2 * Copyright 2016 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.
20 #include <boost/iterator/iterator_adaptor.hpp>
21 #include <boost/iterator/iterator_facade.hpp>
22 #include <folly/Likely.h>
23 #include <folly/Conv.h>
24 #include <folly/Format.h>
26 //////////////////////////////////////////////////////////////////////
31 struct hash< ::folly::dynamic> {
32 size_t operator()(::folly::dynamic const& d) const {
39 //////////////////////////////////////////////////////////////////////
41 // This is a higher-order preprocessor macro to aid going from runtime
42 // types to the compile time type system.
43 #define FB_DYNAMIC_APPLY(type, apply) \
73 //////////////////////////////////////////////////////////////////////
77 struct TypeError : std::runtime_error {
78 explicit TypeError(const std::string& expected, dynamic::Type actual);
79 explicit TypeError(const std::string& expected,
80 dynamic::Type actual1, dynamic::Type actual2);
85 //////////////////////////////////////////////////////////////////////
89 // This helper is used in destroy() to be able to run destructors on
90 // types like "int64_t" without a compiler error.
92 template<class T> static void destroy(T* t) { t->~T(); }
96 * The enable_if junk here is necessary to avoid ambiguous
97 * conversions relating to bool and double when you implicitly
98 * convert an int or long to a dynamic.
100 template<class T, class Enable = void> struct ConversionHelper;
102 struct ConversionHelper<
104 typename std::enable_if<
105 std::is_integral<T>::value && !std::is_same<T,bool>::value
108 typedef int64_t type;
111 struct ConversionHelper<
113 typename std::enable_if<
114 (!std::is_integral<T>::value || std::is_same<T,bool>::value) &&
115 !std::is_same<T,std::nullptr_t>::value
121 struct ConversionHelper<
123 typename std::enable_if<
124 std::is_same<T,std::nullptr_t>::value
131 * Helper for implementing numeric conversions in operators on
132 * numbers. Just promotes to double when one of the arguments is
133 * double, or throws if either is not a numeric type.
135 template<template<class> class Op>
136 dynamic numericOp(dynamic const& a, dynamic const& b) {
137 if (!a.isNumber() || !b.isNumber()) {
138 throw TypeError("numeric", a.type(), b.type());
140 if (a.type() != b.type()) {
141 auto& integ = a.isInt() ? a : b;
142 auto& nonint = a.isInt() ? b : a;
143 return Op<double>()(to<double>(integ.asInt()), nonint.asDouble());
146 return Op<double>()(a.asDouble(), b.asDouble());
148 return Op<int64_t>()(a.asInt(), b.asInt());
153 //////////////////////////////////////////////////////////////////////
156 * We're doing this instead of a simple member typedef to avoid the
157 * undefined behavior of parameterizing std::unordered_map<> with an
160 * Note: Later we may add separate order tracking here (a multi-index
163 struct dynamic::ObjectImpl : std::unordered_map<dynamic, dynamic> {};
165 //////////////////////////////////////////////////////////////////////
167 // Helper object for creating objects conveniently. See object and
168 // the dynamic::dynamic(ObjectMaker&&) ctor.
169 struct dynamic::ObjectMaker {
170 friend struct dynamic;
172 explicit ObjectMaker() : val_(dynamic::object) {}
173 explicit ObjectMaker(dynamic const& key, dynamic val)
174 : val_(dynamic::object)
176 val_.insert(key, std::move(val));
178 explicit ObjectMaker(dynamic&& key, dynamic val)
179 : val_(dynamic::object)
181 val_.insert(std::move(key), std::move(val));
184 // Make sure no one tries to save one of these into an lvalue with
185 // auto or anything like that.
186 ObjectMaker(ObjectMaker&&) = default;
187 ObjectMaker(ObjectMaker const&) = delete;
188 ObjectMaker& operator=(ObjectMaker const&) = delete;
189 ObjectMaker& operator=(ObjectMaker&&) = delete;
191 // These return rvalue-references instead of lvalue-references to allow
192 // constructs like this to moved instead of copied:
193 // dynamic a = dynamic::object("a", "b")("c", "d")
194 ObjectMaker&& operator()(dynamic const& key, dynamic val) {
195 val_.insert(key, std::move(val));
196 return std::move(*this);
199 ObjectMaker&& operator()(dynamic&& key, dynamic val) {
200 val_.insert(std::move(key), std::move(val));
201 return std::move(*this);
208 inline void dynamic::array(EmptyArrayTag) {}
210 template <class... Args>
211 inline dynamic dynamic::array(Args&& ...args) {
212 return dynamic(std::initializer_list<dynamic>{std::forward<Args>(args)...},
216 // This looks like a case for perfect forwarding, but our use of
217 // std::initializer_list for constructing dynamic arrays makes it less
218 // functional than doing this manually.
220 // TODO(ott, 10300209): When the initializer_list constructor is gone,
222 inline dynamic::ObjectMaker dynamic::object() { return ObjectMaker(); }
223 inline dynamic::ObjectMaker dynamic::object(dynamic&& a, dynamic&& b) {
224 return ObjectMaker(std::move(a), std::move(b));
226 inline dynamic::ObjectMaker dynamic::object(dynamic const& a, dynamic&& b) {
227 return ObjectMaker(a, std::move(b));
229 inline dynamic::ObjectMaker dynamic::object(dynamic&& a, dynamic const& b) {
230 return ObjectMaker(std::move(a), b);
232 inline dynamic::ObjectMaker
233 dynamic::object(dynamic const& a, dynamic const& b) {
234 return ObjectMaker(a, b);
237 //////////////////////////////////////////////////////////////////////
239 struct dynamic::const_item_iterator
240 : boost::iterator_adaptor<dynamic::const_item_iterator,
241 dynamic::ObjectImpl::const_iterator> {
242 /* implicit */ const_item_iterator(base_type b) : iterator_adaptor_(b) { }
245 friend class boost::iterator_core_access;
248 struct dynamic::const_key_iterator
249 : boost::iterator_adaptor<dynamic::const_key_iterator,
250 dynamic::ObjectImpl::const_iterator,
252 /* implicit */ const_key_iterator(base_type b) : iterator_adaptor_(b) { }
255 dynamic const& dereference() const {
256 return base_reference()->first;
258 friend class boost::iterator_core_access;
261 struct dynamic::const_value_iterator
262 : boost::iterator_adaptor<dynamic::const_value_iterator,
263 dynamic::ObjectImpl::const_iterator,
265 /* implicit */ const_value_iterator(base_type b) : iterator_adaptor_(b) { }
268 dynamic const& dereference() const {
269 return base_reference()->second;
271 friend class boost::iterator_core_access;
274 //////////////////////////////////////////////////////////////////////
276 inline dynamic::dynamic(void (*)(EmptyArrayTag))
279 new (&u_.array) Array();
282 inline dynamic::dynamic(ObjectMaker (*)())
285 new (getAddress<ObjectImpl>()) ObjectImpl();
288 inline dynamic::dynamic(StringPiece s)
291 new (&u_.string) std::string(s.data(), s.size());
294 inline dynamic::dynamic(char const* s)
297 new (&u_.string) std::string(s);
300 inline dynamic::dynamic(std::string const& s)
303 new (&u_.string) std::string(s);
306 inline dynamic::dynamic(std::string&& s) : type_(STRING) {
307 new (&u_.string) std::string(std::move(s));
310 inline dynamic::dynamic(std::initializer_list<dynamic> il)
311 : dynamic(std::move(il), PrivateTag()) {
314 inline dynamic::dynamic(std::initializer_list<dynamic> il, PrivateTag)
317 new (&u_.array) Array(il.begin(), il.end());
320 inline dynamic& dynamic::operator=(std::initializer_list<dynamic> il) {
321 (*this) = dynamic(il, PrivateTag());
325 inline dynamic::dynamic(ObjectMaker&& maker)
328 new (getAddress<ObjectImpl>())
329 ObjectImpl(std::move(*maker.val_.getAddress<ObjectImpl>()));
332 inline dynamic::dynamic(dynamic const& o)
338 inline dynamic::dynamic(dynamic&& o) noexcept
341 *this = std::move(o);
344 inline dynamic::~dynamic() noexcept { destroy(); }
347 dynamic::dynamic(T t) {
348 typedef typename detail::ConversionHelper<T>::type U;
349 type_ = TypeInfo<U>::type;
350 new (getAddress<U>()) U(std::move(t));
353 template<class Iterator>
354 dynamic::dynamic(Iterator first, Iterator last)
357 new (&u_.array) Array(first, last);
360 //////////////////////////////////////////////////////////////////////
362 inline dynamic::const_iterator dynamic::begin() const {
363 return get<Array>().begin();
365 inline dynamic::const_iterator dynamic::end() const {
366 return get<Array>().end();
370 struct dynamic::IterableProxy {
371 typedef It const_iterator;
372 typedef typename It::value_type value_type;
374 /* implicit */ IterableProxy(const dynamic::ObjectImpl* o) : o_(o) { }
385 const dynamic::ObjectImpl* o_;
388 inline dynamic::IterableProxy<dynamic::const_key_iterator> dynamic::keys()
390 return &(get<ObjectImpl>());
393 inline dynamic::IterableProxy<dynamic::const_value_iterator> dynamic::values()
395 return &(get<ObjectImpl>());
398 inline dynamic::IterableProxy<dynamic::const_item_iterator> dynamic::items()
400 return &(get<ObjectImpl>());
403 inline bool dynamic::isString() const {
404 return get_nothrow<std::string>();
406 inline bool dynamic::isObject() const { return get_nothrow<ObjectImpl>(); }
407 inline bool dynamic::isBool() const { return get_nothrow<bool>(); }
408 inline bool dynamic::isArray() const { return get_nothrow<Array>(); }
409 inline bool dynamic::isDouble() const { return get_nothrow<double>(); }
410 inline bool dynamic::isInt() const { return get_nothrow<int64_t>(); }
411 inline bool dynamic::isNull() const { return get_nothrow<void*>(); }
412 inline bool dynamic::isNumber() const { return isInt() || isDouble(); }
414 inline dynamic::Type dynamic::type() const {
418 inline std::string dynamic::asString() const {
419 return asImpl<std::string>();
421 inline double dynamic::asDouble() const {
422 return asImpl<double>();
424 inline int64_t dynamic::asInt() const {
425 return asImpl<int64_t>();
427 inline bool dynamic::asBool() const {
428 return asImpl<bool>();
431 inline const std::string& dynamic::getString() const& {
432 return get<std::string>();
434 inline double dynamic::getDouble() const& { return get<double>(); }
435 inline int64_t dynamic::getInt() const& { return get<int64_t>(); }
436 inline bool dynamic::getBool() const& { return get<bool>(); }
438 inline std::string& dynamic::getString()& {
439 return get<std::string>();
441 inline double& dynamic::getDouble() & { return get<double>(); }
442 inline int64_t& dynamic::getInt() & { return get<int64_t>(); }
443 inline bool& dynamic::getBool() & { return get<bool>(); }
445 inline std::string dynamic::getString()&& {
446 return std::move(get<std::string>());
448 inline double dynamic::getDouble() && { return get<double>(); }
449 inline int64_t dynamic::getInt() && { return get<int64_t>(); }
450 inline bool dynamic::getBool() && { return get<bool>(); }
452 inline const char* dynamic::data() const& {
453 return get<std::string>().data();
455 inline const char* dynamic::c_str() const& {
456 return get<std::string>().c_str();
458 inline StringPiece dynamic::stringPiece() const {
459 return get<std::string>();
463 struct dynamic::CompareOp {
464 static bool comp(T const& a, T const& b) { return a < b; }
467 struct dynamic::CompareOp<dynamic::ObjectImpl> {
468 static bool comp(ObjectImpl const&, ObjectImpl const&) {
469 // This code never executes; it is just here for the compiler.
474 inline dynamic& dynamic::operator+=(dynamic const& o) {
475 if (type() == STRING && o.type() == STRING) {
476 *getAddress<std::string>() += *o.getAddress<std::string>();
479 *this = detail::numericOp<std::plus>(*this, o);
483 inline dynamic& dynamic::operator-=(dynamic const& o) {
484 *this = detail::numericOp<std::minus>(*this, o);
488 inline dynamic& dynamic::operator*=(dynamic const& o) {
489 *this = detail::numericOp<std::multiplies>(*this, o);
493 inline dynamic& dynamic::operator/=(dynamic const& o) {
494 *this = detail::numericOp<std::divides>(*this, o);
498 #define FB_DYNAMIC_INTEGER_OP(op) \
499 inline dynamic& dynamic::operator op(dynamic const& o) { \
500 if (!isInt() || !o.isInt()) { \
501 throw TypeError("int64", type(), o.type()); \
503 *getAddress<int64_t>() op o.asInt(); \
507 FB_DYNAMIC_INTEGER_OP(%=)
508 FB_DYNAMIC_INTEGER_OP(|=)
509 FB_DYNAMIC_INTEGER_OP(&=)
510 FB_DYNAMIC_INTEGER_OP(^=)
512 #undef FB_DYNAMIC_INTEGER_OP
514 inline dynamic& dynamic::operator++() {
519 inline dynamic& dynamic::operator--() {
524 inline dynamic const& dynamic::operator[](dynamic const& idx) const& {
528 inline dynamic dynamic::operator[](dynamic const& idx) && {
529 return std::move((*this)[idx]);
532 template<class K, class V> inline dynamic& dynamic::setDefault(K&& k, V&& v) {
533 auto& obj = get<ObjectImpl>();
534 return obj.insert(std::make_pair(std::forward<K>(k),
535 std::forward<V>(v))).first->second;
538 inline dynamic* dynamic::get_ptr(dynamic const& idx) & {
539 return const_cast<dynamic*>(const_cast<dynamic const*>(this)->get_ptr(idx));
542 inline dynamic& dynamic::at(dynamic const& idx) & {
543 return const_cast<dynamic&>(const_cast<dynamic const*>(this)->at(idx));
546 inline dynamic dynamic::at(dynamic const& idx) && {
547 return std::move(at(idx));
550 inline bool dynamic::empty() const {
557 inline std::size_t dynamic::count(dynamic const& key) const {
558 return find(key) != items().end();
561 inline dynamic::const_item_iterator dynamic::find(dynamic const& key) const {
562 return get<ObjectImpl>().find(key);
565 template<class K, class V> inline void dynamic::insert(K&& key, V&& val) {
566 auto& obj = get<ObjectImpl>();
567 auto rv = obj.insert({ std::forward<K>(key), nullptr });
568 rv.first->second = std::forward<V>(val);
571 inline void dynamic::update(const dynamic& mergeObj) {
572 if (!isObject() || !mergeObj.isObject()) {
573 throw TypeError("object", type(), mergeObj.type());
576 for (const auto& pair : mergeObj.items()) {
577 (*this)[pair.first] = pair.second;
581 inline void dynamic::update_missing(const dynamic& mergeObj1) {
582 if (!isObject() || !mergeObj1.isObject()) {
583 throw TypeError("object", type(), mergeObj1.type());
586 // Only add if not already there
587 for (const auto& pair : mergeObj1.items()) {
588 if ((*this).find(pair.first) == (*this).items().end()) {
589 (*this)[pair.first] = pair.second;
594 inline dynamic dynamic::merge(
595 const dynamic& mergeObj1,
596 const dynamic& mergeObj2) {
598 // No checks on type needed here because they are done in update_missing
599 // Note that we do update_missing here instead of update() because
600 // it will prevent the extra writes that would occur with update()
601 auto ret = mergeObj2;
602 ret.update_missing(mergeObj1);
606 inline std::size_t dynamic::erase(dynamic const& key) {
607 auto& obj = get<ObjectImpl>();
608 return obj.erase(key);
611 inline dynamic::const_iterator dynamic::erase(const_iterator it) {
612 auto& arr = get<Array>();
613 // std::vector doesn't have an erase method that works on const iterators,
614 // even though the standard says it should, so this hack converts to a
615 // non-const iterator before calling erase.
616 return get<Array>().erase(arr.begin() + (it - arr.begin()));
619 inline dynamic::const_key_iterator dynamic::erase(const_key_iterator it) {
620 return const_key_iterator(get<ObjectImpl>().erase(it.base()));
623 inline dynamic::const_key_iterator dynamic::erase(const_key_iterator first,
624 const_key_iterator last) {
625 return const_key_iterator(get<ObjectImpl>().erase(first.base(),
629 inline dynamic::const_value_iterator dynamic::erase(const_value_iterator it) {
630 return const_value_iterator(get<ObjectImpl>().erase(it.base()));
633 inline dynamic::const_value_iterator dynamic::erase(const_value_iterator first,
634 const_value_iterator last) {
635 return const_value_iterator(get<ObjectImpl>().erase(first.base(),
639 inline dynamic::const_item_iterator dynamic::erase(const_item_iterator it) {
640 return const_item_iterator(get<ObjectImpl>().erase(it.base()));
643 inline dynamic::const_item_iterator dynamic::erase(const_item_iterator first,
644 const_item_iterator last) {
645 return const_item_iterator(get<ObjectImpl>().erase(first.base(),
649 inline void dynamic::resize(std::size_t sz, dynamic const& c) {
650 auto& arr = get<Array>();
654 inline void dynamic::push_back(dynamic const& v) {
655 auto& arr = get<Array>();
659 inline void dynamic::push_back(dynamic&& v) {
660 auto& arr = get<Array>();
661 arr.push_back(std::move(v));
664 inline void dynamic::pop_back() {
665 auto& arr = get<Array>();
669 //////////////////////////////////////////////////////////////////////
671 #define FOLLY_DYNAMIC_DEC_TYPEINFO(T, str, val) \
672 template <> struct dynamic::TypeInfo<T> { \
673 static constexpr const char* name = str; \
674 static constexpr dynamic::Type type = val; \
678 FOLLY_DYNAMIC_DEC_TYPEINFO(void*, "null", dynamic::NULLT)
679 FOLLY_DYNAMIC_DEC_TYPEINFO(bool, "boolean", dynamic::BOOL)
680 FOLLY_DYNAMIC_DEC_TYPEINFO(std::string, "string", dynamic::STRING)
681 FOLLY_DYNAMIC_DEC_TYPEINFO(dynamic::Array, "array", dynamic::ARRAY)
682 FOLLY_DYNAMIC_DEC_TYPEINFO(double, "double", dynamic::DOUBLE)
683 FOLLY_DYNAMIC_DEC_TYPEINFO(int64_t, "int64", dynamic::INT64)
684 FOLLY_DYNAMIC_DEC_TYPEINFO(dynamic::ObjectImpl, "object", dynamic::OBJECT)
686 #undef FOLLY_DYNAMIC_DEC_TYPEINFO
689 T dynamic::asImpl() const {
691 case INT64: return to<T>(*get_nothrow<int64_t>());
692 case DOUBLE: return to<T>(*get_nothrow<double>());
693 case BOOL: return to<T>(*get_nothrow<bool>());
695 return to<T>(*get_nothrow<std::string>());
697 throw TypeError("int/double/bool/string", type());
701 // Return a T* to our type, or null if we're not that type.
703 T* dynamic::get_nothrow() & noexcept {
704 if (type_ != TypeInfo<T>::type) {
707 return getAddress<T>();
711 T const* dynamic::get_nothrow() const& noexcept {
712 return const_cast<dynamic*>(this)->get_nothrow<T>();
715 // Return T* for where we can put a T, without type checking. (Memory
716 // might be uninitialized, even.)
718 T* dynamic::getAddress() noexcept {
719 return GetAddrImpl<T>::get(u_);
723 T const* dynamic::getAddress() const noexcept {
724 return const_cast<dynamic*>(this)->getAddress<T>();
727 template<class T> struct dynamic::GetAddrImpl {};
728 template<> struct dynamic::GetAddrImpl<void*> {
729 static void** get(Data& d) noexcept { return &d.nul; }
731 template<> struct dynamic::GetAddrImpl<dynamic::Array> {
732 static Array* get(Data& d) noexcept { return &d.array; }
734 template<> struct dynamic::GetAddrImpl<bool> {
735 static bool* get(Data& d) noexcept { return &d.boolean; }
737 template<> struct dynamic::GetAddrImpl<int64_t> {
738 static int64_t* get(Data& d) noexcept { return &d.integer; }
740 template<> struct dynamic::GetAddrImpl<double> {
741 static double* get(Data& d) noexcept { return &d.doubl; }
744 struct dynamic::GetAddrImpl<std::string> {
745 static std::string* get(Data& d) noexcept {
749 template<> struct dynamic::GetAddrImpl<dynamic::ObjectImpl> {
750 static_assert(sizeof(ObjectImpl) <= sizeof(Data::objectBuffer),
751 "In your implementation, std::unordered_map<> apparently takes different"
752 " amount of space depending on its template parameters. This is "
753 "weird. Make objectBuffer bigger if you want to compile dynamic.");
755 static ObjectImpl* get(Data& d) noexcept {
756 void* data = &d.objectBuffer;
757 return static_cast<ObjectImpl*>(data);
763 if (auto* p = get_nothrow<T>()) {
766 throw TypeError(TypeInfo<T>::name, type());
770 T const& dynamic::get() const {
771 return const_cast<dynamic*>(this)->get<T>();
774 //////////////////////////////////////////////////////////////////////
777 * Helper for implementing operator<<. Throws if the type shouldn't
781 struct dynamic::PrintImpl {
782 static void print(dynamic const&, std::ostream& out, T const& t) {
786 // Otherwise, null, being (void*)0, would print as 0.
788 struct dynamic::PrintImpl<void*> {
789 static void print(dynamic const& /* d */,
792 DCHECK_EQ((void*)0, nul);
797 struct dynamic::PrintImpl<dynamic::ObjectImpl> {
798 static void print(dynamic const& d,
800 dynamic::ObjectImpl const&) {
801 d.print_as_pseudo_json(out);
805 struct dynamic::PrintImpl<dynamic::Array> {
806 static void print(dynamic const& d,
808 dynamic::Array const&) {
809 d.print_as_pseudo_json(out);
813 inline void dynamic::print(std::ostream& out) const {
814 #define FB_X(T) PrintImpl<T>::print(*this, out, *getAddress<T>())
815 FB_DYNAMIC_APPLY(type_, FB_X);
819 inline std::ostream& operator<<(std::ostream& out, dynamic const& d) {
824 //////////////////////////////////////////////////////////////////////
826 // Secialization of FormatValue so dynamic objects can be formatted
828 class FormatValue<dynamic> {
830 explicit FormatValue(const dynamic& val) : val_(val) { }
832 template <class FormatCallback>
833 void format(FormatArg& arg, FormatCallback& cb) const {
834 switch (val_.type()) {
836 FormatValue<std::nullptr_t>(nullptr).format(arg, cb);
839 FormatValue<bool>(val_.asBool()).format(arg, cb);
842 FormatValue<int64_t>(val_.asInt()).format(arg, cb);
844 case dynamic::STRING:
845 FormatValue<std::string>(val_.asString()).format(arg, cb);
847 case dynamic::DOUBLE:
848 FormatValue<double>(val_.asDouble()).format(arg, cb);
851 FormatValue(val_.at(arg.splitIntKey())).format(arg, cb);
853 case dynamic::OBJECT:
854 FormatValue(val_.at(arg.splitKey().toString())).format(arg, cb);
864 class FormatValue<detail::DefaultValueWrapper<dynamic, V>> {
866 explicit FormatValue(
867 const detail::DefaultValueWrapper<dynamic, V>& val)
870 template <class FormatCallback>
871 void format(FormatArg& arg, FormatCallback& cb) const {
872 auto& c = val_.container;
877 case dynamic::STRING:
878 case dynamic::DOUBLE:
879 FormatValue<dynamic>(c).format(arg, cb);
883 int key = arg.splitIntKey();
884 if (key >= 0 && size_t(key) < c.size()) {
885 FormatValue<dynamic>(c.at(key)).format(arg, cb);
887 FormatValue<V>(val_.defaultValue).format(arg, cb);
891 case dynamic::OBJECT:
893 auto pos = c.find(arg.splitKey());
894 if (pos != c.items().end()) {
895 FormatValue<dynamic>(pos->second).format(arg, cb);
897 FormatValue<V>(val_.defaultValue).format(arg, cb);
905 const detail::DefaultValueWrapper<dynamic, V>& val_;
910 #undef FB_DYNAMIC_APPLY