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/cvs/JSON-XS/XS.xs
Revision: 1.57
Committed: Mon Aug 13 16:05:42 2007 UTC (16 years, 9 months ago) by root
Branch: MAIN
Changes since 1.56: +20 -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 1
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 int count;
516 dSP;
517
518 ENTER; SAVETMPS; PUSHMARK (SP);
519 XPUSHs (sv_bless (sv_2mortal (newRV_inc (sv)), SvSTASH (sv)));
520
521 // calling with G_SCALAR ensures that we always get a 1 return value
522 PUTBACK;
523 call_sv ((SV *)GvCV (to_json), G_SCALAR);
524 SPAGAIN;
525
526 // catch this surprisingly common error
527 if (SvROK (TOPs) && SvRV (TOPs) == sv)
528 croak ("%s::TO_JSON method returned same object as was passed instead of a new one", HvNAME (SvSTASH (sv)));
529
530 sv = POPs;
531 PUTBACK;
532
533 encode_sv (enc, sv);
534
535 FREETMPS; LEAVE;
536 }
537 else if (enc->json.flags & F_ALLOW_BLESSED)
538 encode_str (enc, "null", 4, 0);
539 else
540 croak ("encountered object '%s', but neither allow_blessed enabled nor TO_JSON method available on it",
541 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
542 }
543 else if (enc->json.flags & F_ALLOW_BLESSED)
544 encode_str (enc, "null", 4, 0);
545 else
546 croak ("encountered object '%s', but neither allow_blessed nor convert_blessed settings are enabled",
547 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
548 }
549 }
550 else if (svt == SVt_PVHV)
551 encode_hv (enc, (HV *)sv);
552 else if (svt == SVt_PVAV)
553 encode_av (enc, (AV *)sv);
554 else if (svt < SVt_PVAV)
555 {
556 STRLEN len = 0;
557 char *pv = svt ? SvPV (sv, len) : 0;
558
559 if (len == 1 && *pv == '1')
560 encode_str (enc, "true", 4, 0);
561 else if (len == 1 && *pv == '0')
562 encode_str (enc, "false", 5, 0);
563 else
564 croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
565 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
566 }
567 else
568 croak ("encountered %s, but JSON can only represent references to arrays or hashes",
569 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
570 }
571
572 static void
573 encode_sv (enc_t *enc, SV *sv)
574 {
575 SvGETMAGIC (sv);
576
577 if (SvPOKp (sv))
578 {
579 STRLEN len;
580 char *str = SvPV (sv, len);
581 encode_ch (enc, '"');
582 encode_str (enc, str, len, SvUTF8 (sv));
583 encode_ch (enc, '"');
584 }
585 else if (SvNOKp (sv))
586 {
587 // trust that perl will do the right thing w.r.t. JSON syntax.
588 need (enc, NV_DIG + 32);
589 Gconvert (SvNVX (sv), NV_DIG, 0, enc->cur);
590 enc->cur += strlen (enc->cur);
591 }
592 else if (SvIOKp (sv))
593 {
594 // we assume we can always read an IV as a UV
595 if (SvUV (sv) & ~(UV)0x7fff)
596 {
597 // large integer, use the (rather slow) snprintf way.
598 need (enc, sizeof (UV) * 3);
599 enc->cur +=
600 SvIsUV(sv)
601 ? snprintf (enc->cur, sizeof (UV) * 3, "%"UVuf, (UV)SvUVX (sv))
602 : snprintf (enc->cur, sizeof (UV) * 3, "%"IVdf, (IV)SvIVX (sv));
603 }
604 else
605 {
606 // optimise the "small number case"
607 // code will likely be branchless and use only a single multiplication
608 I32 i = SvIV (sv);
609 U32 u;
610 char digit, nz = 0;
611
612 need (enc, 6);
613
614 *enc->cur = '-'; enc->cur += i < 0 ? 1 : 0;
615 u = i < 0 ? -i : i;
616
617 // convert to 4.28 fixed-point representation
618 u = u * ((0xfffffff + 10000) / 10000); // 10**5, 5 fractional digits
619
620 // now output digit by digit, each time masking out the integer part
621 // and multiplying by 5 while moving the decimal point one to the right,
622 // resulting in a net multiplication by 10.
623 // we always write the digit to memory but conditionally increment
624 // the pointer, to ease the usage of conditional move instructions.
625 digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffff) * 5;
626 digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffff) * 5;
627 digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffff) * 5;
628 digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffff) * 5;
629 digit = u >> 24; *enc->cur = digit + '0'; enc->cur += 1; // correctly generate '0'
630 }
631 }
632 else if (SvROK (sv))
633 encode_rv (enc, SvRV (sv));
634 else if (!SvOK (sv))
635 encode_str (enc, "null", 4, 0);
636 else
637 croak ("encountered perl type (%s,0x%x) that JSON cannot handle, you might want to report this",
638 SvPV_nolen (sv), SvFLAGS (sv));
639 }
640
641 static SV *
642 encode_json (SV *scalar, JSON *json)
643 {
644 enc_t enc;
645
646 if (!(json->flags & F_ALLOW_NONREF) && !SvROK (scalar))
647 croak ("hash- or arrayref expected (not a simple scalar, use allow_nonref to allow this)");
648
649 enc.json = *json;
650 enc.sv = sv_2mortal (NEWSV (0, INIT_SIZE));
651 enc.cur = SvPVX (enc.sv);
652 enc.end = SvEND (enc.sv);
653 enc.indent = 0;
654 enc.maxdepth = DEC_DEPTH (enc.json.flags);
655
656 SvPOK_only (enc.sv);
657 encode_sv (&enc, scalar);
658
659 SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
660 *SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings
661
662 if (!(enc.json.flags & (F_ASCII | F_LATIN1 | F_UTF8)))
663 SvUTF8_on (enc.sv);
664
665 if (enc.json.flags & F_SHRINK)
666 shrink (enc.sv);
667
668 return enc.sv;
669 }
670
671 /////////////////////////////////////////////////////////////////////////////
672 // decoder
673
674 // structure used for decoding JSON
675 typedef struct
676 {
677 char *cur; // current parser pointer
678 char *end; // end of input string
679 const char *err; // parse error, if != 0
680 JSON json;
681 U32 depth; // recursion depth
682 U32 maxdepth; // recursion depth limit
683 } dec_t;
684
685 inline void
686 decode_ws (dec_t *dec)
687 {
688 for (;;)
689 {
690 char ch = *dec->cur;
691
692 if (ch > 0x20
693 || (ch != 0x20 && ch != 0x0a && ch != 0x0d && ch != 0x09))
694 break;
695
696 ++dec->cur;
697 }
698 }
699
700 #define ERR(reason) SB dec->err = reason; goto fail; SE
701
702 #define EXPECT_CH(ch) SB \
703 if (*dec->cur != ch) \
704 ERR (# ch " expected"); \
705 ++dec->cur; \
706 SE
707
708 #define DEC_INC_DEPTH if (++dec->depth > dec->maxdepth) ERR ("json datastructure exceeds maximum nesting level (set a higher max_depth)")
709 #define DEC_DEC_DEPTH --dec->depth
710
711 static SV *decode_sv (dec_t *dec);
712
713 static signed char decode_hexdigit[256];
714
715 static UV
716 decode_4hex (dec_t *dec)
717 {
718 signed char d1, d2, d3, d4;
719 unsigned char *cur = (unsigned char *)dec->cur;
720
721 d1 = decode_hexdigit [cur [0]]; if (expect_false (d1 < 0)) ERR ("exactly four hexadecimal digits expected");
722 d2 = decode_hexdigit [cur [1]]; if (expect_false (d2 < 0)) ERR ("exactly four hexadecimal digits expected");
723 d3 = decode_hexdigit [cur [2]]; if (expect_false (d3 < 0)) ERR ("exactly four hexadecimal digits expected");
724 d4 = decode_hexdigit [cur [3]]; if (expect_false (d4 < 0)) ERR ("exactly four hexadecimal digits expected");
725
726 dec->cur += 4;
727
728 return ((UV)d1) << 12
729 | ((UV)d2) << 8
730 | ((UV)d3) << 4
731 | ((UV)d4);
732
733 fail:
734 return (UV)-1;
735 }
736
737 static SV *
738 decode_str (dec_t *dec)
739 {
740 SV *sv = 0;
741 int utf8 = 0;
742 char *dec_cur = dec->cur;
743
744 do
745 {
746 char buf [SHORT_STRING_LEN + UTF8_MAXBYTES];
747 char *cur = buf;
748
749 do
750 {
751 unsigned char ch = *(unsigned char *)dec_cur++;
752
753 if (expect_false (ch == '"'))
754 {
755 --dec_cur;
756 break;
757 }
758 else if (expect_false (ch == '\\'))
759 {
760 switch (*dec_cur)
761 {
762 case '\\':
763 case '/':
764 case '"': *cur++ = *dec_cur++; break;
765
766 case 'b': ++dec_cur; *cur++ = '\010'; break;
767 case 't': ++dec_cur; *cur++ = '\011'; break;
768 case 'n': ++dec_cur; *cur++ = '\012'; break;
769 case 'f': ++dec_cur; *cur++ = '\014'; break;
770 case 'r': ++dec_cur; *cur++ = '\015'; break;
771
772 case 'u':
773 {
774 UV lo, hi;
775 ++dec_cur;
776
777 dec->cur = dec_cur;
778 hi = decode_4hex (dec);
779 dec_cur = dec->cur;
780 if (hi == (UV)-1)
781 goto fail;
782
783 // possibly a surrogate pair
784 if (hi >= 0xd800)
785 if (hi < 0xdc00)
786 {
787 if (dec_cur [0] != '\\' || dec_cur [1] != 'u')
788 ERR ("missing low surrogate character in surrogate pair");
789
790 dec_cur += 2;
791
792 dec->cur = dec_cur;
793 lo = decode_4hex (dec);
794 dec_cur = dec->cur;
795 if (lo == (UV)-1)
796 goto fail;
797
798 if (lo < 0xdc00 || lo >= 0xe000)
799 ERR ("surrogate pair expected");
800
801 hi = (hi - 0xD800) * 0x400 + (lo - 0xDC00) + 0x10000;
802 }
803 else if (hi < 0xe000)
804 ERR ("missing high surrogate character in surrogate pair");
805
806 if (hi >= 0x80)
807 {
808 utf8 = 1;
809
810 cur = (char *)uvuni_to_utf8_flags (cur, hi, 0);
811 }
812 else
813 *cur++ = hi;
814 }
815 break;
816
817 default:
818 --dec_cur;
819 ERR ("illegal backslash escape sequence in string");
820 }
821 }
822 else if (expect_true (ch >= 0x20 && ch <= 0x7f))
823 *cur++ = ch;
824 else if (ch >= 0x80)
825 {
826 STRLEN clen;
827 UV uch;
828
829 --dec_cur;
830
831 uch = decode_utf8 (dec_cur, dec->end - dec_cur, &clen);
832 if (clen == (STRLEN)-1)
833 ERR ("malformed UTF-8 character in JSON string");
834
835 do
836 *cur++ = *dec_cur++;
837 while (--clen);
838
839 utf8 = 1;
840 }
841 else
842 {
843 --dec_cur;
844
845 if (!ch)
846 ERR ("unexpected end of string while parsing JSON string");
847 else
848 ERR ("invalid character encountered while parsing JSON string");
849 }
850 }
851 while (cur < buf + SHORT_STRING_LEN);
852
853 {
854 STRLEN len = cur - buf;
855
856 if (sv)
857 {
858 SvGROW (sv, SvCUR (sv) + len + 1);
859 memcpy (SvPVX (sv) + SvCUR (sv), buf, len);
860 SvCUR_set (sv, SvCUR (sv) + len);
861 }
862 else
863 sv = newSVpvn (buf, len);
864 }
865 }
866 while (*dec_cur != '"');
867
868 ++dec_cur;
869
870 if (sv)
871 {
872 SvPOK_only (sv);
873 *SvEND (sv) = 0;
874
875 if (utf8)
876 SvUTF8_on (sv);
877 }
878 else
879 sv = newSVpvn ("", 0);
880
881 dec->cur = dec_cur;
882 return sv;
883
884 fail:
885 dec->cur = dec_cur;
886 return 0;
887 }
888
889 static SV *
890 decode_num (dec_t *dec)
891 {
892 int is_nv = 0;
893 char *start = dec->cur;
894
895 // [minus]
896 if (*dec->cur == '-')
897 ++dec->cur;
898
899 if (*dec->cur == '0')
900 {
901 ++dec->cur;
902 if (*dec->cur >= '0' && *dec->cur <= '9')
903 ERR ("malformed number (leading zero must not be followed by another digit)");
904 }
905 else if (*dec->cur < '0' || *dec->cur > '9')
906 ERR ("malformed number (no digits after initial minus)");
907 else
908 do
909 {
910 ++dec->cur;
911 }
912 while (*dec->cur >= '0' && *dec->cur <= '9');
913
914 // [frac]
915 if (*dec->cur == '.')
916 {
917 ++dec->cur;
918
919 if (*dec->cur < '0' || *dec->cur > '9')
920 ERR ("malformed number (no digits after decimal point)");
921
922 do
923 {
924 ++dec->cur;
925 }
926 while (*dec->cur >= '0' && *dec->cur <= '9');
927
928 is_nv = 1;
929 }
930
931 // [exp]
932 if (*dec->cur == 'e' || *dec->cur == 'E')
933 {
934 ++dec->cur;
935
936 if (*dec->cur == '-' || *dec->cur == '+')
937 ++dec->cur;
938
939 if (*dec->cur < '0' || *dec->cur > '9')
940 ERR ("malformed number (no digits after exp sign)");
941
942 do
943 {
944 ++dec->cur;
945 }
946 while (*dec->cur >= '0' && *dec->cur <= '9');
947
948 is_nv = 1;
949 }
950
951 if (!is_nv)
952 {
953 int len = dec->cur - start;
954
955 // special case the rather common 1..4-digit-int case, assumes 32 bit ints or so
956 if (*start == '-')
957 switch (len)
958 {
959 case 2: return newSViv (-( start [1] - '0' * 1));
960 case 3: return newSViv (-( start [1] * 10 + start [2] - '0' * 11));
961 case 4: return newSViv (-( start [1] * 100 + start [2] * 10 + start [3] - '0' * 111));
962 case 5: return newSViv (-(start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 1111));
963 }
964 else
965 switch (len)
966 {
967 case 1: return newSViv ( start [0] - '0' * 1);
968 case 2: return newSViv ( start [0] * 10 + start [1] - '0' * 11);
969 case 3: return newSViv ( start [0] * 100 + start [1] * 10 + start [2] - '0' * 111);
970 case 4: return newSViv ( start [0] * 1000 + start [1] * 100 + start [2] * 10 + start [3] - '0' * 1111);
971 }
972
973 {
974 UV uv;
975 int numtype = grok_number (start, len, &uv);
976 if (numtype & IS_NUMBER_IN_UV)
977 if (numtype & IS_NUMBER_NEG)
978 {
979 if (uv < (UV)IV_MIN)
980 return newSViv (-(IV)uv);
981 }
982 else
983 return newSVuv (uv);
984 }
985
986 len -= *start == '-' ? 1 : 0;
987
988 // does not fit into IV or UV, try NV
989 if ((sizeof (NV) == sizeof (double) && DBL_DIG >= len)
990 #if defined (LDBL_DIG)
991 || (sizeof (NV) == sizeof (long double) && LDBL_DIG >= len)
992 #endif
993 )
994 // fits into NV without loss of precision
995 return newSVnv (Atof (start));
996
997 // everything else fails, convert it to a string
998 return newSVpvn (start, dec->cur - start);
999 }
1000
1001 // loss of precision here
1002 return newSVnv (Atof (start));
1003
1004 fail:
1005 return 0;
1006 }
1007
1008 static SV *
1009 decode_av (dec_t *dec)
1010 {
1011 AV *av = newAV ();
1012
1013 DEC_INC_DEPTH;
1014 decode_ws (dec);
1015
1016 if (*dec->cur == ']')
1017 ++dec->cur;
1018 else
1019 for (;;)
1020 {
1021 SV *value;
1022
1023 value = decode_sv (dec);
1024 if (!value)
1025 goto fail;
1026
1027 av_push (av, value);
1028
1029 decode_ws (dec);
1030
1031 if (*dec->cur == ']')
1032 {
1033 ++dec->cur;
1034 break;
1035 }
1036
1037 if (*dec->cur != ',')
1038 ERR (", or ] expected while parsing array");
1039
1040 ++dec->cur;
1041 }
1042
1043 DEC_DEC_DEPTH;
1044 return newRV_noinc ((SV *)av);
1045
1046 fail:
1047 SvREFCNT_dec (av);
1048 DEC_DEC_DEPTH;
1049 return 0;
1050 }
1051
1052 static SV *
1053 decode_hv (dec_t *dec)
1054 {
1055 SV *sv;
1056 HV *hv = newHV ();
1057
1058 DEC_INC_DEPTH;
1059 decode_ws (dec);
1060
1061 if (*dec->cur == '}')
1062 ++dec->cur;
1063 else
1064 for (;;)
1065 {
1066 decode_ws (dec); EXPECT_CH ('"');
1067
1068 // heuristic: assume that
1069 // a) decode_str + hv_store_ent are abysmally slow.
1070 // b) most hash keys are short, simple ascii text.
1071 // => try to "fast-match" such strings to avoid
1072 // the overhead of decode_str + hv_store_ent.
1073 {
1074 SV *value;
1075 char *p = dec->cur;
1076 char *e = p + 24; // only try up to 24 bytes
1077
1078 for (;;)
1079 {
1080 // the >= 0x80 is true on most architectures
1081 if (p == e || *p < 0x20 || *p >= 0x80 || *p == '\\')
1082 {
1083 // slow path, back up and use decode_str
1084 SV *key = decode_str (dec);
1085 if (!key)
1086 goto fail;
1087
1088 decode_ws (dec); EXPECT_CH (':');
1089
1090 value = decode_sv (dec);
1091 if (!value)
1092 {
1093 SvREFCNT_dec (key);
1094 goto fail;
1095 }
1096
1097 hv_store_ent (hv, key, value, 0);
1098 SvREFCNT_dec (key);
1099
1100 break;
1101 }
1102 else if (*p == '"')
1103 {
1104 // fast path, got a simple key
1105 char *key = dec->cur;
1106 int len = p - key;
1107 dec->cur = p + 1;
1108
1109 decode_ws (dec); EXPECT_CH (':');
1110
1111 value = decode_sv (dec);
1112 if (!value)
1113 goto fail;
1114
1115 hv_store (hv, key, len, value, 0);
1116
1117 break;
1118 }
1119
1120 ++p;
1121 }
1122 }
1123
1124 decode_ws (dec);
1125
1126 if (*dec->cur == '}')
1127 {
1128 ++dec->cur;
1129 break;
1130 }
1131
1132 if (*dec->cur != ',')
1133 ERR (", or } expected while parsing object/hash");
1134
1135 ++dec->cur;
1136 }
1137
1138 DEC_DEC_DEPTH;
1139 sv = newRV_noinc ((SV *)hv);
1140
1141 // check filter callbacks
1142 if (dec->json.flags & F_HOOK)
1143 {
1144 if (dec->json.cb_sk_object && HvKEYS (hv) == 1)
1145 {
1146 HE *cb, *he;
1147
1148 hv_iterinit (hv);
1149 he = hv_iternext (hv);
1150 hv_iterinit (hv);
1151
1152 // the next line creates a mortal sv each time its called.
1153 // might want to optimise this for common cases.
1154 cb = hv_fetch_ent (dec->json.cb_sk_object, hv_iterkeysv (he), 0, 0);
1155
1156 if (cb)
1157 {
1158 dSP;
1159 int count;
1160
1161 ENTER; SAVETMPS; PUSHMARK (SP);
1162 XPUSHs (HeVAL (he));
1163
1164 PUTBACK; count = call_sv (HeVAL (cb), G_ARRAY); SPAGAIN;
1165
1166 if (count == 1)
1167 {
1168 sv = newSVsv (POPs);
1169 FREETMPS; LEAVE;
1170 return sv;
1171 }
1172
1173 FREETMPS; LEAVE;
1174 }
1175 }
1176
1177 if (dec->json.cb_object)
1178 {
1179 dSP;
1180 int count;
1181
1182 ENTER; SAVETMPS; PUSHMARK (SP);
1183 XPUSHs (sv_2mortal (sv));
1184
1185 PUTBACK; count = call_sv (dec->json.cb_object, G_ARRAY); SPAGAIN;
1186
1187 if (count == 1)
1188 {
1189 sv = newSVsv (POPs);
1190 FREETMPS; LEAVE;
1191 return sv;
1192 }
1193
1194 SvREFCNT_inc (sv);
1195 FREETMPS; LEAVE;
1196 }
1197 }
1198
1199 return sv;
1200
1201 fail:
1202 SvREFCNT_dec (hv);
1203 DEC_DEC_DEPTH;
1204 return 0;
1205 }
1206
1207 static SV *
1208 decode_sv (dec_t *dec)
1209 {
1210 decode_ws (dec);
1211
1212 // the beauty of JSON: you need exactly one character lookahead
1213 // to parse anything.
1214 switch (*dec->cur)
1215 {
1216 case '"': ++dec->cur; return decode_str (dec);
1217 case '[': ++dec->cur; return decode_av (dec);
1218 case '{': ++dec->cur; return decode_hv (dec);
1219
1220 case '-':
1221 case '0': case '1': case '2': case '3': case '4':
1222 case '5': case '6': case '7': case '8': case '9':
1223 return decode_num (dec);
1224
1225 case 't':
1226 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "true", 4))
1227 {
1228 dec->cur += 4;
1229 return SvREFCNT_inc (json_true);
1230 }
1231 else
1232 ERR ("'true' expected");
1233
1234 break;
1235
1236 case 'f':
1237 if (dec->end - dec->cur >= 5 && !memcmp (dec->cur, "false", 5))
1238 {
1239 dec->cur += 5;
1240 return SvREFCNT_inc (json_false);
1241 }
1242 else
1243 ERR ("'false' expected");
1244
1245 break;
1246
1247 case 'n':
1248 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "null", 4))
1249 {
1250 dec->cur += 4;
1251 return newSVsv (&PL_sv_undef);
1252 }
1253 else
1254 ERR ("'null' expected");
1255
1256 break;
1257
1258 default:
1259 ERR ("malformed JSON string, neither array, object, number, string or atom");
1260 break;
1261 }
1262
1263 fail:
1264 return 0;
1265 }
1266
1267 static SV *
1268 decode_json (SV *string, JSON *json, UV *offset_return)
1269 {
1270 dec_t dec;
1271 UV offset;
1272 SV *sv;
1273
1274 SvGETMAGIC (string);
1275 SvUPGRADE (string, SVt_PV);
1276
1277 if (json->flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (json->flags))
1278 croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu",
1279 (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (json->flags));
1280
1281 if (json->flags & F_UTF8)
1282 sv_utf8_downgrade (string, 0);
1283 else
1284 sv_utf8_upgrade (string);
1285
1286 SvGROW (string, SvCUR (string) + 1); // should basically be a NOP
1287
1288 dec.json = *json;
1289 dec.cur = SvPVX (string);
1290 dec.end = SvEND (string);
1291 dec.err = 0;
1292 dec.depth = 0;
1293 dec.maxdepth = DEC_DEPTH (dec.json.flags);
1294
1295 if (dec.json.cb_object || dec.json.cb_sk_object)
1296 dec.json.flags |= F_HOOK;
1297
1298 *dec.end = 0; // this should basically be a nop, too, but make sure it's there
1299 sv = decode_sv (&dec);
1300
1301 if (!(offset_return || !sv))
1302 {
1303 // check for trailing garbage
1304 decode_ws (&dec);
1305
1306 if (*dec.cur)
1307 {
1308 dec.err = "garbage after JSON object";
1309 SvREFCNT_dec (sv);
1310 sv = 0;
1311 }
1312 }
1313
1314 if (offset_return || !sv)
1315 {
1316 offset = dec.json.flags & F_UTF8
1317 ? dec.cur - SvPVX (string)
1318 : utf8_distance (dec.cur, SvPVX (string));
1319
1320 if (offset_return)
1321 *offset_return = offset;
1322 }
1323
1324 if (!sv)
1325 {
1326 SV *uni = sv_newmortal ();
1327
1328 // horrible hack to silence warning inside pv_uni_display
1329 COP cop = *PL_curcop;
1330 cop.cop_warnings = pWARN_NONE;
1331 ENTER;
1332 SAVEVPTR (PL_curcop);
1333 PL_curcop = &cop;
1334 pv_uni_display (uni, dec.cur, dec.end - dec.cur, 20, UNI_DISPLAY_QQ);
1335 LEAVE;
1336
1337 croak ("%s, at character offset %d [\"%s\"]",
1338 dec.err,
1339 (int)offset,
1340 dec.cur != dec.end ? SvPV_nolen (uni) : "(end of string)");
1341 }
1342
1343 sv = sv_2mortal (sv);
1344
1345 if (!(dec.json.flags & F_ALLOW_NONREF) && !SvROK (sv))
1346 croak ("JSON text must be an object or array (but found number, string, true, false or null, use allow_nonref to allow this)");
1347
1348 return sv;
1349 }
1350
1351 /////////////////////////////////////////////////////////////////////////////
1352 // XS interface functions
1353
1354 MODULE = JSON::XS PACKAGE = JSON::XS
1355
1356 BOOT:
1357 {
1358 int i;
1359
1360 for (i = 0; i < 256; ++i)
1361 decode_hexdigit [i] =
1362 i >= '0' && i <= '9' ? i - '0'
1363 : i >= 'a' && i <= 'f' ? i - 'a' + 10
1364 : i >= 'A' && i <= 'F' ? i - 'A' + 10
1365 : -1;
1366
1367 json_stash = gv_stashpv ("JSON::XS" , 1);
1368 json_boolean_stash = gv_stashpv ("JSON::XS::Boolean", 1);
1369
1370 json_true = get_sv ("JSON::XS::true" , 1); SvREADONLY_on (json_true );
1371 json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false);
1372 }
1373
1374 PROTOTYPES: DISABLE
1375
1376 void CLONE (...)
1377 CODE:
1378 json_stash = 0;
1379 json_boolean_stash = 0;
1380
1381 void new (char *klass)
1382 PPCODE:
1383 {
1384 HV *stash = !JSON_SLOW || json_stash
1385 ? json_stash
1386 : gv_stashpv ("JSON::XS", 1);
1387 SV *pv = NEWSV (0, sizeof (JSON));
1388 SvPOK_only (pv);
1389 Zero (SvPVX (pv), 1, JSON);
1390 ((JSON *)SvPVX (pv))->flags = F_DEFAULT;
1391 XPUSHs (sv_2mortal (sv_bless (newRV_noinc (pv), stash)));
1392 }
1393
1394 void ascii (JSON *self, int enable = 1)
1395 ALIAS:
1396 ascii = F_ASCII
1397 latin1 = F_LATIN1
1398 utf8 = F_UTF8
1399 indent = F_INDENT
1400 canonical = F_CANONICAL
1401 space_before = F_SPACE_BEFORE
1402 space_after = F_SPACE_AFTER
1403 pretty = F_PRETTY
1404 allow_nonref = F_ALLOW_NONREF
1405 shrink = F_SHRINK
1406 allow_blessed = F_ALLOW_BLESSED
1407 convert_blessed = F_CONV_BLESSED
1408 PPCODE:
1409 {
1410 if (enable)
1411 self->flags |= ix;
1412 else
1413 self->flags &= ~ix;
1414
1415 XPUSHs (ST (0));
1416 }
1417
1418 void max_depth (JSON *self, UV max_depth = 0x80000000UL)
1419 PPCODE:
1420 {
1421 UV log2 = 0;
1422
1423 if (max_depth > 0x80000000UL) max_depth = 0x80000000UL;
1424
1425 while ((1UL << log2) < max_depth)
1426 ++log2;
1427
1428 self->flags = self->flags & ~F_MAXDEPTH | (log2 << S_MAXDEPTH);
1429
1430 XPUSHs (ST (0));
1431 }
1432
1433 void max_size (JSON *self, UV max_size = 0)
1434 PPCODE:
1435 {
1436 UV log2 = 0;
1437
1438 if (max_size > 0x80000000UL) max_size = 0x80000000UL;
1439 if (max_size == 1) max_size = 2;
1440
1441 while ((1UL << log2) < max_size)
1442 ++log2;
1443
1444 self->flags = self->flags & ~F_MAXSIZE | (log2 << S_MAXSIZE);
1445
1446 XPUSHs (ST (0));
1447 }
1448
1449 void filter_json_object (JSON *self, SV *cb = &PL_sv_undef)
1450 PPCODE:
1451 {
1452 SvREFCNT_dec (self->cb_object);
1453 self->cb_object = SvOK (cb) ? newSVsv (cb) : 0;
1454
1455 XPUSHs (ST (0));
1456 }
1457
1458 void filter_json_single_key_object (JSON *self, SV *key, SV *cb = &PL_sv_undef)
1459 PPCODE:
1460 {
1461 if (!self->cb_sk_object)
1462 self->cb_sk_object = newHV ();
1463
1464 if (SvOK (cb))
1465 hv_store_ent (self->cb_sk_object, key, newSVsv (cb), 0);
1466 else
1467 {
1468 hv_delete_ent (self->cb_sk_object, key, G_DISCARD, 0);
1469
1470 if (!HvKEYS (self->cb_sk_object))
1471 {
1472 SvREFCNT_dec (self->cb_sk_object);
1473 self->cb_sk_object = 0;
1474 }
1475 }
1476
1477 XPUSHs (ST (0));
1478 }
1479
1480 void encode (JSON *self, SV *scalar)
1481 PPCODE:
1482 XPUSHs (encode_json (scalar, self));
1483
1484 void decode (JSON *self, SV *jsonstr)
1485 PPCODE:
1486 XPUSHs (decode_json (jsonstr, self, 0));
1487
1488 void decode_prefix (JSON *self, SV *jsonstr)
1489 PPCODE:
1490 {
1491 UV offset;
1492 EXTEND (SP, 2);
1493 PUSHs (decode_json (jsonstr, self, &offset));
1494 PUSHs (sv_2mortal (newSVuv (offset)));
1495 }
1496
1497 void DESTROY (JSON *self)
1498 CODE:
1499 SvREFCNT_dec (self->cb_sk_object);
1500 SvREFCNT_dec (self->cb_object);
1501
1502 PROTOTYPES: ENABLE
1503
1504 void to_json (SV *scalar)
1505 PPCODE:
1506 {
1507 JSON json = { F_DEFAULT | F_UTF8 };
1508 XPUSHs (encode_json (scalar, &json));
1509 }
1510
1511 void from_json (SV *jsonstr)
1512 PPCODE:
1513 {
1514 JSON json = { F_DEFAULT | F_UTF8 };
1515 XPUSHs (decode_json (jsonstr, &json, 0));
1516 }
1517