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/cvs/JSON-XS/XS.xs
Revision: 1.54
Committed: Tue Jul 10 16:22:31 2007 UTC (16 years, 10 months ago) by root
Branch: MAIN
CVS Tags: rel-1_41
Changes since 1.53: +2 -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;
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 encode_indent (enc);
312 encode_sv (enc, *av_fetch (av, i, 0));
313
314 if (i < len)
315 encode_comma (enc);
316 }
317
318 encode_nl (enc);
319
320 --enc->indent;
321 encode_indent (enc); encode_ch (enc, ']');
322 }
323
324 static void
325 encode_he (enc_t *enc, HE *he)
326 {
327 encode_ch (enc, '"');
328
329 if (HeKLEN (he) == HEf_SVKEY)
330 {
331 SV *sv = HeSVKEY (he);
332 STRLEN len;
333 char *str;
334
335 SvGETMAGIC (sv);
336 str = SvPV (sv, len);
337
338 encode_str (enc, str, len, SvUTF8 (sv));
339 }
340 else
341 encode_str (enc, HeKEY (he), HeKLEN (he), HeKUTF8 (he));
342
343 encode_ch (enc, '"');
344
345 if (enc->json.flags & F_SPACE_BEFORE) encode_space (enc);
346 encode_ch (enc, ':');
347 if (enc->json.flags & F_SPACE_AFTER ) encode_space (enc);
348 encode_sv (enc, HeVAL (he));
349 }
350
351 // compare hash entries, used when all keys are bytestrings
352 static int
353 he_cmp_fast (const void *a_, const void *b_)
354 {
355 int cmp;
356
357 HE *a = *(HE **)a_;
358 HE *b = *(HE **)b_;
359
360 STRLEN la = HeKLEN (a);
361 STRLEN lb = HeKLEN (b);
362
363 if (!(cmp = memcmp (HeKEY (a), HeKEY (b), la < lb ? la : lb)))
364 cmp = la - lb;
365
366 return cmp;
367 }
368
369 // compare hash entries, used when some keys are sv's or utf-x
370 static int
371 he_cmp_slow (const void *a, const void *b)
372 {
373 return sv_cmp (HeSVKEY_force (*(HE **)a), HeSVKEY_force (*(HE **)b));
374 }
375
376 static void
377 encode_hv (enc_t *enc, HV *hv)
378 {
379 int count, i;
380
381 if (enc->indent >= enc->maxdepth)
382 croak ("data structure too deep (hit recursion limit)");
383
384 encode_ch (enc, '{'); encode_nl (enc); ++enc->indent;
385
386 if ((count = hv_iterinit (hv)))
387 {
388 // for canonical output we have to sort by keys first
389 // actually, this is mostly due to the stupid so-called
390 // security workaround added somewhere in 5.8.x.
391 // that randomises hash orderings
392 if (enc->json.flags & F_CANONICAL)
393 {
394 int fast = 1;
395 HE *he;
396 #if defined(__BORLANDC__) || defined(_MSC_VER)
397 HE **hes = _alloca (count * sizeof (HE));
398 #else
399 HE *hes [count]; // if your compiler dies here, you need to enable C99 mode
400 #endif
401
402 i = 0;
403 while ((he = hv_iternext (hv)))
404 {
405 hes [i++] = he;
406 if (HeKLEN (he) < 0 || HeKUTF8 (he))
407 fast = 0;
408 }
409
410 assert (i == count);
411
412 if (fast)
413 qsort (hes, count, sizeof (HE *), he_cmp_fast);
414 else
415 {
416 // hack to forcefully disable "use bytes"
417 COP cop = *PL_curcop;
418 cop.op_private = 0;
419
420 ENTER;
421 SAVETMPS;
422
423 SAVEVPTR (PL_curcop);
424 PL_curcop = &cop;
425
426 qsort (hes, count, sizeof (HE *), he_cmp_slow);
427
428 FREETMPS;
429 LEAVE;
430 }
431
432 for (i = 0; i < count; ++i)
433 {
434 encode_indent (enc);
435 encode_he (enc, hes [i]);
436
437 if (i < count - 1)
438 encode_comma (enc);
439 }
440
441 encode_nl (enc);
442 }
443 else
444 {
445 HE *he = hv_iternext (hv);
446
447 for (;;)
448 {
449 encode_indent (enc);
450 encode_he (enc, he);
451
452 if (!(he = hv_iternext (hv)))
453 break;
454
455 encode_comma (enc);
456 }
457
458 encode_nl (enc);
459 }
460 }
461
462 --enc->indent; encode_indent (enc); encode_ch (enc, '}');
463 }
464
465 // encode objects, arrays and special \0=false and \1=true values.
466 static void
467 encode_rv (enc_t *enc, SV *sv)
468 {
469 svtype svt;
470
471 SvGETMAGIC (sv);
472 svt = SvTYPE (sv);
473
474 if (expect_false (SvOBJECT (sv)))
475 {
476 if (SvSTASH (sv) == json_boolean_stash)
477 {
478 if (SvIV (sv))
479 encode_str (enc, "true", 4, 0);
480 else
481 encode_str (enc, "false", 5, 0);
482 }
483 else
484 {
485 #if 0
486 if (0 && sv_derived_from (rv, "JSON::Literal"))
487 {
488 // not yet
489 }
490 #endif
491 if (enc->json.flags & F_CONV_BLESSED)
492 {
493 // we re-bless the reference to get overload and other niceties right
494 GV *to_json = gv_fetchmethod_autoload (SvSTASH (sv), "TO_JSON", 0);
495
496 if (to_json)
497 {
498 int count;
499 dSP;
500
501 ENTER; SAVETMPS; PUSHMARK (SP);
502 XPUSHs (sv_bless (sv_2mortal (newRV_inc (sv)), SvSTASH (sv)));
503
504 // calling with G_SCALAR ensures that we always get a 1 return value
505 PUTBACK;
506 call_sv ((SV *)GvCV (to_json), G_SCALAR);
507 SPAGAIN;
508
509 // catch this surprisingly common error
510 if (SvROK (TOPs) && SvRV (TOPs) == sv)
511 croak ("%s::TO_JSON method returned same object as was passed instead of a new one", HvNAME (SvSTASH (sv)));
512
513 sv = POPs;
514 PUTBACK;
515
516 encode_sv (enc, sv);
517
518 FREETMPS; LEAVE;
519 }
520 else if (enc->json.flags & F_ALLOW_BLESSED)
521 encode_str (enc, "null", 4, 0);
522 else
523 croak ("encountered object '%s', but neither allow_blessed enabled nor TO_JSON method available on it",
524 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
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 nor convert_blessed settings are enabled",
530 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
531 }
532 }
533 else if (svt == SVt_PVHV)
534 encode_hv (enc, (HV *)sv);
535 else if (svt == SVt_PVAV)
536 encode_av (enc, (AV *)sv);
537 else if (svt < SVt_PVAV)
538 {
539 STRLEN len = 0;
540 char *pv = svt ? SvPV (sv, len) : 0;
541
542 if (len == 1 && *pv == '1')
543 encode_str (enc, "true", 4, 0);
544 else if (len == 1 && *pv == '0')
545 encode_str (enc, "false", 5, 0);
546 else
547 croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
548 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
549 }
550 else
551 croak ("encountered %s, but JSON can only represent references to arrays or hashes",
552 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
553 }
554
555 static void
556 encode_sv (enc_t *enc, SV *sv)
557 {
558 SvGETMAGIC (sv);
559
560 if (SvPOKp (sv))
561 {
562 STRLEN len;
563 char *str = SvPV (sv, len);
564 encode_ch (enc, '"');
565 encode_str (enc, str, len, SvUTF8 (sv));
566 encode_ch (enc, '"');
567 }
568 else if (SvNOKp (sv))
569 {
570 // trust that perl will do the right thing w.r.t. JSON syntax.
571 need (enc, NV_DIG + 32);
572 Gconvert (SvNVX (sv), NV_DIG, 0, enc->cur);
573 enc->cur += strlen (enc->cur);
574 }
575 else if (SvIOKp (sv))
576 {
577 // we assume we can always read an IV as a UV
578 if (SvUV (sv) & ~(UV)0x7fff)
579 {
580 // large integer, use the (rather slow) snprintf way.
581 need (enc, sizeof (UV) * 3);
582 enc->cur +=
583 SvIsUV(sv)
584 ? snprintf (enc->cur, sizeof (UV) * 3, "%"UVuf, (UV)SvUVX (sv))
585 : snprintf (enc->cur, sizeof (UV) * 3, "%"IVdf, (IV)SvIVX (sv));
586 }
587 else
588 {
589 // optimise the "small number case"
590 // code will likely be branchless and use only a single multiplication
591 I32 i = SvIV (sv);
592 U32 u;
593 char digit, nz = 0;
594
595 need (enc, 6);
596
597 *enc->cur = '-'; enc->cur += i < 0 ? 1 : 0;
598 u = i < 0 ? -i : i;
599
600 // convert to 4.28 fixed-point representation
601 u = u * ((0xfffffff + 10000) / 10000); // 10**5, 5 fractional digits
602
603 // now output digit by digit, each time masking out the integer part
604 // and multiplying by 5 while moving the decimal point one to the right,
605 // resulting in a net multiplication by 10.
606 // we always write the digit to memory but conditionally increment
607 // the pointer, to ease the usage of conditional move instructions.
608 digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffff) * 5;
609 digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffff) * 5;
610 digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffff) * 5;
611 digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffff) * 5;
612 digit = u >> 24; *enc->cur = digit + '0'; enc->cur += 1; // correctly generate '0'
613 }
614 }
615 else if (SvROK (sv))
616 encode_rv (enc, SvRV (sv));
617 else if (!SvOK (sv))
618 encode_str (enc, "null", 4, 0);
619 else
620 croak ("encountered perl type (%s,0x%x) that JSON cannot handle, you might want to report this",
621 SvPV_nolen (sv), SvFLAGS (sv));
622 }
623
624 static SV *
625 encode_json (SV *scalar, JSON *json)
626 {
627 enc_t enc;
628
629 if (!(json->flags & F_ALLOW_NONREF) && !SvROK (scalar))
630 croak ("hash- or arrayref expected (not a simple scalar, use allow_nonref to allow this)");
631
632 enc.json = *json;
633 enc.sv = sv_2mortal (NEWSV (0, INIT_SIZE));
634 enc.cur = SvPVX (enc.sv);
635 enc.end = SvEND (enc.sv);
636 enc.indent = 0;
637 enc.maxdepth = DEC_DEPTH (enc.json.flags);
638
639 SvPOK_only (enc.sv);
640 encode_sv (&enc, scalar);
641
642 SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
643 *SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings
644
645 if (!(enc.json.flags & (F_ASCII | F_LATIN1 | F_UTF8)))
646 SvUTF8_on (enc.sv);
647
648 if (enc.json.flags & F_SHRINK)
649 shrink (enc.sv);
650
651 return enc.sv;
652 }
653
654 /////////////////////////////////////////////////////////////////////////////
655 // decoder
656
657 // structure used for decoding JSON
658 typedef struct
659 {
660 char *cur; // current parser pointer
661 char *end; // end of input string
662 const char *err; // parse error, if != 0
663 JSON json;
664 U32 depth; // recursion depth
665 U32 maxdepth; // recursion depth limit
666 } dec_t;
667
668 inline void
669 decode_ws (dec_t *dec)
670 {
671 for (;;)
672 {
673 char ch = *dec->cur;
674
675 if (ch > 0x20
676 || (ch != 0x20 && ch != 0x0a && ch != 0x0d && ch != 0x09))
677 break;
678
679 ++dec->cur;
680 }
681 }
682
683 #define ERR(reason) SB dec->err = reason; goto fail; SE
684
685 #define EXPECT_CH(ch) SB \
686 if (*dec->cur != ch) \
687 ERR (# ch " expected"); \
688 ++dec->cur; \
689 SE
690
691 #define DEC_INC_DEPTH if (++dec->depth > dec->maxdepth) ERR ("json datastructure exceeds maximum nesting level (set a higher max_depth)")
692 #define DEC_DEC_DEPTH --dec->depth
693
694 static SV *decode_sv (dec_t *dec);
695
696 static signed char decode_hexdigit[256];
697
698 static UV
699 decode_4hex (dec_t *dec)
700 {
701 signed char d1, d2, d3, d4;
702 unsigned char *cur = (unsigned char *)dec->cur;
703
704 d1 = decode_hexdigit [cur [0]]; if (expect_false (d1 < 0)) ERR ("exactly four hexadecimal digits expected");
705 d2 = decode_hexdigit [cur [1]]; if (expect_false (d2 < 0)) ERR ("exactly four hexadecimal digits expected");
706 d3 = decode_hexdigit [cur [2]]; if (expect_false (d3 < 0)) ERR ("exactly four hexadecimal digits expected");
707 d4 = decode_hexdigit [cur [3]]; if (expect_false (d4 < 0)) ERR ("exactly four hexadecimal digits expected");
708
709 dec->cur += 4;
710
711 return ((UV)d1) << 12
712 | ((UV)d2) << 8
713 | ((UV)d3) << 4
714 | ((UV)d4);
715
716 fail:
717 return (UV)-1;
718 }
719
720 static SV *
721 decode_str (dec_t *dec)
722 {
723 SV *sv = 0;
724 int utf8 = 0;
725 char *dec_cur = dec->cur;
726
727 do
728 {
729 char buf [SHORT_STRING_LEN + UTF8_MAXBYTES];
730 char *cur = buf;
731
732 do
733 {
734 unsigned char ch = *(unsigned char *)dec_cur++;
735
736 if (expect_false (ch == '"'))
737 {
738 --dec_cur;
739 break;
740 }
741 else if (expect_false (ch == '\\'))
742 {
743 switch (*dec_cur)
744 {
745 case '\\':
746 case '/':
747 case '"': *cur++ = *dec_cur++; break;
748
749 case 'b': ++dec_cur; *cur++ = '\010'; break;
750 case 't': ++dec_cur; *cur++ = '\011'; break;
751 case 'n': ++dec_cur; *cur++ = '\012'; break;
752 case 'f': ++dec_cur; *cur++ = '\014'; break;
753 case 'r': ++dec_cur; *cur++ = '\015'; break;
754
755 case 'u':
756 {
757 UV lo, hi;
758 ++dec_cur;
759
760 dec->cur = dec_cur;
761 hi = decode_4hex (dec);
762 dec_cur = dec->cur;
763 if (hi == (UV)-1)
764 goto fail;
765
766 // possibly a surrogate pair
767 if (hi >= 0xd800)
768 if (hi < 0xdc00)
769 {
770 if (dec_cur [0] != '\\' || dec_cur [1] != 'u')
771 ERR ("missing low surrogate character in surrogate pair");
772
773 dec_cur += 2;
774
775 dec->cur = dec_cur;
776 lo = decode_4hex (dec);
777 dec_cur = dec->cur;
778 if (lo == (UV)-1)
779 goto fail;
780
781 if (lo < 0xdc00 || lo >= 0xe000)
782 ERR ("surrogate pair expected");
783
784 hi = (hi - 0xD800) * 0x400 + (lo - 0xDC00) + 0x10000;
785 }
786 else if (hi < 0xe000)
787 ERR ("missing high surrogate character in surrogate pair");
788
789 if (hi >= 0x80)
790 {
791 utf8 = 1;
792
793 cur = (char *)uvuni_to_utf8_flags (cur, hi, 0);
794 }
795 else
796 *cur++ = hi;
797 }
798 break;
799
800 default:
801 --dec_cur;
802 ERR ("illegal backslash escape sequence in string");
803 }
804 }
805 else if (expect_true (ch >= 0x20 && ch <= 0x7f))
806 *cur++ = ch;
807 else if (ch >= 0x80)
808 {
809 STRLEN clen;
810 UV uch;
811
812 --dec_cur;
813
814 uch = decode_utf8 (dec_cur, dec->end - dec_cur, &clen);
815 if (clen == (STRLEN)-1)
816 ERR ("malformed UTF-8 character in JSON string");
817
818 do
819 *cur++ = *dec_cur++;
820 while (--clen);
821
822 utf8 = 1;
823 }
824 else
825 {
826 --dec_cur;
827
828 if (!ch)
829 ERR ("unexpected end of string while parsing JSON string");
830 else
831 ERR ("invalid character encountered while parsing JSON string");
832 }
833 }
834 while (cur < buf + SHORT_STRING_LEN);
835
836 {
837 STRLEN len = cur - buf;
838
839 if (sv)
840 {
841 SvGROW (sv, SvCUR (sv) + len + 1);
842 memcpy (SvPVX (sv) + SvCUR (sv), buf, len);
843 SvCUR_set (sv, SvCUR (sv) + len);
844 }
845 else
846 sv = newSVpvn (buf, len);
847 }
848 }
849 while (*dec_cur != '"');
850
851 ++dec_cur;
852
853 if (sv)
854 {
855 SvPOK_only (sv);
856 *SvEND (sv) = 0;
857
858 if (utf8)
859 SvUTF8_on (sv);
860 }
861 else
862 sv = newSVpvn ("", 0);
863
864 dec->cur = dec_cur;
865 return sv;
866
867 fail:
868 dec->cur = dec_cur;
869 return 0;
870 }
871
872 static SV *
873 decode_num (dec_t *dec)
874 {
875 int is_nv = 0;
876 char *start = dec->cur;
877
878 // [minus]
879 if (*dec->cur == '-')
880 ++dec->cur;
881
882 if (*dec->cur == '0')
883 {
884 ++dec->cur;
885 if (*dec->cur >= '0' && *dec->cur <= '9')
886 ERR ("malformed number (leading zero must not be followed by another digit)");
887 }
888 else if (*dec->cur < '0' || *dec->cur > '9')
889 ERR ("malformed number (no digits after initial minus)");
890 else
891 do
892 {
893 ++dec->cur;
894 }
895 while (*dec->cur >= '0' && *dec->cur <= '9');
896
897 // [frac]
898 if (*dec->cur == '.')
899 {
900 ++dec->cur;
901
902 if (*dec->cur < '0' || *dec->cur > '9')
903 ERR ("malformed number (no digits after decimal point)");
904
905 do
906 {
907 ++dec->cur;
908 }
909 while (*dec->cur >= '0' && *dec->cur <= '9');
910
911 is_nv = 1;
912 }
913
914 // [exp]
915 if (*dec->cur == 'e' || *dec->cur == 'E')
916 {
917 ++dec->cur;
918
919 if (*dec->cur == '-' || *dec->cur == '+')
920 ++dec->cur;
921
922 if (*dec->cur < '0' || *dec->cur > '9')
923 ERR ("malformed number (no digits after exp sign)");
924
925 do
926 {
927 ++dec->cur;
928 }
929 while (*dec->cur >= '0' && *dec->cur <= '9');
930
931 is_nv = 1;
932 }
933
934 if (!is_nv)
935 {
936 // special case the rather common 1..4-digit-int case, assumes 32 bit ints or so
937 if (*start == '-')
938 switch (dec->cur - start)
939 {
940 case 2: return newSViv (-( start [1] - '0' * 1));
941 case 3: return newSViv (-( start [1] * 10 + start [2] - '0' * 11));
942 case 4: return newSViv (-( start [1] * 100 + start [2] * 10 + start [3] - '0' * 111));
943 case 5: return newSViv (-(start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 1111));
944 }
945 else
946 switch (dec->cur - start)
947 {
948 case 1: return newSViv ( start [0] - '0' * 1);
949 case 2: return newSViv ( start [0] * 10 + start [1] - '0' * 11);
950 case 3: return newSViv ( start [0] * 100 + start [1] * 10 + start [2] - '0' * 111);
951 case 4: return newSViv ( start [0] * 1000 + start [1] * 100 + start [2] * 10 + start [3] - '0' * 1111);
952 }
953
954 {
955 UV uv;
956 int numtype = grok_number (start, dec->cur - start, &uv);
957 if (numtype & IS_NUMBER_IN_UV)
958 if (numtype & IS_NUMBER_NEG)
959 {
960 if (uv < (UV)IV_MIN)
961 return newSViv (-(IV)uv);
962 }
963 else
964 return newSVuv (uv);
965
966 // here would likely be the place for bigint support
967 }
968 }
969
970 // if we ever support bigint or bigfloat, this is the place for bigfloat
971 return newSVnv (Atof (start));
972
973 fail:
974 return 0;
975 }
976
977 static SV *
978 decode_av (dec_t *dec)
979 {
980 AV *av = newAV ();
981
982 DEC_INC_DEPTH;
983 decode_ws (dec);
984
985 if (*dec->cur == ']')
986 ++dec->cur;
987 else
988 for (;;)
989 {
990 SV *value;
991
992 value = decode_sv (dec);
993 if (!value)
994 goto fail;
995
996 av_push (av, value);
997
998 decode_ws (dec);
999
1000 if (*dec->cur == ']')
1001 {
1002 ++dec->cur;
1003 break;
1004 }
1005
1006 if (*dec->cur != ',')
1007 ERR (", or ] expected while parsing array");
1008
1009 ++dec->cur;
1010 }
1011
1012 DEC_DEC_DEPTH;
1013 return newRV_noinc ((SV *)av);
1014
1015 fail:
1016 SvREFCNT_dec (av);
1017 DEC_DEC_DEPTH;
1018 return 0;
1019 }
1020
1021 static SV *
1022 decode_hv (dec_t *dec)
1023 {
1024 SV *sv;
1025 HV *hv = newHV ();
1026
1027 DEC_INC_DEPTH;
1028 decode_ws (dec);
1029
1030 if (*dec->cur == '}')
1031 ++dec->cur;
1032 else
1033 for (;;)
1034 {
1035 decode_ws (dec); EXPECT_CH ('"');
1036
1037 // heuristic: assume that
1038 // a) decode_str + hv_store_ent are abysmally slow.
1039 // b) most hash keys are short, simple ascii text.
1040 // => try to "fast-match" such strings to avoid
1041 // the overhead of decode_str + hv_store_ent.
1042 {
1043 SV *value;
1044 char *p = dec->cur;
1045 char *e = p + 24; // only try up to 24 bytes
1046
1047 for (;;)
1048 {
1049 // the >= 0x80 is true on most architectures
1050 if (p == e || *p < 0x20 || *p >= 0x80 || *p == '\\')
1051 {
1052 // slow path, back up and use decode_str
1053 SV *key = decode_str (dec);
1054 if (!key)
1055 goto fail;
1056
1057 decode_ws (dec); EXPECT_CH (':');
1058
1059 value = decode_sv (dec);
1060 if (!value)
1061 {
1062 SvREFCNT_dec (key);
1063 goto fail;
1064 }
1065
1066 hv_store_ent (hv, key, value, 0);
1067 SvREFCNT_dec (key);
1068
1069 break;
1070 }
1071 else if (*p == '"')
1072 {
1073 // fast path, got a simple key
1074 char *key = dec->cur;
1075 int len = p - key;
1076 dec->cur = p + 1;
1077
1078 decode_ws (dec); EXPECT_CH (':');
1079
1080 value = decode_sv (dec);
1081 if (!value)
1082 goto fail;
1083
1084 hv_store (hv, key, len, value, 0);
1085
1086 break;
1087 }
1088
1089 ++p;
1090 }
1091 }
1092
1093 decode_ws (dec);
1094
1095 if (*dec->cur == '}')
1096 {
1097 ++dec->cur;
1098 break;
1099 }
1100
1101 if (*dec->cur != ',')
1102 ERR (", or } expected while parsing object/hash");
1103
1104 ++dec->cur;
1105 }
1106
1107 DEC_DEC_DEPTH;
1108 sv = newRV_noinc ((SV *)hv);
1109
1110 // check filter callbacks
1111 if (dec->json.flags & F_HOOK)
1112 {
1113 if (dec->json.cb_sk_object && HvKEYS (hv) == 1)
1114 {
1115 HE *cb, *he;
1116
1117 hv_iterinit (hv);
1118 he = hv_iternext (hv);
1119 hv_iterinit (hv);
1120
1121 // the next line creates a mortal sv each time its called.
1122 // might want to optimise this for common cases.
1123 cb = hv_fetch_ent (dec->json.cb_sk_object, hv_iterkeysv (he), 0, 0);
1124
1125 if (cb)
1126 {
1127 dSP;
1128 int count;
1129
1130 ENTER; SAVETMPS; PUSHMARK (SP);
1131 XPUSHs (HeVAL (he));
1132
1133 PUTBACK; count = call_sv (HeVAL (cb), G_ARRAY); SPAGAIN;
1134
1135 if (count == 1)
1136 {
1137 sv = newSVsv (POPs);
1138 FREETMPS; LEAVE;
1139 return sv;
1140 }
1141
1142 FREETMPS; LEAVE;
1143 }
1144 }
1145
1146 if (dec->json.cb_object)
1147 {
1148 dSP;
1149 int count;
1150
1151 ENTER; SAVETMPS; PUSHMARK (SP);
1152 XPUSHs (sv_2mortal (sv));
1153
1154 PUTBACK; count = call_sv (dec->json.cb_object, G_ARRAY); SPAGAIN;
1155
1156 if (count == 1)
1157 {
1158 sv = newSVsv (POPs);
1159 FREETMPS; LEAVE;
1160 return sv;
1161 }
1162
1163 SvREFCNT_inc (sv);
1164 FREETMPS; LEAVE;
1165 }
1166 }
1167
1168 return sv;
1169
1170 fail:
1171 SvREFCNT_dec (hv);
1172 DEC_DEC_DEPTH;
1173 return 0;
1174 }
1175
1176 static SV *
1177 decode_sv (dec_t *dec)
1178 {
1179 decode_ws (dec);
1180
1181 // the beauty of JSON: you need exactly one character lookahead
1182 // to parse anything.
1183 switch (*dec->cur)
1184 {
1185 case '"': ++dec->cur; return decode_str (dec);
1186 case '[': ++dec->cur; return decode_av (dec);
1187 case '{': ++dec->cur; return decode_hv (dec);
1188
1189 case '-':
1190 case '0': case '1': case '2': case '3': case '4':
1191 case '5': case '6': case '7': case '8': case '9':
1192 return decode_num (dec);
1193
1194 case 't':
1195 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "true", 4))
1196 {
1197 dec->cur += 4;
1198 return SvREFCNT_inc (json_true);
1199 }
1200 else
1201 ERR ("'true' expected");
1202
1203 break;
1204
1205 case 'f':
1206 if (dec->end - dec->cur >= 5 && !memcmp (dec->cur, "false", 5))
1207 {
1208 dec->cur += 5;
1209 return SvREFCNT_inc (json_false);
1210 }
1211 else
1212 ERR ("'false' expected");
1213
1214 break;
1215
1216 case 'n':
1217 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "null", 4))
1218 {
1219 dec->cur += 4;
1220 return newSVsv (&PL_sv_undef);
1221 }
1222 else
1223 ERR ("'null' expected");
1224
1225 break;
1226
1227 default:
1228 ERR ("malformed JSON string, neither array, object, number, string or atom");
1229 break;
1230 }
1231
1232 fail:
1233 return 0;
1234 }
1235
1236 static SV *
1237 decode_json (SV *string, JSON *json, UV *offset_return)
1238 {
1239 dec_t dec;
1240 UV offset;
1241 SV *sv;
1242
1243 SvGETMAGIC (string);
1244 SvUPGRADE (string, SVt_PV);
1245
1246 if (json->flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (json->flags))
1247 croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu",
1248 (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (json->flags));
1249
1250 if (json->flags & F_UTF8)
1251 sv_utf8_downgrade (string, 0);
1252 else
1253 sv_utf8_upgrade (string);
1254
1255 SvGROW (string, SvCUR (string) + 1); // should basically be a NOP
1256
1257 dec.json = *json;
1258 dec.cur = SvPVX (string);
1259 dec.end = SvEND (string);
1260 dec.err = 0;
1261 dec.depth = 0;
1262 dec.maxdepth = DEC_DEPTH (dec.json.flags);
1263
1264 if (dec.json.cb_object || dec.json.cb_sk_object)
1265 dec.json.flags |= F_HOOK;
1266
1267 *dec.end = 0; // this should basically be a nop, too, but make sure it's there
1268 sv = decode_sv (&dec);
1269
1270 if (!(offset_return || !sv))
1271 {
1272 // check for trailing garbage
1273 decode_ws (&dec);
1274
1275 if (*dec.cur)
1276 {
1277 dec.err = "garbage after JSON object";
1278 SvREFCNT_dec (sv);
1279 sv = 0;
1280 }
1281 }
1282
1283 if (offset_return || !sv)
1284 {
1285 offset = dec.json.flags & F_UTF8
1286 ? dec.cur - SvPVX (string)
1287 : utf8_distance (dec.cur, SvPVX (string));
1288
1289 if (offset_return)
1290 *offset_return = offset;
1291 }
1292
1293 if (!sv)
1294 {
1295 SV *uni = sv_newmortal ();
1296
1297 // horrible hack to silence warning inside pv_uni_display
1298 COP cop = *PL_curcop;
1299 cop.cop_warnings = pWARN_NONE;
1300 ENTER;
1301 SAVEVPTR (PL_curcop);
1302 PL_curcop = &cop;
1303 pv_uni_display (uni, dec.cur, dec.end - dec.cur, 20, UNI_DISPLAY_QQ);
1304 LEAVE;
1305
1306 croak ("%s, at character offset %d [\"%s\"]",
1307 dec.err,
1308 (int)offset,
1309 dec.cur != dec.end ? SvPV_nolen (uni) : "(end of string)");
1310 }
1311
1312 sv = sv_2mortal (sv);
1313
1314 if (!(dec.json.flags & F_ALLOW_NONREF) && !SvROK (sv))
1315 croak ("JSON text must be an object or array (but found number, string, true, false or null, use allow_nonref to allow this)");
1316
1317 return sv;
1318 }
1319
1320 /////////////////////////////////////////////////////////////////////////////
1321 // XS interface functions
1322
1323 MODULE = JSON::XS PACKAGE = JSON::XS
1324
1325 BOOT:
1326 {
1327 int i;
1328
1329 for (i = 0; i < 256; ++i)
1330 decode_hexdigit [i] =
1331 i >= '0' && i <= '9' ? i - '0'
1332 : i >= 'a' && i <= 'f' ? i - 'a' + 10
1333 : i >= 'A' && i <= 'F' ? i - 'A' + 10
1334 : -1;
1335
1336 json_stash = gv_stashpv ("JSON::XS" , 1);
1337 json_boolean_stash = gv_stashpv ("JSON::XS::Boolean", 1);
1338
1339 json_true = get_sv ("JSON::XS::true" , 1); SvREADONLY_on (json_true );
1340 json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false);
1341 }
1342
1343 PROTOTYPES: DISABLE
1344
1345 void new (char *klass)
1346 PPCODE:
1347 {
1348 SV *pv = NEWSV (0, sizeof (JSON));
1349 SvPOK_only (pv);
1350 Zero (SvPVX (pv), 1, JSON);
1351 ((JSON *)SvPVX (pv))->flags = F_DEFAULT;
1352 XPUSHs (sv_2mortal (sv_bless (newRV_noinc (pv), json_stash)));
1353 }
1354
1355 void ascii (JSON *self, int enable = 1)
1356 ALIAS:
1357 ascii = F_ASCII
1358 latin1 = F_LATIN1
1359 utf8 = F_UTF8
1360 indent = F_INDENT
1361 canonical = F_CANONICAL
1362 space_before = F_SPACE_BEFORE
1363 space_after = F_SPACE_AFTER
1364 pretty = F_PRETTY
1365 allow_nonref = F_ALLOW_NONREF
1366 shrink = F_SHRINK
1367 allow_blessed = F_ALLOW_BLESSED
1368 convert_blessed = F_CONV_BLESSED
1369 PPCODE:
1370 {
1371 if (enable)
1372 self->flags |= ix;
1373 else
1374 self->flags &= ~ix;
1375
1376 XPUSHs (ST (0));
1377 }
1378
1379 void max_depth (JSON *self, UV max_depth = 0x80000000UL)
1380 PPCODE:
1381 {
1382 UV log2 = 0;
1383
1384 if (max_depth > 0x80000000UL) max_depth = 0x80000000UL;
1385
1386 while ((1UL << log2) < max_depth)
1387 ++log2;
1388
1389 self->flags = self->flags & ~F_MAXDEPTH | (log2 << S_MAXDEPTH);
1390
1391 XPUSHs (ST (0));
1392 }
1393
1394 void max_size (JSON *self, UV max_size = 0)
1395 PPCODE:
1396 {
1397 UV log2 = 0;
1398
1399 if (max_size > 0x80000000UL) max_size = 0x80000000UL;
1400 if (max_size == 1) max_size = 2;
1401
1402 while ((1UL << log2) < max_size)
1403 ++log2;
1404
1405 self->flags = self->flags & ~F_MAXSIZE | (log2 << S_MAXSIZE);
1406
1407 XPUSHs (ST (0));
1408 }
1409
1410 void filter_json_object (JSON *self, SV *cb = &PL_sv_undef)
1411 PPCODE:
1412 {
1413 SvREFCNT_dec (self->cb_object);
1414 self->cb_object = SvOK (cb) ? newSVsv (cb) : 0;
1415
1416 XPUSHs (ST (0));
1417 }
1418
1419 void filter_json_single_key_object (JSON *self, SV *key, SV *cb = &PL_sv_undef)
1420 PPCODE:
1421 {
1422 if (!self->cb_sk_object)
1423 self->cb_sk_object = newHV ();
1424
1425 if (SvOK (cb))
1426 hv_store_ent (self->cb_sk_object, key, newSVsv (cb), 0);
1427 else
1428 {
1429 hv_delete_ent (self->cb_sk_object, key, G_DISCARD, 0);
1430
1431 if (!HvKEYS (self->cb_sk_object))
1432 {
1433 SvREFCNT_dec (self->cb_sk_object);
1434 self->cb_sk_object = 0;
1435 }
1436 }
1437
1438 XPUSHs (ST (0));
1439 }
1440
1441 void encode (JSON *self, SV *scalar)
1442 PPCODE:
1443 XPUSHs (encode_json (scalar, self));
1444
1445 void decode (JSON *self, SV *jsonstr)
1446 PPCODE:
1447 XPUSHs (decode_json (jsonstr, self, 0));
1448
1449 void decode_prefix (JSON *self, SV *jsonstr)
1450 PPCODE:
1451 {
1452 UV offset;
1453 EXTEND (SP, 2);
1454 PUSHs (decode_json (jsonstr, self, &offset));
1455 PUSHs (sv_2mortal (newSVuv (offset)));
1456 }
1457
1458 void DESTROY (JSON *self)
1459 CODE:
1460 SvREFCNT_dec (self->cb_sk_object);
1461 SvREFCNT_dec (self->cb_object);
1462
1463 PROTOTYPES: ENABLE
1464
1465 void to_json (SV *scalar)
1466 PPCODE:
1467 {
1468 JSON json = { F_DEFAULT | F_UTF8 };
1469 XPUSHs (encode_json (scalar, &json));
1470 }
1471
1472 void from_json (SV *jsonstr)
1473 PPCODE:
1474 {
1475 JSON json = { F_DEFAULT | F_UTF8 };
1476 XPUSHs (decode_json (jsonstr, &json, 0));
1477 }
1478