ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/JSON-XS/XS.xs
Revision: 1.55
Committed: Mon Jul 23 22:57:40 2007 UTC (16 years, 9 months ago) by root
Branch: MAIN
Changes since 1.54: +7 -1 lines
Log Message:
*** empty log message ***

File Contents

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