '0' && *dec->cur <= '9')
875 ERR ("malformed number (leading zero must not be followed by another digit)");
876 }
877 else if (*dec->cur < '0' || *dec->cur > '9')
878 ERR ("malformed number (no digits after initial minus)");
879 else
880 do
881 {
882 ++dec->cur;
883 }
884 while (*dec->cur >= '0' && *dec->cur <= '9');
885
886 // [frac]
887 if (*dec->cur == '.')
888 {
889 ++dec->cur;
890
891 if (*dec->cur < '0' || *dec->cur > '9')
892 ERR ("malformed number (no digits after decimal point)");
893
894 do
895 {
896 ++dec->cur;
897 }
898 while (*dec->cur >= '0' && *dec->cur <= '9');
899
900 is_nv = 1;
901 }
902
903 // [exp]
904 if (*dec->cur == 'e' || *dec->cur == 'E')
905 {
906 ++dec->cur;
907
908 if (*dec->cur == '-' || *dec->cur == '+')
909 ++dec->cur;
910
911 if (*dec->cur < '0' || *dec->cur > '9')
912 ERR ("malformed number (no digits after exp sign)");
913
914 do
915 {
916 ++dec->cur;
917 }
918 while (*dec->cur >= '0' && *dec->cur <= '9');
919
920 is_nv = 1;
921 }
922
923 if (!is_nv)
924 {
925 // special case the rather common 1..4-digit-int case, assumes 32 bit ints or so
926 if (*start == '-')
927 switch (dec->cur - start)
928 {
929 case 2: return newSViv (-( start [1] - '0' * 1));
930 case 3: return newSViv (-( start [1] * 10 + start [2] - '0' * 11));
931 case 4: return newSViv (-( start [1] * 100 + start [2] * 10 + start [3] - '0' * 111));
932 case 5: return newSViv (-(start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 1111));
933 }
934 else
935 switch (dec->cur - start)
936 {
937 case 1: return newSViv ( start [0] - '0' * 1);
938 case 2: return newSViv ( start [0] * 10 + start [1] - '0' * 11);
939 case 3: return newSViv ( start [0] * 100 + start [1] * 10 + start [2] - '0' * 111);
940 case 4: return newSViv ( start [0] * 1000 + start [1] * 100 + start [2] * 10 + start [3] - '0' * 1111);
941 }
942
943 {
944 UV uv;
945 int numtype = grok_number (start, dec->cur - start, &uv);
946 if (numtype & IS_NUMBER_IN_UV)
947 if (numtype & IS_NUMBER_NEG)
948 {
949 if (uv < (UV)IV_MIN)
950 return newSViv (-(IV)uv);
951 }
952 else
953 return newSVuv (uv);
954
955 // here would likely be the place for bigint support
956 }
957 }
958
959 // if we ever support bigint or bigfloat, this is the place for bigfloat
960 return newSVnv (Atof (start));
961
962 fail:
963 return 0;
964 }
965
966 static SV *
967 decode_av (dec_t *dec)
968 {
969 AV *av = newAV ();
970
971 DEC_INC_DEPTH;
972 decode_ws (dec);
973
974 if (*dec->cur == ']')
975 ++dec->cur;
976 else
977 for (;;)
978 {
979 SV *value;
980
981 value = decode_sv (dec);
982 if (!value)
983 goto fail;
984
985 av_push (av, value);
986
987 decode_ws (dec);
988
989 if (*dec->cur == ']')
990 {
991 ++dec->cur;
992 break;
993 }
994
995 if (*dec->cur != ',')
996 ERR (", or ] expected while parsing array");
997
998 ++dec->cur;
999 }
1000
1001 DEC_DEC_DEPTH;
1002 return newRV_noinc ((SV *)av);
1003
1004 fail:
1005 SvREFCNT_dec (av);
1006 DEC_DEC_DEPTH;
1007 return 0;
1008 }
1009
1010 static SV *
1011 decode_hv (dec_t *dec)
1012 {
1013 HV *hv = newHV ();
1014
1015 DEC_INC_DEPTH;
1016 decode_ws (dec);
1017
1018 if (*dec->cur == '}')
1019 ++dec->cur;
1020 else
1021 for (;;)
1022 {
1023 decode_ws (dec); EXPECT_CH ('"');
1024
1025 // heuristic: assume that
1026 // a) decode_str + hv_store_ent are abysmally slow.
1027 // b) most hash keys are short, simple ascii text.
1028 // => try to "fast-match" such strings to avoid
1029 // the overhead of decode_str + hv_store_ent.
1030 {
1031 SV *value;
1032 char *p = dec->cur;
1033 char *e = p + 24; // only try up to 24 bytes
1034
1035 for (;;)
1036 {
1037 // the >= 0x80 is true on most architectures
1038 if (p == e || *p < 0x20 || *p >= 0x80 || *p == '\\')
1039 {
1040 // slow path, back up and use decode_str
1041 SV *key = decode_str (dec);
1042 if (!key)
1043 goto fail;
1044
1045 decode_ws (dec); EXPECT_CH (':');
1046
1047 value = decode_sv (dec);
1048 if (!value)
1049 {
1050 SvREFCNT_dec (key);
1051 goto fail;
1052 }
1053
1054 hv_store_ent (hv, key, value, 0);
1055 SvREFCNT_dec (key);
1056
1057 break;
1058 }
1059 else if (*p == '"')
1060 {
1061 // fast path, got a simple key
1062 char *key = dec->cur;
1063 int len = p - key;
1064 dec->cur = p + 1;
1065
1066 decode_ws (dec); EXPECT_CH (':');
1067
1068 value = decode_sv (dec);
1069 if (!value)
1070 goto fail;
1071
1072 hv_store (hv, key, len, value, 0);
1073
1074 break;
1075 }
1076
1077 ++p;
1078 }
1079 }
1080
1081 decode_ws (dec);
1082
1083 if (*dec->cur == '}')
1084 {
1085 ++dec->cur;
1086 break;
1087 }
1088
1089 if (*dec->cur != ',')
1090 ERR (", or } expected while parsing object/hash");
1091
1092 ++dec->cur;
1093 }
1094
1095 DEC_DEC_DEPTH;
1096 return newRV_noinc ((SV *)hv);
1097
1098 fail:
1099 SvREFCNT_dec (hv);
1100 DEC_DEC_DEPTH;
1101 return 0;
1102 }
1103
1104 static SV *
1105 decode_sv (dec_t *dec)
1106 {
1107 decode_ws (dec);
1108
1109 // the beauty of JSON: you need exactly one character lookahead
1110 // to parse anything.
1111 switch (*dec->cur)
1112 {
1113 case '"': ++dec->cur; return decode_str (dec);
1114 case '[': ++dec->cur; return decode_av (dec);
1115 case '{': ++dec->cur; return decode_hv (dec);
1116
1117 case '-':
1118 case '0': case '1': case '2': case '3': case '4':
1119 case '5': case '6': case '7': case '8': case '9':
1120 return decode_num (dec);
1121
1122 case 't':
1123 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "true", 4))
1124 {
1125 dec->cur += 4;
1126 return SvREFCNT_inc (json_true);
1127 }
1128 else
1129 ERR ("'true' expected");
1130
1131 break;
1132
1133 case 'f':
1134 if (dec->end - dec->cur >= 5 && !memcmp (dec->cur, "false", 5))
1135 {
1136 dec->cur += 5;
1137 return SvREFCNT_inc (json_false);
1138 }
1139 else
1140 ERR ("'false' expected");
1141
1142 break;
1143
1144 case 'n':
1145 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "null", 4))
1146 {
1147 dec->cur += 4;
1148 return newSVsv (&PL_sv_undef);
1149 }
1150 else
1151 ERR ("'null' expected");
1152
1153 break;
1154
1155 default:
1156 ERR ("malformed JSON string, neither array, object, number, string or atom");
1157 break;
1158 }
1159
1160 fail:
1161 return 0;
1162 }
1163
1164 static SV *
1165 decode_json (SV *string, JSON *json, UV *offset_return)
1166 {
1167 dec_t dec;
1168 UV offset;
1169 SV *sv;
1170
1171 SvGETMAGIC (string);
1172 SvUPGRADE (string, SVt_PV);
1173
1174 if (json->flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (json->flags))
1175 croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu",
1176 (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (json->flags));
1177
1178 if (json->flags & F_UTF8)
1179 sv_utf8_downgrade (string, 0);
1180 else
1181 sv_utf8_upgrade (string);
1182
1183 SvGROW (string, SvCUR (string) + 1); // should basically be a NOP
1184
1185 dec.json = *json;
1186 dec.cur = SvPVX (string);
1187 dec.end = SvEND (string);
1188 dec.err = 0;
1189 dec.depth = 0;
1190 dec.maxdepth = DEC_DEPTH (dec.json.flags);
1191
1192 *dec.end = 0; // this should basically be a nop, too, but make sure it's there
1193 sv = decode_sv (&dec);
1194
1195 if (!(offset_return || !sv))
1196 {
1197 // check for trailing garbage
1198 decode_ws (&dec);
1199
1200 if (*dec.cur)
1201 {
1202 dec.err = "garbage after JSON object";
1203 SvREFCNT_dec (sv);
1204 sv = 0;
1205 }
1206 }
1207
1208 if (offset_return || !sv)
1209 {
1210 offset = dec.json.flags & F_UTF8
1211 ? dec.cur - SvPVX (string)
1212 : utf8_distance (dec.cur, SvPVX (string));
1213
1214 if (offset_return)
1215 *offset_return = offset;
1216 }
1217
1218 if (!sv)
1219 {
1220 SV *uni = sv_newmortal ();
1221
1222 // horrible hack to silence warning inside pv_uni_display
1223 COP cop = *PL_curcop;
1224 cop.cop_warnings = pWARN_NONE;
1225 ENTER;
1226 SAVEVPTR (PL_curcop);
1227 PL_curcop = &cop;
1228 pv_uni_display (uni, dec.cur, dec.end - dec.cur, 20, UNI_DISPLAY_QQ);
1229 LEAVE;
1230
1231 croak ("%s, at character offset %d [\"%s\"]",
1232 dec.err,
1233 (int)offset,
1234 dec.cur != dec.end ? SvPV_nolen (uni) : "(end of string)");
1235 }
1236
1237 sv = sv_2mortal (sv);
1238
1239 if (!(dec.json.flags & F_ALLOW_NONREF) && !SvROK (sv))
1240 croak ("JSON text must be an object or array (but found number, string, true, false or null, use allow_nonref to allow this)");
1241
1242 return sv;
1243 }
1244
1245 /////////////////////////////////////////////////////////////////////////////
1246 // XS interface functions
1247
1248 MODULE = JSON::XS PACKAGE = JSON::XS
1249
1250 BOOT:
1251 {
1252 int i;
1253
1254 for (i = 0; i < 256; ++i)
1255 decode_hexdigit [i] =
1256 i >= '0' && i <= '9' ? i - '0'
1257 : i >= 'a' && i <= 'f' ? i - 'a' + 10
1258 : i >= 'A' && i <= 'F' ? i - 'A' + 10
1259 : -1;
1260
1261 json_stash = gv_stashpv ("JSON::XS" , 1);
1262 json_boolean_stash = gv_stashpv ("JSON::XS::Boolean", 1);
1263
1264 json_true = get_sv ("JSON::XS::true" , 1); SvREADONLY_on (json_true );
1265 json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false);
1266 }
1267
1268 PROTOTYPES: DISABLE
1269
1270 void new (char *klass)
1271 PPCODE:
1272 {
1273 SV *pv = NEWSV (0, sizeof (JSON));
1274 SvPOK_only (pv);
1275 Zero (SvPVX (pv), 1, sizeof (JSON));
1276 ((JSON *)SvPVX (pv))->flags = F_DEFAULT;
1277 XPUSHs (sv_2mortal (sv_bless (newRV_noinc (pv), json_stash)));
1278 }
1279
1280 void ascii (JSON *self, int enable = 1)
1281 ALIAS:
1282 ascii = F_ASCII
1283 latin1 = F_LATIN1
1284 utf8 = F_UTF8
1285 indent = F_INDENT
1286 canonical = F_CANONICAL
1287 space_before = F_SPACE_BEFORE
1288 space_after = F_SPACE_AFTER
1289 pretty = F_PRETTY
1290 allow_nonref = F_ALLOW_NONREF
1291 shrink = F_SHRINK
1292 allow_blessed = F_ALLOW_BLESSED
1293 convert_blessed = F_CONV_BLESSED
1294 PPCODE:
1295 {
1296 if (enable)
1297 self->flags |= ix;
1298 else
1299 self->flags &= ~ix;
1300
1301 XPUSHs (ST (0));
1302 }
1303
1304 void max_depth (JSON *self, UV max_depth = 0x80000000UL)
1305 PPCODE:
1306 {
1307 UV log2 = 0;
1308
1309 if (max_depth > 0x80000000UL) max_depth = 0x80000000UL;
1310
1311 while ((1UL << log2) < max_depth)
1312 ++log2;
1313
1314 self->flags = self->flags & ~F_MAXDEPTH | (log2 << S_MAXDEPTH);
1315
1316 XPUSHs (ST (0));
1317 }
1318
1319 void max_size (JSON *self, UV max_size = 0)
1320 PPCODE:
1321 {
1322 UV log2 = 0;
1323
1324 if (max_size > 0x80000000UL) max_size = 0x80000000UL;
1325 if (max_size == 1) max_size = 2;
1326
1327 while ((1UL << log2) < max_size)
1328 ++log2;
1329
1330 self->flags = self->flags & ~F_MAXSIZE | (log2 << S_MAXSIZE);
1331
1332 XPUSHs (ST (0));
1333 }
1334
1335 void encode (JSON *self, SV *scalar)
1336 PPCODE:
1337 XPUSHs (encode_json (scalar, self));
1338
1339 void decode (JSON *self, SV *jsonstr)
1340 PPCODE:
1341 XPUSHs (decode_json (jsonstr, self, 0));
1342
1343 void decode_prefix (JSON *self, SV *jsonstr)
1344 PPCODE:
1345 {
1346 UV offset;
1347 EXTEND (SP, 2);
1348 PUSHs (decode_json (jsonstr, self, &offset));
1349 PUSHs (sv_2mortal (newSVuv (offset)));
1350 }
1351
1352 PROTOTYPES: ENABLE
1353
1354 void to_json (SV *scalar)
1355 PPCODE:
1356 {
1357 JSON json = { F_DEFAULT | F_UTF8 };
1358 XPUSHs (encode_json (scalar, &json));
1359 }
1360
1361 void from_json (SV *jsonstr)
1362 PPCODE:
1363 {
1364 JSON json = { F_DEFAULT | F_UTF8 };
1365 XPUSHs (decode_json (jsonstr, &json, 0));
1366 }
1367