2 * Copyright 2015 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef FOLLY_DYNAMIC_INL_H_
18 #define FOLLY_DYNAMIC_INL_H_
21 #include <boost/iterator/iterator_adaptor.hpp>
22 #include <boost/iterator/iterator_facade.hpp>
23 #include <folly/Likely.h>
24 #include <folly/Conv.h>
25 #include <folly/Format.h>
27 //////////////////////////////////////////////////////////////////////
32 struct hash< ::folly::dynamic> {
33 size_t operator()(::folly::dynamic const& d) const {
40 //////////////////////////////////////////////////////////////////////
42 // This is a higher-order preprocessor macro to aid going from runtime
43 // types to the compile time type system.
44 #define FB_DYNAMIC_APPLY(type, apply) do { \
46 case NULLT: apply(void*); break; \
47 case ARRAY: apply(Array); break; \
48 case BOOL: apply(bool); break; \
49 case DOUBLE: apply(double); break; \
50 case INT64: apply(int64_t); break; \
51 case OBJECT: apply(ObjectImpl); break; \
52 case STRING: apply(fbstring); break; \
53 default: CHECK(0); abort(); \
57 //////////////////////////////////////////////////////////////////////
61 struct TypeError : std::runtime_error {
62 explicit TypeError(const std::string& expected, dynamic::Type actual);
63 explicit TypeError(const std::string& expected,
64 dynamic::Type actual1, dynamic::Type actual2);
69 //////////////////////////////////////////////////////////////////////
73 // This helper is used in destroy() to be able to run destructors on
74 // types like "int64_t" without a compiler error.
76 template<class T> static void destroy(T* t) { t->~T(); }
80 * The enable_if junk here is necessary to avoid ambiguous
81 * conversions relating to bool and double when you implicitly
82 * convert an int or long to a dynamic.
84 template<class T, class Enable = void> struct ConversionHelper;
86 struct ConversionHelper<
88 typename std::enable_if<
89 std::is_integral<T>::value && !std::is_same<T,bool>::value
95 struct ConversionHelper<
97 typename std::enable_if<
98 (!std::is_integral<T>::value || std::is_same<T,bool>::value) &&
99 !std::is_same<T,std::nullptr_t>::value
105 struct ConversionHelper<
107 typename std::enable_if<
108 std::is_same<T,std::nullptr_t>::value
115 * Helper for implementing numeric conversions in operators on
116 * numbers. Just promotes to double when one of the arguments is
117 * double, or throws if either is not a numeric type.
119 template<template<class> class Op>
120 dynamic numericOp(dynamic const& a, dynamic const& b) {
121 if (!a.isNumber() || !b.isNumber()) {
122 throw TypeError("numeric", a.type(), b.type());
124 if (a.type() != b.type()) {
125 auto& integ = a.isInt() ? a : b;
126 auto& nonint = a.isInt() ? b : a;
127 return Op<double>()(to<double>(integ.asInt()), nonint.asDouble());
130 return Op<double>()(a.asDouble(), b.asDouble());
132 return Op<int64_t>()(a.asInt(), b.asInt());
137 //////////////////////////////////////////////////////////////////////
140 * We're doing this instead of a simple member typedef to avoid the
141 * undefined behavior of parameterizing std::unordered_map<> with an
144 * Note: Later we may add separate order tracking here (a multi-index
147 struct dynamic::ObjectImpl : std::unordered_map<dynamic, dynamic> {};
149 //////////////////////////////////////////////////////////////////////
151 // Helper object for creating objects conveniently. See object and
152 // the dynamic::dynamic(ObjectMaker&&) ctor.
153 struct dynamic::ObjectMaker {
154 friend struct dynamic;
156 explicit ObjectMaker() : val_(dynamic::object) {}
157 explicit ObjectMaker(dynamic const& key, dynamic val)
158 : val_(dynamic::object)
160 val_.insert(key, std::move(val));
162 explicit ObjectMaker(dynamic&& key, dynamic val)
163 : val_(dynamic::object)
165 val_.insert(std::move(key), std::move(val));
168 // Make sure no one tries to save one of these into an lvalue with
169 // auto or anything like that.
170 ObjectMaker(ObjectMaker&&) = default;
171 ObjectMaker(ObjectMaker const&) = delete;
172 ObjectMaker& operator=(ObjectMaker const&) = delete;
173 ObjectMaker& operator=(ObjectMaker&&) = delete;
175 // These return rvalue-references instead of lvalue-references to allow
176 // constructs like this to moved instead of copied:
177 // dynamic a = dynamic::object("a", "b")("c", "d")
178 ObjectMaker&& operator()(dynamic const& key, dynamic val) {
179 val_.insert(key, std::move(val));
180 return std::move(*this);
183 ObjectMaker&& operator()(dynamic&& key, dynamic val) {
184 val_.insert(std::move(key), std::move(val));
185 return std::move(*this);
192 // This looks like a case for perfect forwarding, but our use of
193 // std::initializer_list for constructing dynamic arrays makes it less
194 // functional than doing this manually.
195 inline dynamic::ObjectMaker dynamic::object() { return ObjectMaker(); }
196 inline dynamic::ObjectMaker dynamic::object(dynamic&& a, dynamic&& b) {
197 return ObjectMaker(std::move(a), std::move(b));
199 inline dynamic::ObjectMaker dynamic::object(dynamic const& a, dynamic&& b) {
200 return ObjectMaker(a, std::move(b));
202 inline dynamic::ObjectMaker dynamic::object(dynamic&& a, dynamic const& b) {
203 return ObjectMaker(std::move(a), b);
205 inline dynamic::ObjectMaker
206 dynamic::object(dynamic const& a, dynamic const& b) {
207 return ObjectMaker(a, b);
210 //////////////////////////////////////////////////////////////////////
212 struct dynamic::const_item_iterator
213 : boost::iterator_adaptor<dynamic::const_item_iterator,
214 dynamic::ObjectImpl::const_iterator> {
215 /* implicit */ const_item_iterator(base_type b) : iterator_adaptor_(b) { }
218 friend class boost::iterator_core_access;
221 struct dynamic::const_key_iterator
222 : boost::iterator_adaptor<dynamic::const_key_iterator,
223 dynamic::ObjectImpl::const_iterator,
225 /* implicit */ const_key_iterator(base_type b) : iterator_adaptor_(b) { }
228 dynamic const& dereference() const {
229 return base_reference()->first;
231 friend class boost::iterator_core_access;
234 struct dynamic::const_value_iterator
235 : boost::iterator_adaptor<dynamic::const_value_iterator,
236 dynamic::ObjectImpl::const_iterator,
238 /* implicit */ const_value_iterator(base_type b) : iterator_adaptor_(b) { }
241 dynamic const& dereference() const {
242 return base_reference()->second;
244 friend class boost::iterator_core_access;
247 //////////////////////////////////////////////////////////////////////
249 inline dynamic::dynamic(ObjectMaker (*)())
252 new (getAddress<ObjectImpl>()) ObjectImpl();
255 inline dynamic::dynamic(StringPiece s)
258 new (&u_.string) fbstring(s.data(), s.size());
261 inline dynamic::dynamic(char const* s)
264 new (&u_.string) fbstring(s);
267 inline dynamic::dynamic(std::string const& s)
270 new (&u_.string) fbstring(s);
273 inline dynamic::dynamic(fbstring const& s)
276 new (&u_.string) fbstring(s);
279 inline dynamic::dynamic(fbstring&& s)
282 new (&u_.string) fbstring(std::move(s));
285 inline dynamic::dynamic(std::initializer_list<dynamic> il)
288 new (&u_.array) Array(il.begin(), il.end());
291 inline dynamic::dynamic(ObjectMaker&& maker)
294 new (getAddress<ObjectImpl>())
295 ObjectImpl(std::move(*maker.val_.getAddress<ObjectImpl>()));
298 inline dynamic::dynamic(dynamic const& o)
304 inline dynamic::dynamic(dynamic&& o) noexcept
307 *this = std::move(o);
310 inline dynamic::~dynamic() noexcept { destroy(); }
313 dynamic::dynamic(T t) {
314 typedef typename detail::ConversionHelper<T>::type U;
315 type_ = TypeInfo<U>::type;
316 new (getAddress<U>()) U(std::move(t));
319 template<class Iterator>
320 dynamic::dynamic(Iterator first, Iterator last)
323 new (&u_.array) Array(first, last);
326 //////////////////////////////////////////////////////////////////////
328 inline dynamic::const_iterator dynamic::begin() const {
329 return get<Array>().begin();
331 inline dynamic::const_iterator dynamic::end() const {
332 return get<Array>().end();
336 struct dynamic::IterableProxy {
337 typedef It const_iterator;
338 typedef typename It::value_type value_type;
340 /* implicit */ IterableProxy(const dynamic::ObjectImpl* o) : o_(o) { }
351 const dynamic::ObjectImpl* o_;
354 inline dynamic::IterableProxy<dynamic::const_key_iterator> dynamic::keys()
356 return &(get<ObjectImpl>());
359 inline dynamic::IterableProxy<dynamic::const_value_iterator> dynamic::values()
361 return &(get<ObjectImpl>());
364 inline dynamic::IterableProxy<dynamic::const_item_iterator> dynamic::items()
366 return &(get<ObjectImpl>());
369 inline bool dynamic::isString() const { return get_nothrow<fbstring>(); }
370 inline bool dynamic::isObject() const { return get_nothrow<ObjectImpl>(); }
371 inline bool dynamic::isBool() const { return get_nothrow<bool>(); }
372 inline bool dynamic::isArray() const { return get_nothrow<Array>(); }
373 inline bool dynamic::isDouble() const { return get_nothrow<double>(); }
374 inline bool dynamic::isInt() const { return get_nothrow<int64_t>(); }
375 inline bool dynamic::isNull() const { return get_nothrow<void*>(); }
376 inline bool dynamic::isNumber() const { return isInt() || isDouble(); }
378 inline dynamic::Type dynamic::type() const {
382 inline fbstring dynamic::asString() const { return asImpl<fbstring>(); }
383 inline double dynamic::asDouble() const { return asImpl<double>(); }
384 inline int64_t dynamic::asInt() const { return asImpl<int64_t>(); }
385 inline bool dynamic::asBool() const { return asImpl<bool>(); }
387 inline const fbstring& dynamic::getString() const { return get<fbstring>(); }
388 inline double dynamic::getDouble() const { return get<double>(); }
389 inline int64_t dynamic::getInt() const { return get<int64_t>(); }
390 inline bool dynamic::getBool() const { return get<bool>(); }
392 inline fbstring& dynamic::getString() { return get<fbstring>(); }
393 inline double& dynamic::getDouble() { return get<double>(); }
394 inline int64_t& dynamic::getInt() { return get<int64_t>(); }
395 inline bool& dynamic::getBool() { return get<bool>(); }
397 inline const char* dynamic::data() const& { return get<fbstring>().data(); }
398 inline const char* dynamic::c_str() const& { return get<fbstring>().c_str(); }
399 inline StringPiece dynamic::stringPiece() const { return get<fbstring>(); }
402 struct dynamic::CompareOp {
403 static bool comp(T const& a, T const& b) { return a < b; }
406 struct dynamic::CompareOp<dynamic::ObjectImpl> {
407 static bool comp(ObjectImpl const&, ObjectImpl const&) {
408 // This code never executes; it is just here for the compiler.
413 inline dynamic& dynamic::operator+=(dynamic const& o) {
414 if (type() == STRING && o.type() == STRING) {
415 *getAddress<fbstring>() += *o.getAddress<fbstring>();
418 *this = detail::numericOp<std::plus>(*this, o);
422 inline dynamic& dynamic::operator-=(dynamic const& o) {
423 *this = detail::numericOp<std::minus>(*this, o);
427 inline dynamic& dynamic::operator*=(dynamic const& o) {
428 *this = detail::numericOp<std::multiplies>(*this, o);
432 inline dynamic& dynamic::operator/=(dynamic const& o) {
433 *this = detail::numericOp<std::divides>(*this, o);
437 #define FB_DYNAMIC_INTEGER_OP(op) \
438 inline dynamic& dynamic::operator op(dynamic const& o) { \
439 if (!isInt() || !o.isInt()) { \
440 throw TypeError("int64", type(), o.type()); \
442 *getAddress<int64_t>() op o.asInt(); \
446 FB_DYNAMIC_INTEGER_OP(%=)
447 FB_DYNAMIC_INTEGER_OP(|=)
448 FB_DYNAMIC_INTEGER_OP(&=)
449 FB_DYNAMIC_INTEGER_OP(^=)
451 #undef FB_DYNAMIC_INTEGER_OP
453 inline dynamic& dynamic::operator++() {
458 inline dynamic& dynamic::operator--() {
463 inline dynamic const& dynamic::operator[](dynamic const& idx) const {
467 template<class K, class V> inline dynamic& dynamic::setDefault(K&& k, V&& v) {
468 auto& obj = get<ObjectImpl>();
469 return obj.insert(std::make_pair(std::forward<K>(k),
470 std::forward<V>(v))).first->second;
473 inline dynamic* dynamic::get_ptr(dynamic const& idx) & {
474 return const_cast<dynamic*>(const_cast<dynamic const*>(this)->get_ptr(idx));
477 inline dynamic& dynamic::at(dynamic const& idx) {
478 return const_cast<dynamic&>(const_cast<dynamic const*>(this)->at(idx));
481 inline bool dynamic::empty() const {
488 inline std::size_t dynamic::count(dynamic const& key) const {
489 return find(key) != items().end();
492 inline dynamic::const_item_iterator dynamic::find(dynamic const& key) const {
493 return get<ObjectImpl>().find(key);
496 template<class K, class V> inline void dynamic::insert(K&& key, V&& val) {
497 auto& obj = get<ObjectImpl>();
498 auto rv = obj.insert({ std::forward<K>(key), nullptr });
499 rv.first->second = std::forward<V>(val);
502 inline std::size_t dynamic::erase(dynamic const& key) {
503 auto& obj = get<ObjectImpl>();
504 return obj.erase(key);
507 inline dynamic::const_iterator dynamic::erase(const_iterator it) {
508 auto& arr = get<Array>();
509 // std::vector doesn't have an erase method that works on const iterators,
510 // even though the standard says it should, so this hack converts to a
511 // non-const iterator before calling erase.
512 return get<Array>().erase(arr.begin() + (it - arr.begin()));
515 inline dynamic::const_key_iterator dynamic::erase(const_key_iterator it) {
516 return const_key_iterator(get<ObjectImpl>().erase(it.base()));
519 inline dynamic::const_key_iterator dynamic::erase(const_key_iterator first,
520 const_key_iterator last) {
521 return const_key_iterator(get<ObjectImpl>().erase(first.base(),
525 inline dynamic::const_value_iterator dynamic::erase(const_value_iterator it) {
526 return const_value_iterator(get<ObjectImpl>().erase(it.base()));
529 inline dynamic::const_value_iterator dynamic::erase(const_value_iterator first,
530 const_value_iterator last) {
531 return const_value_iterator(get<ObjectImpl>().erase(first.base(),
535 inline dynamic::const_item_iterator dynamic::erase(const_item_iterator it) {
536 return const_item_iterator(get<ObjectImpl>().erase(it.base()));
539 inline dynamic::const_item_iterator dynamic::erase(const_item_iterator first,
540 const_item_iterator last) {
541 return const_item_iterator(get<ObjectImpl>().erase(first.base(),
545 inline void dynamic::resize(std::size_t sz, dynamic const& c) {
546 auto& array = get<Array>();
550 inline void dynamic::push_back(dynamic const& v) {
551 auto& array = get<Array>();
555 inline void dynamic::push_back(dynamic&& v) {
556 auto& array = get<Array>();
557 array.push_back(std::move(v));
560 inline void dynamic::pop_back() {
561 auto& array = get<Array>();
565 //////////////////////////////////////////////////////////////////////
567 template<class T> struct dynamic::TypeInfo {
568 static char const name[];
569 static Type const type;
572 #define FB_DEC_TYPE(T) \
573 template<> char const dynamic::TypeInfo<T>::name[]; \
574 template<> dynamic::Type const dynamic::TypeInfo<T>::type
578 FB_DEC_TYPE(fbstring);
579 FB_DEC_TYPE(dynamic::Array);
581 FB_DEC_TYPE(int64_t);
582 FB_DEC_TYPE(dynamic::ObjectImpl);
587 T dynamic::asImpl() const {
589 case INT64: return to<T>(*get_nothrow<int64_t>());
590 case DOUBLE: return to<T>(*get_nothrow<double>());
591 case BOOL: return to<T>(*get_nothrow<bool>());
592 case STRING: return to<T>(*get_nothrow<fbstring>());
594 throw TypeError("int/double/bool/string", type());
598 // Return a T* to our type, or null if we're not that type.
600 T* dynamic::get_nothrow() & noexcept {
601 if (type_ != TypeInfo<T>::type) {
604 return getAddress<T>();
608 T const* dynamic::get_nothrow() const& noexcept {
609 return const_cast<dynamic*>(this)->get_nothrow<T>();
612 // Return T* for where we can put a T, without type checking. (Memory
613 // might be uninitialized, even.)
615 T* dynamic::getAddress() noexcept {
616 return GetAddrImpl<T>::get(u_);
620 T const* dynamic::getAddress() const noexcept {
621 return const_cast<dynamic*>(this)->getAddress<T>();
624 template<class T> struct dynamic::GetAddrImpl {};
625 template<> struct dynamic::GetAddrImpl<void*> {
626 static void** get(Data& d) noexcept { return &d.nul; }
628 template<> struct dynamic::GetAddrImpl<dynamic::Array> {
629 static Array* get(Data& d) noexcept { return &d.array; }
631 template<> struct dynamic::GetAddrImpl<bool> {
632 static bool* get(Data& d) noexcept { return &d.boolean; }
634 template<> struct dynamic::GetAddrImpl<int64_t> {
635 static int64_t* get(Data& d) noexcept { return &d.integer; }
637 template<> struct dynamic::GetAddrImpl<double> {
638 static double* get(Data& d) noexcept { return &d.doubl; }
640 template<> struct dynamic::GetAddrImpl<fbstring> {
641 static fbstring* get(Data& d) noexcept { return &d.string; }
643 template<> struct dynamic::GetAddrImpl<dynamic::ObjectImpl> {
644 static_assert(sizeof(ObjectImpl) <= sizeof(Data::objectBuffer),
645 "In your implementation, std::unordered_map<> apparently takes different"
646 " amount of space depending on its template parameters. This is "
647 "weird. Make objectBuffer bigger if you want to compile dynamic.");
649 static ObjectImpl* get(Data& d) noexcept {
650 void* data = &d.objectBuffer;
651 return static_cast<ObjectImpl*>(data);
657 if (auto* p = get_nothrow<T>()) {
660 throw TypeError(TypeInfo<T>::name, type());
664 T const& dynamic::get() const {
665 return const_cast<dynamic*>(this)->get<T>();
668 //////////////////////////////////////////////////////////////////////
671 * Helper for implementing operator<<. Throws if the type shouldn't
675 struct dynamic::PrintImpl {
676 static void print(dynamic const&, std::ostream& out, T const& t) {
681 struct dynamic::PrintImpl<dynamic::ObjectImpl> {
682 static void print(dynamic const& d,
684 dynamic::ObjectImpl const&) {
685 d.print_as_pseudo_json(out);
689 struct dynamic::PrintImpl<dynamic::Array> {
690 static void print(dynamic const& d,
692 dynamic::Array const&) {
693 d.print_as_pseudo_json(out);
697 inline void dynamic::print(std::ostream& out) const {
698 #define FB_X(T) PrintImpl<T>::print(*this, out, *getAddress<T>())
699 FB_DYNAMIC_APPLY(type_, FB_X);
703 inline std::ostream& operator<<(std::ostream& out, dynamic const& d) {
708 //////////////////////////////////////////////////////////////////////
710 // Secialization of FormatValue so dynamic objects can be formatted
712 class FormatValue<dynamic> {
714 explicit FormatValue(const dynamic& val) : val_(val) { }
716 template <class FormatCallback>
717 void format(FormatArg& arg, FormatCallback& cb) const {
718 switch (val_.type()) {
720 FormatValue<std::nullptr_t>(nullptr).format(arg, cb);
723 FormatValue<bool>(val_.asBool()).format(arg, cb);
726 FormatValue<int64_t>(val_.asInt()).format(arg, cb);
728 case dynamic::STRING:
729 FormatValue<fbstring>(val_.asString()).format(arg, cb);
731 case dynamic::DOUBLE:
732 FormatValue<double>(val_.asDouble()).format(arg, cb);
735 FormatValue(val_.at(arg.splitIntKey())).format(arg, cb);
737 case dynamic::OBJECT:
738 FormatValue(val_.at(arg.splitKey().toFbstring())).format(arg, cb);
748 class FormatValue<detail::DefaultValueWrapper<dynamic, V>> {
750 explicit FormatValue(
751 const detail::DefaultValueWrapper<dynamic, V>& val)
754 template <class FormatCallback>
755 void format(FormatArg& arg, FormatCallback& cb) const {
756 auto& c = val_.container;
761 case dynamic::STRING:
762 case dynamic::DOUBLE:
763 FormatValue<dynamic>(c).format(arg, cb);
767 int key = arg.splitIntKey();
768 if (key >= 0 && size_t(key) < c.size()) {
769 FormatValue<dynamic>(c.at(key)).format(arg, cb);
771 FormatValue<V>(val_.defaultValue).format(arg, cb);
775 case dynamic::OBJECT:
777 auto pos = c.find(arg.splitKey());
778 if (pos != c.items().end()) {
779 FormatValue<dynamic>(pos->second).format(arg, cb);
781 FormatValue<V>(val_.defaultValue).format(arg, cb);
789 const detail::DefaultValueWrapper<dynamic, V>& val_;
794 #undef FB_DYNAMIC_APPLY