serializer.ipp 18 KB

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  1. //
  2. // Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)
  3. //
  4. // Distributed under the Boost Software License, Version 1.0. (See accompanying
  5. // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  6. //
  7. // Official repository: https://github.com/boostorg/json
  8. //
  9. #ifndef BOOST_JSON_IMPL_SERIALIZER_IPP
  10. #define BOOST_JSON_IMPL_SERIALIZER_IPP
  11. #include <boost/json/serializer.hpp>
  12. #include <boost/json/detail/format.hpp>
  13. #include <boost/json/detail/sse2.hpp>
  14. #include <ostream>
  15. #ifdef _MSC_VER
  16. #pragma warning(push)
  17. #pragma warning(disable: 4127) // conditional expression is constant
  18. #endif
  19. namespace boost {
  20. namespace json {
  21. enum class serializer::state : char
  22. {
  23. nul1, nul2, nul3, nul4,
  24. tru1, tru2, tru3, tru4,
  25. fal1, fal2, fal3, fal4, fal5,
  26. str1, str2, str3, str4, esc1,
  27. utf1, utf2, utf3, utf4, utf5,
  28. num,
  29. arr1, arr2, arr3, arr4,
  30. obj1, obj2, obj3, obj4, obj5, obj6
  31. };
  32. //----------------------------------------------------------
  33. serializer::
  34. ~serializer() noexcept = default;
  35. serializer::
  36. serializer(
  37. storage_ptr sp,
  38. unsigned char* buf,
  39. std::size_t buf_size) noexcept
  40. : st_(
  41. std::move(sp),
  42. buf,
  43. buf_size)
  44. {
  45. }
  46. bool
  47. serializer::
  48. suspend(state st)
  49. {
  50. st_.push(st);
  51. return false;
  52. }
  53. bool
  54. serializer::
  55. suspend(
  56. state st,
  57. array::const_iterator it,
  58. array const* pa)
  59. {
  60. st_.push(pa);
  61. st_.push(it);
  62. st_.push(st);
  63. return false;
  64. }
  65. bool
  66. serializer::
  67. suspend(
  68. state st,
  69. object::const_iterator it,
  70. object const* po)
  71. {
  72. st_.push(po);
  73. st_.push(it);
  74. st_.push(st);
  75. return false;
  76. }
  77. template<bool StackEmpty>
  78. bool
  79. serializer::
  80. write_null(stream& ss0)
  81. {
  82. local_stream ss(ss0);
  83. if(! StackEmpty && ! st_.empty())
  84. {
  85. state st;
  86. st_.pop(st);
  87. switch(st)
  88. {
  89. default:
  90. case state::nul1: goto do_nul1;
  91. case state::nul2: goto do_nul2;
  92. case state::nul3: goto do_nul3;
  93. case state::nul4: goto do_nul4;
  94. }
  95. }
  96. do_nul1:
  97. if(BOOST_JSON_LIKELY(ss))
  98. ss.append('n');
  99. else
  100. return suspend(state::nul1);
  101. do_nul2:
  102. if(BOOST_JSON_LIKELY(ss))
  103. ss.append('u');
  104. else
  105. return suspend(state::nul2);
  106. do_nul3:
  107. if(BOOST_JSON_LIKELY(ss))
  108. ss.append('l');
  109. else
  110. return suspend(state::nul3);
  111. do_nul4:
  112. if(BOOST_JSON_LIKELY(ss))
  113. ss.append('l');
  114. else
  115. return suspend(state::nul4);
  116. return true;
  117. }
  118. template<bool StackEmpty>
  119. bool
  120. serializer::
  121. write_true(stream& ss0)
  122. {
  123. local_stream ss(ss0);
  124. if(! StackEmpty && ! st_.empty())
  125. {
  126. state st;
  127. st_.pop(st);
  128. switch(st)
  129. {
  130. default:
  131. case state::tru1: goto do_tru1;
  132. case state::tru2: goto do_tru2;
  133. case state::tru3: goto do_tru3;
  134. case state::tru4: goto do_tru4;
  135. }
  136. }
  137. do_tru1:
  138. if(BOOST_JSON_LIKELY(ss))
  139. ss.append('t');
  140. else
  141. return suspend(state::tru1);
  142. do_tru2:
  143. if(BOOST_JSON_LIKELY(ss))
  144. ss.append('r');
  145. else
  146. return suspend(state::tru2);
  147. do_tru3:
  148. if(BOOST_JSON_LIKELY(ss))
  149. ss.append('u');
  150. else
  151. return suspend(state::tru3);
  152. do_tru4:
  153. if(BOOST_JSON_LIKELY(ss))
  154. ss.append('e');
  155. else
  156. return suspend(state::tru4);
  157. return true;
  158. }
  159. template<bool StackEmpty>
  160. bool
  161. serializer::
  162. write_false(stream& ss0)
  163. {
  164. local_stream ss(ss0);
  165. if(! StackEmpty && ! st_.empty())
  166. {
  167. state st;
  168. st_.pop(st);
  169. switch(st)
  170. {
  171. default:
  172. case state::fal1: goto do_fal1;
  173. case state::fal2: goto do_fal2;
  174. case state::fal3: goto do_fal3;
  175. case state::fal4: goto do_fal4;
  176. case state::fal5: goto do_fal5;
  177. }
  178. }
  179. do_fal1:
  180. if(BOOST_JSON_LIKELY(ss))
  181. ss.append('f');
  182. else
  183. return suspend(state::fal1);
  184. do_fal2:
  185. if(BOOST_JSON_LIKELY(ss))
  186. ss.append('a');
  187. else
  188. return suspend(state::fal2);
  189. do_fal3:
  190. if(BOOST_JSON_LIKELY(ss))
  191. ss.append('l');
  192. else
  193. return suspend(state::fal3);
  194. do_fal4:
  195. if(BOOST_JSON_LIKELY(ss))
  196. ss.append('s');
  197. else
  198. return suspend(state::fal4);
  199. do_fal5:
  200. if(BOOST_JSON_LIKELY(ss))
  201. ss.append('e');
  202. else
  203. return suspend(state::fal5);
  204. return true;
  205. }
  206. template<bool StackEmpty>
  207. bool
  208. serializer::
  209. write_string(stream& ss0)
  210. {
  211. local_stream ss(ss0);
  212. local_const_stream cs(cs0_);
  213. if(! StackEmpty && ! st_.empty())
  214. {
  215. state st;
  216. st_.pop(st);
  217. switch(st)
  218. {
  219. default:
  220. case state::str1: goto do_str1;
  221. case state::str2: goto do_str2;
  222. case state::str3: goto do_str3;
  223. case state::str4: goto do_str4;
  224. case state::esc1: goto do_esc1;
  225. case state::utf1: goto do_utf1;
  226. case state::utf2: goto do_utf2;
  227. case state::utf3: goto do_utf3;
  228. case state::utf4: goto do_utf4;
  229. case state::utf5: goto do_utf5;
  230. }
  231. }
  232. static constexpr char hex[] = "0123456789abcdef";
  233. static constexpr char esc[] =
  234. "uuuuuuuubtnufruuuuuuuuuuuuuuuuuu"
  235. "\0\0\"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
  236. "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\\\0\0\0"
  237. "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
  238. "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
  239. "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
  240. "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
  241. "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
  242. // opening quote
  243. do_str1:
  244. if(BOOST_JSON_LIKELY(ss))
  245. ss.append('\x22'); // '"'
  246. else
  247. return suspend(state::str1);
  248. // fast loop,
  249. // copy unescaped
  250. do_str2:
  251. if(BOOST_JSON_LIKELY(ss))
  252. {
  253. std::size_t n = cs.remain();
  254. if(BOOST_JSON_LIKELY(n > 0))
  255. {
  256. if(ss.remain() > n)
  257. n = detail::count_unescaped(
  258. cs.data(), n);
  259. else
  260. n = detail::count_unescaped(
  261. cs.data(), ss.remain());
  262. if(n > 0)
  263. {
  264. ss.append(cs.data(), n);
  265. cs.skip(n);
  266. if(! ss)
  267. return suspend(state::str2);
  268. }
  269. }
  270. else
  271. {
  272. ss.append('\x22'); // '"'
  273. return true;
  274. }
  275. }
  276. else
  277. {
  278. return suspend(state::str2);
  279. }
  280. // slow loop,
  281. // handle escapes
  282. do_str3:
  283. while(BOOST_JSON_LIKELY(ss))
  284. {
  285. if(BOOST_JSON_LIKELY(cs))
  286. {
  287. auto const ch = *cs;
  288. auto const c = esc[static_cast<
  289. unsigned char>(ch)];
  290. ++cs;
  291. if(! c)
  292. {
  293. ss.append(ch);
  294. }
  295. else if(c != 'u')
  296. {
  297. ss.append('\\');
  298. if(BOOST_JSON_LIKELY(ss))
  299. {
  300. ss.append(c);
  301. }
  302. else
  303. {
  304. buf_[0] = c;
  305. return suspend(
  306. state::esc1);
  307. }
  308. }
  309. else
  310. {
  311. if(BOOST_JSON_LIKELY(
  312. ss.remain() >= 6))
  313. {
  314. ss.append("\\u00", 4);
  315. ss.append(hex[static_cast<
  316. unsigned char>(ch) >> 4]);
  317. ss.append(hex[static_cast<
  318. unsigned char>(ch) & 15]);
  319. }
  320. else
  321. {
  322. ss.append('\\');
  323. buf_[0] = hex[static_cast<
  324. unsigned char>(ch) >> 4];
  325. buf_[1] = hex[static_cast<
  326. unsigned char>(ch) & 15];
  327. goto do_utf1;
  328. }
  329. }
  330. }
  331. else
  332. {
  333. ss.append('\x22'); // '"'
  334. return true;
  335. }
  336. }
  337. return suspend(state::str3);
  338. do_str4:
  339. if(BOOST_JSON_LIKELY(ss))
  340. ss.append('\x22'); // '"'
  341. else
  342. return suspend(state::str4);
  343. do_esc1:
  344. if(BOOST_JSON_LIKELY(ss))
  345. ss.append(buf_[0]);
  346. else
  347. return suspend(state::esc1);
  348. goto do_str3;
  349. do_utf1:
  350. if(BOOST_JSON_LIKELY(ss))
  351. ss.append('u');
  352. else
  353. return suspend(state::utf1);
  354. do_utf2:
  355. if(BOOST_JSON_LIKELY(ss))
  356. ss.append('0');
  357. else
  358. return suspend(state::utf2);
  359. do_utf3:
  360. if(BOOST_JSON_LIKELY(ss))
  361. ss.append('0');
  362. else
  363. return suspend(state::utf3);
  364. do_utf4:
  365. if(BOOST_JSON_LIKELY(ss))
  366. ss.append(buf_[0]);
  367. else
  368. return suspend(state::utf4);
  369. do_utf5:
  370. if(BOOST_JSON_LIKELY(ss))
  371. ss.append(buf_[1]);
  372. else
  373. return suspend(state::utf5);
  374. goto do_str3;
  375. }
  376. template<bool StackEmpty>
  377. bool
  378. serializer::
  379. write_number(stream& ss0)
  380. {
  381. local_stream ss(ss0);
  382. if(StackEmpty || st_.empty())
  383. {
  384. switch(jv_->kind())
  385. {
  386. default:
  387. case kind::int64:
  388. if(BOOST_JSON_LIKELY(
  389. ss.remain() >=
  390. detail::max_number_chars))
  391. {
  392. ss.advance(detail::format_int64(
  393. ss.data(), jv_->get_int64()));
  394. return true;
  395. }
  396. cs0_ = { buf_, detail::format_int64(
  397. buf_, jv_->get_int64()) };
  398. break;
  399. case kind::uint64:
  400. if(BOOST_JSON_LIKELY(
  401. ss.remain() >=
  402. detail::max_number_chars))
  403. {
  404. ss.advance(detail::format_uint64(
  405. ss.data(), jv_->get_uint64()));
  406. return true;
  407. }
  408. cs0_ = { buf_, detail::format_uint64(
  409. buf_, jv_->get_uint64()) };
  410. break;
  411. case kind::double_:
  412. if(BOOST_JSON_LIKELY(
  413. ss.remain() >=
  414. detail::max_number_chars))
  415. {
  416. ss.advance(detail::format_double(
  417. ss.data(), jv_->get_double()));
  418. return true;
  419. }
  420. cs0_ = { buf_, detail::format_double(
  421. buf_, jv_->get_double()) };
  422. break;
  423. }
  424. }
  425. else
  426. {
  427. state st;
  428. st_.pop(st);
  429. BOOST_ASSERT(
  430. st == state::num);
  431. }
  432. auto const n = ss.remain();
  433. if(n < cs0_.remain())
  434. {
  435. ss.append(cs0_.data(), n);
  436. cs0_.skip(n);
  437. return suspend(state::num);
  438. }
  439. ss.append(
  440. cs0_.data(), cs0_.remain());
  441. return true;
  442. }
  443. template<bool StackEmpty>
  444. bool
  445. serializer::
  446. write_array(stream& ss0)
  447. {
  448. array const* pa;
  449. local_stream ss(ss0);
  450. array::const_iterator it;
  451. array::const_iterator end;
  452. if(StackEmpty || st_.empty())
  453. {
  454. pa = pa_;
  455. it = pa->begin();
  456. end = pa->end();
  457. }
  458. else
  459. {
  460. state st;
  461. st_.pop(st);
  462. st_.pop(it);
  463. st_.pop(pa);
  464. end = pa->end();
  465. switch(st)
  466. {
  467. default:
  468. case state::arr1: goto do_arr1;
  469. case state::arr2: goto do_arr2;
  470. case state::arr3: goto do_arr3;
  471. case state::arr4: goto do_arr4;
  472. break;
  473. }
  474. }
  475. do_arr1:
  476. if(BOOST_JSON_LIKELY(ss))
  477. ss.append('[');
  478. else
  479. return suspend(
  480. state::arr1, it, pa);
  481. if(it == end)
  482. goto do_arr4;
  483. for(;;)
  484. {
  485. do_arr2:
  486. jv_ = &*it;
  487. if(! write_value<StackEmpty>(ss))
  488. return suspend(
  489. state::arr2, it, pa);
  490. if(BOOST_JSON_UNLIKELY(
  491. ++it == end))
  492. break;
  493. do_arr3:
  494. if(BOOST_JSON_LIKELY(ss))
  495. ss.append(',');
  496. else
  497. return suspend(
  498. state::arr3, it, pa);
  499. }
  500. do_arr4:
  501. if(BOOST_JSON_LIKELY(ss))
  502. ss.append(']');
  503. else
  504. return suspend(
  505. state::arr4, it, pa);
  506. return true;
  507. }
  508. template<bool StackEmpty>
  509. bool
  510. serializer::
  511. write_object(stream& ss0)
  512. {
  513. object const* po;
  514. local_stream ss(ss0);
  515. object::const_iterator it;
  516. object::const_iterator end;
  517. if(StackEmpty || st_.empty())
  518. {
  519. po = po_;
  520. it = po->begin();
  521. end = po->end();
  522. }
  523. else
  524. {
  525. state st;
  526. st_.pop(st);
  527. st_.pop(it);
  528. st_.pop(po);
  529. end = po->end();
  530. switch(st)
  531. {
  532. default:
  533. case state::obj1: goto do_obj1;
  534. case state::obj2: goto do_obj2;
  535. case state::obj3: goto do_obj3;
  536. case state::obj4: goto do_obj4;
  537. case state::obj5: goto do_obj5;
  538. case state::obj6: goto do_obj6;
  539. break;
  540. }
  541. }
  542. do_obj1:
  543. if(BOOST_JSON_LIKELY(ss))
  544. ss.append('{');
  545. else
  546. return suspend(
  547. state::obj1, it, po);
  548. if(BOOST_JSON_UNLIKELY(
  549. it == end))
  550. goto do_obj6;
  551. for(;;)
  552. {
  553. cs0_ = {
  554. it->key().data(),
  555. it->key().size() };
  556. do_obj2:
  557. if(BOOST_JSON_UNLIKELY(
  558. ! write_string<StackEmpty>(ss)))
  559. return suspend(
  560. state::obj2, it, po);
  561. do_obj3:
  562. if(BOOST_JSON_LIKELY(ss))
  563. ss.append(':');
  564. else
  565. return suspend(
  566. state::obj3, it, po);
  567. do_obj4:
  568. jv_ = &it->value();
  569. if(BOOST_JSON_UNLIKELY(
  570. ! write_value<StackEmpty>(ss)))
  571. return suspend(
  572. state::obj4, it, po);
  573. ++it;
  574. if(BOOST_JSON_UNLIKELY(it == end))
  575. break;
  576. do_obj5:
  577. if(BOOST_JSON_LIKELY(ss))
  578. ss.append(',');
  579. else
  580. return suspend(
  581. state::obj5, it, po);
  582. }
  583. do_obj6:
  584. if(BOOST_JSON_LIKELY(ss))
  585. {
  586. ss.append('}');
  587. return true;
  588. }
  589. return suspend(
  590. state::obj6, it, po);
  591. }
  592. template<bool StackEmpty>
  593. bool
  594. serializer::
  595. write_value(stream& ss)
  596. {
  597. if(StackEmpty || st_.empty())
  598. {
  599. auto const& jv(*jv_);
  600. switch(jv.kind())
  601. {
  602. default:
  603. case kind::object:
  604. po_ = &jv.get_object();
  605. return write_object<true>(ss);
  606. case kind::array:
  607. pa_ = &jv.get_array();
  608. return write_array<true>(ss);
  609. case kind::string:
  610. {
  611. auto const& js = jv.get_string();
  612. cs0_ = { js.data(), js.size() };
  613. return write_string<true>(ss);
  614. }
  615. case kind::int64:
  616. case kind::uint64:
  617. case kind::double_:
  618. return write_number<true>(ss);
  619. case kind::bool_:
  620. if(jv.get_bool())
  621. {
  622. if(BOOST_JSON_LIKELY(
  623. ss.remain() >= 4))
  624. {
  625. ss.append("true", 4);
  626. return true;
  627. }
  628. return write_true<true>(ss);
  629. }
  630. else
  631. {
  632. if(BOOST_JSON_LIKELY(
  633. ss.remain() >= 5))
  634. {
  635. ss.append("false", 5);
  636. return true;
  637. }
  638. return write_false<true>(ss);
  639. }
  640. case kind::null:
  641. if(BOOST_JSON_LIKELY(
  642. ss.remain() >= 4))
  643. {
  644. ss.append("null", 4);
  645. return true;
  646. }
  647. return write_null<true>(ss);
  648. }
  649. }
  650. else
  651. {
  652. state st;
  653. st_.peek(st);
  654. switch(st)
  655. {
  656. default:
  657. case state::nul1: case state::nul2:
  658. case state::nul3: case state::nul4:
  659. return write_null<StackEmpty>(ss);
  660. case state::tru1: case state::tru2:
  661. case state::tru3: case state::tru4:
  662. return write_true<StackEmpty>(ss);
  663. case state::fal1: case state::fal2:
  664. case state::fal3: case state::fal4:
  665. case state::fal5:
  666. return write_false<StackEmpty>(ss);
  667. case state::str1: case state::str2:
  668. case state::str3: case state::str4:
  669. case state::esc1:
  670. case state::utf1: case state::utf2:
  671. case state::utf3: case state::utf4:
  672. case state::utf5:
  673. return write_string<StackEmpty>(ss);
  674. case state::num:
  675. return write_number<StackEmpty>(ss);
  676. case state::arr1: case state::arr2:
  677. case state::arr3: case state::arr4:
  678. return write_array<StackEmpty>(ss);
  679. case state::obj1: case state::obj2:
  680. case state::obj3: case state::obj4:
  681. case state::obj5: case state::obj6:
  682. return write_object<StackEmpty>(ss);
  683. }
  684. }
  685. }
  686. string_view
  687. serializer::
  688. read_some(
  689. char* dest, std::size_t size)
  690. {
  691. // If this goes off it means you forgot
  692. // to call reset() before seriailzing a
  693. // new value, or you never checked done()
  694. // to see if you should stop.
  695. BOOST_ASSERT(! done_);
  696. stream ss(dest, size);
  697. if(st_.empty())
  698. (this->*fn0_)(ss);
  699. else
  700. (this->*fn1_)(ss);
  701. if(st_.empty())
  702. {
  703. done_ = true;
  704. jv_ = nullptr;
  705. }
  706. return string_view(
  707. dest, ss.used(dest));
  708. }
  709. //----------------------------------------------------------
  710. serializer::
  711. serializer() noexcept
  712. {
  713. // ensure room for \uXXXX escape plus one
  714. BOOST_STATIC_ASSERT(
  715. sizeof(serializer::buf_) >= 7);
  716. }
  717. void
  718. serializer::
  719. reset(value const* p) noexcept
  720. {
  721. pv_ = p;
  722. fn0_ = &serializer::write_value<true>;
  723. fn1_ = &serializer::write_value<false>;
  724. jv_ = p;
  725. st_.clear();
  726. done_ = false;
  727. }
  728. void
  729. serializer::
  730. reset(array const* p) noexcept
  731. {
  732. pa_ = p;
  733. fn0_ = &serializer::write_array<true>;
  734. fn1_ = &serializer::write_array<false>;
  735. st_.clear();
  736. done_ = false;
  737. }
  738. void
  739. serializer::
  740. reset(object const* p) noexcept
  741. {
  742. po_ = p;
  743. fn0_ = &serializer::write_object<true>;
  744. fn1_ = &serializer::write_object<false>;
  745. st_.clear();
  746. done_ = false;
  747. }
  748. void
  749. serializer::
  750. reset(string const* p) noexcept
  751. {
  752. cs0_ = { p->data(), p->size() };
  753. fn0_ = &serializer::write_string<true>;
  754. fn1_ = &serializer::write_string<false>;
  755. st_.clear();
  756. done_ = false;
  757. }
  758. void
  759. serializer::
  760. reset(string_view sv) noexcept
  761. {
  762. cs0_ = { sv.data(), sv.size() };
  763. fn0_ = &serializer::write_string<true>;
  764. fn1_ = &serializer::write_string<false>;
  765. st_.clear();
  766. done_ = false;
  767. }
  768. string_view
  769. serializer::
  770. read(char* dest, std::size_t size)
  771. {
  772. if(! jv_)
  773. {
  774. static value const null;
  775. jv_ = &null;
  776. }
  777. return read_some(dest, size);
  778. }
  779. } // namespace json
  780. } // namespace boost
  781. #ifdef _MSC_VER
  782. #pragma warning(pop)
  783. #endif
  784. #endif