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/cvs/JSON-XS/XS.xs
Revision: 1.50
Committed: Mon Jul 2 00:29:38 2007 UTC (16 years, 10 months ago) by root
Branch: MAIN
Changes since 1.49: +5 -2 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, *cb_sk_object;
68 } JSON;
69
70 /////////////////////////////////////////////////////////////////////////////
71 // utility functions
72
73 inline void
74 shrink (SV *sv)
75 {
76 sv_utf8_downgrade (sv, 1);
77 if (SvLEN (sv) > SvCUR (sv) + 1)
78 {
79 #ifdef SvPV_shrink_to_cur
80 SvPV_shrink_to_cur (sv);
81 #elif defined (SvPV_renew)
82 SvPV_renew (sv, SvCUR (sv) + 1);
83 #endif
84 }
85 }
86
87 // decode an utf-8 character and return it, or (UV)-1 in
88 // case of an error.
89 // we special-case "safe" characters from U+80 .. U+7FF,
90 // but use the very good perl function to parse anything else.
91 // note that we never call this function for a ascii codepoints
92 inline UV
93 decode_utf8 (unsigned char *s, STRLEN len, STRLEN *clen)
94 {
95 if (expect_false (s[0] > 0xdf || s[0] < 0xc2))
96 return utf8n_to_uvuni (s, len, clen, UTF8_CHECK_ONLY);
97 else if (len > 1 && s[1] >= 0x80 && s[1] <= 0xbf)
98 {
99 *clen = 2;
100 return ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
101 }
102 else
103 {
104 *clen = (STRLEN)-1;
105 return (UV)-1;
106 }
107 }
108
109 /////////////////////////////////////////////////////////////////////////////
110 // encoder
111
112 // structure used for encoding JSON
113 typedef struct
114 {
115 char *cur; // SvPVX (sv) + current output position
116 char *end; // SvEND (sv)
117 SV *sv; // result scalar
118 JSON json;
119 U32 indent; // indentation level
120 U32 maxdepth; // max. indentation/recursion level
121 } enc_t;
122
123 inline void
124 need (enc_t *enc, STRLEN len)
125 {
126 if (expect_false (enc->cur + len >= enc->end))
127 {
128 STRLEN cur = enc->cur - SvPVX (enc->sv);
129 SvGROW (enc->sv, cur + len + 1);
130 enc->cur = SvPVX (enc->sv) + cur;
131 enc->end = SvPVX (enc->sv) + SvLEN (enc->sv) - 1;
132 }
133 }
134
135 inline void
136 encode_ch (enc_t *enc, char ch)
137 {
138 need (enc, 1);
139 *enc->cur++ = ch;
140 }
141
142 static void
143 encode_str (enc_t *enc, char *str, STRLEN len, int is_utf8)
144 {
145 char *end = str + len;
146
147 need (enc, len);
148
149 while (str < end)
150 {
151 unsigned char ch = *(unsigned char *)str;
152
153 if (expect_true (ch >= 0x20 && ch < 0x80)) // most common case
154 {
155 if (expect_false (ch == '"')) // but with slow exceptions
156 {
157 need (enc, len += 1);
158 *enc->cur++ = '\\';
159 *enc->cur++ = '"';
160 }
161 else if (expect_false (ch == '\\'))
162 {
163 need (enc, len += 1);
164 *enc->cur++ = '\\';
165 *enc->cur++ = '\\';
166 }
167 else
168 *enc->cur++ = ch;
169
170 ++str;
171 }
172 else
173 {
174 switch (ch)
175 {
176 case '\010': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'b'; ++str; break;
177 case '\011': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 't'; ++str; break;
178 case '\012': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'n'; ++str; break;
179 case '\014': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'f'; ++str; break;
180 case '\015': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'r'; ++str; break;
181
182 default:
183 {
184 STRLEN clen;
185 UV uch;
186
187 if (is_utf8)
188 {
189 uch = decode_utf8 (str, end - str, &clen);
190 if (clen == (STRLEN)-1)
191 croak ("malformed or illegal unicode character in string [%.11s], cannot convert to JSON", str);
192 }
193 else
194 {
195 uch = ch;
196 clen = 1;
197 }
198
199 if (uch > 0x10FFFFUL)
200 croak ("out of range codepoint (0x%lx) encountered, unrepresentable in JSON", (unsigned long)uch);
201
202 if (uch < 0x80 || enc->json.flags & F_ASCII || (enc->json.flags & F_LATIN1 && uch > 0xFF))
203 {
204 if (uch > 0xFFFFUL)
205 {
206 need (enc, len += 11);
207 sprintf (enc->cur, "\\u%04x\\u%04x",
208 (int)((uch - 0x10000) / 0x400 + 0xD800),
209 (int)((uch - 0x10000) % 0x400 + 0xDC00));
210 enc->cur += 12;
211 }
212 else
213 {
214 static char hexdigit [16] = "0123456789abcdef";
215 need (enc, len += 5);
216 *enc->cur++ = '\\';
217 *enc->cur++ = 'u';
218 *enc->cur++ = hexdigit [ uch >> 12 ];
219 *enc->cur++ = hexdigit [(uch >> 8) & 15];
220 *enc->cur++ = hexdigit [(uch >> 4) & 15];
221 *enc->cur++ = hexdigit [(uch >> 0) & 15];
222 }
223
224 str += clen;
225 }
226 else if (enc->json.flags & F_LATIN1)
227 {
228 *enc->cur++ = uch;
229 str += clen;
230 }
231 else if (is_utf8)
232 {
233 need (enc, len += clen);
234 do
235 {
236 *enc->cur++ = *str++;
237 }
238 while (--clen);
239 }
240 else
241 {
242 need (enc, len += UTF8_MAXBYTES - 1); // never more than 11 bytes needed
243 enc->cur = uvuni_to_utf8_flags (enc->cur, uch, 0);
244 ++str;
245 }
246 }
247 }
248 }
249
250 --len;
251 }
252 }
253
254 inline void
255 encode_indent (enc_t *enc)
256 {
257 if (enc->json.flags & F_INDENT)
258 {
259 int spaces = enc->indent * INDENT_STEP;
260
261 need (enc, spaces);
262 memset (enc->cur, ' ', spaces);
263 enc->cur += spaces;
264 }
265 }
266
267 inline void
268 encode_space (enc_t *enc)
269 {
270 need (enc, 1);
271 encode_ch (enc, ' ');
272 }
273
274 inline void
275 encode_nl (enc_t *enc)
276 {
277 if (enc->json.flags & F_INDENT)
278 {
279 need (enc, 1);
280 encode_ch (enc, '\n');
281 }
282 }
283
284 inline void
285 encode_comma (enc_t *enc)
286 {
287 encode_ch (enc, ',');
288
289 if (enc->json.flags & F_INDENT)
290 encode_nl (enc);
291 else if (enc->json.flags & F_SPACE_AFTER)
292 encode_space (enc);
293 }
294
295 static void encode_sv (enc_t *enc, SV *sv);
296
297 static void
298 encode_av (enc_t *enc, AV *av)
299 {
300 int i, len = av_len (av);
301
302 if (enc->indent >= enc->maxdepth)
303 croak ("data structure too deep (hit recursion limit)");
304
305 encode_ch (enc, '['); encode_nl (enc);
306 ++enc->indent;
307
308 for (i = 0; i <= len; ++i)
309 {
310 encode_indent (enc);
311 encode_sv (enc, *av_fetch (av, i, 0));
312
313 if (i < len)
314 encode_comma (enc);
315 }
316
317 encode_nl (enc);
318
319 --enc->indent;
320 encode_indent (enc); encode_ch (enc, ']');
321 }
322
323 static void
324 encode_he (enc_t *enc, HE *he)
325 {
326 encode_ch (enc, '"');
327
328 if (HeKLEN (he) == HEf_SVKEY)
329 {
330 SV *sv = HeSVKEY (he);
331 STRLEN len;
332 char *str;
333
334 SvGETMAGIC (sv);
335 str = SvPV (sv, len);
336
337 encode_str (enc, str, len, SvUTF8 (sv));
338 }
339 else
340 encode_str (enc, HeKEY (he), HeKLEN (he), HeKUTF8 (he));
341
342 encode_ch (enc, '"');
343
344 if (enc->json.flags & F_SPACE_BEFORE) encode_space (enc);
345 encode_ch (enc, ':');
346 if (enc->json.flags & F_SPACE_AFTER ) encode_space (enc);
347 encode_sv (enc, HeVAL (he));
348 }
349
350 // compare hash entries, used when all keys are bytestrings
351 static int
352 he_cmp_fast (const void *a_, const void *b_)
353 {
354 int cmp;
355
356 HE *a = *(HE **)a_;
357 HE *b = *(HE **)b_;
358
359 STRLEN la = HeKLEN (a);
360 STRLEN lb = HeKLEN (b);
361
362 if (!(cmp = memcmp (HeKEY (a), HeKEY (b), la < lb ? la : lb)))
363 cmp = la - lb;
364
365 return cmp;
366 }
367
368 // compare hash entries, used when some keys are sv's or utf-x
369 static int
370 he_cmp_slow (const void *a, const void *b)
371 {
372 return sv_cmp (HeSVKEY_force (*(HE **)a), HeSVKEY_force (*(HE **)b));
373 }
374
375 static void
376 encode_hv (enc_t *enc, HV *hv)
377 {
378 int count, i;
379
380 if (enc->indent >= enc->maxdepth)
381 croak ("data structure too deep (hit recursion limit)");
382
383 encode_ch (enc, '{'); encode_nl (enc); ++enc->indent;
384
385 if ((count = hv_iterinit (hv)))
386 {
387 // for canonical output we have to sort by keys first
388 // actually, this is mostly due to the stupid so-called
389 // security workaround added somewhere in 5.8.x.
390 // that randomises hash orderings
391 if (enc->json.flags & F_CANONICAL)
392 {
393 int fast = 1;
394 HE *he;
395 #if defined(__BORLANDC__) || defined(_MSC_VER)
396 HE **hes = _alloca (count * sizeof (HE));
397 #else
398 HE *hes [count]; // if your compiler dies here, you need to enable C99 mode
399 #endif
400
401 i = 0;
402 while ((he = hv_iternext (hv)))
403 {
404 hes [i++] = he;
405 if (HeKLEN (he) < 0 || HeKUTF8 (he))
406 fast = 0;
407 }
408
409 assert (i == count);
410
411 if (fast)
412 qsort (hes, count, sizeof (HE *), he_cmp_fast);
413 else
414 {
415 // hack to forcefully disable "use bytes"
416 COP cop = *PL_curcop;
417 cop.op_private = 0;
418
419 ENTER;
420 SAVETMPS;
421
422 SAVEVPTR (PL_curcop);
423 PL_curcop = &cop;
424
425 qsort (hes, count, sizeof (HE *), he_cmp_slow);
426
427 FREETMPS;
428 LEAVE;
429 }
430
431 for (i = 0; i < count; ++i)
432 {
433 encode_indent (enc);
434 encode_he (enc, hes [i]);
435
436 if (i < count - 1)
437 encode_comma (enc);
438 }
439
440 encode_nl (enc);
441 }
442 else
443 {
444 HE *he = hv_iternext (hv);
445
446 for (;;)
447 {
448 encode_indent (enc);
449 encode_he (enc, he);
450
451 if (!(he = hv_iternext (hv)))
452 break;
453
454 encode_comma (enc);
455 }
456
457 encode_nl (enc);
458 }
459 }
460
461 --enc->indent; encode_indent (enc); encode_ch (enc, '}');
462 }
463
464 // encode objects, arrays and special \0=false and \1=true values.
465 static void
466 encode_rv (enc_t *enc, SV *sv)
467 {
468 svtype svt;
469
470 SvGETMAGIC (sv);
471 svt = SvTYPE (sv);
472
473 if (expect_false (SvOBJECT (sv)))
474 {
475 if (SvSTASH (sv) == json_boolean_stash)
476 {
477 if (SvIV (sv) == 0)
478 encode_str (enc, "false", 5, 0);
479 else
480 encode_str (enc, "true", 4, 0);
481 }
482 else
483 {
484 #if 0
485 if (0 && sv_derived_from (rv, "JSON::Literal"))
486 {
487 // not yet
488 }
489 #endif
490 if (enc->json.flags & F_CONV_BLESSED)
491 {
492 // we re-bless the reference to get overload and other niceties right
493 GV *to_json = gv_fetchmethod_autoload (SvSTASH (sv), "TO_JSON", 1);
494
495 if (to_json)
496 {
497 dSP; ENTER; SAVETMPS; PUSHMARK (SP);
498 XPUSHs (sv_bless (sv_2mortal (newRV_inc (sv)), SvSTASH (sv)));
499
500 // calling with G_SCALAR ensures that we always get a 1 reutrn value
501 // check anyways.
502 PUTBACK;
503 assert (1 == call_sv ((SV *)GvCV (to_json), G_SCALAR));
504 SPAGAIN;
505
506 encode_sv (enc, POPs);
507
508 FREETMPS; LEAVE;
509 }
510 else if (enc->json.flags & F_ALLOW_BLESSED)
511 encode_str (enc, "null", 4, 0);
512 else
513 croak ("encountered object '%s', but neither allow_blessed enabled nor TO_JSON method available on it",
514 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
515 }
516 else if (enc->json.flags & F_ALLOW_BLESSED)
517 encode_str (enc, "null", 4, 0);
518 else
519 croak ("encountered object '%s', but neither allow_blessed nor convert_blessed settings are enabled",
520 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
521 }
522 }
523 else if (svt == SVt_PVHV)
524 encode_hv (enc, (HV *)sv);
525 else if (svt == SVt_PVAV)
526 encode_av (enc, (AV *)sv);
527 else if (svt < SVt_PVAV)
528 {
529 STRLEN len = 0;
530 char *pv = svt ? SvPV (sv, len) : 0;
531
532 if (len == 1 && *pv == '0')
533 encode_str (enc, "false", 5, 0);
534 else if (len == 1 && *pv == '1')
535 encode_str (enc, "true", 4, 0);
536 else
537 croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
538 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
539 }
540 else
541 croak ("encountered %s, but JSON can only represent references to arrays or hashes",
542 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
543 }
544
545 static void
546 encode_sv (enc_t *enc, SV *sv)
547 {
548 SvGETMAGIC (sv);
549
550 if (SvPOKp (sv))
551 {
552 STRLEN len;
553 char *str = SvPV (sv, len);
554 encode_ch (enc, '"');
555 encode_str (enc, str, len, SvUTF8 (sv));
556 encode_ch (enc, '"');
557 }
558 else if (SvNOKp (sv))
559 {
560 // trust that perl will do the right thing w.r.t. JSON syntax.
561 need (enc, NV_DIG + 32);
562 Gconvert (SvNVX (sv), NV_DIG, 0, enc->cur);
563 enc->cur += strlen (enc->cur);
564 }
565 else if (SvIOKp (sv))
566 {
567 // we assume we can always read an IV as a UV
568 if (SvUV (sv) & ~(UV)0x7fff)
569 {
570 // large integer, use the (rather slow) snprintf way.
571 need (enc, sizeof (UV) * 3);
572 enc->cur +=
573 SvIsUV(sv)
574 ? snprintf (enc->cur, sizeof (UV) * 3, "%"UVuf, (UV)SvUVX (sv))
575 : snprintf (enc->cur, sizeof (UV) * 3, "%"IVdf, (IV)SvIVX (sv));
576 }
577 else
578 {
579 // optimise the "small number case"
580 // code will likely be branchless and use only a single multiplication
581 I32 i = SvIV (sv);
582 U32 u;
583 char digit, nz = 0;
584
585 need (enc, 6);
586
587 *enc->cur = '-'; enc->cur += i < 0 ? 1 : 0;
588 u = i < 0 ? -i : i;
589
590 // convert to 4.28 fixed-point representation
591 u = u * ((0xfffffff + 10000) / 10000); // 10**5, 5 fractional digits
592
593 // now output digit by digit, each time masking out the integer part
594 // and multiplying by 5 while moving the decimal point one to the right,
595 // resulting in a net multiplication by 10.
596 // we always write the digit to memory but conditionally increment
597 // the pointer, to ease the usage of conditional move instructions.
598 digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffff) * 5;
599 digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffff) * 5;
600 digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffff) * 5;
601 digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffff) * 5;
602 digit = u >> 24; *enc->cur = digit + '0'; enc->cur += 1; // correctly generate '0'
603 }
604 }
605 else if (SvROK (sv))
606 encode_rv (enc, SvRV (sv));
607 else if (!SvOK (sv))
608 encode_str (enc, "null", 4, 0);
609 else
610 croak ("encountered perl type (%s,0x%x) that JSON cannot handle, you might want to report this",
611 SvPV_nolen (sv), SvFLAGS (sv));
612 }
613
614 static SV *
615 encode_json (SV *scalar, JSON *json)
616 {
617 enc_t enc;
618
619 if (!(json->flags & F_ALLOW_NONREF) && !SvROK (scalar))
620 croak ("hash- or arrayref expected (not a simple scalar, use allow_nonref to allow this)");
621
622 enc.json = *json;
623 enc.sv = sv_2mortal (NEWSV (0, INIT_SIZE));
624 enc.cur = SvPVX (enc.sv);
625 enc.end = SvEND (enc.sv);
626 enc.indent = 0;
627 enc.maxdepth = DEC_DEPTH (enc.json.flags);
628
629 SvPOK_only (enc.sv);
630 encode_sv (&enc, scalar);
631
632 SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
633 *SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings
634
635 if (!(enc.json.flags & (F_ASCII | F_LATIN1 | F_UTF8)))
636 SvUTF8_on (enc.sv);
637
638 if (enc.json.flags & F_SHRINK)
639 shrink (enc.sv);
640
641 return enc.sv;
642 }
643
644 /////////////////////////////////////////////////////////////////////////////
645 // decoder
646
647 // structure used for decoding JSON
648 typedef struct
649 {
650 char *cur; // current parser pointer
651 char *end; // end of input string
652 const char *err; // parse error, if != 0
653 JSON json;
654 U32 depth; // recursion depth
655 U32 maxdepth; // recursion depth limit
656 } dec_t;
657
658 inline void
659 decode_ws (dec_t *dec)
660 {
661 for (;;)
662 {
663 char ch = *dec->cur;
664
665 if (ch > 0x20
666 || (ch != 0x20 && ch != 0x0a && ch != 0x0d && ch != 0x09))
667 break;
668
669 ++dec->cur;
670 }
671 }
672
673 #define ERR(reason) SB dec->err = reason; goto fail; SE
674
675 #define EXPECT_CH(ch) SB \
676 if (*dec->cur != ch) \
677 ERR (# ch " expected"); \
678 ++dec->cur; \
679 SE
680
681 #define DEC_INC_DEPTH if (++dec->depth > dec->maxdepth) ERR ("json datastructure exceeds maximum nesting level (set a higher max_depth)")
682 #define DEC_DEC_DEPTH --dec->depth
683
684 static SV *decode_sv (dec_t *dec);
685
686 static signed char decode_hexdigit[256];
687
688 static UV
689 decode_4hex (dec_t *dec)
690 {
691 signed char d1, d2, d3, d4;
692 unsigned char *cur = (unsigned char *)dec->cur;
693
694 d1 = decode_hexdigit [cur [0]]; if (expect_false (d1 < 0)) ERR ("exactly four hexadecimal digits expected");
695 d2 = decode_hexdigit [cur [1]]; if (expect_false (d2 < 0)) ERR ("exactly four hexadecimal digits expected");
696 d3 = decode_hexdigit [cur [2]]; if (expect_false (d3 < 0)) ERR ("exactly four hexadecimal digits expected");
697 d4 = decode_hexdigit [cur [3]]; if (expect_false (d4 < 0)) ERR ("exactly four hexadecimal digits expected");
698
699 dec->cur += 4;
700
701 return ((UV)d1) << 12
702 | ((UV)d2) << 8
703 | ((UV)d3) << 4
704 | ((UV)d4);
705
706 fail:
707 return (UV)-1;
708 }
709
710 static SV *
711 decode_str (dec_t *dec)
712 {
713 SV *sv = 0;
714 int utf8 = 0;
715 char *dec_cur = dec->cur;
716
717 do
718 {
719 char buf [SHORT_STRING_LEN + UTF8_MAXBYTES];
720 char *cur = buf;
721
722 do
723 {
724 unsigned char ch = *(unsigned char *)dec_cur++;
725
726 if (expect_false (ch == '"'))
727 {
728 --dec_cur;
729 break;
730 }
731 else if (expect_false (ch == '\\'))
732 {
733 switch (*dec_cur)
734 {
735 case '\\':
736 case '/':
737 case '"': *cur++ = *dec_cur++; break;
738
739 case 'b': ++dec_cur; *cur++ = '\010'; break;
740 case 't': ++dec_cur; *cur++ = '\011'; break;
741 case 'n': ++dec_cur; *cur++ = '\012'; break;
742 case 'f': ++dec_cur; *cur++ = '\014'; break;
743 case 'r': ++dec_cur; *cur++ = '\015'; break;
744
745 case 'u':
746 {
747 UV lo, hi;
748 ++dec_cur;
749
750 dec->cur = dec_cur;
751 hi = decode_4hex (dec);
752 dec_cur = dec->cur;
753 if (hi == (UV)-1)
754 goto fail;
755
756 // possibly a surrogate pair
757 if (hi >= 0xd800)
758 if (hi < 0xdc00)
759 {
760 if (dec_cur [0] != '\\' || dec_cur [1] != 'u')
761 ERR ("missing low surrogate character in surrogate pair");
762
763 dec_cur += 2;
764
765 dec->cur = dec_cur;
766 lo = decode_4hex (dec);
767 dec_cur = dec->cur;
768 if (lo == (UV)-1)
769 goto fail;
770
771 if (lo < 0xdc00 || lo >= 0xe000)
772 ERR ("surrogate pair expected");
773
774 hi = (hi - 0xD800) * 0x400 + (lo - 0xDC00) + 0x10000;
775 }
776 else if (hi < 0xe000)
777 ERR ("missing high surrogate character in surrogate pair");
778
779 if (hi >= 0x80)
780 {
781 utf8 = 1;
782
783 cur = (char *)uvuni_to_utf8_flags (cur, hi, 0);
784 }
785 else
786 *cur++ = hi;
787 }
788 break;
789
790 default:
791 --dec_cur;
792 ERR ("illegal backslash escape sequence in string");
793 }
794 }
795 else if (expect_true (ch >= 0x20 && ch <= 0x7f))
796 *cur++ = ch;
797 else if (ch >= 0x80)
798 {
799 STRLEN clen;
800 UV uch;
801
802 --dec_cur;
803
804 uch = decode_utf8 (dec_cur, dec->end - dec_cur, &clen);
805 if (clen == (STRLEN)-1)
806 ERR ("malformed UTF-8 character in JSON string");
807
808 do
809 *cur++ = *dec_cur++;
810 while (--clen);
811
812 utf8 = 1;
813 }
814 else
815 {
816 --dec_cur;
817
818 if (!ch)
819 ERR ("unexpected end of string while parsing JSON string");
820 else
821 ERR ("invalid character encountered while parsing JSON string");
822 }
823 }
824 while (cur < buf + SHORT_STRING_LEN);
825
826 {
827 STRLEN len = cur - buf;
828
829 if (sv)
830 {
831 SvGROW (sv, SvCUR (sv) + len + 1);
832 memcpy (SvPVX (sv) + SvCUR (sv), buf, len);
833 SvCUR_set (sv, SvCUR (sv) + len);
834 }
835 else
836 sv = newSVpvn (buf, len);
837 }
838 }
839 while (*dec_cur != '"');
840
841 ++dec_cur;
842
843 if (sv)
844 {
845 SvPOK_only (sv);
846 *SvEND (sv) = 0;
847
848 if (utf8)
849 SvUTF8_on (sv);
850 }
851 else
852 sv = newSVpvn ("", 0);
853
854 dec->cur = dec_cur;
855 return sv;
856
857 fail:
858 dec->cur = dec_cur;
859 return 0;
860 }
861
862 static SV *
863 decode_num (dec_t *dec)
864 {
865 int is_nv = 0;
866 char *start = dec->cur;
867
868 // [minus]
869 if (*dec->cur == '-')
870 ++dec->cur;
871
872 if (*dec->cur == '0')
873 {
874 ++dec->cur;
875 if (*dec->cur >= '0' && *dec->cur <= '9')
876 ERR ("malformed number (leading zero must not be followed by another digit)");
877 }
878 else if (*dec->cur < '0' || *dec->cur > '9')
879 ERR ("malformed number (no digits after initial minus)");
880 else
881 do
882 {
883 ++dec->cur;
884 }
885 while (*dec->cur >= '0' && *dec->cur <= '9');
886
887 // [frac]
888 if (*dec->cur == '.')
889 {
890 ++dec->cur;
891
892 if (*dec->cur < '0' || *dec->cur > '9')
893 ERR ("malformed number (no digits after decimal point)");
894
895 do
896 {
897 ++dec->cur;
898 }
899 while (*dec->cur >= '0' && *dec->cur <= '9');
900
901 is_nv = 1;
902 }
903
904 // [exp]
905 if (*dec->cur == 'e' || *dec->cur == 'E')
906 {
907 ++dec->cur;
908
909 if (*dec->cur == '-' || *dec->cur == '+')
910 ++dec->cur;
911
912 if (*dec->cur < '0' || *dec->cur > '9')
913 ERR ("malformed number (no digits after exp sign)");
914
915 do
916 {
917 ++dec->cur;
918 }
919 while (*dec->cur >= '0' && *dec->cur <= '9');
920
921 is_nv = 1;
922 }
923
924 if (!is_nv)
925 {
926 // special case the rather common 1..4-digit-int case, assumes 32 bit ints or so
927 if (*start == '-')
928 switch (dec->cur - start)
929 {
930 case 2: return newSViv (-( start [1] - '0' * 1));
931 case 3: return newSViv (-( start [1] * 10 + start [2] - '0' * 11));
932 case 4: return newSViv (-( start [1] * 100 + start [2] * 10 + start [3] - '0' * 111));
933 case 5: return newSViv (-(start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 1111));
934 }
935 else
936 switch (dec->cur - start)
937 {
938 case 1: return newSViv ( start [0] - '0' * 1);
939 case 2: return newSViv ( start [0] * 10 + start [1] - '0' * 11);
940 case 3: return newSViv ( start [0] * 100 + start [1] * 10 + start [2] - '0' * 111);
941 case 4: return newSViv ( start [0] * 1000 + start [1] * 100 + start [2] * 10 + start [3] - '0' * 1111);
942 }
943
944 {
945 UV uv;
946 int numtype = grok_number (start, dec->cur - start, &uv);
947 if (numtype & IS_NUMBER_IN_UV)
948 if (numtype & IS_NUMBER_NEG)
949 {
950 if (uv < (UV)IV_MIN)
951 return newSViv (-(IV)uv);
952 }
953 else
954 return newSVuv (uv);
955
956 // here would likely be the place for bigint support
957 }
958 }
959
960 // if we ever support bigint or bigfloat, this is the place for bigfloat
961 return newSVnv (Atof (start));
962
963 fail:
964 return 0;
965 }
966
967 static SV *
968 decode_av (dec_t *dec)
969 {
970 AV *av = newAV ();
971
972 DEC_INC_DEPTH;
973 decode_ws (dec);
974
975 if (*dec->cur == ']')
976 ++dec->cur;
977 else
978 for (;;)
979 {
980 SV *value;
981
982 value = decode_sv (dec);
983 if (!value)
984 goto fail;
985
986 av_push (av, value);
987
988 decode_ws (dec);
989
990 if (*dec->cur == ']')
991 {
992 ++dec->cur;
993 break;
994 }
995
996 if (*dec->cur != ',')
997 ERR (", or ] expected while parsing array");
998
999 ++dec->cur;
1000 }
1001
1002 DEC_DEC_DEPTH;
1003 return newRV_noinc ((SV *)av);
1004
1005 fail:
1006 SvREFCNT_dec (av);
1007 DEC_DEC_DEPTH;
1008 return 0;
1009 }
1010
1011 static SV *
1012 decode_hv (dec_t *dec)
1013 {
1014 SV *sv;
1015 HV *hv = newHV ();
1016
1017 DEC_INC_DEPTH;
1018 decode_ws (dec);
1019
1020 if (*dec->cur == '}')
1021 ++dec->cur;
1022 else
1023 for (;;)
1024 {
1025 decode_ws (dec); EXPECT_CH ('"');
1026
1027 // heuristic: assume that
1028 // a) decode_str + hv_store_ent are abysmally slow.
1029 // b) most hash keys are short, simple ascii text.
1030 // => try to "fast-match" such strings to avoid
1031 // the overhead of decode_str + hv_store_ent.
1032 {
1033 SV *value;
1034 char *p = dec->cur;
1035 char *e = p + 24; // only try up to 24 bytes
1036
1037 for (;;)
1038 {
1039 // the >= 0x80 is true on most architectures
1040 if (p == e || *p < 0x20 || *p >= 0x80 || *p == '\\')
1041 {
1042 // slow path, back up and use decode_str
1043 SV *key = decode_str (dec);
1044 if (!key)
1045 goto fail;
1046
1047 decode_ws (dec); EXPECT_CH (':');
1048
1049 value = decode_sv (dec);
1050 if (!value)
1051 {
1052 SvREFCNT_dec (key);
1053 goto fail;
1054 }
1055
1056 hv_store_ent (hv, key, value, 0);
1057 SvREFCNT_dec (key);
1058
1059 break;
1060 }
1061 else if (*p == '"')
1062 {
1063 // fast path, got a simple key
1064 char *key = dec->cur;
1065 int len = p - key;
1066 dec->cur = p + 1;
1067
1068 decode_ws (dec); EXPECT_CH (':');
1069
1070 value = decode_sv (dec);
1071 if (!value)
1072 goto fail;
1073
1074 hv_store (hv, key, len, value, 0);
1075
1076 break;
1077 }
1078
1079 ++p;
1080 }
1081 }
1082
1083 decode_ws (dec);
1084
1085 if (*dec->cur == '}')
1086 {
1087 ++dec->cur;
1088 break;
1089 }
1090
1091 if (*dec->cur != ',')
1092 ERR (", or } expected while parsing object/hash");
1093
1094 ++dec->cur;
1095 }
1096
1097 DEC_DEC_DEPTH;
1098 sv = newRV_noinc ((SV *)hv);
1099
1100 // check filter callbacks
1101 if (dec->json.flags & F_HOOK)
1102 {
1103 ENTER; SAVETMPS;
1104
1105 if (HvKEYS (hv) == 1 && dec->json.cb_sk_object)
1106 {
1107 int count;
1108
1109 dSP; PUSHMARK (SP);
1110 XPUSHs (sv_2mortal (sv));
1111
1112 PUTBACK; count = call_sv (dec->json.cb_sk_object, G_ARRAY); SPAGAIN;
1113
1114 if (count == 1)
1115 sv = newSVsv (POPs);
1116 else
1117 SvREFCNT_inc (sv);
1118 }
1119
1120 if (dec->json.cb_object)
1121 {
1122 int count;
1123
1124 dSP; ENTER; SAVETMPS; PUSHMARK (SP);
1125 XPUSHs (sv_2mortal (sv));
1126
1127 PUTBACK; count = call_sv (dec->json.cb_object, G_ARRAY); SPAGAIN;
1128
1129 if (count == 1)
1130 sv = newSVsv (POPs);
1131 else
1132 SvREFCNT_inc (sv);
1133 }
1134
1135 FREETMPS; LEAVE;
1136 }
1137
1138 return newRV_noinc ((SV *)hv);
1139
1140 fail:
1141 SvREFCNT_dec (hv);
1142 DEC_DEC_DEPTH;
1143 return 0;
1144 }
1145
1146 static SV *
1147 decode_sv (dec_t *dec)
1148 {
1149 decode_ws (dec);
1150
1151 // the beauty of JSON: you need exactly one character lookahead
1152 // to parse anything.
1153 switch (*dec->cur)
1154 {
1155 case '"': ++dec->cur; return decode_str (dec);
1156 case '[': ++dec->cur; return decode_av (dec);
1157 case '{': ++dec->cur; return decode_hv (dec);
1158
1159 case '-':
1160 case '0': case '1': case '2': case '3': case '4':
1161 case '5': case '6': case '7': case '8': case '9':
1162 return decode_num (dec);
1163
1164 case 't':
1165 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "true", 4))
1166 {
1167 dec->cur += 4;
1168 return SvREFCNT_inc (json_true);
1169 }
1170 else
1171 ERR ("'true' expected");
1172
1173 break;
1174
1175 case 'f':
1176 if (dec->end - dec->cur >= 5 && !memcmp (dec->cur, "false", 5))
1177 {
1178 dec->cur += 5;
1179 return SvREFCNT_inc (json_false);
1180 }
1181 else
1182 ERR ("'false' expected");
1183
1184 break;
1185
1186 case 'n':
1187 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "null", 4))
1188 {
1189 dec->cur += 4;
1190 return newSVsv (&PL_sv_undef);
1191 }
1192 else
1193 ERR ("'null' expected");
1194
1195 break;
1196
1197 default:
1198 ERR ("malformed JSON string, neither array, object, number, string or atom");
1199 break;
1200 }
1201
1202 fail:
1203 return 0;
1204 }
1205
1206 static SV *
1207 decode_json (SV *string, JSON *json, UV *offset_return)
1208 {
1209 dec_t dec;
1210 UV offset;
1211 SV *sv;
1212
1213 SvGETMAGIC (string);
1214 SvUPGRADE (string, SVt_PV);
1215
1216 if (json->flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (json->flags))
1217 croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu",
1218 (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (json->flags));
1219
1220 if (json->flags & F_UTF8)
1221 sv_utf8_downgrade (string, 0);
1222 else
1223 sv_utf8_upgrade (string);
1224
1225 SvGROW (string, SvCUR (string) + 1); // should basically be a NOP
1226
1227 dec.json = *json;
1228 dec.cur = SvPVX (string);
1229 dec.end = SvEND (string);
1230 dec.err = 0;
1231 dec.depth = 0;
1232 dec.maxdepth = DEC_DEPTH (dec.json.flags);
1233
1234 if (dec.json.cb_object || dec.json.cb_sk_object)
1235 dec.json.flags |= F_HOOK;
1236
1237 *dec.end = 0; // this should basically be a nop, too, but make sure it's there
1238 sv = decode_sv (&dec);
1239
1240 if (!(offset_return || !sv))
1241 {
1242 // check for trailing garbage
1243 decode_ws (&dec);
1244
1245 if (*dec.cur)
1246 {
1247 dec.err = "garbage after JSON object";
1248 SvREFCNT_dec (sv);
1249 sv = 0;
1250 }
1251 }
1252
1253 if (offset_return || !sv)
1254 {
1255 offset = dec.json.flags & F_UTF8
1256 ? dec.cur - SvPVX (string)
1257 : utf8_distance (dec.cur, SvPVX (string));
1258
1259 if (offset_return)
1260 *offset_return = offset;
1261 }
1262
1263 if (!sv)
1264 {
1265 SV *uni = sv_newmortal ();
1266
1267 // horrible hack to silence warning inside pv_uni_display
1268 COP cop = *PL_curcop;
1269 cop.cop_warnings = pWARN_NONE;
1270 ENTER;
1271 SAVEVPTR (PL_curcop);
1272 PL_curcop = &cop;
1273 pv_uni_display (uni, dec.cur, dec.end - dec.cur, 20, UNI_DISPLAY_QQ);
1274 LEAVE;
1275
1276 croak ("%s, at character offset %d [\"%s\"]",
1277 dec.err,
1278 (int)offset,
1279 dec.cur != dec.end ? SvPV_nolen (uni) : "(end of string)");
1280 }
1281
1282 sv = sv_2mortal (sv);
1283
1284 if (!(dec.json.flags & F_ALLOW_NONREF) && !SvROK (sv))
1285 croak ("JSON text must be an object or array (but found number, string, true, false or null, use allow_nonref to allow this)");
1286
1287 return sv;
1288 }
1289
1290 /////////////////////////////////////////////////////////////////////////////
1291 // XS interface functions
1292
1293 MODULE = JSON::XS PACKAGE = JSON::XS
1294
1295 BOOT:
1296 {
1297 int i;
1298
1299 for (i = 0; i < 256; ++i)
1300 decode_hexdigit [i] =
1301 i >= '0' && i <= '9' ? i - '0'
1302 : i >= 'a' && i <= 'f' ? i - 'a' + 10
1303 : i >= 'A' && i <= 'F' ? i - 'A' + 10
1304 : -1;
1305
1306 json_stash = gv_stashpv ("JSON::XS" , 1);
1307 json_boolean_stash = gv_stashpv ("JSON::XS::Boolean", 1);
1308
1309 json_true = get_sv ("JSON::XS::true" , 1); SvREADONLY_on (json_true );
1310 json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false);
1311 }
1312
1313 PROTOTYPES: DISABLE
1314
1315 void new (char *klass)
1316 PPCODE:
1317 {
1318 SV *pv = NEWSV (0, sizeof (JSON));
1319 SvPOK_only (pv);
1320 Zero (SvPVX (pv), 1, JSON);
1321 ((JSON *)SvPVX (pv))->flags = F_DEFAULT;
1322 XPUSHs (sv_2mortal (sv_bless (newRV_noinc (pv), json_stash)));
1323 }
1324
1325 void ascii (JSON *self, int enable = 1)
1326 ALIAS:
1327 ascii = F_ASCII
1328 latin1 = F_LATIN1
1329 utf8 = F_UTF8
1330 indent = F_INDENT
1331 canonical = F_CANONICAL
1332 space_before = F_SPACE_BEFORE
1333 space_after = F_SPACE_AFTER
1334 pretty = F_PRETTY
1335 allow_nonref = F_ALLOW_NONREF
1336 shrink = F_SHRINK
1337 allow_blessed = F_ALLOW_BLESSED
1338 convert_blessed = F_CONV_BLESSED
1339 PPCODE:
1340 {
1341 if (enable)
1342 self->flags |= ix;
1343 else
1344 self->flags &= ~ix;
1345
1346 XPUSHs (ST (0));
1347 }
1348
1349 void max_depth (JSON *self, UV max_depth = 0x80000000UL)
1350 PPCODE:
1351 {
1352 UV log2 = 0;
1353
1354 if (max_depth > 0x80000000UL) max_depth = 0x80000000UL;
1355
1356 while ((1UL << log2) < max_depth)
1357 ++log2;
1358
1359 self->flags = self->flags & ~F_MAXDEPTH | (log2 << S_MAXDEPTH);
1360
1361 XPUSHs (ST (0));
1362 }
1363
1364 void max_size (JSON *self, UV max_size = 0)
1365 PPCODE:
1366 {
1367 UV log2 = 0;
1368
1369 if (max_size > 0x80000000UL) max_size = 0x80000000UL;
1370 if (max_size == 1) max_size = 2;
1371
1372 while ((1UL << log2) < max_size)
1373 ++log2;
1374
1375 self->flags = self->flags & ~F_MAXSIZE | (log2 << S_MAXSIZE);
1376
1377 XPUSHs (ST (0));
1378 }
1379
1380 void filter_json_objects (JSON *self, SV *cb = &PL_sv_undef)
1381 ALIAS:
1382 filter_sk_json_objects = 1
1383 PPCODE:
1384 {
1385 if (!SvOK (cb))
1386 cb = 0;
1387
1388 switch (ix)
1389 {
1390 case 0: self->cb_object = cb; break;
1391 case 1: self->cb_sk_object = cb; break;
1392 }
1393
1394 XPUSHs (ST (0));
1395 }
1396
1397 void encode (JSON *self, SV *scalar)
1398 PPCODE:
1399 XPUSHs (encode_json (scalar, self));
1400
1401 void decode (JSON *self, SV *jsonstr)
1402 PPCODE:
1403 XPUSHs (decode_json (jsonstr, self, 0));
1404
1405 void decode_prefix (JSON *self, SV *jsonstr)
1406 PPCODE:
1407 {
1408 UV offset;
1409 EXTEND (SP, 2);
1410 PUSHs (decode_json (jsonstr, self, &offset));
1411 PUSHs (sv_2mortal (newSVuv (offset)));
1412 }
1413
1414 PROTOTYPES: ENABLE
1415
1416 void to_json (SV *scalar)
1417 PPCODE:
1418 {
1419 JSON json = { F_DEFAULT | F_UTF8 };
1420 XPUSHs (encode_json (scalar, &json));
1421 }
1422
1423 void from_json (SV *jsonstr)
1424 PPCODE:
1425 {
1426 JSON json = { F_DEFAULT | F_UTF8 };
1427 XPUSHs (decode_json (jsonstr, &json, 0));
1428 }
1429