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/cvs/JSON-XS/XS.xs
Revision: 1.47
Committed: Sun Jul 1 14:08:03 2007 UTC (16 years, 10 months ago) by root
Branch: MAIN
Changes since 1.46: +55 -41 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 json {
65 U32 flags;
66 } JSON__XS;
67
68 /////////////////////////////////////////////////////////////////////////////
69 // utility functions
70
71 static UV *
72 SvJSON (SV *sv)
73 {
74 if (!(SvROK (sv) && SvOBJECT (SvRV (sv)) && SvSTASH (SvRV (sv)) == json_stash))
75 croak ("object is not of type JSON::XS");
76
77 return &SvUVX (SvRV (sv));
78 }
79
80 static void
81 shrink (SV *sv)
82 {
83 sv_utf8_downgrade (sv, 1);
84 if (SvLEN (sv) > SvCUR (sv) + 1)
85 {
86 #ifdef SvPV_shrink_to_cur
87 SvPV_shrink_to_cur (sv);
88 #elif defined (SvPV_renew)
89 SvPV_renew (sv, SvCUR (sv) + 1);
90 #endif
91 }
92 }
93
94 // decode an utf-8 character and return it, or (UV)-1 in
95 // case of an error.
96 // we special-case "safe" characters from U+80 .. U+7FF,
97 // but use the very good perl function to parse anything else.
98 // note that we never call this function for a ascii codepoints
99 inline UV
100 decode_utf8 (unsigned char *s, STRLEN len, STRLEN *clen)
101 {
102 if (expect_false (s[0] > 0xdf || s[0] < 0xc2))
103 return utf8n_to_uvuni (s, len, clen, UTF8_CHECK_ONLY);
104 else if (len > 1 && s[1] >= 0x80 && s[1] <= 0xbf)
105 {
106 *clen = 2;
107 return ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
108 }
109 else
110 {
111 *clen = (STRLEN)-1;
112 return (UV)-1;
113 }
114 }
115
116 /////////////////////////////////////////////////////////////////////////////
117 // encoder
118
119 // structure used for encoding JSON
120 typedef struct
121 {
122 char *cur; // SvPVX (sv) + current output position
123 char *end; // SvEND (sv)
124 SV *sv; // result scalar
125 struct json json;
126 U32 indent; // indentation level
127 U32 maxdepth; // max. indentation/recursion level
128 } enc_t;
129
130 inline void
131 need (enc_t *enc, STRLEN len)
132 {
133 if (expect_false (enc->cur + len >= enc->end))
134 {
135 STRLEN cur = enc->cur - SvPVX (enc->sv);
136 SvGROW (enc->sv, cur + len + 1);
137 enc->cur = SvPVX (enc->sv) + cur;
138 enc->end = SvPVX (enc->sv) + SvLEN (enc->sv) - 1;
139 }
140 }
141
142 inline void
143 encode_ch (enc_t *enc, char ch)
144 {
145 need (enc, 1);
146 *enc->cur++ = ch;
147 }
148
149 static void
150 encode_str (enc_t *enc, char *str, STRLEN len, int is_utf8)
151 {
152 char *end = str + len;
153
154 need (enc, len);
155
156 while (str < end)
157 {
158 unsigned char ch = *(unsigned char *)str;
159
160 if (expect_true (ch >= 0x20 && ch < 0x80)) // most common case
161 {
162 if (expect_false (ch == '"')) // but with slow exceptions
163 {
164 need (enc, len += 1);
165 *enc->cur++ = '\\';
166 *enc->cur++ = '"';
167 }
168 else if (expect_false (ch == '\\'))
169 {
170 need (enc, len += 1);
171 *enc->cur++ = '\\';
172 *enc->cur++ = '\\';
173 }
174 else
175 *enc->cur++ = ch;
176
177 ++str;
178 }
179 else
180 {
181 switch (ch)
182 {
183 case '\010': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'b'; ++str; break;
184 case '\011': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 't'; ++str; break;
185 case '\012': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'n'; ++str; break;
186 case '\014': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'f'; ++str; break;
187 case '\015': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'r'; ++str; break;
188
189 default:
190 {
191 STRLEN clen;
192 UV uch;
193
194 if (is_utf8)
195 {
196 uch = decode_utf8 (str, end - str, &clen);
197 if (clen == (STRLEN)-1)
198 croak ("malformed or illegal unicode character in string [%.11s], cannot convert to JSON", str);
199 }
200 else
201 {
202 uch = ch;
203 clen = 1;
204 }
205
206 if (uch > 0x10FFFFUL)
207 croak ("out of range codepoint (0x%lx) encountered, unrepresentable in JSON", (unsigned long)uch);
208
209 if (uch < 0x80 || enc->json.flags & F_ASCII || (enc->json.flags & F_LATIN1 && uch > 0xFF))
210 {
211 if (uch > 0xFFFFUL)
212 {
213 need (enc, len += 11);
214 sprintf (enc->cur, "\\u%04x\\u%04x",
215 (int)((uch - 0x10000) / 0x400 + 0xD800),
216 (int)((uch - 0x10000) % 0x400 + 0xDC00));
217 enc->cur += 12;
218 }
219 else
220 {
221 static char hexdigit [16] = "0123456789abcdef";
222 need (enc, len += 5);
223 *enc->cur++ = '\\';
224 *enc->cur++ = 'u';
225 *enc->cur++ = hexdigit [ uch >> 12 ];
226 *enc->cur++ = hexdigit [(uch >> 8) & 15];
227 *enc->cur++ = hexdigit [(uch >> 4) & 15];
228 *enc->cur++ = hexdigit [(uch >> 0) & 15];
229 }
230
231 str += clen;
232 }
233 else if (enc->json.flags & F_LATIN1)
234 {
235 *enc->cur++ = uch;
236 str += clen;
237 }
238 else if (is_utf8)
239 {
240 need (enc, len += clen);
241 do
242 {
243 *enc->cur++ = *str++;
244 }
245 while (--clen);
246 }
247 else
248 {
249 need (enc, len += UTF8_MAXBYTES - 1); // never more than 11 bytes needed
250 enc->cur = uvuni_to_utf8_flags (enc->cur, uch, 0);
251 ++str;
252 }
253 }
254 }
255 }
256
257 --len;
258 }
259 }
260
261 inline void
262 encode_indent (enc_t *enc)
263 {
264 if (enc->json.flags & F_INDENT)
265 {
266 int spaces = enc->indent * INDENT_STEP;
267
268 need (enc, spaces);
269 memset (enc->cur, ' ', spaces);
270 enc->cur += spaces;
271 }
272 }
273
274 inline void
275 encode_space (enc_t *enc)
276 {
277 need (enc, 1);
278 encode_ch (enc, ' ');
279 }
280
281 inline void
282 encode_nl (enc_t *enc)
283 {
284 if (enc->json.flags & F_INDENT)
285 {
286 need (enc, 1);
287 encode_ch (enc, '\n');
288 }
289 }
290
291 inline void
292 encode_comma (enc_t *enc)
293 {
294 encode_ch (enc, ',');
295
296 if (enc->json.flags & F_INDENT)
297 encode_nl (enc);
298 else if (enc->json.flags & F_SPACE_AFTER)
299 encode_space (enc);
300 }
301
302 static void encode_sv (enc_t *enc, SV *sv);
303
304 static void
305 encode_av (enc_t *enc, AV *av)
306 {
307 int i, len = av_len (av);
308
309 if (enc->indent >= enc->maxdepth)
310 croak ("data structure too deep (hit recursion limit)");
311
312 encode_ch (enc, '['); encode_nl (enc);
313 ++enc->indent;
314
315 for (i = 0; i <= len; ++i)
316 {
317 encode_indent (enc);
318 encode_sv (enc, *av_fetch (av, i, 0));
319
320 if (i < len)
321 encode_comma (enc);
322 }
323
324 encode_nl (enc);
325
326 --enc->indent;
327 encode_indent (enc); encode_ch (enc, ']');
328 }
329
330 static void
331 encode_he (enc_t *enc, HE *he)
332 {
333 encode_ch (enc, '"');
334
335 if (HeKLEN (he) == HEf_SVKEY)
336 {
337 SV *sv = HeSVKEY (he);
338 STRLEN len;
339 char *str;
340
341 SvGETMAGIC (sv);
342 str = SvPV (sv, len);
343
344 encode_str (enc, str, len, SvUTF8 (sv));
345 }
346 else
347 encode_str (enc, HeKEY (he), HeKLEN (he), HeKUTF8 (he));
348
349 encode_ch (enc, '"');
350
351 if (enc->json.flags & F_SPACE_BEFORE) encode_space (enc);
352 encode_ch (enc, ':');
353 if (enc->json.flags & F_SPACE_AFTER ) encode_space (enc);
354 encode_sv (enc, HeVAL (he));
355 }
356
357 // compare hash entries, used when all keys are bytestrings
358 static int
359 he_cmp_fast (const void *a_, const void *b_)
360 {
361 int cmp;
362
363 HE *a = *(HE **)a_;
364 HE *b = *(HE **)b_;
365
366 STRLEN la = HeKLEN (a);
367 STRLEN lb = HeKLEN (b);
368
369 if (!(cmp = memcmp (HeKEY (a), HeKEY (b), la < lb ? la : lb)))
370 cmp = la - lb;
371
372 return cmp;
373 }
374
375 // compare hash entries, used when some keys are sv's or utf-x
376 static int
377 he_cmp_slow (const void *a, const void *b)
378 {
379 return sv_cmp (HeSVKEY_force (*(HE **)a), HeSVKEY_force (*(HE **)b));
380 }
381
382 static void
383 encode_hv (enc_t *enc, HV *hv)
384 {
385 int count, i;
386
387 if (enc->indent >= enc->maxdepth)
388 croak ("data structure too deep (hit recursion limit)");
389
390 encode_ch (enc, '{'); encode_nl (enc); ++enc->indent;
391
392 if ((count = hv_iterinit (hv)))
393 {
394 // for canonical output we have to sort by keys first
395 // actually, this is mostly due to the stupid so-called
396 // security workaround added somewhere in 5.8.x.
397 // that randomises hash orderings
398 if (enc->json.flags & F_CANONICAL)
399 {
400 int fast = 1;
401 HE *he;
402 #if defined(__BORLANDC__) || defined(_MSC_VER)
403 HE **hes = _alloca (count * sizeof (HE));
404 #else
405 HE *hes [count]; // if your compiler dies here, you need to enable C99 mode
406 #endif
407
408 i = 0;
409 while ((he = hv_iternext (hv)))
410 {
411 hes [i++] = he;
412 if (HeKLEN (he) < 0 || HeKUTF8 (he))
413 fast = 0;
414 }
415
416 assert (i == count);
417
418 if (fast)
419 qsort (hes, count, sizeof (HE *), he_cmp_fast);
420 else
421 {
422 // hack to forcefully disable "use bytes"
423 COP cop = *PL_curcop;
424 cop.op_private = 0;
425
426 ENTER;
427 SAVETMPS;
428
429 SAVEVPTR (PL_curcop);
430 PL_curcop = &cop;
431
432 qsort (hes, count, sizeof (HE *), he_cmp_slow);
433
434 FREETMPS;
435 LEAVE;
436 }
437
438 for (i = 0; i < count; ++i)
439 {
440 encode_indent (enc);
441 encode_he (enc, hes [i]);
442
443 if (i < count - 1)
444 encode_comma (enc);
445 }
446
447 encode_nl (enc);
448 }
449 else
450 {
451 HE *he = hv_iternext (hv);
452
453 for (;;)
454 {
455 encode_indent (enc);
456 encode_he (enc, he);
457
458 if (!(he = hv_iternext (hv)))
459 break;
460
461 encode_comma (enc);
462 }
463
464 encode_nl (enc);
465 }
466 }
467
468 --enc->indent; encode_indent (enc); encode_ch (enc, '}');
469 }
470
471 // encode objects, arrays and special \0=false and \1=true values.
472 static void
473 encode_rv (enc_t *enc, SV *sv)
474 {
475 svtype svt;
476
477 SvGETMAGIC (sv);
478 svt = SvTYPE (sv);
479
480 if (expect_false (SvOBJECT (sv)))
481 {
482 if (SvSTASH (sv) == json_boolean_stash)
483 {
484 if (SvIV (sv) == 0)
485 encode_str (enc, "false", 5, 0);
486 else
487 encode_str (enc, "true", 4, 0);
488 }
489 else
490 {
491 #if 0
492 if (0 && sv_derived_from (rv, "JSON::Literal"))
493 {
494 // not yet
495 }
496 #endif
497 if (enc->json.flags & F_CONV_BLESSED)
498 {
499 // we re-bless the reference to get overload and other niceties right
500 GV *to_json = gv_fetchmethod_autoload (SvSTASH (sv), "TO_JSON", 1);
501
502 if (to_json)
503 {
504 dSP;
505 ENTER;
506 SAVETMPS;
507 PUSHMARK (SP);
508 XPUSHs (sv_bless (sv_2mortal (newRV_inc (sv)), SvSTASH (sv)));
509
510 // calling with G_SCALAR ensures that we always get a 1 reutrn value
511 // check anyways.
512 PUTBACK;
513 assert (1 == call_sv ((SV *)GvCV (to_json), G_SCALAR));
514 SPAGAIN;
515
516 encode_sv (enc, POPs);
517
518 FREETMPS;
519 LEAVE;
520 }
521 else if (enc->json.flags & F_ALLOW_BLESSED)
522 encode_str (enc, "null", 4, 0);
523 else
524 croak ("encountered object '%s', but neither allow_blessed enabled nor TO_JSON method available on it",
525 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
526 }
527 else if (enc->json.flags & F_ALLOW_BLESSED)
528 encode_str (enc, "null", 4, 0);
529 else
530 croak ("encountered object '%s', but neither allow_blessed nor convert_blessed settings are enabled",
531 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
532 }
533 }
534 else if (svt == SVt_PVHV)
535 encode_hv (enc, (HV *)sv);
536 else if (svt == SVt_PVAV)
537 encode_av (enc, (AV *)sv);
538 else if (svt < SVt_PVAV)
539 {
540 if (SvNIOK (sv) && SvIV (sv) == 0)
541 encode_str (enc, "false", 5, 0);
542 else if (SvNIOK (sv) && SvIV (sv) == 1)
543 encode_str (enc, "true", 4, 0);
544 else
545 croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
546 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
547 }
548 else
549 croak ("encountered %s, but JSON can only represent references to arrays or hashes",
550 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
551 }
552
553 static void
554 encode_sv (enc_t *enc, SV *sv)
555 {
556 SvGETMAGIC (sv);
557
558 if (SvPOKp (sv))
559 {
560 STRLEN len;
561 char *str = SvPV (sv, len);
562 encode_ch (enc, '"');
563 encode_str (enc, str, len, SvUTF8 (sv));
564 encode_ch (enc, '"');
565 }
566 else if (SvNOKp (sv))
567 {
568 // trust that perl will do the right thing w.r.t. JSON syntax.
569 need (enc, NV_DIG + 32);
570 Gconvert (SvNVX (sv), NV_DIG, 0, enc->cur);
571 enc->cur += strlen (enc->cur);
572 }
573 else if (SvIOKp (sv))
574 {
575 // we assume we can always read an IV as a UV
576 if (SvUV (sv) & ~(UV)0x7fff)
577 {
578 // large integer, use the (rather slow) snprintf way.
579 need (enc, sizeof (UV) * 3);
580 enc->cur +=
581 SvIsUV(sv)
582 ? snprintf (enc->cur, sizeof (UV) * 3, "%"UVuf, (UV)SvUVX (sv))
583 : snprintf (enc->cur, sizeof (UV) * 3, "%"IVdf, (IV)SvIVX (sv));
584 }
585 else
586 {
587 // optimise the "small number case"
588 // code will likely be branchless and use only a single multiplication
589 I32 i = SvIV (sv);
590 U32 u;
591 char digit, nz = 0;
592
593 need (enc, 6);
594
595 *enc->cur = '-'; enc->cur += i < 0 ? 1 : 0;
596 u = i < 0 ? -i : i;
597
598 // convert to 4.28 fixed-point representation
599 u = u * ((0xfffffff + 10000) / 10000); // 10**5, 5 fractional digits
600
601 // now output digit by digit, each time masking out the integer part
602 // and multiplying by 5 while moving the decimal point one to the right,
603 // resulting in a net multiplication by 10.
604 // we always write the digit to memory but conditionally increment
605 // the pointer, to ease the usage of conditional move instructions.
606 digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffff) * 5;
607 digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffff) * 5;
608 digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffff) * 5;
609 digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffff) * 5;
610 digit = u >> 24; *enc->cur = digit + '0'; enc->cur += 1; // correctly generate '0'
611 }
612 }
613 else if (SvROK (sv))
614 encode_rv (enc, SvRV (sv));
615 else if (!SvOK (sv))
616 encode_str (enc, "null", 4, 0);
617 else
618 croak ("encountered perl type (%s,0x%x) that JSON cannot handle, you might want to report this",
619 SvPV_nolen (sv), SvFLAGS (sv));
620 }
621
622 static SV *
623 encode_json (SV *scalar, struct json *json)
624 {
625 enc_t enc;
626
627 if (!(json->flags & F_ALLOW_NONREF) && !SvROK (scalar))
628 croak ("hash- or arrayref expected (not a simple scalar, use allow_nonref to allow this)");
629
630 enc.json = *json;
631 enc.sv = sv_2mortal (NEWSV (0, INIT_SIZE));
632 enc.cur = SvPVX (enc.sv);
633 enc.end = SvEND (enc.sv);
634 enc.indent = 0;
635 enc.maxdepth = DEC_DEPTH (enc.json.flags);
636
637 SvPOK_only (enc.sv);
638 encode_sv (&enc, scalar);
639
640 SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
641 *SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings
642
643 if (!(enc.json.flags & (F_ASCII | F_LATIN1 | F_UTF8)))
644 SvUTF8_on (enc.sv);
645
646 if (enc.json.flags & F_SHRINK)
647 shrink (enc.sv);
648
649 return enc.sv;
650 }
651
652 /////////////////////////////////////////////////////////////////////////////
653 // decoder
654
655 // structure used for decoding JSON
656 typedef struct
657 {
658 char *cur; // current parser pointer
659 char *end; // end of input string
660 const char *err; // parse error, if != 0
661 struct json json;
662 U32 depth; // recursion depth
663 U32 maxdepth; // recursion depth limit
664 } dec_t;
665
666 inline void
667 decode_ws (dec_t *dec)
668 {
669 for (;;)
670 {
671 char ch = *dec->cur;
672
673 if (ch > 0x20
674 || (ch != 0x20 && ch != 0x0a && ch != 0x0d && ch != 0x09))
675 break;
676
677 ++dec->cur;
678 }
679 }
680
681 #define ERR(reason) SB dec->err = reason; goto fail; SE
682
683 #define EXPECT_CH(ch) SB \
684 if (*dec->cur != ch) \
685 ERR (# ch " expected"); \
686 ++dec->cur; \
687 SE
688
689 #define DEC_INC_DEPTH if (++dec->depth > dec->maxdepth) ERR ("json datastructure exceeds maximum nesting level (set a higher max_depth)")
690 #define DEC_DEC_DEPTH --dec->depth
691
692 static SV *decode_sv (dec_t *dec);
693
694 static signed char decode_hexdigit[256];
695
696 static UV
697 decode_4hex (dec_t *dec)
698 {
699 signed char d1, d2, d3, d4;
700 unsigned char *cur = (unsigned char *)dec->cur;
701
702 d1 = decode_hexdigit [cur [0]]; if (expect_false (d1 < 0)) ERR ("exactly four hexadecimal digits expected");
703 d2 = decode_hexdigit [cur [1]]; if (expect_false (d2 < 0)) ERR ("exactly four hexadecimal digits expected");
704 d3 = decode_hexdigit [cur [2]]; if (expect_false (d3 < 0)) ERR ("exactly four hexadecimal digits expected");
705 d4 = decode_hexdigit [cur [3]]; if (expect_false (d4 < 0)) ERR ("exactly four hexadecimal digits expected");
706
707 dec->cur += 4;
708
709 return ((UV)d1) << 12
710 | ((UV)d2) << 8
711 | ((UV)d3) << 4
712 | ((UV)d4);
713
714 fail:
715 return (UV)-1;
716 }
717
718 static SV *
719 decode_str (dec_t *dec)
720 {
721 SV *sv = 0;
722 int utf8 = 0;
723 char *dec_cur = dec->cur;
724
725 do
726 {
727 char buf [SHORT_STRING_LEN + UTF8_MAXBYTES];
728 char *cur = buf;
729
730 do
731 {
732 unsigned char ch = *(unsigned char *)dec_cur++;
733
734 if (expect_false (ch == '"'))
735 {
736 --dec_cur;
737 break;
738 }
739 else if (expect_false (ch == '\\'))
740 {
741 switch (*dec_cur)
742 {
743 case '\\':
744 case '/':
745 case '"': *cur++ = *dec_cur++; break;
746
747 case 'b': ++dec_cur; *cur++ = '\010'; break;
748 case 't': ++dec_cur; *cur++ = '\011'; break;
749 case 'n': ++dec_cur; *cur++ = '\012'; break;
750 case 'f': ++dec_cur; *cur++ = '\014'; break;
751 case 'r': ++dec_cur; *cur++ = '\015'; break;
752
753 case 'u':
754 {
755 UV lo, hi;
756 ++dec_cur;
757
758 dec->cur = dec_cur;
759 hi = decode_4hex (dec);
760 dec_cur = dec->cur;
761 if (hi == (UV)-1)
762 goto fail;
763
764 // possibly a surrogate pair
765 if (hi >= 0xd800)
766 if (hi < 0xdc00)
767 {
768 if (dec_cur [0] != '\\' || dec_cur [1] != 'u')
769 ERR ("missing low surrogate character in surrogate pair");
770
771 dec_cur += 2;
772
773 dec->cur = dec_cur;
774 lo = decode_4hex (dec);
775 dec_cur = dec->cur;
776 if (lo == (UV)-1)
777 goto fail;
778
779 if (lo < 0xdc00 || lo >= 0xe000)
780 ERR ("surrogate pair expected");
781
782 hi = (hi - 0xD800) * 0x400 + (lo - 0xDC00) + 0x10000;
783 }
784 else if (hi < 0xe000)
785 ERR ("missing high surrogate character in surrogate pair");
786
787 if (hi >= 0x80)
788 {
789 utf8 = 1;
790
791 cur = (char *)uvuni_to_utf8_flags (cur, hi, 0);
792 }
793 else
794 *cur++ = hi;
795 }
796 break;
797
798 default:
799 --dec_cur;
800 ERR ("illegal backslash escape sequence in string");
801 }
802 }
803 else if (expect_true (ch >= 0x20 && ch <= 0x7f))
804 *cur++ = ch;
805 else if (ch >= 0x80)
806 {
807 STRLEN clen;
808 UV uch;
809
810 --dec_cur;
811
812 uch = decode_utf8 (dec_cur, dec->end - dec_cur, &clen);
813 if (clen == (STRLEN)-1)
814 ERR ("malformed UTF-8 character in JSON string");
815
816 do
817 *cur++ = *dec_cur++;
818 while (--clen);
819
820 utf8 = 1;
821 }
822 else
823 {
824 --dec_cur;
825
826 if (!ch)
827 ERR ("unexpected end of string while parsing JSON string");
828 else
829 ERR ("invalid character encountered while parsing JSON string");
830 }
831 }
832 while (cur < buf + SHORT_STRING_LEN);
833
834 {
835 STRLEN len = cur - buf;
836
837 if (sv)
838 {
839 SvGROW (sv, SvCUR (sv) + len + 1);
840 memcpy (SvPVX (sv) + SvCUR (sv), buf, len);
841 SvCUR_set (sv, SvCUR (sv) + len);
842 }
843 else
844 sv = newSVpvn (buf, len);
845 }
846 }
847 while (*dec_cur != '"');
848
849 ++dec_cur;
850
851 if (sv)
852 {
853 SvPOK_only (sv);
854 *SvEND (sv) = 0;
855
856 if (utf8)
857 SvUTF8_on (sv);
858 }
859 else
860 sv = newSVpvn ("", 0);
861
862 dec->cur = dec_cur;
863 return sv;
864
865 fail:
866 dec->cur = dec_cur;
867 return 0;
868 }
869
870 static SV *
871 decode_num (dec_t *dec)
872 {
873 int is_nv = 0;
874 char *start = dec->cur;
875
876 // [minus]
877 if (*dec->cur == '-')
878 ++dec->cur;
879
880 if (*dec->cur == '0')
881 {
882 ++dec->cur;
883 if (*dec->cur >= '0' && *dec->cur <= '9')
884 ERR ("malformed number (leading zero must not be followed by another digit)");
885 }
886 else if (*dec->cur < '0' || *dec->cur > '9')
887 ERR ("malformed number (no digits after initial minus)");
888 else
889 do
890 {
891 ++dec->cur;
892 }
893 while (*dec->cur >= '0' && *dec->cur <= '9');
894
895 // [frac]
896 if (*dec->cur == '.')
897 {
898 ++dec->cur;
899
900 if (*dec->cur < '0' || *dec->cur > '9')
901 ERR ("malformed number (no digits after decimal point)");
902
903 do
904 {
905 ++dec->cur;
906 }
907 while (*dec->cur >= '0' && *dec->cur <= '9');
908
909 is_nv = 1;
910 }
911
912 // [exp]
913 if (*dec->cur == 'e' || *dec->cur == 'E')
914 {
915 ++dec->cur;
916
917 if (*dec->cur == '-' || *dec->cur == '+')
918 ++dec->cur;
919
920 if (*dec->cur < '0' || *dec->cur > '9')
921 ERR ("malformed number (no digits after exp sign)");
922
923 do
924 {
925 ++dec->cur;
926 }
927 while (*dec->cur >= '0' && *dec->cur <= '9');
928
929 is_nv = 1;
930 }
931
932 if (!is_nv)
933 {
934 // special case the rather common 1..4-digit-int case, assumes 32 bit ints or so
935 if (*start == '-')
936 switch (dec->cur - start)
937 {
938 case 2: return newSViv (-( start [1] - '0' * 1));
939 case 3: return newSViv (-( start [1] * 10 + start [2] - '0' * 11));
940 case 4: return newSViv (-( start [1] * 100 + start [2] * 10 + start [3] - '0' * 111));
941 case 5: return newSViv (-(start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 1111));
942 }
943 else
944 switch (dec->cur - start)
945 {
946 case 1: return newSViv ( start [0] - '0' * 1);
947 case 2: return newSViv ( start [0] * 10 + start [1] - '0' * 11);
948 case 3: return newSViv ( start [0] * 100 + start [1] * 10 + start [2] - '0' * 111);
949 case 4: return newSViv ( start [0] * 1000 + start [1] * 100 + start [2] * 10 + start [3] - '0' * 1111);
950 }
951
952 {
953 UV uv;
954 int numtype = grok_number (start, dec->cur - start, &uv);
955 if (numtype & IS_NUMBER_IN_UV)
956 if (numtype & IS_NUMBER_NEG)
957 {
958 if (uv < (UV)IV_MIN)
959 return newSViv (-(IV)uv);
960 }
961 else
962 return newSVuv (uv);
963
964 // here would likely be the place for bigint support
965 }
966 }
967
968 // if we ever support bigint or bigfloat, this is the place for bigfloat
969 return newSVnv (Atof (start));
970
971 fail:
972 return 0;
973 }
974
975 static SV *
976 decode_av (dec_t *dec)
977 {
978 AV *av = newAV ();
979
980 DEC_INC_DEPTH;
981 decode_ws (dec);
982
983 if (*dec->cur == ']')
984 ++dec->cur;
985 else
986 for (;;)
987 {
988 SV *value;
989
990 value = decode_sv (dec);
991 if (!value)
992 goto fail;
993
994 av_push (av, value);
995
996 decode_ws (dec);
997
998 if (*dec->cur == ']')
999 {
1000 ++dec->cur;
1001 break;
1002 }
1003
1004 if (*dec->cur != ',')
1005 ERR (", or ] expected while parsing array");
1006
1007 ++dec->cur;
1008 }
1009
1010 DEC_DEC_DEPTH;
1011 return newRV_noinc ((SV *)av);
1012
1013 fail:
1014 SvREFCNT_dec (av);
1015 DEC_DEC_DEPTH;
1016 return 0;
1017 }
1018
1019 static SV *
1020 decode_hv (dec_t *dec)
1021 {
1022 HV *hv = newHV ();
1023
1024 DEC_INC_DEPTH;
1025 decode_ws (dec);
1026
1027 if (*dec->cur == '}')
1028 ++dec->cur;
1029 else
1030 for (;;)
1031 {
1032 decode_ws (dec); EXPECT_CH ('"');
1033
1034 // heuristic: assume that
1035 // a) decode_str + hv_store_ent are abysmally slow.
1036 // b) most hash keys are short, simple ascii text.
1037 // => try to "fast-match" such strings to avoid
1038 // the overhead of decode_str + hv_store_ent.
1039 {
1040 SV *value;
1041 char *p = dec->cur;
1042 char *e = p + 24; // only try up to 24 bytes
1043
1044 for (;;)
1045 {
1046 // the >= 0x80 is true on most architectures
1047 if (p == e || *p < 0x20 || *p >= 0x80 || *p == '\\')
1048 {
1049 // slow path, back up and use decode_str
1050 SV *key = decode_str (dec);
1051 if (!key)
1052 goto fail;
1053
1054 decode_ws (dec); EXPECT_CH (':');
1055
1056 value = decode_sv (dec);
1057 if (!value)
1058 {
1059 SvREFCNT_dec (key);
1060 goto fail;
1061 }
1062
1063 hv_store_ent (hv, key, value, 0);
1064 SvREFCNT_dec (key);
1065
1066 break;
1067 }
1068 else if (*p == '"')
1069 {
1070 // fast path, got a simple key
1071 char *key = dec->cur;
1072 int len = p - key;
1073 dec->cur = p + 1;
1074
1075 decode_ws (dec); EXPECT_CH (':');
1076
1077 value = decode_sv (dec);
1078 if (!value)
1079 goto fail;
1080
1081 hv_store (hv, key, len, value, 0);
1082
1083 break;
1084 }
1085
1086 ++p;
1087 }
1088 }
1089
1090 decode_ws (dec);
1091
1092 if (*dec->cur == '}')
1093 {
1094 ++dec->cur;
1095 break;
1096 }
1097
1098 if (*dec->cur != ',')
1099 ERR (", or } expected while parsing object/hash");
1100
1101 ++dec->cur;
1102 }
1103
1104 DEC_DEC_DEPTH;
1105 return newRV_noinc ((SV *)hv);
1106
1107 fail:
1108 SvREFCNT_dec (hv);
1109 DEC_DEC_DEPTH;
1110 return 0;
1111 }
1112
1113 static SV *
1114 decode_sv (dec_t *dec)
1115 {
1116 decode_ws (dec);
1117
1118 // the beauty of JSON: you need exactly one character lookahead
1119 // to parse anything.
1120 switch (*dec->cur)
1121 {
1122 case '"': ++dec->cur; return decode_str (dec);
1123 case '[': ++dec->cur; return decode_av (dec);
1124 case '{': ++dec->cur; return decode_hv (dec);
1125
1126 case '-':
1127 case '0': case '1': case '2': case '3': case '4':
1128 case '5': case '6': case '7': case '8': case '9':
1129 return decode_num (dec);
1130
1131 case 't':
1132 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "true", 4))
1133 {
1134 dec->cur += 4;
1135 return SvREFCNT_inc (json_true);
1136 }
1137 else
1138 ERR ("'true' expected");
1139
1140 break;
1141
1142 case 'f':
1143 if (dec->end - dec->cur >= 5 && !memcmp (dec->cur, "false", 5))
1144 {
1145 dec->cur += 5;
1146 return SvREFCNT_inc (json_false);
1147 }
1148 else
1149 ERR ("'false' expected");
1150
1151 break;
1152
1153 case 'n':
1154 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "null", 4))
1155 {
1156 dec->cur += 4;
1157 return newSVsv (&PL_sv_undef);
1158 }
1159 else
1160 ERR ("'null' expected");
1161
1162 break;
1163
1164 default:
1165 ERR ("malformed JSON string, neither array, object, number, string or atom");
1166 break;
1167 }
1168
1169 fail:
1170 return 0;
1171 }
1172
1173 static SV *
1174 decode_json (SV *string, struct json *json, UV *offset_return)
1175 {
1176 dec_t dec;
1177 UV offset;
1178 SV *sv;
1179
1180 SvGETMAGIC (string);
1181 SvUPGRADE (string, SVt_PV);
1182
1183 if (json->flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (json->flags))
1184 croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu",
1185 (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (json->flags));
1186
1187 if (json->flags & F_UTF8)
1188 sv_utf8_downgrade (string, 0);
1189 else
1190 sv_utf8_upgrade (string);
1191
1192 SvGROW (string, SvCUR (string) + 1); // should basically be a NOP
1193
1194 dec.json = *json;
1195 dec.cur = SvPVX (string);
1196 dec.end = SvEND (string);
1197 dec.err = 0;
1198 dec.depth = 0;
1199 dec.maxdepth = DEC_DEPTH (dec.json.flags);
1200
1201 *dec.end = 0; // this should basically be a nop, too, but make sure it's there
1202 sv = decode_sv (&dec);
1203
1204 if (!(offset_return || !sv))
1205 {
1206 // check for trailing garbage
1207 decode_ws (&dec);
1208
1209 if (*dec.cur)
1210 {
1211 dec.err = "garbage after JSON object";
1212 SvREFCNT_dec (sv);
1213 sv = 0;
1214 }
1215 }
1216
1217 if (offset_return || !sv)
1218 {
1219 offset = dec.json.flags & F_UTF8
1220 ? dec.cur - SvPVX (string)
1221 : utf8_distance (dec.cur, SvPVX (string));
1222
1223 if (offset_return)
1224 *offset_return = offset;
1225 }
1226
1227 if (!sv)
1228 {
1229 SV *uni = sv_newmortal ();
1230
1231 // horrible hack to silence warning inside pv_uni_display
1232 COP cop = *PL_curcop;
1233 cop.cop_warnings = pWARN_NONE;
1234 ENTER;
1235 SAVEVPTR (PL_curcop);
1236 PL_curcop = &cop;
1237 pv_uni_display (uni, dec.cur, dec.end - dec.cur, 20, UNI_DISPLAY_QQ);
1238 LEAVE;
1239
1240 croak ("%s, at character offset %d [\"%s\"]",
1241 dec.err,
1242 (int)offset,
1243 dec.cur != dec.end ? SvPV_nolen (uni) : "(end of string)");
1244 }
1245
1246 sv = sv_2mortal (sv);
1247
1248 if (!(dec.json.flags & F_ALLOW_NONREF) && !SvROK (sv))
1249 croak ("JSON text must be an object or array (but found number, string, true, false or null, use allow_nonref to allow this)");
1250
1251 return sv;
1252 }
1253
1254 /////////////////////////////////////////////////////////////////////////////
1255 // XS interface functions
1256
1257 MODULE = JSON::XS PACKAGE = JSON::XS
1258
1259 BOOT:
1260 {
1261 int i;
1262
1263 for (i = 0; i < 256; ++i)
1264 decode_hexdigit [i] =
1265 i >= '0' && i <= '9' ? i - '0'
1266 : i >= 'a' && i <= 'f' ? i - 'a' + 10
1267 : i >= 'A' && i <= 'F' ? i - 'A' + 10
1268 : -1;
1269
1270 json_stash = gv_stashpv ("JSON::XS" , 1);
1271 json_boolean_stash = gv_stashpv ("JSON::XS::Boolean", 1);
1272
1273 json_true = get_sv ("JSON::XS::true" , 1); SvREADONLY_on (json_true );
1274 json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false);
1275 }
1276
1277 PROTOTYPES: DISABLE
1278
1279 SV *new (char *dummy)
1280 CODE:
1281 RETVAL = sv_bless (newRV_noinc (newSVuv (F_DEFAULT)), json_stash);
1282 OUTPUT:
1283 RETVAL
1284
1285 SV *ascii (SV *self, int enable = 1)
1286 ALIAS:
1287 ascii = F_ASCII
1288 latin1 = F_LATIN1
1289 utf8 = F_UTF8
1290 indent = F_INDENT
1291 canonical = F_CANONICAL
1292 space_before = F_SPACE_BEFORE
1293 space_after = F_SPACE_AFTER
1294 pretty = F_PRETTY
1295 allow_nonref = F_ALLOW_NONREF
1296 shrink = F_SHRINK
1297 allow_blessed = F_ALLOW_BLESSED
1298 convert_blessed = F_CONV_BLESSED
1299 CODE:
1300 {
1301 UV *uv = SvJSON (self);
1302 if (enable)
1303 *uv |= ix;
1304 else
1305 *uv &= ~ix;
1306
1307 RETVAL = newSVsv (self);
1308 }
1309 OUTPUT:
1310 RETVAL
1311
1312 SV *max_depth (SV *self, UV max_depth = 0x80000000UL)
1313 CODE:
1314 {
1315 UV *uv = SvJSON (self);
1316 UV log2 = 0;
1317
1318 if (max_depth > 0x80000000UL) max_depth = 0x80000000UL;
1319
1320 while ((1UL << log2) < max_depth)
1321 ++log2;
1322
1323 *uv = *uv & ~F_MAXDEPTH | (log2 << S_MAXDEPTH);
1324
1325 RETVAL = newSVsv (self);
1326 }
1327 OUTPUT:
1328 RETVAL
1329
1330 SV *max_size (SV *self, UV max_size = 0)
1331 CODE:
1332 {
1333 UV *uv = SvJSON (self);
1334 UV log2 = 0;
1335
1336 if (max_size > 0x80000000UL) max_size = 0x80000000UL;
1337 if (max_size == 1) max_size = 2;
1338
1339 while ((1UL << log2) < max_size)
1340 ++log2;
1341
1342 *uv = *uv & ~F_MAXSIZE | (log2 << S_MAXSIZE);
1343
1344 RETVAL = newSVsv (self);
1345 }
1346 OUTPUT:
1347 RETVAL
1348
1349 void encode (SV *self, SV *scalar)
1350 PPCODE:
1351 {
1352 struct json json = { *SvJSON (self) };
1353 XPUSHs (encode_json (scalar, &json));
1354 }
1355
1356 void decode (SV *self, SV *jsonstr)
1357 PPCODE:
1358 {
1359 struct json json = { *SvJSON (self) };
1360 XPUSHs (decode_json (jsonstr, &json, 0));
1361 }
1362
1363 void decode_prefix (SV *self, SV *jsonstr)
1364 PPCODE:
1365 {
1366 UV offset;
1367 struct json json = { *SvJSON (self) };
1368 EXTEND (SP, 2);
1369 PUSHs (decode_json (jsonstr, &json, &offset));
1370 PUSHs (sv_2mortal (newSVuv (offset)));
1371 }
1372
1373 PROTOTYPES: ENABLE
1374
1375 void to_json (SV *scalar)
1376 PPCODE:
1377 {
1378 struct json json = { F_DEFAULT | F_UTF8 };
1379 XPUSHs (encode_json (scalar, &json));
1380 }
1381
1382 void from_json (SV *jsonstr)
1383 PPCODE:
1384 {
1385 struct json json = { F_DEFAULT | F_UTF8 };
1386 XPUSHs (decode_json (jsonstr, &json, 0));
1387 }
1388