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/cvs/JSON-XS/XS.xs
Revision: 1.58
Committed: Mon Aug 13 16:06:25 2007 UTC (16 years, 9 months ago) by root
Branch: MAIN
Changes since 1.57: +1 -2 lines
Log Message:
bleh

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 #include <float.h>
10
11 #if defined(__BORLANDC__) || defined(_MSC_VER)
12 # define snprintf _snprintf // C compilers have this in stdio.h
13 #endif
14
15 // some old perls do not have this, try to make it work, no
16 // guarentees, though. if it breaks, you get to keep the pieces.
17 #ifndef UTF8_MAXBYTES
18 # define UTF8_MAXBYTES 13
19 #endif
20
21 #define F_ASCII 0x00000001UL
22 #define F_LATIN1 0x00000002UL
23 #define F_UTF8 0x00000004UL
24 #define F_INDENT 0x00000008UL
25 #define F_CANONICAL 0x00000010UL
26 #define F_SPACE_BEFORE 0x00000020UL
27 #define F_SPACE_AFTER 0x00000040UL
28 #define F_ALLOW_NONREF 0x00000100UL
29 #define F_SHRINK 0x00000200UL
30 #define F_ALLOW_BLESSED 0x00000400UL
31 #define F_CONV_BLESSED 0x00000800UL
32 #define F_MAXDEPTH 0xf8000000UL
33 #define S_MAXDEPTH 27
34 #define F_MAXSIZE 0x01f00000UL
35 #define S_MAXSIZE 20
36 #define F_HOOK 0x00080000UL // some hooks exist, so slow-path processing
37
38 #define DEC_DEPTH(flags) (1UL << ((flags & F_MAXDEPTH) >> S_MAXDEPTH))
39 #define DEC_SIZE(flags) (1UL << ((flags & F_MAXSIZE ) >> S_MAXSIZE ))
40
41 #define F_PRETTY F_INDENT | F_SPACE_BEFORE | F_SPACE_AFTER
42 #define F_DEFAULT (9UL << S_MAXDEPTH)
43
44 #define INIT_SIZE 32 // initial scalar size to be allocated
45 #define INDENT_STEP 3 // spaces per indentation level
46
47 #define SHORT_STRING_LEN 16384 // special-case strings of up to this size
48
49 #define SB do {
50 #define SE } while (0)
51
52 #if __GNUC__ >= 3
53 # define expect(expr,value) __builtin_expect ((expr),(value))
54 # define inline inline
55 #else
56 # define expect(expr,value) (expr)
57 # define inline static
58 #endif
59
60 #define expect_false(expr) expect ((expr) != 0, 0)
61 #define expect_true(expr) expect ((expr) != 0, 1)
62
63 #ifdef USE_ITHREADS
64 # define JSON_SLOW 1
65 #else
66 # define JSON_SLOW 0
67 #endif
68
69 static HV *json_stash, *json_boolean_stash; // JSON::XS::
70 static SV *json_true, *json_false;
71
72 typedef struct {
73 U32 flags;
74 SV *cb_object;
75 HV *cb_sk_object;
76 } JSON;
77
78 /////////////////////////////////////////////////////////////////////////////
79 // utility functions
80
81 inline void
82 shrink (SV *sv)
83 {
84 sv_utf8_downgrade (sv, 1);
85 if (SvLEN (sv) > SvCUR (sv) + 1)
86 {
87 #ifdef SvPV_shrink_to_cur
88 SvPV_shrink_to_cur (sv);
89 #elif defined (SvPV_renew)
90 SvPV_renew (sv, SvCUR (sv) + 1);
91 #endif
92 }
93 }
94
95 // decode an utf-8 character and return it, or (UV)-1 in
96 // case of an error.
97 // we special-case "safe" characters from U+80 .. U+7FF,
98 // but use the very good perl function to parse anything else.
99 // note that we never call this function for a ascii codepoints
100 inline UV
101 decode_utf8 (unsigned char *s, STRLEN len, STRLEN *clen)
102 {
103 if (expect_false (s[0] > 0xdf || s[0] < 0xc2))
104 return utf8n_to_uvuni (s, len, clen, UTF8_CHECK_ONLY);
105 else if (len > 1 && s[1] >= 0x80 && s[1] <= 0xbf)
106 {
107 *clen = 2;
108 return ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
109 }
110 else
111 {
112 *clen = (STRLEN)-1;
113 return (UV)-1;
114 }
115 }
116
117 /////////////////////////////////////////////////////////////////////////////
118 // encoder
119
120 // structure used for encoding JSON
121 typedef struct
122 {
123 char *cur; // SvPVX (sv) + current output position
124 char *end; // SvEND (sv)
125 SV *sv; // result scalar
126 JSON json;
127 U32 indent; // indentation level
128 U32 maxdepth; // max. indentation/recursion level
129 } enc_t;
130
131 inline void
132 need (enc_t *enc, STRLEN len)
133 {
134 if (expect_false (enc->cur + len >= enc->end))
135 {
136 STRLEN cur = enc->cur - SvPVX (enc->sv);
137 SvGROW (enc->sv, cur + len + 1);
138 enc->cur = SvPVX (enc->sv) + cur;
139 enc->end = SvPVX (enc->sv) + SvLEN (enc->sv) - 1;
140 }
141 }
142
143 inline void
144 encode_ch (enc_t *enc, char ch)
145 {
146 need (enc, 1);
147 *enc->cur++ = ch;
148 }
149
150 static void
151 encode_str (enc_t *enc, char *str, STRLEN len, int is_utf8)
152 {
153 char *end = str + len;
154
155 need (enc, len);
156
157 while (str < end)
158 {
159 unsigned char ch = *(unsigned char *)str;
160
161 if (expect_true (ch >= 0x20 && ch < 0x80)) // most common case
162 {
163 if (expect_false (ch == '"')) // but with slow exceptions
164 {
165 need (enc, len += 1);
166 *enc->cur++ = '\\';
167 *enc->cur++ = '"';
168 }
169 else if (expect_false (ch == '\\'))
170 {
171 need (enc, len += 1);
172 *enc->cur++ = '\\';
173 *enc->cur++ = '\\';
174 }
175 else
176 *enc->cur++ = ch;
177
178 ++str;
179 }
180 else
181 {
182 switch (ch)
183 {
184 case '\010': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'b'; ++str; break;
185 case '\011': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 't'; ++str; break;
186 case '\012': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'n'; ++str; break;
187 case '\014': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'f'; ++str; break;
188 case '\015': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'r'; ++str; break;
189
190 default:
191 {
192 STRLEN clen;
193 UV uch;
194
195 if (is_utf8)
196 {
197 uch = decode_utf8 (str, end - str, &clen);
198 if (clen == (STRLEN)-1)
199 croak ("malformed or illegal unicode character in string [%.11s], cannot convert to JSON", str);
200 }
201 else
202 {
203 uch = ch;
204 clen = 1;
205 }
206
207 if (uch > 0x10FFFFUL)
208 croak ("out of range codepoint (0x%lx) encountered, unrepresentable in JSON", (unsigned long)uch);
209
210 if (uch < 0x80 || enc->json.flags & F_ASCII || (enc->json.flags & F_LATIN1 && uch > 0xFF))
211 {
212 if (uch > 0xFFFFUL)
213 {
214 need (enc, len += 11);
215 sprintf (enc->cur, "\\u%04x\\u%04x",
216 (int)((uch - 0x10000) / 0x400 + 0xD800),
217 (int)((uch - 0x10000) % 0x400 + 0xDC00));
218 enc->cur += 12;
219 }
220 else
221 {
222 static char hexdigit [16] = "0123456789abcdef";
223 need (enc, len += 5);
224 *enc->cur++ = '\\';
225 *enc->cur++ = 'u';
226 *enc->cur++ = hexdigit [ uch >> 12 ];
227 *enc->cur++ = hexdigit [(uch >> 8) & 15];
228 *enc->cur++ = hexdigit [(uch >> 4) & 15];
229 *enc->cur++ = hexdigit [(uch >> 0) & 15];
230 }
231
232 str += clen;
233 }
234 else if (enc->json.flags & F_LATIN1)
235 {
236 *enc->cur++ = uch;
237 str += clen;
238 }
239 else if (is_utf8)
240 {
241 need (enc, len += clen);
242 do
243 {
244 *enc->cur++ = *str++;
245 }
246 while (--clen);
247 }
248 else
249 {
250 need (enc, len += UTF8_MAXBYTES - 1); // never more than 11 bytes needed
251 enc->cur = uvuni_to_utf8_flags (enc->cur, uch, 0);
252 ++str;
253 }
254 }
255 }
256 }
257
258 --len;
259 }
260 }
261
262 inline void
263 encode_indent (enc_t *enc)
264 {
265 if (enc->json.flags & F_INDENT)
266 {
267 int spaces = enc->indent * INDENT_STEP;
268
269 need (enc, spaces);
270 memset (enc->cur, ' ', spaces);
271 enc->cur += spaces;
272 }
273 }
274
275 inline void
276 encode_space (enc_t *enc)
277 {
278 need (enc, 1);
279 encode_ch (enc, ' ');
280 }
281
282 inline void
283 encode_nl (enc_t *enc)
284 {
285 if (enc->json.flags & F_INDENT)
286 {
287 need (enc, 1);
288 encode_ch (enc, '\n');
289 }
290 }
291
292 inline void
293 encode_comma (enc_t *enc)
294 {
295 encode_ch (enc, ',');
296
297 if (enc->json.flags & F_INDENT)
298 encode_nl (enc);
299 else if (enc->json.flags & F_SPACE_AFTER)
300 encode_space (enc);
301 }
302
303 static void encode_sv (enc_t *enc, SV *sv);
304
305 static void
306 encode_av (enc_t *enc, AV *av)
307 {
308 int i, len = av_len (av);
309
310 if (enc->indent >= enc->maxdepth)
311 croak ("data structure too deep (hit recursion limit)");
312
313 encode_ch (enc, '['); encode_nl (enc);
314 ++enc->indent;
315
316 for (i = 0; i <= len; ++i)
317 {
318 SV **svp = av_fetch (av, i, 0);
319
320 encode_indent (enc);
321
322 if (svp)
323 encode_sv (enc, *svp);
324 else
325 encode_str (enc, "null", 4, 0);
326
327 if (i < len)
328 encode_comma (enc);
329 }
330
331 encode_nl (enc);
332
333 --enc->indent;
334 encode_indent (enc); encode_ch (enc, ']');
335 }
336
337 static void
338 encode_he (enc_t *enc, HE *he)
339 {
340 encode_ch (enc, '"');
341
342 if (HeKLEN (he) == HEf_SVKEY)
343 {
344 SV *sv = HeSVKEY (he);
345 STRLEN len;
346 char *str;
347
348 SvGETMAGIC (sv);
349 str = SvPV (sv, len);
350
351 encode_str (enc, str, len, SvUTF8 (sv));
352 }
353 else
354 encode_str (enc, HeKEY (he), HeKLEN (he), HeKUTF8 (he));
355
356 encode_ch (enc, '"');
357
358 if (enc->json.flags & F_SPACE_BEFORE) encode_space (enc);
359 encode_ch (enc, ':');
360 if (enc->json.flags & F_SPACE_AFTER ) encode_space (enc);
361 encode_sv (enc, HeVAL (he));
362 }
363
364 // compare hash entries, used when all keys are bytestrings
365 static int
366 he_cmp_fast (const void *a_, const void *b_)
367 {
368 int cmp;
369
370 HE *a = *(HE **)a_;
371 HE *b = *(HE **)b_;
372
373 STRLEN la = HeKLEN (a);
374 STRLEN lb = HeKLEN (b);
375
376 if (!(cmp = memcmp (HeKEY (a), HeKEY (b), la < lb ? la : lb)))
377 cmp = la - lb;
378
379 return cmp;
380 }
381
382 // compare hash entries, used when some keys are sv's or utf-x
383 static int
384 he_cmp_slow (const void *a, const void *b)
385 {
386 return sv_cmp (HeSVKEY_force (*(HE **)a), HeSVKEY_force (*(HE **)b));
387 }
388
389 static void
390 encode_hv (enc_t *enc, HV *hv)
391 {
392 int count, i;
393
394 if (enc->indent >= enc->maxdepth)
395 croak ("data structure too deep (hit recursion limit)");
396
397 encode_ch (enc, '{'); encode_nl (enc); ++enc->indent;
398
399 if ((count = hv_iterinit (hv)))
400 {
401 // for canonical output we have to sort by keys first
402 // actually, this is mostly due to the stupid so-called
403 // security workaround added somewhere in 5.8.x.
404 // that randomises hash orderings
405 if (enc->json.flags & F_CANONICAL)
406 {
407 int fast = 1;
408 HE *he;
409 #if defined(__BORLANDC__) || defined(_MSC_VER)
410 HE **hes = _alloca (count * sizeof (HE));
411 #else
412 HE *hes [count]; // if your compiler dies here, you need to enable C99 mode
413 #endif
414
415 i = 0;
416 while ((he = hv_iternext (hv)))
417 {
418 hes [i++] = he;
419 if (HeKLEN (he) < 0 || HeKUTF8 (he))
420 fast = 0;
421 }
422
423 assert (i == count);
424
425 if (fast)
426 qsort (hes, count, sizeof (HE *), he_cmp_fast);
427 else
428 {
429 // hack to forcefully disable "use bytes"
430 COP cop = *PL_curcop;
431 cop.op_private = 0;
432
433 ENTER;
434 SAVETMPS;
435
436 SAVEVPTR (PL_curcop);
437 PL_curcop = &cop;
438
439 qsort (hes, count, sizeof (HE *), he_cmp_slow);
440
441 FREETMPS;
442 LEAVE;
443 }
444
445 for (i = 0; i < count; ++i)
446 {
447 encode_indent (enc);
448 encode_he (enc, hes [i]);
449
450 if (i < count - 1)
451 encode_comma (enc);
452 }
453
454 encode_nl (enc);
455 }
456 else
457 {
458 HE *he = hv_iternext (hv);
459
460 for (;;)
461 {
462 encode_indent (enc);
463 encode_he (enc, he);
464
465 if (!(he = hv_iternext (hv)))
466 break;
467
468 encode_comma (enc);
469 }
470
471 encode_nl (enc);
472 }
473 }
474
475 --enc->indent; encode_indent (enc); encode_ch (enc, '}');
476 }
477
478 // encode objects, arrays and special \0=false and \1=true values.
479 static void
480 encode_rv (enc_t *enc, SV *sv)
481 {
482 svtype svt;
483
484 SvGETMAGIC (sv);
485 svt = SvTYPE (sv);
486
487 if (expect_false (SvOBJECT (sv)))
488 {
489 HV *stash = !JSON_SLOW || json_boolean_stash
490 ? json_boolean_stash
491 : gv_stashpv ("JSON::XS::Boolean", 1);
492
493 if (SvSTASH (sv) == stash)
494 {
495 if (SvIV (sv))
496 encode_str (enc, "true", 4, 0);
497 else
498 encode_str (enc, "false", 5, 0);
499 }
500 else
501 {
502 #if 0
503 if (0 && sv_derived_from (rv, "JSON::Literal"))
504 {
505 // not yet
506 }
507 #endif
508 if (enc->json.flags & F_CONV_BLESSED)
509 {
510 // we re-bless the reference to get overload and other niceties right
511 GV *to_json = gv_fetchmethod_autoload (SvSTASH (sv), "TO_JSON", 0);
512
513 if (to_json)
514 {
515 dSP;
516
517 ENTER; SAVETMPS; PUSHMARK (SP);
518 XPUSHs (sv_bless (sv_2mortal (newRV_inc (sv)), SvSTASH (sv)));
519
520 // calling with G_SCALAR ensures that we always get a 1 return value
521 PUTBACK;
522 call_sv ((SV *)GvCV (to_json), G_SCALAR);
523 SPAGAIN;
524
525 // catch this surprisingly common error
526 if (SvROK (TOPs) && SvRV (TOPs) == sv)
527 croak ("%s::TO_JSON method returned same object as was passed instead of a new one", HvNAME (SvSTASH (sv)));
528
529 sv = POPs;
530 PUTBACK;
531
532 encode_sv (enc, sv);
533
534 FREETMPS; LEAVE;
535 }
536 else if (enc->json.flags & F_ALLOW_BLESSED)
537 encode_str (enc, "null", 4, 0);
538 else
539 croak ("encountered object '%s', but neither allow_blessed enabled nor TO_JSON method available on it",
540 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
541 }
542 else if (enc->json.flags & F_ALLOW_BLESSED)
543 encode_str (enc, "null", 4, 0);
544 else
545 croak ("encountered object '%s', but neither allow_blessed nor convert_blessed settings are enabled",
546 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
547 }
548 }
549 else if (svt == SVt_PVHV)
550 encode_hv (enc, (HV *)sv);
551 else if (svt == SVt_PVAV)
552 encode_av (enc, (AV *)sv);
553 else if (svt < SVt_PVAV)
554 {
555 STRLEN len = 0;
556 char *pv = svt ? SvPV (sv, len) : 0;
557
558 if (len == 1 && *pv == '1')
559 encode_str (enc, "true", 4, 0);
560 else if (len == 1 && *pv == '0')
561 encode_str (enc, "false", 5, 0);
562 else
563 croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
564 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
565 }
566 else
567 croak ("encountered %s, but JSON can only represent references to arrays or hashes",
568 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
569 }
570
571 static void
572 encode_sv (enc_t *enc, SV *sv)
573 {
574 SvGETMAGIC (sv);
575
576 if (SvPOKp (sv))
577 {
578 STRLEN len;
579 char *str = SvPV (sv, len);
580 encode_ch (enc, '"');
581 encode_str (enc, str, len, SvUTF8 (sv));
582 encode_ch (enc, '"');
583 }
584 else if (SvNOKp (sv))
585 {
586 // trust that perl will do the right thing w.r.t. JSON syntax.
587 need (enc, NV_DIG + 32);
588 Gconvert (SvNVX (sv), NV_DIG, 0, enc->cur);
589 enc->cur += strlen (enc->cur);
590 }
591 else if (SvIOKp (sv))
592 {
593 // we assume we can always read an IV as a UV
594 if (SvUV (sv) & ~(UV)0x7fff)
595 {
596 // large integer, use the (rather slow) snprintf way.
597 need (enc, sizeof (UV) * 3);
598 enc->cur +=
599 SvIsUV(sv)
600 ? snprintf (enc->cur, sizeof (UV) * 3, "%"UVuf, (UV)SvUVX (sv))
601 : snprintf (enc->cur, sizeof (UV) * 3, "%"IVdf, (IV)SvIVX (sv));
602 }
603 else
604 {
605 // optimise the "small number case"
606 // code will likely be branchless and use only a single multiplication
607 I32 i = SvIV (sv);
608 U32 u;
609 char digit, nz = 0;
610
611 need (enc, 6);
612
613 *enc->cur = '-'; enc->cur += i < 0 ? 1 : 0;
614 u = i < 0 ? -i : i;
615
616 // convert to 4.28 fixed-point representation
617 u = u * ((0xfffffff + 10000) / 10000); // 10**5, 5 fractional digits
618
619 // now output digit by digit, each time masking out the integer part
620 // and multiplying by 5 while moving the decimal point one to the right,
621 // resulting in a net multiplication by 10.
622 // we always write the digit to memory but conditionally increment
623 // the pointer, to ease the usage of conditional move instructions.
624 digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffff) * 5;
625 digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffff) * 5;
626 digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffff) * 5;
627 digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffff) * 5;
628 digit = u >> 24; *enc->cur = digit + '0'; enc->cur += 1; // correctly generate '0'
629 }
630 }
631 else if (SvROK (sv))
632 encode_rv (enc, SvRV (sv));
633 else if (!SvOK (sv))
634 encode_str (enc, "null", 4, 0);
635 else
636 croak ("encountered perl type (%s,0x%x) that JSON cannot handle, you might want to report this",
637 SvPV_nolen (sv), SvFLAGS (sv));
638 }
639
640 static SV *
641 encode_json (SV *scalar, JSON *json)
642 {
643 enc_t enc;
644
645 if (!(json->flags & F_ALLOW_NONREF) && !SvROK (scalar))
646 croak ("hash- or arrayref expected (not a simple scalar, use allow_nonref to allow this)");
647
648 enc.json = *json;
649 enc.sv = sv_2mortal (NEWSV (0, INIT_SIZE));
650 enc.cur = SvPVX (enc.sv);
651 enc.end = SvEND (enc.sv);
652 enc.indent = 0;
653 enc.maxdepth = DEC_DEPTH (enc.json.flags);
654
655 SvPOK_only (enc.sv);
656 encode_sv (&enc, scalar);
657
658 SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
659 *SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings
660
661 if (!(enc.json.flags & (F_ASCII | F_LATIN1 | F_UTF8)))
662 SvUTF8_on (enc.sv);
663
664 if (enc.json.flags & F_SHRINK)
665 shrink (enc.sv);
666
667 return enc.sv;
668 }
669
670 /////////////////////////////////////////////////////////////////////////////
671 // decoder
672
673 // structure used for decoding JSON
674 typedef struct
675 {
676 char *cur; // current parser pointer
677 char *end; // end of input string
678 const char *err; // parse error, if != 0
679 JSON json;
680 U32 depth; // recursion depth
681 U32 maxdepth; // recursion depth limit
682 } dec_t;
683
684 inline void
685 decode_ws (dec_t *dec)
686 {
687 for (;;)
688 {
689 char ch = *dec->cur;
690
691 if (ch > 0x20
692 || (ch != 0x20 && ch != 0x0a && ch != 0x0d && ch != 0x09))
693 break;
694
695 ++dec->cur;
696 }
697 }
698
699 #define ERR(reason) SB dec->err = reason; goto fail; SE
700
701 #define EXPECT_CH(ch) SB \
702 if (*dec->cur != ch) \
703 ERR (# ch " expected"); \
704 ++dec->cur; \
705 SE
706
707 #define DEC_INC_DEPTH if (++dec->depth > dec->maxdepth) ERR ("json datastructure exceeds maximum nesting level (set a higher max_depth)")
708 #define DEC_DEC_DEPTH --dec->depth
709
710 static SV *decode_sv (dec_t *dec);
711
712 static signed char decode_hexdigit[256];
713
714 static UV
715 decode_4hex (dec_t *dec)
716 {
717 signed char d1, d2, d3, d4;
718 unsigned char *cur = (unsigned char *)dec->cur;
719
720 d1 = decode_hexdigit [cur [0]]; if (expect_false (d1 < 0)) ERR ("exactly four hexadecimal digits expected");
721 d2 = decode_hexdigit [cur [1]]; if (expect_false (d2 < 0)) ERR ("exactly four hexadecimal digits expected");
722 d3 = decode_hexdigit [cur [2]]; if (expect_false (d3 < 0)) ERR ("exactly four hexadecimal digits expected");
723 d4 = decode_hexdigit [cur [3]]; if (expect_false (d4 < 0)) ERR ("exactly four hexadecimal digits expected");
724
725 dec->cur += 4;
726
727 return ((UV)d1) << 12
728 | ((UV)d2) << 8
729 | ((UV)d3) << 4
730 | ((UV)d4);
731
732 fail:
733 return (UV)-1;
734 }
735
736 static SV *
737 decode_str (dec_t *dec)
738 {
739 SV *sv = 0;
740 int utf8 = 0;
741 char *dec_cur = dec->cur;
742
743 do
744 {
745 char buf [SHORT_STRING_LEN + UTF8_MAXBYTES];
746 char *cur = buf;
747
748 do
749 {
750 unsigned char ch = *(unsigned char *)dec_cur++;
751
752 if (expect_false (ch == '"'))
753 {
754 --dec_cur;
755 break;
756 }
757 else if (expect_false (ch == '\\'))
758 {
759 switch (*dec_cur)
760 {
761 case '\\':
762 case '/':
763 case '"': *cur++ = *dec_cur++; break;
764
765 case 'b': ++dec_cur; *cur++ = '\010'; break;
766 case 't': ++dec_cur; *cur++ = '\011'; break;
767 case 'n': ++dec_cur; *cur++ = '\012'; break;
768 case 'f': ++dec_cur; *cur++ = '\014'; break;
769 case 'r': ++dec_cur; *cur++ = '\015'; break;
770
771 case 'u':
772 {
773 UV lo, hi;
774 ++dec_cur;
775
776 dec->cur = dec_cur;
777 hi = decode_4hex (dec);
778 dec_cur = dec->cur;
779 if (hi == (UV)-1)
780 goto fail;
781
782 // possibly a surrogate pair
783 if (hi >= 0xd800)
784 if (hi < 0xdc00)
785 {
786 if (dec_cur [0] != '\\' || dec_cur [1] != 'u')
787 ERR ("missing low surrogate character in surrogate pair");
788
789 dec_cur += 2;
790
791 dec->cur = dec_cur;
792 lo = decode_4hex (dec);
793 dec_cur = dec->cur;
794 if (lo == (UV)-1)
795 goto fail;
796
797 if (lo < 0xdc00 || lo >= 0xe000)
798 ERR ("surrogate pair expected");
799
800 hi = (hi - 0xD800) * 0x400 + (lo - 0xDC00) + 0x10000;
801 }
802 else if (hi < 0xe000)
803 ERR ("missing high surrogate character in surrogate pair");
804
805 if (hi >= 0x80)
806 {
807 utf8 = 1;
808
809 cur = (char *)uvuni_to_utf8_flags (cur, hi, 0);
810 }
811 else
812 *cur++ = hi;
813 }
814 break;
815
816 default:
817 --dec_cur;
818 ERR ("illegal backslash escape sequence in string");
819 }
820 }
821 else if (expect_true (ch >= 0x20 && ch <= 0x7f))
822 *cur++ = ch;
823 else if (ch >= 0x80)
824 {
825 STRLEN clen;
826 UV uch;
827
828 --dec_cur;
829
830 uch = decode_utf8 (dec_cur, dec->end - dec_cur, &clen);
831 if (clen == (STRLEN)-1)
832 ERR ("malformed UTF-8 character in JSON string");
833
834 do
835 *cur++ = *dec_cur++;
836 while (--clen);
837
838 utf8 = 1;
839 }
840 else
841 {
842 --dec_cur;
843
844 if (!ch)
845 ERR ("unexpected end of string while parsing JSON string");
846 else
847 ERR ("invalid character encountered while parsing JSON string");
848 }
849 }
850 while (cur < buf + SHORT_STRING_LEN);
851
852 {
853 STRLEN len = cur - buf;
854
855 if (sv)
856 {
857 SvGROW (sv, SvCUR (sv) + len + 1);
858 memcpy (SvPVX (sv) + SvCUR (sv), buf, len);
859 SvCUR_set (sv, SvCUR (sv) + len);
860 }
861 else
862 sv = newSVpvn (buf, len);
863 }
864 }
865 while (*dec_cur != '"');
866
867 ++dec_cur;
868
869 if (sv)
870 {
871 SvPOK_only (sv);
872 *SvEND (sv) = 0;
873
874 if (utf8)
875 SvUTF8_on (sv);
876 }
877 else
878 sv = newSVpvn ("", 0);
879
880 dec->cur = dec_cur;
881 return sv;
882
883 fail:
884 dec->cur = dec_cur;
885 return 0;
886 }
887
888 static SV *
889 decode_num (dec_t *dec)
890 {
891 int is_nv = 0;
892 char *start = dec->cur;
893
894 // [minus]
895 if (*dec->cur == '-')
896 ++dec->cur;
897
898 if (*dec->cur == '0')
899 {
900 ++dec->cur;
901 if (*dec->cur >= '0' && *dec->cur <= '9')
902 ERR ("malformed number (leading zero must not be followed by another digit)");
903 }
904 else if (*dec->cur < '0' || *dec->cur > '9')
905 ERR ("malformed number (no digits after initial minus)");
906 else
907 do
908 {
909 ++dec->cur;
910 }
911 while (*dec->cur >= '0' && *dec->cur <= '9');
912
913 // [frac]
914 if (*dec->cur == '.')
915 {
916 ++dec->cur;
917
918 if (*dec->cur < '0' || *dec->cur > '9')
919 ERR ("malformed number (no digits after decimal point)");
920
921 do
922 {
923 ++dec->cur;
924 }
925 while (*dec->cur >= '0' && *dec->cur <= '9');
926
927 is_nv = 1;
928 }
929
930 // [exp]
931 if (*dec->cur == 'e' || *dec->cur == 'E')
932 {
933 ++dec->cur;
934
935 if (*dec->cur == '-' || *dec->cur == '+')
936 ++dec->cur;
937
938 if (*dec->cur < '0' || *dec->cur > '9')
939 ERR ("malformed number (no digits after exp sign)");
940
941 do
942 {
943 ++dec->cur;
944 }
945 while (*dec->cur >= '0' && *dec->cur <= '9');
946
947 is_nv = 1;
948 }
949
950 if (!is_nv)
951 {
952 int len = dec->cur - start;
953
954 // special case the rather common 1..4-digit-int case, assumes 32 bit ints or so
955 if (*start == '-')
956 switch (len)
957 {
958 case 2: return newSViv (-( start [1] - '0' * 1));
959 case 3: return newSViv (-( start [1] * 10 + start [2] - '0' * 11));
960 case 4: return newSViv (-( start [1] * 100 + start [2] * 10 + start [3] - '0' * 111));
961 case 5: return newSViv (-(start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 1111));
962 }
963 else
964 switch (len)
965 {
966 case 1: return newSViv ( start [0] - '0' * 1);
967 case 2: return newSViv ( start [0] * 10 + start [1] - '0' * 11);
968 case 3: return newSViv ( start [0] * 100 + start [1] * 10 + start [2] - '0' * 111);
969 case 4: return newSViv ( start [0] * 1000 + start [1] * 100 + start [2] * 10 + start [3] - '0' * 1111);
970 }
971
972 {
973 UV uv;
974 int numtype = grok_number (start, len, &uv);
975 if (numtype & IS_NUMBER_IN_UV)
976 if (numtype & IS_NUMBER_NEG)
977 {
978 if (uv < (UV)IV_MIN)
979 return newSViv (-(IV)uv);
980 }
981 else
982 return newSVuv (uv);
983 }
984
985 len -= *start == '-' ? 1 : 0;
986
987 // does not fit into IV or UV, try NV
988 if ((sizeof (NV) == sizeof (double) && DBL_DIG >= len)
989 #if defined (LDBL_DIG)
990 || (sizeof (NV) == sizeof (long double) && LDBL_DIG >= len)
991 #endif
992 )
993 // fits into NV without loss of precision
994 return newSVnv (Atof (start));
995
996 // everything else fails, convert it to a string
997 return newSVpvn (start, dec->cur - start);
998 }
999
1000 // loss of precision here
1001 return newSVnv (Atof (start));
1002
1003 fail:
1004 return 0;
1005 }
1006
1007 static SV *
1008 decode_av (dec_t *dec)
1009 {
1010 AV *av = newAV ();
1011
1012 DEC_INC_DEPTH;
1013 decode_ws (dec);
1014
1015 if (*dec->cur == ']')
1016 ++dec->cur;
1017 else
1018 for (;;)
1019 {
1020 SV *value;
1021
1022 value = decode_sv (dec);
1023 if (!value)
1024 goto fail;
1025
1026 av_push (av, value);
1027
1028 decode_ws (dec);
1029
1030 if (*dec->cur == ']')
1031 {
1032 ++dec->cur;
1033 break;
1034 }
1035
1036 if (*dec->cur != ',')
1037 ERR (", or ] expected while parsing array");
1038
1039 ++dec->cur;
1040 }
1041
1042 DEC_DEC_DEPTH;
1043 return newRV_noinc ((SV *)av);
1044
1045 fail:
1046 SvREFCNT_dec (av);
1047 DEC_DEC_DEPTH;
1048 return 0;
1049 }
1050
1051 static SV *
1052 decode_hv (dec_t *dec)
1053 {
1054 SV *sv;
1055 HV *hv = newHV ();
1056
1057 DEC_INC_DEPTH;
1058 decode_ws (dec);
1059
1060 if (*dec->cur == '}')
1061 ++dec->cur;
1062 else
1063 for (;;)
1064 {
1065 decode_ws (dec); EXPECT_CH ('"');
1066
1067 // heuristic: assume that
1068 // a) decode_str + hv_store_ent are abysmally slow.
1069 // b) most hash keys are short, simple ascii text.
1070 // => try to "fast-match" such strings to avoid
1071 // the overhead of decode_str + hv_store_ent.
1072 {
1073 SV *value;
1074 char *p = dec->cur;
1075 char *e = p + 24; // only try up to 24 bytes
1076
1077 for (;;)
1078 {
1079 // the >= 0x80 is true on most architectures
1080 if (p == e || *p < 0x20 || *p >= 0x80 || *p == '\\')
1081 {
1082 // slow path, back up and use decode_str
1083 SV *key = decode_str (dec);
1084 if (!key)
1085 goto fail;
1086
1087 decode_ws (dec); EXPECT_CH (':');
1088
1089 value = decode_sv (dec);
1090 if (!value)
1091 {
1092 SvREFCNT_dec (key);
1093 goto fail;
1094 }
1095
1096 hv_store_ent (hv, key, value, 0);
1097 SvREFCNT_dec (key);
1098
1099 break;
1100 }
1101 else if (*p == '"')
1102 {
1103 // fast path, got a simple key
1104 char *key = dec->cur;
1105 int len = p - key;
1106 dec->cur = p + 1;
1107
1108 decode_ws (dec); EXPECT_CH (':');
1109
1110 value = decode_sv (dec);
1111 if (!value)
1112 goto fail;
1113
1114 hv_store (hv, key, len, value, 0);
1115
1116 break;
1117 }
1118
1119 ++p;
1120 }
1121 }
1122
1123 decode_ws (dec);
1124
1125 if (*dec->cur == '}')
1126 {
1127 ++dec->cur;
1128 break;
1129 }
1130
1131 if (*dec->cur != ',')
1132 ERR (", or } expected while parsing object/hash");
1133
1134 ++dec->cur;
1135 }
1136
1137 DEC_DEC_DEPTH;
1138 sv = newRV_noinc ((SV *)hv);
1139
1140 // check filter callbacks
1141 if (dec->json.flags & F_HOOK)
1142 {
1143 if (dec->json.cb_sk_object && HvKEYS (hv) == 1)
1144 {
1145 HE *cb, *he;
1146
1147 hv_iterinit (hv);
1148 he = hv_iternext (hv);
1149 hv_iterinit (hv);
1150
1151 // the next line creates a mortal sv each time its called.
1152 // might want to optimise this for common cases.
1153 cb = hv_fetch_ent (dec->json.cb_sk_object, hv_iterkeysv (he), 0, 0);
1154
1155 if (cb)
1156 {
1157 dSP;
1158 int count;
1159
1160 ENTER; SAVETMPS; PUSHMARK (SP);
1161 XPUSHs (HeVAL (he));
1162
1163 PUTBACK; count = call_sv (HeVAL (cb), G_ARRAY); SPAGAIN;
1164
1165 if (count == 1)
1166 {
1167 sv = newSVsv (POPs);
1168 FREETMPS; LEAVE;
1169 return sv;
1170 }
1171
1172 FREETMPS; LEAVE;
1173 }
1174 }
1175
1176 if (dec->json.cb_object)
1177 {
1178 dSP;
1179 int count;
1180
1181 ENTER; SAVETMPS; PUSHMARK (SP);
1182 XPUSHs (sv_2mortal (sv));
1183
1184 PUTBACK; count = call_sv (dec->json.cb_object, G_ARRAY); SPAGAIN;
1185
1186 if (count == 1)
1187 {
1188 sv = newSVsv (POPs);
1189 FREETMPS; LEAVE;
1190 return sv;
1191 }
1192
1193 SvREFCNT_inc (sv);
1194 FREETMPS; LEAVE;
1195 }
1196 }
1197
1198 return sv;
1199
1200 fail:
1201 SvREFCNT_dec (hv);
1202 DEC_DEC_DEPTH;
1203 return 0;
1204 }
1205
1206 static SV *
1207 decode_sv (dec_t *dec)
1208 {
1209 decode_ws (dec);
1210
1211 // the beauty of JSON: you need exactly one character lookahead
1212 // to parse anything.
1213 switch (*dec->cur)
1214 {
1215 case '"': ++dec->cur; return decode_str (dec);
1216 case '[': ++dec->cur; return decode_av (dec);
1217 case '{': ++dec->cur; return decode_hv (dec);
1218
1219 case '-':
1220 case '0': case '1': case '2': case '3': case '4':
1221 case '5': case '6': case '7': case '8': case '9':
1222 return decode_num (dec);
1223
1224 case 't':
1225 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "true", 4))
1226 {
1227 dec->cur += 4;
1228 return SvREFCNT_inc (json_true);
1229 }
1230 else
1231 ERR ("'true' expected");
1232
1233 break;
1234
1235 case 'f':
1236 if (dec->end - dec->cur >= 5 && !memcmp (dec->cur, "false", 5))
1237 {
1238 dec->cur += 5;
1239 return SvREFCNT_inc (json_false);
1240 }
1241 else
1242 ERR ("'false' expected");
1243
1244 break;
1245
1246 case 'n':
1247 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "null", 4))
1248 {
1249 dec->cur += 4;
1250 return newSVsv (&PL_sv_undef);
1251 }
1252 else
1253 ERR ("'null' expected");
1254
1255 break;
1256
1257 default:
1258 ERR ("malformed JSON string, neither array, object, number, string or atom");
1259 break;
1260 }
1261
1262 fail:
1263 return 0;
1264 }
1265
1266 static SV *
1267 decode_json (SV *string, JSON *json, UV *offset_return)
1268 {
1269 dec_t dec;
1270 UV offset;
1271 SV *sv;
1272
1273 SvGETMAGIC (string);
1274 SvUPGRADE (string, SVt_PV);
1275
1276 if (json->flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (json->flags))
1277 croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu",
1278 (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (json->flags));
1279
1280 if (json->flags & F_UTF8)
1281 sv_utf8_downgrade (string, 0);
1282 else
1283 sv_utf8_upgrade (string);
1284
1285 SvGROW (string, SvCUR (string) + 1); // should basically be a NOP
1286
1287 dec.json = *json;
1288 dec.cur = SvPVX (string);
1289 dec.end = SvEND (string);
1290 dec.err = 0;
1291 dec.depth = 0;
1292 dec.maxdepth = DEC_DEPTH (dec.json.flags);
1293
1294 if (dec.json.cb_object || dec.json.cb_sk_object)
1295 dec.json.flags |= F_HOOK;
1296
1297 *dec.end = 0; // this should basically be a nop, too, but make sure it's there
1298 sv = decode_sv (&dec);
1299
1300 if (!(offset_return || !sv))
1301 {
1302 // check for trailing garbage
1303 decode_ws (&dec);
1304
1305 if (*dec.cur)
1306 {
1307 dec.err = "garbage after JSON object";
1308 SvREFCNT_dec (sv);
1309 sv = 0;
1310 }
1311 }
1312
1313 if (offset_return || !sv)
1314 {
1315 offset = dec.json.flags & F_UTF8
1316 ? dec.cur - SvPVX (string)
1317 : utf8_distance (dec.cur, SvPVX (string));
1318
1319 if (offset_return)
1320 *offset_return = offset;
1321 }
1322
1323 if (!sv)
1324 {
1325 SV *uni = sv_newmortal ();
1326
1327 // horrible hack to silence warning inside pv_uni_display
1328 COP cop = *PL_curcop;
1329 cop.cop_warnings = pWARN_NONE;
1330 ENTER;
1331 SAVEVPTR (PL_curcop);
1332 PL_curcop = &cop;
1333 pv_uni_display (uni, dec.cur, dec.end - dec.cur, 20, UNI_DISPLAY_QQ);
1334 LEAVE;
1335
1336 croak ("%s, at character offset %d [\"%s\"]",
1337 dec.err,
1338 (int)offset,
1339 dec.cur != dec.end ? SvPV_nolen (uni) : "(end of string)");
1340 }
1341
1342 sv = sv_2mortal (sv);
1343
1344 if (!(dec.json.flags & F_ALLOW_NONREF) && !SvROK (sv))
1345 croak ("JSON text must be an object or array (but found number, string, true, false or null, use allow_nonref to allow this)");
1346
1347 return sv;
1348 }
1349
1350 /////////////////////////////////////////////////////////////////////////////
1351 // XS interface functions
1352
1353 MODULE = JSON::XS PACKAGE = JSON::XS
1354
1355 BOOT:
1356 {
1357 int i;
1358
1359 for (i = 0; i < 256; ++i)
1360 decode_hexdigit [i] =
1361 i >= '0' && i <= '9' ? i - '0'
1362 : i >= 'a' && i <= 'f' ? i - 'a' + 10
1363 : i >= 'A' && i <= 'F' ? i - 'A' + 10
1364 : -1;
1365
1366 json_stash = gv_stashpv ("JSON::XS" , 1);
1367 json_boolean_stash = gv_stashpv ("JSON::XS::Boolean", 1);
1368
1369 json_true = get_sv ("JSON::XS::true" , 1); SvREADONLY_on (json_true );
1370 json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false);
1371 }
1372
1373 PROTOTYPES: DISABLE
1374
1375 void CLONE (...)
1376 CODE:
1377 json_stash = 0;
1378 json_boolean_stash = 0;
1379
1380 void new (char *klass)
1381 PPCODE:
1382 {
1383 HV *stash = !JSON_SLOW || json_stash
1384 ? json_stash
1385 : gv_stashpv ("JSON::XS", 1);
1386 SV *pv = NEWSV (0, sizeof (JSON));
1387 SvPOK_only (pv);
1388 Zero (SvPVX (pv), 1, JSON);
1389 ((JSON *)SvPVX (pv))->flags = F_DEFAULT;
1390 XPUSHs (sv_2mortal (sv_bless (newRV_noinc (pv), stash)));
1391 }
1392
1393 void ascii (JSON *self, int enable = 1)
1394 ALIAS:
1395 ascii = F_ASCII
1396 latin1 = F_LATIN1
1397 utf8 = F_UTF8
1398 indent = F_INDENT
1399 canonical = F_CANONICAL
1400 space_before = F_SPACE_BEFORE
1401 space_after = F_SPACE_AFTER
1402 pretty = F_PRETTY
1403 allow_nonref = F_ALLOW_NONREF
1404 shrink = F_SHRINK
1405 allow_blessed = F_ALLOW_BLESSED
1406 convert_blessed = F_CONV_BLESSED
1407 PPCODE:
1408 {
1409 if (enable)
1410 self->flags |= ix;
1411 else
1412 self->flags &= ~ix;
1413
1414 XPUSHs (ST (0));
1415 }
1416
1417 void max_depth (JSON *self, UV max_depth = 0x80000000UL)
1418 PPCODE:
1419 {
1420 UV log2 = 0;
1421
1422 if (max_depth > 0x80000000UL) max_depth = 0x80000000UL;
1423
1424 while ((1UL << log2) < max_depth)
1425 ++log2;
1426
1427 self->flags = self->flags & ~F_MAXDEPTH | (log2 << S_MAXDEPTH);
1428
1429 XPUSHs (ST (0));
1430 }
1431
1432 void max_size (JSON *self, UV max_size = 0)
1433 PPCODE:
1434 {
1435 UV log2 = 0;
1436
1437 if (max_size > 0x80000000UL) max_size = 0x80000000UL;
1438 if (max_size == 1) max_size = 2;
1439
1440 while ((1UL << log2) < max_size)
1441 ++log2;
1442
1443 self->flags = self->flags & ~F_MAXSIZE | (log2 << S_MAXSIZE);
1444
1445 XPUSHs (ST (0));
1446 }
1447
1448 void filter_json_object (JSON *self, SV *cb = &PL_sv_undef)
1449 PPCODE:
1450 {
1451 SvREFCNT_dec (self->cb_object);
1452 self->cb_object = SvOK (cb) ? newSVsv (cb) : 0;
1453
1454 XPUSHs (ST (0));
1455 }
1456
1457 void filter_json_single_key_object (JSON *self, SV *key, SV *cb = &PL_sv_undef)
1458 PPCODE:
1459 {
1460 if (!self->cb_sk_object)
1461 self->cb_sk_object = newHV ();
1462
1463 if (SvOK (cb))
1464 hv_store_ent (self->cb_sk_object, key, newSVsv (cb), 0);
1465 else
1466 {
1467 hv_delete_ent (self->cb_sk_object, key, G_DISCARD, 0);
1468
1469 if (!HvKEYS (self->cb_sk_object))
1470 {
1471 SvREFCNT_dec (self->cb_sk_object);
1472 self->cb_sk_object = 0;
1473 }
1474 }
1475
1476 XPUSHs (ST (0));
1477 }
1478
1479 void encode (JSON *self, SV *scalar)
1480 PPCODE:
1481 XPUSHs (encode_json (scalar, self));
1482
1483 void decode (JSON *self, SV *jsonstr)
1484 PPCODE:
1485 XPUSHs (decode_json (jsonstr, self, 0));
1486
1487 void decode_prefix (JSON *self, SV *jsonstr)
1488 PPCODE:
1489 {
1490 UV offset;
1491 EXTEND (SP, 2);
1492 PUSHs (decode_json (jsonstr, self, &offset));
1493 PUSHs (sv_2mortal (newSVuv (offset)));
1494 }
1495
1496 void DESTROY (JSON *self)
1497 CODE:
1498 SvREFCNT_dec (self->cb_sk_object);
1499 SvREFCNT_dec (self->cb_object);
1500
1501 PROTOTYPES: ENABLE
1502
1503 void to_json (SV *scalar)
1504 PPCODE:
1505 {
1506 JSON json = { F_DEFAULT | F_UTF8 };
1507 XPUSHs (encode_json (scalar, &json));
1508 }
1509
1510 void from_json (SV *jsonstr)
1511 PPCODE:
1512 {
1513 JSON json = { F_DEFAULT | F_UTF8 };
1514 XPUSHs (decode_json (jsonstr, &json, 0));
1515 }
1516