2 * Copyright 2013 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 : std::runtime_error(to<std::string>("TypeError: expected dynamic "
64 "type `", expected, '\'', ", but had type `",
65 dynamic::typeName(actual), '\''))
67 explicit TypeError(const std::string& expected,
68 dynamic::Type actual1, dynamic::Type actual2)
69 : std::runtime_error(to<std::string>("TypeError: expected dynamic "
70 "types `", expected, '\'', ", but had types `",
71 dynamic::typeName(actual1), "' and `", dynamic::typeName(actual2),
77 //////////////////////////////////////////////////////////////////////
81 // This helper is used in destroy() to be able to run destructors on
82 // types like "int64_t" without a compiler error.
84 template<class T> static void destroy(T* t) { t->~T(); }
88 * The enable_if junk here is necessary to avoid ambiguous
89 * conversions relating to bool and double when you implicitly
90 * convert an int or long to a dynamic.
92 template<class T, class Enable = void> struct ConversionHelper;
94 struct ConversionHelper<
96 typename std::enable_if<
97 std::is_integral<T>::value && !std::is_same<T,bool>::value
100 typedef int64_t type;
103 struct ConversionHelper<
105 typename std::enable_if<
106 (!std::is_integral<T>::value || std::is_same<T,bool>::value) &&
107 !std::is_same<T,std::nullptr_t>::value
113 struct ConversionHelper<
115 typename std::enable_if<
116 std::is_same<T,std::nullptr_t>::value
123 * Helper for implementing numeric conversions in operators on
124 * numbers. Just promotes to double when one of the arguments is
125 * double, or throws if either is not a numeric type.
127 template<template<class> class Op>
128 dynamic numericOp(dynamic const& a, dynamic const& b) {
129 if (!a.isNumber() || !b.isNumber()) {
130 throw TypeError("numeric", a.type(), b.type());
132 if (a.type() != b.type()) {
133 auto& integ = a.isInt() ? a : b;
134 auto& nonint = a.isInt() ? b : a;
135 return Op<double>()(to<double>(integ.asInt()), nonint.asDouble());
138 return Op<double>()(a.asDouble(), b.asDouble());
140 return Op<int64_t>()(a.asInt(), b.asInt());
145 //////////////////////////////////////////////////////////////////////
148 * We're doing this instead of a simple member typedef to avoid the
149 * undefined behavior of parameterizing std::unordered_map<> with an
152 * Note: Later we may add separate order tracking here (a multi-index
155 struct dynamic::ObjectImpl : std::unordered_map<dynamic, dynamic> {};
157 //////////////////////////////////////////////////////////////////////
159 // Helper object for creating objects conveniently. See object and
160 // the dynamic::dynamic(ObjectMaker&&) ctor.
161 struct dynamic::ObjectMaker {
162 friend struct dynamic;
164 explicit ObjectMaker() : val_(dynamic::object) {}
165 explicit ObjectMaker(dynamic const& key, dynamic val)
166 : val_(dynamic::object)
168 val_.insert(key, std::move(val));
170 explicit ObjectMaker(dynamic&& key, dynamic val)
171 : val_(dynamic::object)
173 val_.insert(std::move(key), std::move(val));
176 // Make sure no one tries to save one of these into an lvalue with
177 // auto or anything like that.
178 ObjectMaker(ObjectMaker&&) = default;
179 ObjectMaker(ObjectMaker const&) = delete;
180 ObjectMaker& operator=(ObjectMaker const&) = delete;
181 ObjectMaker& operator=(ObjectMaker&&) = delete;
183 // These return rvalue-references instead of lvalue-references to allow
184 // constructs like this to moved instead of copied:
185 // dynamic a = dynamic::object("a", "b")("c", "d")
186 ObjectMaker&& operator()(dynamic const& key, dynamic val) {
187 val_.insert(key, std::move(val));
188 return std::move(*this);
191 ObjectMaker&& operator()(dynamic&& key, dynamic val) {
192 val_.insert(std::move(key), std::move(val));
193 return std::move(*this);
200 // This looks like a case for perfect forwarding, but our use of
201 // std::initializer_list for constructing dynamic arrays makes it less
202 // functional than doing this manually.
203 inline dynamic::ObjectMaker dynamic::object() { return ObjectMaker(); }
204 inline dynamic::ObjectMaker dynamic::object(dynamic&& a, dynamic&& b) {
205 return ObjectMaker(std::move(a), std::move(b));
207 inline dynamic::ObjectMaker dynamic::object(dynamic const& a, dynamic&& b) {
208 return ObjectMaker(a, std::move(b));
210 inline dynamic::ObjectMaker dynamic::object(dynamic&& a, dynamic const& b) {
211 return ObjectMaker(std::move(a), b);
213 inline dynamic::ObjectMaker
214 dynamic::object(dynamic const& a, dynamic const& b) {
215 return ObjectMaker(a, b);
218 //////////////////////////////////////////////////////////////////////
220 struct dynamic::const_item_iterator
221 : boost::iterator_adaptor<dynamic::const_item_iterator,
222 dynamic::ObjectImpl::const_iterator> {
223 /* implicit */ const_item_iterator(base_type b) : iterator_adaptor_(b) { }
226 friend class boost::iterator_core_access;
229 struct dynamic::const_key_iterator
230 : boost::iterator_adaptor<dynamic::const_key_iterator,
231 dynamic::ObjectImpl::const_iterator,
233 /* implicit */ const_key_iterator(base_type b) : iterator_adaptor_(b) { }
236 dynamic const& dereference() const {
237 return base_reference()->first;
239 friend class boost::iterator_core_access;
242 struct dynamic::const_value_iterator
243 : boost::iterator_adaptor<dynamic::const_value_iterator,
244 dynamic::ObjectImpl::const_iterator,
246 /* implicit */ const_value_iterator(base_type b) : iterator_adaptor_(b) { }
249 dynamic const& dereference() const {
250 return base_reference()->second;
252 friend class boost::iterator_core_access;
255 //////////////////////////////////////////////////////////////////////
257 inline dynamic::dynamic(ObjectMaker (*)())
260 new (getAddress<ObjectImpl>()) ObjectImpl();
263 inline dynamic::dynamic(char const* s)
266 new (&u_.string) fbstring(s);
269 inline dynamic::dynamic(std::string const& s)
272 new (&u_.string) fbstring(s);
275 inline dynamic::dynamic(std::initializer_list<dynamic> il)
278 new (&u_.array) Array(il.begin(), il.end());
281 inline dynamic::dynamic(ObjectMaker&& maker)
284 new (getAddress<ObjectImpl>())
285 ObjectImpl(std::move(*maker.val_.getAddress<ObjectImpl>()));
288 inline dynamic::dynamic(dynamic const& o)
294 inline dynamic::dynamic(dynamic&& o)
297 *this = std::move(o);
300 inline dynamic::~dynamic() { destroy(); }
303 dynamic::dynamic(T t) {
304 typedef typename detail::ConversionHelper<T>::type U;
305 type_ = TypeInfo<U>::type;
306 new (getAddress<U>()) U(std::move(t));
309 template<class Iterator>
310 dynamic::dynamic(Iterator first, Iterator last)
313 new (&u_.array) Array(first, last);
316 //////////////////////////////////////////////////////////////////////
318 inline dynamic::const_iterator dynamic::begin() const {
319 return get<Array>().begin();
321 inline dynamic::const_iterator dynamic::end() const {
322 return get<Array>().end();
326 struct dynamic::IterableProxy {
327 typedef It const_iterator;
328 typedef typename It::value_type value_type;
330 /* implicit */ IterableProxy(const dynamic::ObjectImpl* o) : o_(o) { }
341 const dynamic::ObjectImpl* o_;
344 inline dynamic::IterableProxy<dynamic::const_key_iterator> dynamic::keys()
346 return &(get<ObjectImpl>());
349 inline dynamic::IterableProxy<dynamic::const_value_iterator> dynamic::values()
351 return &(get<ObjectImpl>());
354 inline dynamic::IterableProxy<dynamic::const_item_iterator> dynamic::items()
356 return &(get<ObjectImpl>());
359 inline bool dynamic::isString() const { return get_nothrow<fbstring>(); }
360 inline bool dynamic::isObject() const { return get_nothrow<ObjectImpl>(); }
361 inline bool dynamic::isBool() const { return get_nothrow<bool>(); }
362 inline bool dynamic::isArray() const { return get_nothrow<Array>(); }
363 inline bool dynamic::isDouble() const { return get_nothrow<double>(); }
364 inline bool dynamic::isInt() const { return get_nothrow<int64_t>(); }
365 inline bool dynamic::isNull() const { return get_nothrow<void*>(); }
366 inline bool dynamic::isNumber() const { return isInt() || isDouble(); }
368 inline dynamic::Type dynamic::type() const {
372 inline fbstring dynamic::asString() const { return asImpl<fbstring>(); }
373 inline double dynamic::asDouble() const { return asImpl<double>(); }
374 inline int64_t dynamic::asInt() const { return asImpl<int64_t>(); }
375 inline bool dynamic::asBool() const { return asImpl<bool>(); }
378 struct dynamic::CompareOp {
379 static bool comp(T const& a, T const& b) { return a < b; }
382 struct dynamic::CompareOp<dynamic::ObjectImpl> {
383 static bool comp(ObjectImpl const& a, ObjectImpl const& b) {
384 // This code never executes; it is just here for the compiler.
389 inline bool dynamic::operator<(dynamic const& o) const {
390 if (UNLIKELY(type_ == OBJECT || o.type_ == OBJECT)) {
391 throw TypeError("object", type_);
393 if (type_ != o.type_) {
394 return type_ < o.type_;
397 #define FB_X(T) return CompareOp<T>::comp(*getAddress<T>(), \
399 FB_DYNAMIC_APPLY(type_, FB_X);
403 inline bool dynamic::operator==(dynamic const& o) const {
404 if (type() != o.type()) {
405 if (isNumber() && o.isNumber()) {
406 auto& integ = isInt() ? *this : o;
407 auto& doubl = isInt() ? o : *this;
408 return integ.asInt() == doubl.asDouble();
413 #define FB_X(T) return *getAddress<T>() == *o.getAddress<T>();
414 FB_DYNAMIC_APPLY(type_, FB_X);
418 inline dynamic& dynamic::operator+=(dynamic const& o) {
419 if (type() == STRING && o.type() == STRING) {
420 *getAddress<fbstring>() += *o.getAddress<fbstring>();
423 *this = detail::numericOp<std::plus>(*this, o);
427 inline dynamic& dynamic::operator-=(dynamic const& o) {
428 *this = detail::numericOp<std::minus>(*this, o);
432 inline dynamic& dynamic::operator*=(dynamic const& o) {
433 *this = detail::numericOp<std::multiplies>(*this, o);
437 inline dynamic& dynamic::operator/=(dynamic const& o) {
438 *this = detail::numericOp<std::divides>(*this, o);
442 #define FB_DYNAMIC_INTEGER_OP(op) \
443 inline dynamic& dynamic::operator op(dynamic const& o) { \
444 if (!isInt() || !o.isInt()) { \
445 throw TypeError("int64", type(), o.type()); \
447 *getAddress<int64_t>() op o.asInt(); \
451 FB_DYNAMIC_INTEGER_OP(%=)
452 FB_DYNAMIC_INTEGER_OP(|=)
453 FB_DYNAMIC_INTEGER_OP(&=)
454 FB_DYNAMIC_INTEGER_OP(^=)
456 #undef FB_DYNAMIC_INTEGER_OP
458 inline dynamic& dynamic::operator++() {
463 inline dynamic& dynamic::operator--() {
468 inline dynamic& dynamic::operator=(dynamic const& o) {
471 #define FB_X(T) new (getAddress<T>()) T(*o.getAddress<T>())
472 FB_DYNAMIC_APPLY(o.type_, FB_X);
479 inline dynamic& dynamic::operator=(dynamic&& o) {
482 #define FB_X(T) new (getAddress<T>()) T(std::move(*o.getAddress<T>()))
483 FB_DYNAMIC_APPLY(o.type_, FB_X);
490 inline dynamic& dynamic::operator[](dynamic const& k) {
491 if (!isObject() && !isArray()) {
492 throw TypeError("object/array", type());
497 auto& obj = get<ObjectImpl>();
498 auto ret = obj.insert({k, nullptr});
499 return ret.first->second;
502 inline dynamic const& dynamic::operator[](dynamic const& idx) const {
506 inline dynamic dynamic::getDefault(const dynamic& k, const dynamic& v) const {
507 auto& obj = get<ObjectImpl>();
508 auto it = obj.find(k);
509 return it == obj.end() ? v : it->second;
512 inline dynamic&& dynamic::getDefault(const dynamic& k, dynamic&& v) const {
513 auto& obj = get<ObjectImpl>();
514 auto it = obj.find(k);
515 if (it != obj.end()) {
522 template<class K, class V> inline dynamic& dynamic::setDefault(K&& k, V&& v) {
523 auto& obj = get<ObjectImpl>();
524 return obj.insert(std::make_pair(std::forward<K>(k),
525 std::forward<V>(v))).first->second;
528 inline dynamic const& dynamic::at(dynamic const& idx) const {
529 return const_cast<dynamic*>(this)->at(idx);
532 inline dynamic& dynamic::at(dynamic const& idx) {
533 if (!isObject() && !isArray()) {
534 throw TypeError("object/array", type());
537 if (auto* parray = get_nothrow<Array>()) {
538 if (idx >= parray->size()) {
539 throw std::out_of_range("out of range in dynamic array");
542 throw TypeError("int64", idx.type());
544 return (*parray)[idx.asInt()];
547 assert(get_nothrow<ObjectImpl>());
549 if (it == items().end()) {
550 throw std::out_of_range(to<std::string>(
551 "couldn't find key ", idx.asString(), " in dynamic object"));
553 return const_cast<dynamic&>(it->second);
556 inline bool dynamic::empty() const {
563 inline std::size_t dynamic::size() const {
564 if (auto* ar = get_nothrow<Array>()) {
567 if (auto* obj = get_nothrow<ObjectImpl>()) {
570 if (auto* str = get_nothrow<fbstring>()) {
573 throw TypeError("array/object", type());
576 inline std::size_t dynamic::count(dynamic const& key) const {
577 return find(key) != items().end();
580 inline dynamic::const_item_iterator dynamic::find(dynamic const& key) const {
581 return get<ObjectImpl>().find(key);
584 template<class K, class V> inline void dynamic::insert(K&& key, V&& val) {
585 auto& obj = get<ObjectImpl>();
586 auto rv = obj.insert(std::make_pair(std::forward<K>(key),
587 std::forward<V>(val)));
589 // note, the second use of std:forward<V>(val) is only correct
590 // if the first one did not result in a move. obj[key] = val
591 // would be preferrable but doesn't compile because dynamic
592 // is (intentionally) not default constructable
593 rv.first->second = std::forward<V>(val);
597 inline std::size_t dynamic::erase(dynamic const& key) {
598 auto& obj = get<ObjectImpl>();
599 return obj.erase(key);
602 inline dynamic::const_iterator dynamic::erase(const_iterator it) {
603 auto& arr = get<Array>();
604 // std::vector doesn't have an erase method that works on const iterators,
605 // even though the standard says it should, so this hack converts to a
606 // non-const iterator before calling erase.
607 return get<Array>().erase(arr.begin() + (it - arr.begin()));
610 inline dynamic::const_iterator
611 dynamic::erase(const_iterator first, const_iterator last) {
612 auto& arr = get<Array>();
613 return get<Array>().erase(
614 arr.begin() + (first - arr.begin()),
615 arr.begin() + (last - arr.begin()));
618 inline dynamic::const_key_iterator dynamic::erase(const_key_iterator it) {
619 return const_key_iterator(get<ObjectImpl>().erase(it.base()));
622 inline dynamic::const_key_iterator dynamic::erase(const_key_iterator first,
623 const_key_iterator last) {
624 return const_key_iterator(get<ObjectImpl>().erase(first.base(),
628 inline dynamic::const_value_iterator dynamic::erase(const_value_iterator it) {
629 return const_value_iterator(get<ObjectImpl>().erase(it.base()));
632 inline dynamic::const_value_iterator dynamic::erase(const_value_iterator first,
633 const_value_iterator last) {
634 return const_value_iterator(get<ObjectImpl>().erase(first.base(),
638 inline dynamic::const_item_iterator dynamic::erase(const_item_iterator it) {
639 return const_item_iterator(get<ObjectImpl>().erase(it.base()));
642 inline dynamic::const_item_iterator dynamic::erase(const_item_iterator first,
643 const_item_iterator last) {
644 return const_item_iterator(get<ObjectImpl>().erase(first.base(),
648 inline void dynamic::resize(std::size_t sz, dynamic const& c) {
649 auto& array = get<Array>();
653 inline void dynamic::push_back(dynamic const& v) {
654 auto& array = get<Array>();
658 inline void dynamic::push_back(dynamic&& v) {
659 auto& array = get<Array>();
660 array.push_back(std::move(v));
663 inline void dynamic::pop_back() {
664 auto& array = get<Array>();
668 inline std::size_t dynamic::hash() const {
673 throw TypeError("not null/object/array", type());
675 return std::hash<int64_t>()(asInt());
677 return std::hash<double>()(asDouble());
679 return std::hash<bool>()(asBool());
681 return std::hash<fbstring>()(asString());
687 //////////////////////////////////////////////////////////////////////
689 template<class T> struct dynamic::TypeInfo {
690 static char const name[];
691 static Type const type;
694 #define FB_DEC_TYPE(T) \
695 template<> char const dynamic::TypeInfo<T>::name[]; \
696 template<> dynamic::Type const dynamic::TypeInfo<T>::type
700 FB_DEC_TYPE(fbstring);
701 FB_DEC_TYPE(dynamic::Array);
703 FB_DEC_TYPE(int64_t);
704 FB_DEC_TYPE(dynamic::ObjectImpl);
709 T dynamic::asImpl() const {
711 case INT64: return to<T>(*get_nothrow<int64_t>());
712 case DOUBLE: return to<T>(*get_nothrow<double>());
713 case BOOL: return to<T>(*get_nothrow<bool>());
714 case STRING: return to<T>(*get_nothrow<fbstring>());
716 throw TypeError("int/double/bool/string", type());
720 // Return a T* to our type, or null if we're not that type.
722 T* dynamic::get_nothrow() {
723 if (type_ != TypeInfo<T>::type) {
726 return getAddress<T>();
730 T const* dynamic::get_nothrow() const {
731 return const_cast<dynamic*>(this)->get_nothrow<T>();
734 // Return T* for where we can put a T, without type checking. (Memory
735 // might be uninitialized, even.)
737 T* dynamic::getAddress() {
738 return GetAddrImpl<T>::get(u_);
742 T const* dynamic::getAddress() const {
743 return const_cast<dynamic*>(this)->getAddress<T>();
746 template<class T> struct dynamic::GetAddrImpl {};
747 template<> struct dynamic::GetAddrImpl<void*> {
748 static void** get(Data& d) { return &d.nul; }
750 template<> struct dynamic::GetAddrImpl<dynamic::Array> {
751 static Array* get(Data& d) { return &d.array; }
753 template<> struct dynamic::GetAddrImpl<bool> {
754 static bool* get(Data& d) { return &d.boolean; }
756 template<> struct dynamic::GetAddrImpl<int64_t> {
757 static int64_t* get(Data& d) { return &d.integer; }
759 template<> struct dynamic::GetAddrImpl<double> {
760 static double* get(Data& d) { return &d.doubl; }
762 template<> struct dynamic::GetAddrImpl<fbstring> {
763 static fbstring* get(Data& d) { return &d.string; }
765 template<> struct dynamic::GetAddrImpl<dynamic::ObjectImpl> {
766 static_assert(sizeof(ObjectImpl) <= sizeof(Data::objectBuffer),
767 "In your implementation, std::unordered_map<> apparently takes different"
768 " amount of space depending on its template parameters. This is "
769 "weird. Make objectBuffer bigger if you want to compile dynamic.");
771 static ObjectImpl* get(Data& d) {
772 void* data = &d.objectBuffer;
773 return static_cast<ObjectImpl*>(data);
779 if (auto* p = get_nothrow<T>()) {
782 throw TypeError(TypeInfo<T>::name, type());
786 T const& dynamic::get() const {
787 return const_cast<dynamic*>(this)->get<T>();
790 inline char const* dynamic::typeName(Type t) {
791 #define FB_X(T) return TypeInfo<T>::name
792 FB_DYNAMIC_APPLY(t, FB_X);
796 inline void dynamic::destroy() {
797 // This short-circuit speeds up some microbenchmarks.
798 if (type_ == NULLT) return;
800 #define FB_X(T) detail::Destroy::destroy(getAddress<T>())
801 FB_DYNAMIC_APPLY(type_, FB_X);
807 //////////////////////////////////////////////////////////////////////
810 * Helper for implementing operator<<. Throws if the type shouldn't
814 struct dynamic::PrintImpl {
815 static void print(dynamic const&, std::ostream& out, T const& t) {
820 struct dynamic::PrintImpl<dynamic::ObjectImpl> {
821 static void print(dynamic const& d,
823 dynamic::ObjectImpl const&) {
824 d.print_as_pseudo_json(out);
828 struct dynamic::PrintImpl<dynamic::Array> {
829 static void print(dynamic const& d,
831 dynamic::Array const&) {
832 d.print_as_pseudo_json(out);
836 inline void dynamic::print(std::ostream& out) const {
837 #define FB_X(T) PrintImpl<T>::print(*this, out, *getAddress<T>())
838 FB_DYNAMIC_APPLY(type_, FB_X);
842 inline std::ostream& operator<<(std::ostream& out, dynamic const& d) {
847 //////////////////////////////////////////////////////////////////////
849 // Secialization of FormatValue so dynamic objects can be formatted
851 class FormatValue<dynamic> {
853 explicit FormatValue(const dynamic& val) : val_(val) { }
855 template <class FormatCallback>
856 void format(FormatArg& arg, FormatCallback& cb) const {
857 switch (val_.type()) {
859 FormatValue<std::nullptr_t>(nullptr).format(arg, cb);
862 FormatValue<bool>(val_.asBool()).format(arg, cb);
865 FormatValue<int64_t>(val_.asInt()).format(arg, cb);
867 case dynamic::STRING:
868 FormatValue<fbstring>(val_.asString()).format(arg, cb);
870 case dynamic::DOUBLE:
871 FormatValue<double>(val_.asDouble()).format(arg, cb);
874 FormatValue(val_.at(arg.splitIntKey())).format(arg, cb);
876 case dynamic::OBJECT:
877 FormatValue(val_.at(arg.splitKey().toFbstring())).format(arg, cb);
888 #undef FB_DYNAMIC_APPLY