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/cvs/JSON-XS/XS.xs
Revision: 1.61
Committed: Sun Aug 26 21:56:47 2007 UTC (16 years, 8 months ago) by root
Branch: MAIN
Changes since 1.60: +43 -27 lines
Log Message:
tied hashes, maybe

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 #ifdef USE_ITHREADS
64 # define JSON_SLOW 1
65 # define JSON_STASH (json_stash ? json_stash : gv_stashpv ("JSON::XS", 1))
66 #else
67 # define JSON_SLOW 0
68 # define JSON_STASH json_stash
69 #endif
70
71 static HV *json_stash, *json_boolean_stash; // JSON::XS::
72 static SV *json_true, *json_false;
73
74 typedef struct {
75 U32 flags;
76 SV *cb_object;
77 HV *cb_sk_object;
78 } JSON;
79
80 /////////////////////////////////////////////////////////////////////////////
81 // utility functions
82
83 inline void
84 shrink (SV *sv)
85 {
86 sv_utf8_downgrade (sv, 1);
87 if (SvLEN (sv) > SvCUR (sv) + 1)
88 {
89 #ifdef SvPV_shrink_to_cur
90 SvPV_shrink_to_cur (sv);
91 #elif defined (SvPV_renew)
92 SvPV_renew (sv, SvCUR (sv) + 1);
93 #endif
94 }
95 }
96
97 // decode an utf-8 character and return it, or (UV)-1 in
98 // case of an error.
99 // we special-case "safe" characters from U+80 .. U+7FF,
100 // but use the very good perl function to parse anything else.
101 // note that we never call this function for a ascii codepoints
102 inline UV
103 decode_utf8 (unsigned char *s, STRLEN len, STRLEN *clen)
104 {
105 if (expect_false (s[0] > 0xdf || s[0] < 0xc2))
106 return utf8n_to_uvuni (s, len, clen, UTF8_CHECK_ONLY);
107 else if (len > 1 && s[1] >= 0x80 && s[1] <= 0xbf)
108 {
109 *clen = 2;
110 return ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
111 }
112 else
113 {
114 *clen = (STRLEN)-1;
115 return (UV)-1;
116 }
117 }
118
119 /////////////////////////////////////////////////////////////////////////////
120 // encoder
121
122 // structure used for encoding JSON
123 typedef struct
124 {
125 char *cur; // SvPVX (sv) + current output position
126 char *end; // SvEND (sv)
127 SV *sv; // result scalar
128 JSON json;
129 U32 indent; // indentation level
130 U32 maxdepth; // max. indentation/recursion level
131 } enc_t;
132
133 inline void
134 need (enc_t *enc, STRLEN len)
135 {
136 if (expect_false (enc->cur + len >= enc->end))
137 {
138 STRLEN cur = enc->cur - SvPVX (enc->sv);
139 SvGROW (enc->sv, cur + len + 1);
140 enc->cur = SvPVX (enc->sv) + cur;
141 enc->end = SvPVX (enc->sv) + SvLEN (enc->sv) - 1;
142 }
143 }
144
145 inline void
146 encode_ch (enc_t *enc, char ch)
147 {
148 need (enc, 1);
149 *enc->cur++ = ch;
150 }
151
152 static void
153 encode_str (enc_t *enc, char *str, STRLEN len, int is_utf8)
154 {
155 char *end = str + len;
156
157 need (enc, len);
158
159 while (str < end)
160 {
161 unsigned char ch = *(unsigned char *)str;
162
163 if (expect_true (ch >= 0x20 && ch < 0x80)) // most common case
164 {
165 if (expect_false (ch == '"')) // but with slow exceptions
166 {
167 need (enc, len += 1);
168 *enc->cur++ = '\\';
169 *enc->cur++ = '"';
170 }
171 else if (expect_false (ch == '\\'))
172 {
173 need (enc, len += 1);
174 *enc->cur++ = '\\';
175 *enc->cur++ = '\\';
176 }
177 else
178 *enc->cur++ = ch;
179
180 ++str;
181 }
182 else
183 {
184 switch (ch)
185 {
186 case '\010': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'b'; ++str; break;
187 case '\011': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 't'; ++str; break;
188 case '\012': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'n'; ++str; break;
189 case '\014': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'f'; ++str; break;
190 case '\015': need (enc, len += 1); *enc->cur++ = '\\'; *enc->cur++ = 'r'; ++str; break;
191
192 default:
193 {
194 STRLEN clen;
195 UV uch;
196
197 if (is_utf8)
198 {
199 uch = decode_utf8 (str, end - str, &clen);
200 if (clen == (STRLEN)-1)
201 croak ("malformed or illegal unicode character in string [%.11s], cannot convert to JSON", str);
202 }
203 else
204 {
205 uch = ch;
206 clen = 1;
207 }
208
209 if (uch > 0x10FFFFUL)
210 croak ("out of range codepoint (0x%lx) encountered, unrepresentable in JSON", (unsigned long)uch);
211
212 if (uch < 0x80 || enc->json.flags & F_ASCII || (enc->json.flags & F_LATIN1 && uch > 0xFF))
213 {
214 if (uch > 0xFFFFUL)
215 {
216 need (enc, len += 11);
217 sprintf (enc->cur, "\\u%04x\\u%04x",
218 (int)((uch - 0x10000) / 0x400 + 0xD800),
219 (int)((uch - 0x10000) % 0x400 + 0xDC00));
220 enc->cur += 12;
221 }
222 else
223 {
224 static char hexdigit [16] = "0123456789abcdef";
225 need (enc, len += 5);
226 *enc->cur++ = '\\';
227 *enc->cur++ = 'u';
228 *enc->cur++ = hexdigit [ uch >> 12 ];
229 *enc->cur++ = hexdigit [(uch >> 8) & 15];
230 *enc->cur++ = hexdigit [(uch >> 4) & 15];
231 *enc->cur++ = hexdigit [(uch >> 0) & 15];
232 }
233
234 str += clen;
235 }
236 else if (enc->json.flags & F_LATIN1)
237 {
238 *enc->cur++ = uch;
239 str += clen;
240 }
241 else if (is_utf8)
242 {
243 need (enc, len += clen);
244 do
245 {
246 *enc->cur++ = *str++;
247 }
248 while (--clen);
249 }
250 else
251 {
252 need (enc, len += UTF8_MAXBYTES - 1); // never more than 11 bytes needed
253 enc->cur = uvuni_to_utf8_flags (enc->cur, uch, 0);
254 ++str;
255 }
256 }
257 }
258 }
259
260 --len;
261 }
262 }
263
264 inline void
265 encode_indent (enc_t *enc)
266 {
267 if (enc->json.flags & F_INDENT)
268 {
269 int spaces = enc->indent * INDENT_STEP;
270
271 need (enc, spaces);
272 memset (enc->cur, ' ', spaces);
273 enc->cur += spaces;
274 }
275 }
276
277 inline void
278 encode_space (enc_t *enc)
279 {
280 need (enc, 1);
281 encode_ch (enc, ' ');
282 }
283
284 inline void
285 encode_nl (enc_t *enc)
286 {
287 if (enc->json.flags & F_INDENT)
288 {
289 need (enc, 1);
290 encode_ch (enc, '\n');
291 }
292 }
293
294 inline void
295 encode_comma (enc_t *enc)
296 {
297 encode_ch (enc, ',');
298
299 if (enc->json.flags & F_INDENT)
300 encode_nl (enc);
301 else if (enc->json.flags & F_SPACE_AFTER)
302 encode_space (enc);
303 }
304
305 static void encode_sv (enc_t *enc, SV *sv);
306
307 static void
308 encode_av (enc_t *enc, AV *av)
309 {
310 int i, len = av_len (av);
311
312 if (enc->indent >= enc->maxdepth)
313 croak ("data structure too deep (hit recursion limit)");
314
315 encode_ch (enc, '['); encode_nl (enc);
316 ++enc->indent;
317
318 for (i = 0; i <= len; ++i)
319 {
320 SV **svp = av_fetch (av, i, 0);
321
322 encode_indent (enc);
323
324 if (svp)
325 encode_sv (enc, *svp);
326 else
327 encode_str (enc, "null", 4, 0);
328
329 if (i < len)
330 encode_comma (enc);
331 }
332
333 encode_nl (enc);
334
335 --enc->indent;
336 encode_indent (enc); encode_ch (enc, ']');
337 }
338
339 static void
340 encode_hk (enc_t *enc, HE *he)
341 {
342 encode_ch (enc, '"');
343
344 if (HeKLEN (he) == HEf_SVKEY)
345 {
346 SV *sv = HeSVKEY (he);
347 STRLEN len;
348 char *str;
349
350 SvGETMAGIC (sv);
351 str = SvPV (sv, len);
352
353 encode_str (enc, str, len, SvUTF8 (sv));
354 }
355 else
356 encode_str (enc, HeKEY (he), HeKLEN (he), HeKUTF8 (he));
357
358 encode_ch (enc, '"');
359
360 if (enc->json.flags & F_SPACE_BEFORE) encode_space (enc);
361 encode_ch (enc, ':');
362 if (enc->json.flags & F_SPACE_AFTER ) encode_space (enc);
363 }
364
365 // compare hash entries, used when all keys are bytestrings
366 static int
367 he_cmp_fast (const void *a_, const void *b_)
368 {
369 int cmp;
370
371 HE *a = *(HE **)a_;
372 HE *b = *(HE **)b_;
373
374 STRLEN la = HeKLEN (a);
375 STRLEN lb = HeKLEN (b);
376
377 if (!(cmp = memcmp (HeKEY (b), HeKEY (a), lb < la ? lb : la)))
378 cmp = lb - la;
379
380 return cmp;
381 }
382
383 // compare hash entries, used when some keys are sv's or utf-x
384 static int
385 he_cmp_slow (const void *a, const void *b)
386 {
387 return sv_cmp (HeSVKEY_force (*(HE **)b), HeSVKEY_force (*(HE **)a));
388 }
389
390 static void
391 encode_hv (enc_t *enc, HV *hv)
392 {
393 HE *he;
394 int count;
395
396 if (enc->indent >= enc->maxdepth)
397 croak ("data structure too deep (hit recursion limit)");
398
399 encode_ch (enc, '{'); encode_nl (enc); ++enc->indent;
400
401 // for canonical output we have to sort by keys first
402 // actually, this is mostly due to the stupid so-called
403 // security workaround added somewhere in 5.8.x.
404 // that randomises hash orderings
405 if (enc->json.flags & F_CANONICAL)
406 {
407 int count = hv_iterinit (hv);
408
409 if (SvMAGICAL (hv))
410 {
411 // need to count by iterating. could improve by dynamically building the vector below
412 // but I don't care for the speed of this special case.
413 // note also that we will run into undefined behaviour when the two iterations
414 // do not result in the same count, something I might care for in some later release.
415
416 count = 0;
417 while (hv_iternext (hv))
418 ++count;
419
420 hv_iterinit (hv);
421 }
422
423 if (count)
424 {
425 int i, fast = 1;
426 #if defined(__BORLANDC__) || defined(_MSC_VER)
427 HE **hes = _alloca (count * sizeof (HE));
428 #else
429 HE *hes [count]; // if your compiler dies here, you need to enable C99 mode
430 #endif
431
432 i = 0;
433 while ((he = hv_iternext (hv)))
434 {
435 hes [i++] = he;
436 if (HeKLEN (he) < 0 || HeKUTF8 (he))
437 fast = 0;
438 }
439
440 assert (i == count);
441
442 if (fast)
443 qsort (hes, count, sizeof (HE *), he_cmp_fast);
444 else
445 {
446 // hack to forcefully disable "use bytes"
447 COP cop = *PL_curcop;
448 cop.op_private = 0;
449
450 ENTER;
451 SAVETMPS;
452
453 SAVEVPTR (PL_curcop);
454 PL_curcop = &cop;
455
456 qsort (hes, count, sizeof (HE *), he_cmp_slow);
457
458 FREETMPS;
459 LEAVE;
460 }
461
462 while (count--)
463 {
464 encode_indent (enc);
465 he = hes [count];
466 encode_hk (enc, he);
467 encode_sv (enc, SvMAGICAL (hv) ? hv_iterval (hv, he) : HeVAL (he));
468
469 if (count)
470 encode_comma (enc);
471 }
472 }
473 }
474 else
475 {
476 if (hv_iterinit (hv) || SvMAGICAL (hv))
477 if ((he = hv_iternext (hv)))
478 for (;;)
479 {
480 encode_indent (enc);
481 encode_hk (enc, he);
482 encode_sv (enc, SvMAGICAL (hv) ? hv_iterval (hv, he) : HeVAL (he));
483
484 if (!(he = hv_iternext (hv)))
485 break;
486
487 encode_comma (enc);
488 }
489 }
490
491 encode_nl (enc);
492
493 --enc->indent; encode_indent (enc); encode_ch (enc, '}');
494 }
495
496 // encode objects, arrays and special \0=false and \1=true values.
497 static void
498 encode_rv (enc_t *enc, SV *sv)
499 {
500 svtype svt;
501
502 SvGETMAGIC (sv);
503 svt = SvTYPE (sv);
504
505 if (expect_false (SvOBJECT (sv)))
506 {
507 HV *stash = !JSON_SLOW || json_boolean_stash
508 ? json_boolean_stash
509 : gv_stashpv ("JSON::XS::Boolean", 1);
510
511 if (SvSTASH (sv) == stash)
512 {
513 if (SvIV (sv))
514 encode_str (enc, "true", 4, 0);
515 else
516 encode_str (enc, "false", 5, 0);
517 }
518 else
519 {
520 #if 0
521 if (0 && sv_derived_from (rv, "JSON::Literal"))
522 {
523 // not yet
524 }
525 #endif
526 if (enc->json.flags & F_CONV_BLESSED)
527 {
528 // we re-bless the reference to get overload and other niceties right
529 GV *to_json = gv_fetchmethod_autoload (SvSTASH (sv), "TO_JSON", 0);
530
531 if (to_json)
532 {
533 dSP;
534
535 ENTER; SAVETMPS; PUSHMARK (SP);
536 XPUSHs (sv_bless (sv_2mortal (newRV_inc (sv)), SvSTASH (sv)));
537
538 // calling with G_SCALAR ensures that we always get a 1 return value
539 PUTBACK;
540 call_sv ((SV *)GvCV (to_json), G_SCALAR);
541 SPAGAIN;
542
543 // catch this surprisingly common error
544 if (SvROK (TOPs) && SvRV (TOPs) == sv)
545 croak ("%s::TO_JSON method returned same object as was passed instead of a new one", HvNAME (SvSTASH (sv)));
546
547 sv = POPs;
548 PUTBACK;
549
550 encode_sv (enc, sv);
551
552 FREETMPS; LEAVE;
553 }
554 else if (enc->json.flags & F_ALLOW_BLESSED)
555 encode_str (enc, "null", 4, 0);
556 else
557 croak ("encountered object '%s', but neither allow_blessed enabled nor TO_JSON method available on it",
558 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
559 }
560 else if (enc->json.flags & F_ALLOW_BLESSED)
561 encode_str (enc, "null", 4, 0);
562 else
563 croak ("encountered object '%s', but neither allow_blessed nor convert_blessed settings are enabled",
564 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
565 }
566 }
567 else if (svt == SVt_PVHV)
568 encode_hv (enc, (HV *)sv);
569 else if (svt == SVt_PVAV)
570 encode_av (enc, (AV *)sv);
571 else if (svt < SVt_PVAV)
572 {
573 STRLEN len = 0;
574 char *pv = svt ? SvPV (sv, len) : 0;
575
576 if (len == 1 && *pv == '1')
577 encode_str (enc, "true", 4, 0);
578 else if (len == 1 && *pv == '0')
579 encode_str (enc, "false", 5, 0);
580 else
581 croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
582 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
583 }
584 else
585 croak ("encountered %s, but JSON can only represent references to arrays or hashes",
586 SvPV_nolen (sv_2mortal (newRV_inc (sv))));
587 }
588
589 static void
590 encode_sv (enc_t *enc, SV *sv)
591 {
592 SvGETMAGIC (sv);
593
594 if (SvPOKp (sv))
595 {
596 STRLEN len;
597 char *str = SvPV (sv, len);
598 encode_ch (enc, '"');
599 encode_str (enc, str, len, SvUTF8 (sv));
600 encode_ch (enc, '"');
601 }
602 else if (SvNOKp (sv))
603 {
604 // trust that perl will do the right thing w.r.t. JSON syntax.
605 need (enc, NV_DIG + 32);
606 Gconvert (SvNVX (sv), NV_DIG, 0, enc->cur);
607 enc->cur += strlen (enc->cur);
608 }
609 else if (SvIOKp (sv))
610 {
611 // we assume we can always read an IV as a UV
612 if (SvUV (sv) & ~(UV)0x7fff)
613 {
614 // large integer, use the (rather slow) snprintf way.
615 need (enc, sizeof (UV) * 3);
616 enc->cur +=
617 SvIsUV(sv)
618 ? snprintf (enc->cur, sizeof (UV) * 3, "%"UVuf, (UV)SvUVX (sv))
619 : snprintf (enc->cur, sizeof (UV) * 3, "%"IVdf, (IV)SvIVX (sv));
620 }
621 else
622 {
623 // optimise the "small number case"
624 // code will likely be branchless and use only a single multiplication
625 I32 i = SvIV (sv);
626 U32 u;
627 char digit, nz = 0;
628
629 need (enc, 6);
630
631 *enc->cur = '-'; enc->cur += i < 0 ? 1 : 0;
632 u = i < 0 ? -i : i;
633
634 // convert to 4.28 fixed-point representation
635 u = u * ((0xfffffff + 10000) / 10000); // 10**5, 5 fractional digits
636
637 // now output digit by digit, each time masking out the integer part
638 // and multiplying by 5 while moving the decimal point one to the right,
639 // resulting in a net multiplication by 10.
640 // we always write the digit to memory but conditionally increment
641 // the pointer, to ease the usage of conditional move instructions.
642 digit = u >> 28; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0xfffffff) * 5;
643 digit = u >> 27; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x7ffffff) * 5;
644 digit = u >> 26; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x3ffffff) * 5;
645 digit = u >> 25; *enc->cur = digit + '0'; enc->cur += (nz = nz || digit); u = (u & 0x1ffffff) * 5;
646 digit = u >> 24; *enc->cur = digit + '0'; enc->cur += 1; // correctly generate '0'
647 }
648 }
649 else if (SvROK (sv))
650 encode_rv (enc, SvRV (sv));
651 else if (!SvOK (sv))
652 encode_str (enc, "null", 4, 0);
653 else
654 croak ("encountered perl type (%s,0x%x) that JSON cannot handle, you might want to report this",
655 SvPV_nolen (sv), SvFLAGS (sv));
656 }
657
658 static SV *
659 encode_json (SV *scalar, JSON *json)
660 {
661 enc_t enc;
662
663 if (!(json->flags & F_ALLOW_NONREF) && !SvROK (scalar))
664 croak ("hash- or arrayref expected (not a simple scalar, use allow_nonref to allow this)");
665
666 enc.json = *json;
667 enc.sv = sv_2mortal (NEWSV (0, INIT_SIZE));
668 enc.cur = SvPVX (enc.sv);
669 enc.end = SvEND (enc.sv);
670 enc.indent = 0;
671 enc.maxdepth = DEC_DEPTH (enc.json.flags);
672
673 SvPOK_only (enc.sv);
674 encode_sv (&enc, scalar);
675
676 SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
677 *SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings
678
679 if (!(enc.json.flags & (F_ASCII | F_LATIN1 | F_UTF8)))
680 SvUTF8_on (enc.sv);
681
682 if (enc.json.flags & F_SHRINK)
683 shrink (enc.sv);
684
685 return enc.sv;
686 }
687
688 /////////////////////////////////////////////////////////////////////////////
689 // decoder
690
691 // structure used for decoding JSON
692 typedef struct
693 {
694 char *cur; // current parser pointer
695 char *end; // end of input string
696 const char *err; // parse error, if != 0
697 JSON json;
698 U32 depth; // recursion depth
699 U32 maxdepth; // recursion depth limit
700 } dec_t;
701
702 inline void
703 decode_ws (dec_t *dec)
704 {
705 for (;;)
706 {
707 char ch = *dec->cur;
708
709 if (ch > 0x20
710 || (ch != 0x20 && ch != 0x0a && ch != 0x0d && ch != 0x09))
711 break;
712
713 ++dec->cur;
714 }
715 }
716
717 #define ERR(reason) SB dec->err = reason; goto fail; SE
718
719 #define EXPECT_CH(ch) SB \
720 if (*dec->cur != ch) \
721 ERR (# ch " expected"); \
722 ++dec->cur; \
723 SE
724
725 #define DEC_INC_DEPTH if (++dec->depth > dec->maxdepth) ERR ("json datastructure exceeds maximum nesting level (set a higher max_depth)")
726 #define DEC_DEC_DEPTH --dec->depth
727
728 static SV *decode_sv (dec_t *dec);
729
730 static signed char decode_hexdigit[256];
731
732 static UV
733 decode_4hex (dec_t *dec)
734 {
735 signed char d1, d2, d3, d4;
736 unsigned char *cur = (unsigned char *)dec->cur;
737
738 d1 = decode_hexdigit [cur [0]]; if (expect_false (d1 < 0)) ERR ("exactly four hexadecimal digits expected");
739 d2 = decode_hexdigit [cur [1]]; if (expect_false (d2 < 0)) ERR ("exactly four hexadecimal digits expected");
740 d3 = decode_hexdigit [cur [2]]; if (expect_false (d3 < 0)) ERR ("exactly four hexadecimal digits expected");
741 d4 = decode_hexdigit [cur [3]]; if (expect_false (d4 < 0)) ERR ("exactly four hexadecimal digits expected");
742
743 dec->cur += 4;
744
745 return ((UV)d1) << 12
746 | ((UV)d2) << 8
747 | ((UV)d3) << 4
748 | ((UV)d4);
749
750 fail:
751 return (UV)-1;
752 }
753
754 static SV *
755 decode_str (dec_t *dec)
756 {
757 SV *sv = 0;
758 int utf8 = 0;
759 char *dec_cur = dec->cur;
760
761 do
762 {
763 char buf [SHORT_STRING_LEN + UTF8_MAXBYTES];
764 char *cur = buf;
765
766 do
767 {
768 unsigned char ch = *(unsigned char *)dec_cur++;
769
770 if (expect_false (ch == '"'))
771 {
772 --dec_cur;
773 break;
774 }
775 else if (expect_false (ch == '\\'))
776 {
777 switch (*dec_cur)
778 {
779 case '\\':
780 case '/':
781 case '"': *cur++ = *dec_cur++; break;
782
783 case 'b': ++dec_cur; *cur++ = '\010'; break;
784 case 't': ++dec_cur; *cur++ = '\011'; break;
785 case 'n': ++dec_cur; *cur++ = '\012'; break;
786 case 'f': ++dec_cur; *cur++ = '\014'; break;
787 case 'r': ++dec_cur; *cur++ = '\015'; break;
788
789 case 'u':
790 {
791 UV lo, hi;
792 ++dec_cur;
793
794 dec->cur = dec_cur;
795 hi = decode_4hex (dec);
796 dec_cur = dec->cur;
797 if (hi == (UV)-1)
798 goto fail;
799
800 // possibly a surrogate pair
801 if (hi >= 0xd800)
802 if (hi < 0xdc00)
803 {
804 if (dec_cur [0] != '\\' || dec_cur [1] != 'u')
805 ERR ("missing low surrogate character in surrogate pair");
806
807 dec_cur += 2;
808
809 dec->cur = dec_cur;
810 lo = decode_4hex (dec);
811 dec_cur = dec->cur;
812 if (lo == (UV)-1)
813 goto fail;
814
815 if (lo < 0xdc00 || lo >= 0xe000)
816 ERR ("surrogate pair expected");
817
818 hi = (hi - 0xD800) * 0x400 + (lo - 0xDC00) + 0x10000;
819 }
820 else if (hi < 0xe000)
821 ERR ("missing high surrogate character in surrogate pair");
822
823 if (hi >= 0x80)
824 {
825 utf8 = 1;
826
827 cur = (char *)uvuni_to_utf8_flags (cur, hi, 0);
828 }
829 else
830 *cur++ = hi;
831 }
832 break;
833
834 default:
835 --dec_cur;
836 ERR ("illegal backslash escape sequence in string");
837 }
838 }
839 else if (expect_true (ch >= 0x20 && ch <= 0x7f))
840 *cur++ = ch;
841 else if (ch >= 0x80)
842 {
843 STRLEN clen;
844 UV uch;
845
846 --dec_cur;
847
848 uch = decode_utf8 (dec_cur, dec->end - dec_cur, &clen);
849 if (clen == (STRLEN)-1)
850 ERR ("malformed UTF-8 character in JSON string");
851
852 do
853 *cur++ = *dec_cur++;
854 while (--clen);
855
856 utf8 = 1;
857 }
858 else
859 {
860 --dec_cur;
861
862 if (!ch)
863 ERR ("unexpected end of string while parsing JSON string");
864 else
865 ERR ("invalid character encountered while parsing JSON string");
866 }
867 }
868 while (cur < buf + SHORT_STRING_LEN);
869
870 {
871 STRLEN len = cur - buf;
872
873 if (sv)
874 {
875 SvGROW (sv, SvCUR (sv) + len + 1);
876 memcpy (SvPVX (sv) + SvCUR (sv), buf, len);
877 SvCUR_set (sv, SvCUR (sv) + len);
878 }
879 else
880 sv = newSVpvn (buf, len);
881 }
882 }
883 while (*dec_cur != '"');
884
885 ++dec_cur;
886
887 if (sv)
888 {
889 SvPOK_only (sv);
890 *SvEND (sv) = 0;
891
892 if (utf8)
893 SvUTF8_on (sv);
894 }
895 else
896 sv = newSVpvn ("", 0);
897
898 dec->cur = dec_cur;
899 return sv;
900
901 fail:
902 dec->cur = dec_cur;
903 return 0;
904 }
905
906 static SV *
907 decode_num (dec_t *dec)
908 {
909 int is_nv = 0;
910 char *start = dec->cur;
911
912 // [minus]
913 if (*dec->cur == '-')
914 ++dec->cur;
915
916 if (*dec->cur == '0')
917 {
918 ++dec->cur;
919 if (*dec->cur >= '0' && *dec->cur <= '9')
920 ERR ("malformed number (leading zero must not be followed by another digit)");
921 }
922 else if (*dec->cur < '0' || *dec->cur > '9')
923 ERR ("malformed number (no digits after initial minus)");
924 else
925 do
926 {
927 ++dec->cur;
928 }
929 while (*dec->cur >= '0' && *dec->cur <= '9');
930
931 // [frac]
932 if (*dec->cur == '.')
933 {
934 ++dec->cur;
935
936 if (*dec->cur < '0' || *dec->cur > '9')
937 ERR ("malformed number (no digits after decimal point)");
938
939 do
940 {
941 ++dec->cur;
942 }
943 while (*dec->cur >= '0' && *dec->cur <= '9');
944
945 is_nv = 1;
946 }
947
948 // [exp]
949 if (*dec->cur == 'e' || *dec->cur == 'E')
950 {
951 ++dec->cur;
952
953 if (*dec->cur == '-' || *dec->cur == '+')
954 ++dec->cur;
955
956 if (*dec->cur < '0' || *dec->cur > '9')
957 ERR ("malformed number (no digits after exp sign)");
958
959 do
960 {
961 ++dec->cur;
962 }
963 while (*dec->cur >= '0' && *dec->cur <= '9');
964
965 is_nv = 1;
966 }
967
968 if (!is_nv)
969 {
970 int len = dec->cur - start;
971
972 // special case the rather common 1..4-digit-int case, assumes 32 bit ints or so
973 if (*start == '-')
974 switch (len)
975 {
976 case 2: return newSViv (-( start [1] - '0' * 1));
977 case 3: return newSViv (-( start [1] * 10 + start [2] - '0' * 11));
978 case 4: return newSViv (-( start [1] * 100 + start [2] * 10 + start [3] - '0' * 111));
979 case 5: return newSViv (-(start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 1111));
980 }
981 else
982 switch (len)
983 {
984 case 1: return newSViv ( start [0] - '0' * 1);
985 case 2: return newSViv ( start [0] * 10 + start [1] - '0' * 11);
986 case 3: return newSViv ( start [0] * 100 + start [1] * 10 + start [2] - '0' * 111);
987 case 4: return newSViv ( start [0] * 1000 + start [1] * 100 + start [2] * 10 + start [3] - '0' * 1111);
988 }
989
990 {
991 UV uv;
992 int numtype = grok_number (start, len, &uv);
993 if (numtype & IS_NUMBER_IN_UV)
994 if (numtype & IS_NUMBER_NEG)
995 {
996 if (uv < (UV)IV_MIN)
997 return newSViv (-(IV)uv);
998 }
999 else
1000 return newSVuv (uv);
1001 }
1002
1003 len -= *start == '-' ? 1 : 0;
1004
1005 // does not fit into IV or UV, try NV
1006 if ((sizeof (NV) == sizeof (double) && DBL_DIG >= len)
1007 #if defined (LDBL_DIG)
1008 || (sizeof (NV) == sizeof (long double) && LDBL_DIG >= len)
1009 #endif
1010 )
1011 // fits into NV without loss of precision
1012 return newSVnv (Atof (start));
1013
1014 // everything else fails, convert it to a string
1015 return newSVpvn (start, dec->cur - start);
1016 }
1017
1018 // loss of precision here
1019 return newSVnv (Atof (start));
1020
1021 fail:
1022 return 0;
1023 }
1024
1025 static SV *
1026 decode_av (dec_t *dec)
1027 {
1028 AV *av = newAV ();
1029
1030 DEC_INC_DEPTH;
1031 decode_ws (dec);
1032
1033 if (*dec->cur == ']')
1034 ++dec->cur;
1035 else
1036 for (;;)
1037 {
1038 SV *value;
1039
1040 value = decode_sv (dec);
1041 if (!value)
1042 goto fail;
1043
1044 av_push (av, value);
1045
1046 decode_ws (dec);
1047
1048 if (*dec->cur == ']')
1049 {
1050 ++dec->cur;
1051 break;
1052 }
1053
1054 if (*dec->cur != ',')
1055 ERR (", or ] expected while parsing array");
1056
1057 ++dec->cur;
1058 }
1059
1060 DEC_DEC_DEPTH;
1061 return newRV_noinc ((SV *)av);
1062
1063 fail:
1064 SvREFCNT_dec (av);
1065 DEC_DEC_DEPTH;
1066 return 0;
1067 }
1068
1069 static SV *
1070 decode_hv (dec_t *dec)
1071 {
1072 SV *sv;
1073 HV *hv = newHV ();
1074
1075 DEC_INC_DEPTH;
1076 decode_ws (dec);
1077
1078 if (*dec->cur == '}')
1079 ++dec->cur;
1080 else
1081 for (;;)
1082 {
1083 decode_ws (dec); EXPECT_CH ('"');
1084
1085 // heuristic: assume that
1086 // a) decode_str + hv_store_ent are abysmally slow.
1087 // b) most hash keys are short, simple ascii text.
1088 // => try to "fast-match" such strings to avoid
1089 // the overhead of decode_str + hv_store_ent.
1090 {
1091 SV *value;
1092 char *p = dec->cur;
1093 char *e = p + 24; // only try up to 24 bytes
1094
1095 for (;;)
1096 {
1097 // the >= 0x80 is true on most architectures
1098 if (p == e || *p < 0x20 || *p >= 0x80 || *p == '\\')
1099 {
1100 // slow path, back up and use decode_str
1101 SV *key = decode_str (dec);
1102 if (!key)
1103 goto fail;
1104
1105 decode_ws (dec); EXPECT_CH (':');
1106
1107 value = decode_sv (dec);
1108 if (!value)
1109 {
1110 SvREFCNT_dec (key);
1111 goto fail;
1112 }
1113
1114 hv_store_ent (hv, key, value, 0);
1115 SvREFCNT_dec (key);
1116
1117 break;
1118 }
1119 else if (*p == '"')
1120 {
1121 // fast path, got a simple key
1122 char *key = dec->cur;
1123 int len = p - key;
1124 dec->cur = p + 1;
1125
1126 decode_ws (dec); EXPECT_CH (':');
1127
1128 value = decode_sv (dec);
1129 if (!value)
1130 goto fail;
1131
1132 hv_store (hv, key, len, value, 0);
1133
1134 break;
1135 }
1136
1137 ++p;
1138 }
1139 }
1140
1141 decode_ws (dec);
1142
1143 if (*dec->cur == '}')
1144 {
1145 ++dec->cur;
1146 break;
1147 }
1148
1149 if (*dec->cur != ',')
1150 ERR (", or } expected while parsing object/hash");
1151
1152 ++dec->cur;
1153 }
1154
1155 DEC_DEC_DEPTH;
1156 sv = newRV_noinc ((SV *)hv);
1157
1158 // check filter callbacks
1159 if (dec->json.flags & F_HOOK)
1160 {
1161 if (dec->json.cb_sk_object && HvKEYS (hv) == 1)
1162 {
1163 HE *cb, *he;
1164
1165 hv_iterinit (hv);
1166 he = hv_iternext (hv);
1167 hv_iterinit (hv);
1168
1169 // the next line creates a mortal sv each time its called.
1170 // might want to optimise this for common cases.
1171 cb = hv_fetch_ent (dec->json.cb_sk_object, hv_iterkeysv (he), 0, 0);
1172
1173 if (cb)
1174 {
1175 dSP;
1176 int count;
1177
1178 ENTER; SAVETMPS; PUSHMARK (SP);
1179 XPUSHs (HeVAL (he));
1180
1181 PUTBACK; count = call_sv (HeVAL (cb), G_ARRAY); SPAGAIN;
1182
1183 if (count == 1)
1184 {
1185 sv = newSVsv (POPs);
1186 FREETMPS; LEAVE;
1187 return sv;
1188 }
1189
1190 FREETMPS; LEAVE;
1191 }
1192 }
1193
1194 if (dec->json.cb_object)
1195 {
1196 dSP;
1197 int count;
1198
1199 ENTER; SAVETMPS; PUSHMARK (SP);
1200 XPUSHs (sv_2mortal (sv));
1201
1202 PUTBACK; count = call_sv (dec->json.cb_object, G_ARRAY); SPAGAIN;
1203
1204 if (count == 1)
1205 {
1206 sv = newSVsv (POPs);
1207 FREETMPS; LEAVE;
1208 return sv;
1209 }
1210
1211 SvREFCNT_inc (sv);
1212 FREETMPS; LEAVE;
1213 }
1214 }
1215
1216 return sv;
1217
1218 fail:
1219 SvREFCNT_dec (hv);
1220 DEC_DEC_DEPTH;
1221 return 0;
1222 }
1223
1224 static SV *
1225 decode_sv (dec_t *dec)
1226 {
1227 decode_ws (dec);
1228
1229 // the beauty of JSON: you need exactly one character lookahead
1230 // to parse anything.
1231 switch (*dec->cur)
1232 {
1233 case '"': ++dec->cur; return decode_str (dec);
1234 case '[': ++dec->cur; return decode_av (dec);
1235 case '{': ++dec->cur; return decode_hv (dec);
1236
1237 case '-':
1238 case '0': case '1': case '2': case '3': case '4':
1239 case '5': case '6': case '7': case '8': case '9':
1240 return decode_num (dec);
1241
1242 case 't':
1243 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "true", 4))
1244 {
1245 dec->cur += 4;
1246 #if JSON_SLOW
1247 json_true = get_sv ("JSON::XS::true", 1); SvREADONLY_on (json_true);
1248 #endif
1249 return SvREFCNT_inc (json_true);
1250 }
1251 else
1252 ERR ("'true' expected");
1253
1254 break;
1255
1256 case 'f':
1257 if (dec->end - dec->cur >= 5 && !memcmp (dec->cur, "false", 5))
1258 {
1259 dec->cur += 5;
1260 #if JSON_SLOW
1261 json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false);
1262 #endif
1263 return SvREFCNT_inc (json_false);
1264 }
1265 else
1266 ERR ("'false' expected");
1267
1268 break;
1269
1270 case 'n':
1271 if (dec->end - dec->cur >= 4 && !memcmp (dec->cur, "null", 4))
1272 {
1273 dec->cur += 4;
1274 return newSVsv (&PL_sv_undef);
1275 }
1276 else
1277 ERR ("'null' expected");
1278
1279 break;
1280
1281 default:
1282 ERR ("malformed JSON string, neither array, object, number, string or atom");
1283 break;
1284 }
1285
1286 fail:
1287 return 0;
1288 }
1289
1290 static SV *
1291 decode_json (SV *string, JSON *json, UV *offset_return)
1292 {
1293 dec_t dec;
1294 UV offset;
1295 SV *sv;
1296
1297 SvGETMAGIC (string);
1298 SvUPGRADE (string, SVt_PV);
1299
1300 if (json->flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (json->flags))
1301 croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu",
1302 (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (json->flags));
1303
1304 if (json->flags & F_UTF8)
1305 sv_utf8_downgrade (string, 0);
1306 else
1307 sv_utf8_upgrade (string);
1308
1309 SvGROW (string, SvCUR (string) + 1); // should basically be a NOP
1310
1311 dec.json = *json;
1312 dec.cur = SvPVX (string);
1313 dec.end = SvEND (string);
1314 dec.err = 0;
1315 dec.depth = 0;
1316 dec.maxdepth = DEC_DEPTH (dec.json.flags);
1317
1318 if (dec.json.cb_object || dec.json.cb_sk_object)
1319 dec.json.flags |= F_HOOK;
1320
1321 *dec.end = 0; // this should basically be a nop, too, but make sure it's there
1322 sv = decode_sv (&dec);
1323
1324 if (!(offset_return || !sv))
1325 {
1326 // check for trailing garbage
1327 decode_ws (&dec);
1328
1329 if (*dec.cur)
1330 {
1331 dec.err = "garbage after JSON object";
1332 SvREFCNT_dec (sv);
1333 sv = 0;
1334 }
1335 }
1336
1337 if (offset_return || !sv)
1338 {
1339 offset = dec.json.flags & F_UTF8
1340 ? dec.cur - SvPVX (string)
1341 : utf8_distance (dec.cur, SvPVX (string));
1342
1343 if (offset_return)
1344 *offset_return = offset;
1345 }
1346
1347 if (!sv)
1348 {
1349 SV *uni = sv_newmortal ();
1350
1351 // horrible hack to silence warning inside pv_uni_display
1352 COP cop = *PL_curcop;
1353 cop.cop_warnings = pWARN_NONE;
1354 ENTER;
1355 SAVEVPTR (PL_curcop);
1356 PL_curcop = &cop;
1357 pv_uni_display (uni, dec.cur, dec.end - dec.cur, 20, UNI_DISPLAY_QQ);
1358 LEAVE;
1359
1360 croak ("%s, at character offset %d [\"%s\"]",
1361 dec.err,
1362 (int)offset,
1363 dec.cur != dec.end ? SvPV_nolen (uni) : "(end of string)");
1364 }
1365
1366 sv = sv_2mortal (sv);
1367
1368 if (!(dec.json.flags & F_ALLOW_NONREF) && !SvROK (sv))
1369 croak ("JSON text must be an object or array (but found number, string, true, false or null, use allow_nonref to allow this)");
1370
1371 return sv;
1372 }
1373
1374 /////////////////////////////////////////////////////////////////////////////
1375 // XS interface functions
1376
1377 MODULE = JSON::XS PACKAGE = JSON::XS
1378
1379 BOOT:
1380 {
1381 int i;
1382
1383 for (i = 0; i < 256; ++i)
1384 decode_hexdigit [i] =
1385 i >= '0' && i <= '9' ? i - '0'
1386 : i >= 'a' && i <= 'f' ? i - 'a' + 10
1387 : i >= 'A' && i <= 'F' ? i - 'A' + 10
1388 : -1;
1389
1390 json_stash = gv_stashpv ("JSON::XS" , 1);
1391 json_boolean_stash = gv_stashpv ("JSON::XS::Boolean", 1);
1392
1393 json_true = get_sv ("JSON::XS::true" , 1); SvREADONLY_on (json_true );
1394 json_false = get_sv ("JSON::XS::false", 1); SvREADONLY_on (json_false);
1395 }
1396
1397 PROTOTYPES: DISABLE
1398
1399 void CLONE (...)
1400 CODE:
1401 json_stash = 0;
1402 json_boolean_stash = 0;
1403
1404 void new (char *klass)
1405 PPCODE:
1406 {
1407 SV *pv = NEWSV (0, sizeof (JSON));
1408 SvPOK_only (pv);
1409 Zero (SvPVX (pv), 1, JSON);
1410 ((JSON *)SvPVX (pv))->flags = F_DEFAULT;
1411 XPUSHs (sv_2mortal (sv_bless (newRV_noinc (pv), JSON_STASH)));
1412 }
1413
1414 void ascii (JSON *self, int enable = 1)
1415 ALIAS:
1416 ascii = F_ASCII
1417 latin1 = F_LATIN1
1418 utf8 = F_UTF8
1419 indent = F_INDENT
1420 canonical = F_CANONICAL
1421 space_before = F_SPACE_BEFORE
1422 space_after = F_SPACE_AFTER
1423 pretty = F_PRETTY
1424 allow_nonref = F_ALLOW_NONREF
1425 shrink = F_SHRINK
1426 allow_blessed = F_ALLOW_BLESSED
1427 convert_blessed = F_CONV_BLESSED
1428 PPCODE:
1429 {
1430 if (enable)
1431 self->flags |= ix;
1432 else
1433 self->flags &= ~ix;
1434
1435 XPUSHs (ST (0));
1436 }
1437
1438 void max_depth (JSON *self, UV max_depth = 0x80000000UL)
1439 PPCODE:
1440 {
1441 UV log2 = 0;
1442
1443 if (max_depth > 0x80000000UL) max_depth = 0x80000000UL;
1444
1445 while ((1UL << log2) < max_depth)
1446 ++log2;
1447
1448 self->flags = self->flags & ~F_MAXDEPTH | (log2 << S_MAXDEPTH);
1449
1450 XPUSHs (ST (0));
1451 }
1452
1453 void max_size (JSON *self, UV max_size = 0)
1454 PPCODE:
1455 {
1456 UV log2 = 0;
1457
1458 if (max_size > 0x80000000UL) max_size = 0x80000000UL;
1459 if (max_size == 1) max_size = 2;
1460
1461 while ((1UL << log2) < max_size)
1462 ++log2;
1463
1464 self->flags = self->flags & ~F_MAXSIZE | (log2 << S_MAXSIZE);
1465
1466 XPUSHs (ST (0));
1467 }
1468
1469 void filter_json_object (JSON *self, SV *cb = &PL_sv_undef)
1470 PPCODE:
1471 {
1472 SvREFCNT_dec (self->cb_object);
1473 self->cb_object = SvOK (cb) ? newSVsv (cb) : 0;
1474
1475 XPUSHs (ST (0));
1476 }
1477
1478 void filter_json_single_key_object (JSON *self, SV *key, SV *cb = &PL_sv_undef)
1479 PPCODE:
1480 {
1481 if (!self->cb_sk_object)
1482 self->cb_sk_object = newHV ();
1483
1484 if (SvOK (cb))
1485 hv_store_ent (self->cb_sk_object, key, newSVsv (cb), 0);
1486 else
1487 {
1488 hv_delete_ent (self->cb_sk_object, key, G_DISCARD, 0);
1489
1490 if (!HvKEYS (self->cb_sk_object))
1491 {
1492 SvREFCNT_dec (self->cb_sk_object);
1493 self->cb_sk_object = 0;
1494 }
1495 }
1496
1497 XPUSHs (ST (0));
1498 }
1499
1500 void encode (JSON *self, SV *scalar)
1501 PPCODE:
1502 XPUSHs (encode_json (scalar, self));
1503
1504 void decode (JSON *self, SV *jsonstr)
1505 PPCODE:
1506 XPUSHs (decode_json (jsonstr, self, 0));
1507
1508 void decode_prefix (JSON *self, SV *jsonstr)
1509 PPCODE:
1510 {
1511 UV offset;
1512 EXTEND (SP, 2);
1513 PUSHs (decode_json (jsonstr, self, &offset));
1514 PUSHs (sv_2mortal (newSVuv (offset)));
1515 }
1516
1517 void DESTROY (JSON *self)
1518 CODE:
1519 SvREFCNT_dec (self->cb_sk_object);
1520 SvREFCNT_dec (self->cb_object);
1521
1522 PROTOTYPES: ENABLE
1523
1524 void to_json (SV *scalar)
1525 PPCODE:
1526 {
1527 JSON json = { F_DEFAULT | F_UTF8 };
1528 XPUSHs (encode_json (scalar, &json));
1529 }
1530
1531 void from_json (SV *jsonstr)
1532 PPCODE:
1533 {
1534 JSON json = { F_DEFAULT | F_UTF8 };
1535 XPUSHs (decode_json (jsonstr, &json, 0));
1536 }
1537