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/cvs/JSON-XS/XS.xs
Revision: 1.56
Committed: Thu Jul 26 11:33:35 2007 UTC (16 years, 9 months ago) by root
Branch: MAIN
CVS Tags: rel-1_43
Changes since 1.55: +25 -10 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 #include <float.h>
10
11 #if defined(__BORLANDC__) || defined(_MSC_VER)
12 # define snprintf _snprintf // C compilers have this in stdio.h
13 #endif
14
15 // some old perls do not have this, try to make it work, no
16 // guarentees, though. if it breaks, you get to keep the pieces.
17 #ifndef UTF8_MAXBYTES
18 # define UTF8_MAXBYTES 13
19 #endif
20
21 #define F_ASCII 0x00000001UL
22 #define F_LATIN1 0x00000002UL
23 #define F_UTF8 0x00000004UL
24 #define F_INDENT 0x00000008UL
25 #define F_CANONICAL 0x00000010UL
26 #define F_SPACE_BEFORE 0x00000020UL
27 #define F_SPACE_AFTER 0x00000040UL
28 #define F_ALLOW_NONREF 0x00000100UL
29 #define F_SHRINK 0x00000200UL
30 #define F_ALLOW_BLESSED 0x00000400UL
31 #define F_CONV_BLESSED 0x00000800UL
32 #define F_MAXDEPTH 0xf8000000UL
33 #define S_MAXDEPTH 27
34 #define F_MAXSIZE 0x01f00000UL
35 #define S_MAXSIZE 20
36 #define F_HOOK 0x00080000UL // some hooks exist, so slow-path processing
37
38 #define DEC_DEPTH(flags) (1UL << ((flags & F_MAXDEPTH) >> S_MAXDEPTH))
39 #define DEC_SIZE(flags) (1UL << ((flags & F_MAXSIZE ) >> S_MAXSIZE ))
40
41 #define F_PRETTY F_INDENT | F_SPACE_BEFORE | F_SPACE_AFTER
42 #define F_DEFAULT (9UL << S_MAXDEPTH)
43
44 #define INIT_SIZE 32 // initial scalar size to be allocated
45 #define INDENT_STEP 3 // spaces per indentation level
46
47 #define SHORT_STRING_LEN 16384 // special-case strings of up to this size
48
49 #define SB do {
50 #define SE } while (0)
51
52 #if __GNUC__ >= 3
53 # define expect(expr,value) __builtin_expect ((expr),(value))
54 # define inline inline
55 #else
56 # define expect(expr,value) (expr)
57 # define inline static
58 #endif
59
60 #define expect_false(expr) expect ((expr) != 0, 0)
61 #define expect_true(expr) expect ((expr) != 0, 1)
62
63 static HV *json_stash, *json_boolean_stash; // JSON::XS::
64 static SV *json_true, *json_false;
65
66 typedef struct {
67 U32 flags;
68 SV *cb_object;
69 HV *cb_sk_object;
70 } JSON;
71
72 /////////////////////////////////////////////////////////////////////////////
73 // utility functions
74
75 inline void
76 shrink (SV *sv)
77 {
78 sv_utf8_downgrade (sv, 1);
79 if (SvLEN (sv) > SvCUR (sv) + 1)
80 {
81 #ifdef SvPV_shrink_to_cur
82 SvPV_shrink_to_cur (sv);
83 #elif defined (SvPV_renew)
84 SvPV_renew (sv, SvCUR (sv) + 1);
85 #endif
86 }
87 }
88
89 // decode an utf-8 character and return it, or (UV)-1 in
90 // case of an error.
91 // we special-case "safe" characters from U+80 .. U+7FF,
92 // but use the very good perl function to parse anything else.
93 // note that we never call this function for a ascii codepoints
94 inline UV
95 decode_utf8 (unsigned char *s, STRLEN len, STRLEN *clen)
96 {
97 if (expect_false (s[0] > 0xdf || s[0] < 0xc2))
98 return utf8n_to_uvuni (s, len, clen, UTF8_CHECK_ONLY);
99 else if (len > 1 && s[1] >= 0x80 && s[1] <= 0xbf)
100 {
101 *clen = 2;
102 return ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
103 }
104 else
105 {
106 *clen = (STRLEN)-1;
107 return (UV)-1;
108 }
109 }
110
111 /////////////////////////////////////////////////////////////////////////////
112 // encoder
113
114 // structure used for encoding JSON
115 typedef struct
116 {
117 char *cur; // SvPVX (sv) + current output position
118 char *end; // SvEND (sv)
119 SV *sv; // result scalar
120 JSON json;
121 U32 indent; // indentation level
122 U32 maxdepth; // max. indentation/recursion level
123 } enc_t;
124
125 inline void
126 need (enc_t *enc, STRLEN len)
127 {
128 if (expect_false (enc->cur + len >= enc->end))
129 {
130 STRLEN cur = enc->cur - SvPVX (enc->sv);
131 SvGROW (enc->sv, cur + len + 1);
132 enc->cur = SvPVX (enc->sv) + cur;
133 enc->end = SvPVX (enc->sv) + SvLEN (enc->sv) - 1;
134 }
135 }
136
137 inline void
138 encode_ch (enc_t *enc, char ch)
139 {
140 need (enc, 1);
141 *enc->cur++ = ch;
142 }
143
144 static void
145 encode_str (enc_t *enc, char *str, STRLEN len, int is_utf8)
146 {
147 char *end = str + len;
148
149 need (enc, len);
150
151 while (str < end)
152 {
153 unsigned char ch = *(unsigned char *)str;
154
155 if (expect_true (ch >= 0x20 && ch < 0x80)) // most common case
156 {
157 if (expect_false (ch == '"')) // but with slow exceptions
158 {
159 need (enc, len += 1);
160 *enc->cur++ = '\\';
161 *enc->cur++ = '"';
162 }
163 else if (expect_false (ch == '\\'))
164 {
165 need (enc, len += 1);
166 *enc->cur++ = '\\';
167 *enc->cur++ = '\\';
168 }
169 else
170 *enc->cur++ = ch;
171
172 ++str;
173 }
174 else
175 {
176 switch (ch)
177 {
178 case '\010': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'b'; ++str; break;
179 case '\011': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 't'; ++str; break;
180 case '\012': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'n'; ++str; break;
181 case '\014': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'f'; ++str; break;
182 case '\015': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'r'; ++str; break;
183
184 default:
185 {
186 STRLEN clen;
187 UV uch;
188
189 if (is_utf8)
190 {
191 uch = decode_utf8 (str, end - str, &clen);
192 if (clen == (STRLEN)-1)
193 croak ("malformed or illegal unicode character in string [%.11s], cannot convert to JSON", str);
194 }
195 else
196 {
197 uch = ch;
198 clen = 1;
199 }
200
201 if (uch > 0x10FFFFUL)
202 croak ("out of range codepoint (0x%lx) encountered, unrepresentable in JSON", (unsigned long)uch);
203
204 if (uch < 0x80 || enc->json.flags & F_ASCII || (enc->json.flags & F_LATIN1 && uch > 0xFF))
205 {
206 if (uch > 0xFFFFUL)
207 {
208 need (enc, len += 11);
209 sprintf (enc->cur, "\\u%04x\\u%04x",
210 (int)((uch - 0x10000) / 0x400 + 0xD800),
211 (int)((uch - 0x10000) % 0x400 + 0xDC00));
212 enc->cur += 12;
213 }
214 else
215 {
216 static char hexdigit [16] = "0123456789abcdef";
217 need (enc, len += 5);
218 *enc->cur++ = '\\';
219 *enc->cur++ = 'u';
220 *enc->cur++ = hexdigit [ uch >> 12 ];
221 *enc->cur++ = hexdigit [(uch >> 8) & 15];
222 *enc->cur++ = hexdigit [(uch >> 4) & 15];
223 *enc->cur++ = hexdigit [(uch >> 0) & 15];
224 }
225
226 str += clen;
227 }
228 else if (enc->json.flags & F_LATIN1)
229 {
230 *enc->cur++ = uch;
231 str += clen;
232 }
233 else if (is_utf8)
234 {
235 need (enc, len += clen);
236 do
237 {
238 *enc->cur++ = *str++;
239 }
240 while (--clen);
241 }
242 else
243 {
244 need (enc, len += UTF8_MAXBYTES - 1); // never more than 11 bytes needed
245 enc->cur = uvuni_to_utf8_flags (enc->cur, uch, 0);
246 ++str;
247 }
248 }
249 }
250 }
251
252 --len;
253 }
254 }
255
256 inline void
257 encode_indent (enc_t *enc)
258 {
259 if (enc->json.flags & F_INDENT)
260 {
261 int spaces = enc->indent * INDENT_STEP;
262
263 need (enc, spaces);
264 memset (enc->cur, ' ', spaces);
265 enc->cur += spaces;
266 }
267 }
268
269 inline void
270 encode_space (enc_t *enc)
271 {
272 need (enc, 1);
273 encode_ch (enc, ' ');
274 }
275
276 inline void
277 encode_nl (enc_t *enc)
278 {
279 if (enc->json.flags & F_INDENT)
280 {
281 need (enc, 1);
282 encode_ch (enc, '\n');
283 }
284 }
285
286 inline void
287 encode_comma (enc_t *enc)
288 {
289 encode_ch (enc, ',');
290
291 if (enc->json.flags & F_INDENT)
292 encode_nl (enc);
293 else if (enc->json.flags & F_SPACE_AFTER)
294 encode_space (enc);
295 }
296
297 static void encode_sv (enc_t *enc, SV *sv);
298
299 static void
300 encode_av (enc_t *enc, AV *av)
301 {
302 int i, len = av_len (av);
303
304 if (enc->indent >= enc->maxdepth)
305 croak ("data structure too deep (hit recursion limit)");
306
307 encode_ch (enc, '['); encode_nl (enc);
308 ++enc->indent;
309
310 for (i = 0; i <= len; ++i)
311 {
312 SV **svp = av_fetch (av, i, 0);
313
314 encode_indent (enc);
315
316 if (svp)
317 encode_sv (enc, *svp);
318 else
319 encode_str (enc, "null", 4, 0);
320
321 if (i < len)
322 encode_comma (enc);
323 }
324
325 encode_nl (enc);
326
327 --enc->indent;
328 encode_indent (enc); encode_ch (enc, ']');
329 }
330
331 static void
332 encode_he (enc_t *enc, HE *he)
333 {
334 encode_ch (enc, '"');
335
336 if (HeKLEN (he) == HEf_SVKEY)
337 {
338 SV *sv = HeSVKEY (he);
339 STRLEN len;
340 char *str;
341
342 SvGETMAGIC (sv);
343 str = SvPV (sv, len);
344
345 encode_str (enc, str, len, SvUTF8 (sv));
346 }
347 else
348 encode_str (enc, HeKEY (he), HeKLEN (he), HeKUTF8 (he));
349
350 encode_ch (enc, '"');
351
352 if (enc->json.flags & F_SPACE_BEFORE) encode_space (enc);
353 encode_ch (enc, ':');
354 if (enc->json.flags & F_SPACE_AFTER ) encode_space (enc);
355 encode_sv (enc, HeVAL (he));
356 }
357
358 // compare hash entries, used when all keys are bytestrings
359 static int
360 he_cmp_fast (const void *a_, const void *b_)
361 {
362 int cmp;
363
364 HE *a = *(HE **)a_;
365 HE *b = *(HE **)b_;
366
367 STRLEN la = HeKLEN (a);
368 STRLEN lb = HeKLEN (b);
369
370 if (!(cmp = memcmp (HeKEY (a), HeKEY (b), la < lb ? la : lb)))
371 cmp = la - lb;
372
373 return cmp;
374 }
375
376 // compare hash entries, used when some keys are sv's or utf-x
377 static int
378 he_cmp_slow (const void *a, const void *b)
379 {
380 return sv_cmp (HeSVKEY_force (*(HE **)a), HeSVKEY_force (*(HE **)b));
381 }
382
383 static void
384 encode_hv (enc_t *enc, HV *hv)
385 {
386 int count, i;
387
388 if (enc->indent >= enc->maxdepth)
389 croak ("data structure too deep (hit recursion limit)");
390
391 encode_ch (enc, '{'); encode_nl (enc); ++enc->indent;
392
393 if ((count = hv_iterinit (hv)))
394 {
395 // for canonical output we have to sort by keys first
396 // actually, this is mostly due to the stupid so-called
397 // security workaround added somewhere in 5.8.x.
398 // that randomises hash orderings
399 if (enc->json.flags & F_CANONICAL)
400 {
401 int fast = 1;
402 HE *he;
403 #if defined(__BORLANDC__) || defined(_MSC_VER)
404 HE **hes = _alloca (count * sizeof (HE));
405 #else
406 HE *hes [count]; // if your compiler dies here, you need to enable C99 mode
407 #endif
408
409 i = 0;
410 while ((he = hv_iternext (hv)))
411 {
412 hes [i++] = he;
413 if (HeKLEN (he) < 0 || HeKUTF8 (he))
414 fast = 0;
415 }
416
417 assert (i == count);
418
419 if (fast)
420 qsort (hes, count, sizeof (HE *), he_cmp_fast);
421 else
422 {
423 // hack to forcefully disable "use bytes"
424 COP cop = *PL_curcop;
425 cop.op_private = 0;
426
427 ENTER;
428 SAVETMPS;
429
430 SAVEVPTR (PL_curcop);
431 PL_curcop = &cop;
432
433 qsort (hes, count, sizeof (HE *), he_cmp_slow);
434
435 FREETMPS;
436 LEAVE;
437 }
438
439 for (i = 0; i < count; ++i)
440 {
441 encode_indent (enc);
442 encode_he (enc, hes [i]);
443
444 if (i < count - 1)
445 encode_comma (enc);
446 }
447
448 encode_nl (enc);
449 }
450 else
451 {
452 HE *he = hv_iternext (hv);
453
454 for (;;)
455 {
456 encode_indent (enc);
457 encode_he (enc, he);
458
459 if (!(he = hv_iternext (hv)))
460 break;
461
462 encode_comma (enc);
463 }
464
465 encode_nl (enc);
466 }
467 }
468
469 --enc->indent; encode_indent (enc); encode_ch (enc, '}');
470 }
471
472 // encode objects, arrays and special \0=false and \1=true values.
473 static void
474 encode_rv (enc_t *enc, SV *sv)
475 {
476 svtype svt;
477
478 SvGETMAGIC (sv);
479 svt = SvTYPE (sv);
480
481 if (expect_false (SvOBJECT (sv)))
482 {
483 if (SvSTASH (sv) == json_boolean_stash)
484 {
485 if (SvIV (sv))
486 encode_str (enc, "true", 4, 0);
487 else
488 encode_str (enc, "false", 5, 0);
489 }
490 else
491 {
492 #if 0
493 if (0 && sv_derived_from (rv, "JSON::Literal"))
494 {
495 // not yet
496 }
497 #endif
498 if (enc->json.flags & F_CONV_BLESSED)
499 {
500 // we re-bless the reference to get overload and other niceties right
501 GV *to_json = gv_fetchmethod_autoload (SvSTASH (sv), "TO_JSON", 0);
502
503 if (to_json)
504 {
505 int count;
506 dSP;
507
508 ENTER; SAVETMPS; PUSHMARK (SP);
509 XPUSHs (sv_bless (sv_2mortal (newRV_inc (sv)), SvSTASH (sv)));
510
511 // calling with G_SCALAR ensures that we always get a 1 return value
512 PUTBACK;
513 call_sv ((SV *)GvCV (to_json), G_SCALAR);
514 SPAGAIN;
515
516 // catch this surprisingly common error
517 if (SvROK (TOPs) && SvRV (TOPs) == sv)
518 croak ("%s::TO_JSON method returned same object as was passed instead of a new one", HvNAME (SvSTASH (sv)));
519
520 sv = POPs;
521 PUTBACK;
522
523 encode_sv (enc, sv);
524
525 FREETMPS; LEAVE;
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 enabled nor TO_JSON method available on it",
531 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
532 }
533 else if (enc->json.flags & F_ALLOW_BLESSED)
534 encode_str (enc, "null", 4, 0);
535 else
536 croak ("encountered object '%s', but neither allow_blessed nor convert_blessed settings are enabled",
537 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
538 }
539 }
540 else if (svt == SVt_PVHV)
541 encode_hv (enc, (HV *)sv);
542 else if (svt == SVt_PVAV)
543 encode_av (enc, (AV *)sv);
544 else if (svt < SVt_PVAV)
545 {
546 STRLEN len = 0;
547 char *pv = svt ? SvPV (sv, len) : 0;
548
549 if (len == 1 && *pv == '1')
550 encode_str (enc, "true", 4, 0);
551 else if (len == 1 && *pv == '0')
552 encode_str (enc, "false", 5, 0);
553 else
554 croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
555 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
556 }
557 else
558 croak ("encountered %s, but JSON can only represent references to arrays or hashes",
559 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
560 }
561
562 static void
563 encode_sv (enc_t *enc, SV *sv)
564 {
565 SvGETMAGIC (sv);
566
567 if (SvPOKp (sv))
568 {
569 STRLEN len;
570 char *str = SvPV (sv, len);
571 encode_ch (enc, '"');
572 encode_str (enc, str, len, SvUTF8 (sv));
573 encode_ch (enc, '"');
574 }
575 else if (SvNOKp (sv))
576 {
577 // trust that perl will do the right thing w.r.t. JSON syntax.
578 need (enc, NV_DIG + 32);
579 Gconvert (SvNVX (sv), NV_DIG, 0, enc->cur);
580 enc->cur += strlen (enc->cur);
581 }
582 else if (SvIOKp (sv))
583 {
584 // we assume we can always read an IV as a UV
585 if (SvUV (sv) & ~(UV)0x7fff)
586 {
587 // large integer, use the (rather slow) snprintf way.
588 need (enc, sizeof (UV) * 3);
589 enc->cur +=
590 SvIsUV(sv)
591 ? snprintf (enc->cur, sizeof (UV) * 3, "%"UVuf, (UV)SvUVX (sv))
592 : snprintf (enc->cur, sizeof (UV) * 3, "%"IVdf, (IV)SvIVX (sv));
593 }
594 else
595 {
596 // optimise the "small number case"
597 // code will likely be branchless and use only a single multiplication
598 I32 i = SvIV (sv);
599 U32 u;
600 char digit, nz = 0;
601
602 need (enc, 6);
603
604 *enc->cur = '-'; enc->cur += i < 0 ? 1 : 0;
605 u = i < 0 ? -i : i;
606
607 // convert to 4.28 fixed-point representation
608 u = u * ((0xfffffff + 10000) / 10000); // 10**5, 5 fractional digits
609
610 // now output digit by digit, each time masking out the integer part
611 // and multiplying by 5 while moving the decimal point one to the right,
612 // resulting in a net multiplication by 10.
613 // we always write the digit to memory but conditionally increment
614 // the pointer, to ease the usage of conditional move instructions.
615 digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffff) * 5;
616 digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffff) * 5;
617 digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffff) * 5;
618 digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffff) * 5;
619 digit = u >> 24; *enc->cur = digit + '0'; enc->cur += 1; // correctly generate '0'
620 }
621 }
622 else if (SvROK (sv))
623 encode_rv (enc, SvRV (sv));
624 else if (!SvOK (sv))
625 encode_str (enc, "null", 4, 0);
626 else
627 croak ("encountered perl type (%s,0x%x) that JSON cannot handle, you might want to report this",
628 SvPV_nolen (sv), SvFLAGS (sv));
629 }
630
631 static SV *
632 encode_json (SV *scalar, JSON *json)
633 {
634 enc_t enc;
635
636 if (!(json->flags & F_ALLOW_NONREF) && !SvROK (scalar))
637 croak ("hash- or arrayref expected (not a simple scalar, use allow_nonref to allow this)");
638
639 enc.json = *json;
640 enc.sv = sv_2mortal (NEWSV (0, INIT_SIZE));
641 enc.cur = SvPVX (enc.sv);
642 enc.end = SvEND (enc.sv);
643 enc.indent = 0;
644 enc.maxdepth = DEC_DEPTH (enc.json.flags);
645
646 SvPOK_only (enc.sv);
647 encode_sv (&enc, scalar);
648
649 SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
650 *SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings
651
652 if (!(enc.json.flags & (F_ASCII | F_LATIN1 | F_UTF8)))
653 SvUTF8_on (enc.sv);
654
655 if (enc.json.flags & F_SHRINK)
656 shrink (enc.sv);
657
658 return enc.sv;
659 }
660
661 /////////////////////////////////////////////////////////////////////////////
662 // decoder
663
664 // structure used for decoding JSON
665 typedef struct
666 {
667 char *cur; // current parser pointer
668 char *end; // end of input string
669 const char *err; // parse error, if != 0
670 JSON json;
671 U32 depth; // recursion depth
672 U32 maxdepth; // recursion depth limit
673 } dec_t;
674
675 inline void
676 decode_ws (dec_t *dec)
677 {
678 for (;;)
679 {
680 char ch = *dec->cur;
681
682 if (ch > 0x20
683 || (ch != 0x20 && ch != 0x0a && ch != 0x0d && ch != 0x09))
684 break;
685
686 ++dec->cur;
687 }
688 }
689
690 #define ERR(reason) SB dec->err = reason; goto fail; SE
691
692 #define EXPECT_CH(ch) SB \
693 if (*dec->cur != ch) \
694 ERR (# ch " expected"); \
695 ++dec->cur; \
696 SE
697
698 #define DEC_INC_DEPTH if (++dec->depth > dec->maxdepth) ERR ("json datastructure exceeds maximum nesting level (set a higher max_depth)")
699 #define DEC_DEC_DEPTH --dec->depth
700
701 static SV *decode_sv (dec_t *dec);
702
703 static signed char decode_hexdigit[256];
704
705 static UV
706 decode_4hex (dec_t *dec)
707 {
708 signed char d1, d2, d3, d4;
709 unsigned char *cur = (unsigned char *)dec->cur;
710
711 d1 = decode_hexdigit [cur [0]]; if (expect_false (d1 < 0)) ERR ("exactly four hexadecimal digits expected");
712 d2 = decode_hexdigit [cur [1]]; if (expect_false (d2 < 0)) ERR ("exactly four hexadecimal digits expected");
713 d3 = decode_hexdigit [cur [2]]; if (expect_false (d3 < 0)) ERR ("exactly four hexadecimal digits expected");
714 d4 = decode_hexdigit [cur [3]]; if (expect_false (d4 < 0)) ERR ("exactly four hexadecimal digits expected");
715
716 dec->cur += 4;
717
718 return ((UV)d1) << 12
719 | ((UV)d2) << 8
720 | ((UV)d3) << 4
721 | ((UV)d4);
722
723 fail:
724 return (UV)-1;
725 }
726
727 static SV *
728 decode_str (dec_t *dec)
729 {
730 SV *sv = 0;
731 int utf8 = 0;
732 char *dec_cur = dec->cur;
733
734 do
735 {
736 char buf [SHORT_STRING_LEN + UTF8_MAXBYTES];
737 char *cur = buf;
738
739 do
740 {
741 unsigned char ch = *(unsigned char *)dec_cur++;
742
743 if (expect_false (ch == '"'))
744 {
745 --dec_cur;
746 break;
747 }
748 else if (expect_false (ch == '\\'))
749 {
750 switch (*dec_cur)
751 {
752 case '\\':
753 case '/':
754 case '"': *cur++ = *dec_cur++; break;
755
756 case 'b': ++dec_cur; *cur++ = '\010'; break;
757 case 't': ++dec_cur; *cur++ = '\011'; break;
758 case 'n': ++dec_cur; *cur++ = '\012'; break;
759 case 'f': ++dec_cur; *cur++ = '\014'; break;
760 case 'r': ++dec_cur; *cur++ = '\015'; break;
761
762 case 'u':
763 {
764 UV lo, hi;
765 ++dec_cur;
766
767 dec->cur = dec_cur;
768 hi = decode_4hex (dec);
769 dec_cur = dec->cur;
770 if (hi == (UV)-1)
771 goto fail;
772
773 // possibly a surrogate pair
774 if (hi >= 0xd800)
775 if (hi < 0xdc00)
776 {
777 if (dec_cur [0] != '\\' || dec_cur [1] != 'u')
778 ERR ("missing low surrogate character in surrogate pair");
779
780 dec_cur += 2;
781
782 dec->cur = dec_cur;
783 lo = decode_4hex (dec);
784 dec_cur = dec->cur;
785 if (lo == (UV)-1)
786 goto fail;
787
788 if (lo < 0xdc00 || lo >= 0xe000)
789 ERR ("surrogate pair expected");
790
791 hi = (hi - 0xD800) * 0x400 + (lo - 0xDC00) + 0x10000;
792 }
793 else if (hi < 0xe000)
794 ERR ("missing high surrogate character in surrogate pair");
795
796 if (hi >= 0x80)
797 {
798 utf8 = 1;
799
800 cur = (char *)uvuni_to_utf8_flags (cur, hi, 0);
801 }
802 else
803 *cur++ = hi;
804 }
805 break;
806
807 default:
808 --dec_cur;
809 ERR ("illegal backslash escape sequence in string");
810 }
811 }
812 else if (expect_true (ch >= 0x20 && ch <= 0x7f))
813 *cur++ = ch;
814 else if (ch >= 0x80)
815 {
816 STRLEN clen;
817 UV uch;
818
819 --dec_cur;
820
821 uch = decode_utf8 (dec_cur, dec->end - dec_cur, &clen);
822 if (clen == (STRLEN)-1)
823 ERR ("malformed UTF-8 character in JSON string");
824
825 do
826 *cur++ = *dec_cur++;
827 while (--clen);
828
829 utf8 = 1;
830 }
831 else
832 {
833 --dec_cur;
834
835 if (!ch)
836 ERR ("unexpected end of string while parsing JSON string");
837 else
838 ERR ("invalid character encountered while parsing JSON string");
839 }
840 }
841 while (cur < buf + SHORT_STRING_LEN);
842
843 {
844 STRLEN len = cur - buf;
845
846 if (sv)
847 {
848 SvGROW (sv, SvCUR (sv) + len + 1);
849 memcpy (SvPVX (sv) + SvCUR (sv), buf, len);
850 SvCUR_set (sv, SvCUR (sv) + len);
851 }
852 else
853 sv = newSVpvn (buf, len);
854 }
855 }
856 while (*dec_cur != '"');
857
858 ++dec_cur;
859
860 if (sv)
861 {
862 SvPOK_only (sv);
863 *SvEND (sv) = 0;
864
865 if (utf8)
866 SvUTF8_on (sv);
867 }
868 else
869 sv = newSVpvn ("", 0);
870
871 dec->cur = dec_cur;
872 return sv;
873
874 fail:
875 dec->cur = dec_cur;
876 return 0;
877 }
878
879 static SV *
880 decode_num (dec_t *dec)
881 {
882 int is_nv = 0;
883 char *start = dec->cur;
884
885 // [minus]
886 if (*dec->cur == '-')
887 ++dec->cur;
888
889 if (*dec->cur == '0')
890 {
891 ++dec->cur;
892 if (*dec->cur >= '0' && *dec->cur <= '9')
893 ERR ("malformed number (leading zero must not be followed by another digit)");
894 }
895 else if (*dec->cur < '0' || *dec->cur > '9')
896 ERR ("malformed number (no digits after initial minus)");
897 else
898 do
899 {
900 ++dec->cur;
901 }
902 while (*dec->cur >= '0' && *dec->cur <= '9');
903
904 // [frac]
905 if (*dec->cur == '.')
906 {
907 ++dec->cur;
908
909 if (*dec->cur < '0' || *dec->cur > '9')
910 ERR ("malformed number (no digits after decimal point)");
911
912 do
913 {
914 ++dec->cur;
915 }
916 while (*dec->cur >= '0' && *dec->cur <= '9');
917
918 is_nv = 1;
919 }
920
921 // [exp]
922 if (*dec->cur == 'e' || *dec->cur == 'E')
923 {
924 ++dec->cur;
925
926 if (*dec->cur == '-' || *dec->cur == '+')
927 ++dec->cur;
928
929 if (*dec->cur < '0' || *dec->cur > '9')
930 ERR ("malformed number (no digits after exp sign)");
931
932 do
933 {
934 ++dec->cur;
935 }
936 while (*dec->cur >= '0' && *dec->cur <= '9');
937
938 is_nv = 1;
939 }
940
941 if (!is_nv)
942 {
943 int len = dec->cur - start;
944
945 // special case the rather common 1..4-digit-int case, assumes 32 bit ints or so
946 if (*start == '-')
947 switch (len)
948 {
949 case 2: return newSViv (-( start [1] - '0' * 1));
950 case 3: return newSViv (-( start [1] * 10 + start [2] - '0' * 11));
951 case 4: return newSViv (-( start [1] * 100 + start [2] * 10 + start [3] - '0' * 111));
952 case 5: return newSViv (-(start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 1111));
953 }
954 else
955 switch (len)
956 {
957 case 1: return newSViv ( start [0] - '0' * 1);
958 case 2: return newSViv ( start [0] * 10 + start [1] - '0' * 11);
959 case 3: return newSViv ( start [0] * 100 + start [1] * 10 + start [2] - '0' * 111);
960 case 4: return newSViv ( start [0] * 1000 + start [1] * 100 + start [2] * 10 + start [3] - '0' * 1111);
961 }
962
963 {
964 UV uv;
965 int numtype = grok_number (start, len, &uv);
966 if (numtype & IS_NUMBER_IN_UV)
967 if (numtype & IS_NUMBER_NEG)
968 {
969 if (uv < (UV)IV_MIN)
970 return newSViv (-(IV)uv);
971 }
972 else
973 return newSVuv (uv);
974 }
975
976 len -= *start == '-' ? 1 : 0;
977
978 // does not fit into IV or UV, try NV
979 if ((sizeof (NV) == sizeof (double) && DBL_DIG >= len)
980 #if defined (LDBL_DIG)
981 || (sizeof (NV) == sizeof (long double) && LDBL_DIG >= len)
982 #endif
983 )
984 // fits into NV without loss of precision
985 return newSVnv (Atof (start));
986
987 // everything else fails, convert it to a string
988 return newSVpvn (start, dec->cur - start);
989 }
990
991 // loss of precision here
992 return newSVnv (Atof (start));
993
994 fail:
995 return 0;
996 }
997
998 static SV *
999 decode_av (dec_t *dec)
1000 {
1001 AV *av = newAV ();
1002
1003 DEC_INC_DEPTH;
1004 decode_ws (dec);
1005
1006 if (*dec->cur == ']')
1007 ++dec->cur;
1008 else
1009 for (;;)
1010 {
1011 SV *value;
1012
1013 value = decode_sv (dec);
1014 if (!value)
1015 goto fail;
1016
1017 av_push (av, value);
1018
1019 decode_ws (dec);
1020
1021 if (*dec->cur == ']')
1022 {
1023 ++dec->cur;
1024 break;
1025 }
1026
1027 if (*dec->cur != ',')
1028 ERR (", or ] expected while parsing array");
1029
1030 ++dec->cur;
1031 }
1032
1033 DEC_DEC_DEPTH;
1034 return newRV_noinc ((SV *)av);
1035
1036 fail:
1037 SvREFCNT_dec (av);
1038 DEC_DEC_DEPTH;
1039 return 0;
1040 }
1041
1042 static SV *
1043 decode_hv (dec_t *dec)
1044 {
1045 SV *sv;
1046 HV *hv = newHV ();
1047
1048 DEC_INC_DEPTH;
1049 decode_ws (dec);
1050
1051 if (*dec->cur == '}')
1052 ++dec->cur;
1053 else
1054 for (;;)
1055 {
1056 decode_ws (dec); EXPECT_CH ('"');
1057
1058 // heuristic: assume that
1059 // a) decode_str + hv_store_ent are abysmally slow.
1060 // b) most hash keys are short, simple ascii text.
1061 // => try to "fast-match" such strings to avoid
1062 // the overhead of decode_str + hv_store_ent.
1063 {
1064 SV *value;
1065 char *p = dec->cur;
1066 char *e = p + 24; // only try up to 24 bytes
1067
1068 for (;;)
1069 {
1070 // the >= 0x80 is true on most architectures
1071 if (p == e || *p < 0x20 || *p >= 0x80 || *p == '\\')
1072 {
1073 // slow path, back up and use decode_str
1074 SV *key = decode_str (dec);
1075 if (!key)
1076 goto fail;
1077
1078 decode_ws (dec); EXPECT_CH (':');
1079
1080 value = decode_sv (dec);
1081 if (!value)
1082 {
1083 SvREFCNT_dec (key);
1084 goto fail;
1085 }
1086
1087 hv_store_ent (hv, key, value, 0);
1088 SvREFCNT_dec (key);
1089
1090 break;
1091 }
1092 else if (*p == '"')
1093 {
1094 // fast path, got a simple key
1095 char *key = dec->cur;
1096 int len = p - key;
1097 dec->cur = p + 1;
1098
1099 decode_ws (dec); EXPECT_CH (':');
1100
1101 value = decode_sv (dec);
1102 if (!value)
1103 goto fail;
1104
1105 hv_store (hv, key, len, value, 0);
1106
1107 break;
1108 }
1109
1110 ++p;
1111 }
1112 }
1113
1114 decode_ws (dec);
1115
1116 if (*dec->cur == '}')
1117 {
1118 ++dec->cur;
1119 break;
1120 }
1121
1122 if (*dec->cur != ',')
1123 ERR (", or } expected while parsing object/hash");
1124
1125 ++dec->cur;
1126 }
1127
1128 DEC_DEC_DEPTH;
1129 sv = newRV_noinc ((SV *)hv);
1130
1131 // check filter callbacks
1132 if (dec->json.flags & F_HOOK)
1133 {
1134 if (dec->json.cb_sk_object && HvKEYS (hv) == 1)
1135 {
1136 HE *cb, *he;
1137
1138 hv_iterinit (hv);
1139 he = hv_iternext (hv);
1140 hv_iterinit (hv);
1141
1142 // the next line creates a mortal sv each time its called.
1143 // might want to optimise this for common cases.
1144 cb = hv_fetch_ent (dec->json.cb_sk_object, hv_iterkeysv (he), 0, 0);
1145
1146 if (cb)
1147 {
1148 dSP;
1149 int count;
1150
1151 ENTER; SAVETMPS; PUSHMARK (SP);
1152 XPUSHs (HeVAL (he));
1153
1154 PUTBACK; count = call_sv (HeVAL (cb), G_ARRAY); SPAGAIN;
1155
1156 if (count == 1)
1157 {
1158 sv = newSVsv (POPs);
1159 FREETMPS; LEAVE;
1160 return sv;
1161 }
1162
1163 FREETMPS; LEAVE;
1164 }
1165 }
1166
1167 if (dec->json.cb_object)
1168 {
1169 dSP;
1170 int count;
1171
1172 ENTER; SAVETMPS; PUSHMARK (SP);
1173 XPUSHs (sv_2mortal (sv));
1174
1175 PUTBACK; count = call_sv (dec->json.cb_object, G_ARRAY); SPAGAIN;
1176
1177 if (count == 1)
1178 {
1179 sv = newSVsv (POPs);
1180 FREETMPS; LEAVE;
1181 return sv;
1182 }
1183
1184 SvREFCNT_inc (sv);
1185 FREETMPS; LEAVE;
1186 }
1187 }
1188
1189 return sv;
1190
1191 fail:
1192 SvREFCNT_dec (hv);
1193 DEC_DEC_DEPTH;
1194 return 0;
1195 }
1196
1197 static SV *
1198 decode_sv (dec_t *dec)
1199 {
1200 decode_ws (dec);
1201
1202 // the beauty of JSON: you need exactly one character lookahead
1203 // to parse anything.
1204 switch (*dec->cur)
1205 {
1206 case '"': ++dec->cur; return decode_str (dec);
1207 case '[': ++dec->cur; return decode_av (dec);
1208 case '{': ++dec->cur; return decode_hv (dec);
1209
1210 case '-':
1211 case '0': case '1': case '2': case '3': case '4':
1212 case '5': case '6': case '7': case '8': case '9':
1213 return decode_num (dec);
1214
1215 case 't':
1216 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "true", 4))
1217 {
1218 dec->cur += 4;
1219 return SvREFCNT_inc (json_true);
1220 }
1221 else
1222 ERR ("'true' expected");
1223
1224 break;
1225
1226 case 'f':
1227 if (dec->end - dec->cur >= 5 && !memcmp (dec->cur, "false", 5))
1228 {
1229 dec->cur += 5;
1230 return SvREFCNT_inc (json_false);
1231 }
1232 else
1233 ERR ("'false' expected");
1234
1235 break;
1236
1237 case 'n':
1238 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "null", 4))
1239 {
1240 dec->cur += 4;
1241 return newSVsv (&PL_sv_undef);
1242 }
1243 else
1244 ERR ("'null' expected");
1245
1246 break;
1247
1248 default:
1249 ERR ("malformed JSON string, neither array, object, number, string or atom");
1250 break;
1251 }
1252
1253 fail:
1254 return 0;
1255 }
1256
1257 static SV *
1258 decode_json (SV *string, JSON *json, UV *offset_return)
1259 {
1260 dec_t dec;
1261 UV offset;
1262 SV *sv;
1263
1264 SvGETMAGIC (string);
1265 SvUPGRADE (string, SVt_PV);
1266
1267 if (json->flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (json->flags))
1268 croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu",
1269 (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (json->flags));
1270
1271 if (json->flags & F_UTF8)
1272 sv_utf8_downgrade (string, 0);
1273 else
1274 sv_utf8_upgrade (string);
1275
1276 SvGROW (string, SvCUR (string) + 1); // should basically be a NOP
1277
1278 dec.json = *json;
1279 dec.cur = SvPVX (string);
1280 dec.end = SvEND (string);
1281 dec.err = 0;
1282 dec.depth = 0;
1283 dec.maxdepth = DEC_DEPTH (dec.json.flags);
1284
1285 if (dec.json.cb_object || dec.json.cb_sk_object)
1286 dec.json.flags |= F_HOOK;
1287
1288 *dec.end = 0; // this should basically be a nop, too, but make sure it's there
1289 sv = decode_sv (&dec);
1290
1291 if (!(offset_return || !sv))
1292 {
1293 // check for trailing garbage
1294 decode_ws (&dec);
1295
1296 if (*dec.cur)
1297 {
1298 dec.err = "garbage after JSON object";
1299 SvREFCNT_dec (sv);
1300 sv = 0;
1301 }
1302 }
1303
1304 if (offset_return || !sv)
1305 {
1306 offset = dec.json.flags & F_UTF8
1307 ? dec.cur - SvPVX (string)
1308 : utf8_distance (dec.cur, SvPVX (string));
1309
1310 if (offset_return)
1311 *offset_return = offset;
1312 }
1313
1314 if (!sv)
1315 {
1316 SV *uni = sv_newmortal ();
1317
1318 // horrible hack to silence warning inside pv_uni_display
1319 COP cop = *PL_curcop;
1320 cop.cop_warnings = pWARN_NONE;
1321 ENTER;
1322 SAVEVPTR (PL_curcop);
1323 PL_curcop = &cop;
1324 pv_uni_display (uni, dec.cur, dec.end - dec.cur, 20, UNI_DISPLAY_QQ);
1325 LEAVE;
1326
1327 croak ("%s, at character offset %d [\"%s\"]",
1328 dec.err,
1329 (int)offset,
1330 dec.cur != dec.end ? SvPV_nolen (uni) : "(end of string)");
1331 }
1332
1333 sv = sv_2mortal (sv);
1334
1335 if (!(dec.json.flags & F_ALLOW_NONREF) && !SvROK (sv))
1336 croak ("JSON text must be an object or array (but found number, string, true, false or null, use allow_nonref to allow this)");
1337
1338 return sv;
1339 }
1340
1341 /////////////////////////////////////////////////////////////////////////////
1342 // XS interface functions
1343
1344 MODULE = JSON::XS PACKAGE = JSON::XS
1345
1346 BOOT:
1347 {
1348 int i;
1349
1350 for (i = 0; i < 256; ++i)
1351 decode_hexdigit [i] =
1352 i >= '0' && i <= '9' ? i - '0'
1353 : i >= 'a' && i <= 'f' ? i - 'a' + 10
1354 : i >= 'A' && i <= 'F' ? i - 'A' + 10
1355 : -1;
1356
1357 json_stash = gv_stashpv ("JSON::XS" , 1);
1358 json_boolean_stash = gv_stashpv ("JSON::XS::Boolean", 1);
1359
1360 json_true = get_sv ("JSON::XS::true" , 1); SvREADONLY_on (json_true );
1361 json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false);
1362 }
1363
1364 PROTOTYPES: DISABLE
1365
1366 void new (char *klass)
1367 PPCODE:
1368 {
1369 SV *pv = NEWSV (0, sizeof (JSON));
1370 SvPOK_only (pv);
1371 Zero (SvPVX (pv), 1, JSON);
1372 ((JSON *)SvPVX (pv))->flags = F_DEFAULT;
1373 XPUSHs (sv_2mortal (sv_bless (newRV_noinc (pv), json_stash)));
1374 }
1375
1376 void ascii (JSON *self, int enable = 1)
1377 ALIAS:
1378 ascii = F_ASCII
1379 latin1 = F_LATIN1
1380 utf8 = F_UTF8
1381 indent = F_INDENT
1382 canonical = F_CANONICAL
1383 space_before = F_SPACE_BEFORE
1384 space_after = F_SPACE_AFTER
1385 pretty = F_PRETTY
1386 allow_nonref = F_ALLOW_NONREF
1387 shrink = F_SHRINK
1388 allow_blessed = F_ALLOW_BLESSED
1389 convert_blessed = F_CONV_BLESSED
1390 PPCODE:
1391 {
1392 if (enable)
1393 self->flags |= ix;
1394 else
1395 self->flags &= ~ix;
1396
1397 XPUSHs (ST (0));
1398 }
1399
1400 void max_depth (JSON *self, UV max_depth = 0x80000000UL)
1401 PPCODE:
1402 {
1403 UV log2 = 0;
1404
1405 if (max_depth > 0x80000000UL) max_depth = 0x80000000UL;
1406
1407 while ((1UL << log2) < max_depth)
1408 ++log2;
1409
1410 self->flags = self->flags & ~F_MAXDEPTH | (log2 << S_MAXDEPTH);
1411
1412 XPUSHs (ST (0));
1413 }
1414
1415 void max_size (JSON *self, UV max_size = 0)
1416 PPCODE:
1417 {
1418 UV log2 = 0;
1419
1420 if (max_size > 0x80000000UL) max_size = 0x80000000UL;
1421 if (max_size == 1) max_size = 2;
1422
1423 while ((1UL << log2) < max_size)
1424 ++log2;
1425
1426 self->flags = self->flags & ~F_MAXSIZE | (log2 << S_MAXSIZE);
1427
1428 XPUSHs (ST (0));
1429 }
1430
1431 void filter_json_object (JSON *self, SV *cb = &PL_sv_undef)
1432 PPCODE:
1433 {
1434 SvREFCNT_dec (self->cb_object);
1435 self->cb_object = SvOK (cb) ? newSVsv (cb) : 0;
1436
1437 XPUSHs (ST (0));
1438 }
1439
1440 void filter_json_single_key_object (JSON *self, SV *key, SV *cb = &PL_sv_undef)
1441 PPCODE:
1442 {
1443 if (!self->cb_sk_object)
1444 self->cb_sk_object = newHV ();
1445
1446 if (SvOK (cb))
1447 hv_store_ent (self->cb_sk_object, key, newSVsv (cb), 0);
1448 else
1449 {
1450 hv_delete_ent (self->cb_sk_object, key, G_DISCARD, 0);
1451
1452 if (!HvKEYS (self->cb_sk_object))
1453 {
1454 SvREFCNT_dec (self->cb_sk_object);
1455 self->cb_sk_object = 0;
1456 }
1457 }
1458
1459 XPUSHs (ST (0));
1460 }
1461
1462 void encode (JSON *self, SV *scalar)
1463 PPCODE:
1464 XPUSHs (encode_json (scalar, self));
1465
1466 void decode (JSON *self, SV *jsonstr)
1467 PPCODE:
1468 XPUSHs (decode_json (jsonstr, self, 0));
1469
1470 void decode_prefix (JSON *self, SV *jsonstr)
1471 PPCODE:
1472 {
1473 UV offset;
1474 EXTEND (SP, 2);
1475 PUSHs (decode_json (jsonstr, self, &offset));
1476 PUSHs (sv_2mortal (newSVuv (offset)));
1477 }
1478
1479 void DESTROY (JSON *self)
1480 CODE:
1481 SvREFCNT_dec (self->cb_sk_object);
1482 SvREFCNT_dec (self->cb_object);
1483
1484 PROTOTYPES: ENABLE
1485
1486 void to_json (SV *scalar)
1487 PPCODE:
1488 {
1489 JSON json = { F_DEFAULT | F_UTF8 };
1490 XPUSHs (encode_json (scalar, &json));
1491 }
1492
1493 void from_json (SV *jsonstr)
1494 PPCODE:
1495 {
1496 JSON json = { F_DEFAULT | F_UTF8 };
1497 XPUSHs (decode_json (jsonstr, &json, 0));
1498 }
1499