| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // This file specifies a recursive data storage class called Value intended for |
| // storing settings and other persistable data. |
| // |
| // A Value represents something that can be stored in JSON or passed to/from |
| // JavaScript. As such, it is NOT a generalized variant type, since only the |
| // types supported by JavaScript/JSON are supported. |
| // |
| // IN PARTICULAR this means that there is no support for int64_t or unsigned |
| // numbers. Writing JSON with such types would violate the spec. If you need |
| // something like this, either use a double or make a string value containing |
| // the number you want. |
| // |
| // NOTE: A Value parameter that is always a Value::STRING should just be passed |
| // as a std::string. Similarly for Values that are always Value::DICTIONARY |
| // (should be flat_map), Value::LIST (should be std::vector), et cetera. |
| |
| #ifndef BASE_VALUES_H_ |
| #define BASE_VALUES_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <iosfwd> |
| #include <map> |
| #include <memory> |
| #include <string> |
| #include <utility> |
| #include <vector> |
| |
| #include "base/base_export.h" |
| #include "base/containers/checked_iterators.h" |
| #include "base/containers/checked_range.h" |
| #include "base/containers/flat_map.h" |
| #include "base/containers/span.h" |
| #include "base/strings/string16.h" |
| #include "base/strings/string_piece.h" |
| #include "base/value_iterators.h" |
| #include "third_party/abseil-cpp/absl/types/variant.h" |
| |
| namespace base { |
| |
| class DictionaryValue; |
| class ListValue; |
| class Value; |
| |
| // The Value class is the base class for Values. A Value can be instantiated |
| // via passing the appropriate type or backing storage to the constructor. |
| // |
| // See the file-level comment above for more information. |
| // |
| // base::Value is currently in the process of being refactored. Design doc: |
| // https://docs.google.com/document/d/1uDLu5uTRlCWePxQUEHc8yNQdEoE1BDISYdpggWEABnw |
| // |
| // Previously (which is how most code that currently exists is written), Value |
| // used derived types to implement the individual data types, and base::Value |
| // was just a base class to refer to them. This required everything be heap |
| // allocated. |
| // |
| // OLD WAY: |
| // |
| // std::unique_ptr<base::Value> GetFoo() { |
| // std::unique_ptr<DictionaryValue> dict; |
| // dict->SetString("mykey", foo); |
| // return dict; |
| // } |
| // |
| // The new design makes base::Value a variant type that holds everything in |
| // a union. It is now recommended to pass by value with std::move rather than |
| // use heap allocated values. The DictionaryValue and ListValue subclasses |
| // exist only as a compatibility shim that we're in the process of removing. |
| // |
| // NEW WAY: |
| // |
| // base::Value GetFoo() { |
| // base::Value dict(base::Value::Type::DICTIONARY); |
| // dict.SetKey("mykey", base::Value(foo)); |
| // return dict; |
| // } |
| class BASE_EXPORT Value { |
| public: |
| using BlobStorage = std::vector<uint8_t>; |
| using DictStorage = flat_map<std::string, std::unique_ptr<Value>>; |
| using ListStorage = std::vector<Value>; |
| |
| using ListView = CheckedContiguousRange<ListStorage>; |
| using ConstListView = CheckedContiguousConstRange<ListStorage>; |
| |
| enum class Type : unsigned char { |
| NONE = 0, |
| BOOLEAN, |
| INTEGER, |
| DOUBLE, |
| STRING, |
| BINARY, |
| DICTIONARY, |
| LIST, |
| // TODO(crbug.com/859477): Remove once root cause is found. |
| DEAD |
| // Note: Do not add more types. See the file-level comment above for why. |
| }; |
| |
| // For situations where you want to keep ownership of your buffer, this |
| // factory method creates a new BinaryValue by copying the contents of the |
| // buffer that's passed in. |
| // DEPRECATED, use std::make_unique<Value>(const BlobStorage&) instead. |
| // TODO(crbug.com/646113): Delete this and migrate callsites. |
| static std::unique_ptr<Value> CreateWithCopiedBuffer(const char* buffer, |
| size_t size); |
| |
| // Adaptors for converting from the old way to the new way and vice versa. |
| static Value FromUniquePtrValue(std::unique_ptr<Value> val); |
| static std::unique_ptr<Value> ToUniquePtrValue(Value val); |
| static const DictionaryValue& AsDictionaryValue(const Value& val); |
| static const ListValue& AsListValue(const Value& val); |
| |
| Value() noexcept; |
| Value(Value&& that) noexcept; |
| |
| // Value's copy constructor and copy assignment operator are deleted. Use this |
| // to obtain a deep copy explicitly. |
| Value Clone() const; |
| |
| explicit Value(Type type); |
| explicit Value(bool in_bool); |
| explicit Value(int in_int); |
| explicit Value(double in_double); |
| |
| // Value(const char*) and Value(const char16*) are required despite |
| // Value(StringPiece) and Value(StringPiece16) because otherwise the |
| // compiler will choose the Value(bool) constructor for these arguments. |
| // Value(std::string&&) allow for efficient move construction. |
| explicit Value(const char* in_string); |
| explicit Value(StringPiece in_string); |
| explicit Value(std::string&& in_string) noexcept; |
| explicit Value(const char16* in_string16); |
| explicit Value(StringPiece16 in_string16); |
| |
| explicit Value(const std::vector<char>& in_blob); |
| explicit Value(base::span<const uint8_t> in_blob); |
| explicit Value(BlobStorage&& in_blob) noexcept; |
| |
| explicit Value(const DictStorage& in_dict); |
| explicit Value(DictStorage&& in_dict) noexcept; |
| |
| explicit Value(span<const Value> in_list); |
| explicit Value(ListStorage&& in_list) noexcept; |
| |
| Value& operator=(Value&& that) noexcept; |
| Value(const Value&) = delete; |
| Value& operator=(const Value&) = delete; |
| |
| ~Value(); |
| |
| // Returns the name for a given |type|. |
| static const char* GetTypeName(Type type); |
| |
| // Returns the type of the value stored by the current Value object. |
| Type type() const { return static_cast<Type>(data_.index()); } |
| |
| // Returns true if the current object represents a given type. |
| bool is_none() const { return type() == Type::NONE; } |
| bool is_bool() const { return type() == Type::BOOLEAN; } |
| bool is_int() const { return type() == Type::INTEGER; } |
| bool is_double() const { return type() == Type::DOUBLE; } |
| bool is_string() const { return type() == Type::STRING; } |
| bool is_blob() const { return type() == Type::BINARY; } |
| bool is_dict() const { return type() == Type::DICTIONARY; } |
| bool is_list() const { return type() == Type::LIST; } |
| |
| // These will all CHECK that the type matches. |
| bool GetBool() const; |
| int GetInt() const; |
| double GetDouble() const; // Implicitly converts from int if necessary. |
| const std::string& GetString() const; |
| std::string& GetString(); |
| const BlobStorage& GetBlob() const; |
| |
| // Returns the Values in a list as a view. The mutable overload allows for |
| // modification of the underlying values, but does not allow changing the |
| // structure of the list. If this is desired, use TakeList(), perform the |
| // operations, and return the list back to the Value via move assignment. |
| ListView GetList(); |
| ConstListView GetList() const; |
| |
| // Transfers ownership of the underlying list to the caller. Subsequent |
| // calls to GetList() will return an empty list. |
| // Note: This requires that type() is Type::LIST. |
| ListStorage TakeList(); |
| |
| // Appends |value| to the end of the list. |
| // Note: These CHECK that type() is Type::LIST. |
| void Append(bool value); |
| void Append(int value); |
| void Append(double value); |
| void Append(const char* value); |
| void Append(StringPiece value); |
| void Append(std::string&& value); |
| void Append(const char16* value); |
| void Append(StringPiece16 value); |
| void Append(Value&& value); |
| |
| // Inserts |value| before |pos|. |
| // Note: This CHECK that type() is Type::LIST. |
| CheckedContiguousIterator<Value> Insert( |
| CheckedContiguousConstIterator<Value> pos, |
| Value&& value); |
| |
| // Erases the Value pointed to by |iter|. Returns false if |iter| is out of |
| // bounds. |
| // Note: This requires that type() is Type::LIST. |
| bool EraseListIter(CheckedContiguousConstIterator<Value> iter); |
| |
| // Erases all Values that compare equal to |val|. Returns the number of |
| // deleted Values. |
| // Note: This requires that type() is Type::LIST. |
| size_t EraseListValue(const Value& val); |
| |
| // Erases all Values for which |pred| returns true. Returns the number of |
| // deleted Values. |
| // Note: This requires that type() is Type::LIST. |
| template <typename Predicate> |
| size_t EraseListValueIf(Predicate pred) { |
| return base::EraseIf(list(), pred); |
| } |
| |
| // Erases all Values from the list. |
| // Note: This requires that type() is Type::LIST. |
| void ClearList(); |
| |
| // |FindKey| looks up |key| in the underlying dictionary. If found, it returns |
| // a pointer to the element. Otherwise it returns nullptr. |
| // returned. Callers are expected to perform a check against null before using |
| // the pointer. |
| // Note: This requires that type() is Type::DICTIONARY. |
| // |
| // Example: |
| // auto* found = FindKey("foo"); |
| Value* FindKey(StringPiece key); |
| const Value* FindKey(StringPiece key) const; |
| |
| // |FindKeyOfType| is similar to |FindKey|, but it also requires the found |
| // value to have type |type|. If no type is found, or the found value is of a |
| // different type nullptr is returned. |
| // Callers are expected to perform a check against null before using the |
| // pointer. |
| // Note: This requires that type() is Type::DICTIONARY. |
| // |
| // Example: |
| // auto* found = FindKey("foo", Type::DOUBLE); |
| Value* FindKeyOfType(StringPiece key, Type type); |
| const Value* FindKeyOfType(StringPiece key, Type type) const; |
| |
| // These are convenience forms of |FindKey|. They return |base::nullopt| if |
| // the value is not found or doesn't have the type specified in the |
| // function's name. |
| base::Optional<bool> FindBoolKey(StringPiece key) const; |
| base::Optional<int> FindIntKey(StringPiece key) const; |
| // Note FindDoubleKey() will auto-convert INTEGER keys to their double |
| // value, for consistency with GetDouble(). |
| base::Optional<double> FindDoubleKey(StringPiece key) const; |
| |
| // |FindStringKey| returns |nullptr| if value is not found or not a string. |
| const std::string* FindStringKey(StringPiece key) const; |
| std::string* FindStringKey(StringPiece key); |
| |
| // Returns nullptr is value is not found or not a binary. |
| const BlobStorage* FindBlobKey(StringPiece key) const; |
| |
| // Returns nullptr if value is not found or not a dictionary. |
| const Value* FindDictKey(StringPiece key) const; |
| Value* FindDictKey(StringPiece key); |
| |
| // Returns nullptr if value is not found or not a list. |
| const Value* FindListKey(StringPiece key) const; |
| Value* FindListKey(StringPiece key); |
| |
| // |SetKey| looks up |key| in the underlying dictionary and sets the mapped |
| // value to |value|. If |key| could not be found, a new element is inserted. |
| // A pointer to the modified item is returned. |
| // Note: This requires that type() is Type::DICTIONARY. |
| // Note: Prefer Set<Type>Key() for simple values. |
| // |
| // Example: |
| // SetKey("foo", std::move(myvalue)); |
| Value* SetKey(StringPiece key, Value&& value); |
| // This overload results in a performance improvement for std::string&&. |
| Value* SetKey(std::string&& key, Value&& value); |
| // This overload is necessary to avoid ambiguity for const char* arguments. |
| Value* SetKey(const char* key, Value&& value); |
| |
| // |Set<Type>Key| looks up |key| in the underlying dictionary and associates |
| // a corresponding Value() constructed from the second parameter. Compared |
| // to SetKey(), this avoids un-necessary temporary Value() creation, as well |
| // ambiguities in the value type. |
| Value* SetBoolKey(StringPiece key, bool val); |
| Value* SetIntKey(StringPiece key, int val); |
| Value* SetDoubleKey(StringPiece key, double val); |
| Value* SetStringKey(StringPiece key, StringPiece val); |
| Value* SetStringKey(StringPiece key, StringPiece16 val); |
| // NOTE: The following two overloads are provided as performance / code |
| // generation optimizations. |
| Value* SetStringKey(StringPiece key, const char* val); |
| Value* SetStringKey(StringPiece key, std::string&& val); |
| |
| // This attempts to remove the value associated with |key|. In case of |
| // failure, e.g. the key does not exist, false is returned and the underlying |
| // dictionary is not changed. In case of success, |key| is deleted from the |
| // dictionary and the method returns true. |
| // Note: This requires that type() is Type::DICTIONARY. |
| // |
| // Example: |
| // bool success = dict.RemoveKey("foo"); |
| bool RemoveKey(StringPiece key); |
| |
| // This attempts to extract the value associated with |key|. In case of |
| // failure, e.g. the key does not exist, nullopt is returned and the |
| // underlying dictionary is not changed. In case of success, |key| is deleted |
| // from the dictionary and the method returns the extracted Value. |
| // Note: This requires that type() is Type::DICTIONARY. |
| // |
| // Example: |
| // Optional<Value> maybe_value = dict.ExtractKey("foo"); |
| Optional<Value> ExtractKey(StringPiece key); |
| |
| // Searches a hierarchy of dictionary values for a given value. If a path |
| // of dictionaries exist, returns the item at that path. If any of the path |
| // components do not exist or if any but the last path components are not |
| // dictionaries, returns nullptr. |
| // |
| // The type of the leaf Value is not checked. |
| // |
| // Implementation note: This can't return an iterator because the iterator |
| // will actually be into another Value, so it can't be compared to iterators |
| // from this one (in particular, the DictItems().end() iterator). |
| // |
| // This version takes a StringPiece for the path, using dots as separators. |
| // Example: |
| // auto* found = FindPath("foo.bar"); |
| Value* FindPath(StringPiece path); |
| const Value* FindPath(StringPiece path) const; |
| |
| // There are also deprecated versions that take the path parameter |
| // as either a std::initializer_list<StringPiece> or a |
| // span<const StringPiece>. The latter is useful to use a |
| // std::vector<std::string> as a parameter but creates huge dynamic |
| // allocations and should be avoided! |
| // Note: If there is only one component in the path, use FindKey() instead. |
| // |
| // Example: |
| // std::vector<StringPiece> components = ... |
| // auto* found = FindPath(components); |
| Value* FindPath(std::initializer_list<StringPiece> path); |
| Value* FindPath(span<const StringPiece> path); |
| const Value* FindPath(std::initializer_list<StringPiece> path) const; |
| const Value* FindPath(span<const StringPiece> path) const; |
| |
| // Like FindPath() but will only return the value if the leaf Value type |
| // matches the given type. Will return nullptr otherwise. |
| // Note: Prefer Find<Type>Path() for simple values. |
| // |
| // Note: If there is only one component in the path, use FindKeyOfType() |
| // instead for slightly better performance. |
| Value* FindPathOfType(StringPiece path, Type type); |
| const Value* FindPathOfType(StringPiece path, Type type) const; |
| |
| // Convenience accessors used when the expected type of a value is known. |
| // Similar to Find<Type>Key() but accepts paths instead of keys. |
| base::Optional<bool> FindBoolPath(StringPiece path) const; |
| base::Optional<int> FindIntPath(StringPiece path) const; |
| base::Optional<double> FindDoublePath(StringPiece path) const; |
| const std::string* FindStringPath(StringPiece path) const; |
| std::string* FindStringPath(StringPiece path); |
| const BlobStorage* FindBlobPath(StringPiece path) const; |
| Value* FindDictPath(StringPiece path); |
| const Value* FindDictPath(StringPiece path) const; |
| Value* FindListPath(StringPiece path); |
| const Value* FindListPath(StringPiece path) const; |
| |
| // The following forms are deprecated too, use the ones that take the path |
| // as a single StringPiece instead. |
| Value* FindPathOfType(std::initializer_list<StringPiece> path, Type type); |
| Value* FindPathOfType(span<const StringPiece> path, Type type); |
| const Value* FindPathOfType(std::initializer_list<StringPiece> path, |
| Type type) const; |
| const Value* FindPathOfType(span<const StringPiece> path, Type type) const; |
| |
| // Sets the given path, expanding and creating dictionary keys as necessary. |
| // |
| // If the current value is not a dictionary, the function returns nullptr. If |
| // path components do not exist, they will be created. If any but the last |
| // components matches a value that is not a dictionary, the function will fail |
| // (it will not overwrite the value) and return nullptr. The last path |
| // component will be unconditionally overwritten if it exists, and created if |
| // it doesn't. |
| // |
| // Example: |
| // value.SetPath("foo.bar", std::move(myvalue)); |
| // |
| // Note: If there is only one component in the path, use SetKey() instead. |
| // Note: Using Set<Type>Path() might be more convenient and efficient. |
| Value* SetPath(StringPiece path, Value&& value); |
| |
| // These setters are more convenient and efficient than the corresponding |
| // SetPath(...) call. |
| Value* SetBoolPath(StringPiece path, bool value); |
| Value* SetIntPath(StringPiece path, int value); |
| Value* SetDoublePath(StringPiece path, double value); |
| Value* SetStringPath(StringPiece path, StringPiece value); |
| Value* SetStringPath(StringPiece path, const char* value); |
| Value* SetStringPath(StringPiece path, std::string&& value); |
| Value* SetStringPath(StringPiece path, StringPiece16 value); |
| |
| // Deprecated: use the ones that take a StringPiece path parameter instead. |
| Value* SetPath(std::initializer_list<StringPiece> path, Value&& value); |
| Value* SetPath(span<const StringPiece> path, Value&& value); |
| |
| // Tries to remove a Value at the given path. |
| // |
| // If the current value is not a dictionary or any path component does not |
| // exist, this operation fails, leaves underlying Values untouched and returns |
| // |false|. In case intermediate dictionaries become empty as a result of this |
| // path removal, they will be removed as well. |
| // Note: If there is only one component in the path, use ExtractKey() instead. |
| // |
| // Example: |
| // bool success = value.RemovePath("foo.bar"); |
| bool RemovePath(StringPiece path); |
| |
| // Tries to extract a Value at the given path. |
| // |
| // If the current value is not a dictionary or any path component does not |
| // exist, this operation fails, leaves underlying Values untouched and returns |
| // nullopt. In case intermediate dictionaries become empty as a result of this |
| // path removal, they will be removed as well. Returns the extracted value on |
| // success. |
| // Note: If there is only one component in the path, use ExtractKey() instead. |
| // |
| // Example: |
| // Optional<Value> maybe_value = value.ExtractPath("foo.bar"); |
| Optional<Value> ExtractPath(StringPiece path); |
| |
| using dict_iterator_proxy = detail::dict_iterator_proxy; |
| using const_dict_iterator_proxy = detail::const_dict_iterator_proxy; |
| |
| // |DictItems| returns a proxy object that exposes iterators to the underlying |
| // dictionary. These are intended for iteration over all items in the |
| // dictionary and are compatible with for-each loops and standard library |
| // algorithms. |
| // |
| // Unlike with std::map, a range-for over the non-const version of DictItems() |
| // will range over items of type pair<const std::string&, Value&>, so code of |
| // the form |
| // for (auto kv : my_value.DictItems()) |
| // Mutate(kv.second); |
| // will actually alter |my_value| in place (if it isn't const). |
| // |
| // Note: These CHECK that type() is Type::DICTIONARY. |
| dict_iterator_proxy DictItems(); |
| const_dict_iterator_proxy DictItems() const; |
| |
| // Returns the size of the dictionary, and if the dictionary is empty. |
| // Note: These CHECK that type() is Type::DICTIONARY. |
| size_t DictSize() const; |
| bool DictEmpty() const; |
| |
| // Merge |dictionary| into this value. This is done recursively, i.e. any |
| // sub-dictionaries will be merged as well. In case of key collisions, the |
| // passed in dictionary takes precedence and data already present will be |
| // replaced. Values within |dictionary| are deep-copied, so |dictionary| may |
| // be freed any time after this call. |
| // Note: This requires that type() and dictionary->type() is Type::DICTIONARY. |
| void MergeDictionary(const Value* dictionary); |
| |
| // These methods allow the convenient retrieval of the contents of the Value. |
| // If the current object can be converted into the given type, the value is |
| // returned through the |out_value| parameter and true is returned; |
| // otherwise, false is returned and |out_value| is unchanged. |
| // DEPRECATED, use GetBool() instead. |
| bool GetAsBoolean(bool* out_value) const; |
| // DEPRECATED, use GetInt() instead. |
| bool GetAsInteger(int* out_value) const; |
| // DEPRECATED, use GetDouble() instead. |
| bool GetAsDouble(double* out_value) const; |
| // DEPRECATED, use GetString() instead. |
| bool GetAsString(std::string* out_value) const; |
| bool GetAsString(string16* out_value) const; |
| bool GetAsString(const Value** out_value) const; |
| bool GetAsString(StringPiece* out_value) const; |
| // ListValue::From is the equivalent for std::unique_ptr conversions. |
| // DEPRECATED, use GetList() instead. |
| bool GetAsList(ListValue** out_value); |
| bool GetAsList(const ListValue** out_value) const; |
| // DictionaryValue::From is the equivalent for std::unique_ptr conversions. |
| bool GetAsDictionary(DictionaryValue** out_value); |
| bool GetAsDictionary(const DictionaryValue** out_value) const; |
| // Note: Do not add more types. See the file-level comment above for why. |
| |
| // This creates a deep copy of the entire Value tree, and returns a pointer |
| // to the copy. The caller gets ownership of the copy, of course. |
| // Subclasses return their own type directly in their overrides; |
| // this works because C++ supports covariant return types. |
| // DEPRECATED, use Value::Clone() instead. |
| // TODO(crbug.com/646113): Delete this and migrate callsites. |
| Value* DeepCopy() const; |
| // DEPRECATED, use Value::Clone() instead. |
| // TODO(crbug.com/646113): Delete this and migrate callsites. |
| std::unique_ptr<Value> CreateDeepCopy() const; |
| |
| // Comparison operators so that Values can easily be used with standard |
| // library algorithms and associative containers. |
| BASE_EXPORT friend bool operator==(const Value& lhs, const Value& rhs); |
| BASE_EXPORT friend bool operator!=(const Value& lhs, const Value& rhs); |
| BASE_EXPORT friend bool operator<(const Value& lhs, const Value& rhs); |
| BASE_EXPORT friend bool operator>(const Value& lhs, const Value& rhs); |
| BASE_EXPORT friend bool operator<=(const Value& lhs, const Value& rhs); |
| BASE_EXPORT friend bool operator>=(const Value& lhs, const Value& rhs); |
| |
| // Compares if two Value objects have equal contents. |
| // DEPRECATED, use operator==(const Value& lhs, const Value& rhs) instead. |
| // TODO(crbug.com/646113): Delete this and migrate callsites. |
| bool Equals(const Value* other) const; |
| |
| // Estimates dynamic memory usage. Requires tracing support |
| // (enable_base_tracing gn flag), otherwise always returns 0. See |
| // base/trace_event/memory_usage_estimator.h for more info. |
| size_t EstimateMemoryUsage() const; |
| |
| protected: |
| // Checked convenience accessors for dict and list. |
| const DictStorage& dict() const { return absl::get<DictStorage>(data_); } |
| DictStorage& dict() { return absl::get<DictStorage>(data_); } |
| const ListStorage& list() const { return absl::get<ListStorage>(data_); } |
| ListStorage& list() { return absl::get<ListStorage>(data_); } |
| |
| private: |
| // Special case for doubles, which are aligned to 8 bytes on some |
| // 32-bit architectures. In this case, a simple declaration as a |
| // double member would make the whole union 8 byte-aligned, which |
| // would also force 4 bytes of wasted padding space before it in |
| // the Value layout. |
| // |
| // To override this, store the value as an array of 32-bit integers, and |
| // perform the appropriate bit casts when reading / writing to it. |
| using DoubleStorage = struct { alignas(4) char v[sizeof(double)]; }; |
| |
| // Internal constructors, allowing the simplify the implementation of Clone(). |
| explicit Value(absl::monostate); |
| explicit Value(DoubleStorage storage); |
| |
| friend class ValuesTest_SizeOfValue_Test; |
| double AsDoubleInternal() const; |
| |
| // NOTE: Using a movable reference here is done for performance (it avoids |
| // creating + moving + destroying a temporary unique ptr). |
| Value* SetKeyInternal(StringPiece key, std::unique_ptr<Value>&& val_ptr); |
| Value* SetPathInternal(StringPiece path, std::unique_ptr<Value>&& value_ptr); |
| |
| absl::variant<absl::monostate, |
| bool, |
| int, |
| DoubleStorage, |
| std::string, |
| BlobStorage, |
| DictStorage, |
| ListStorage> |
| data_; |
| }; |
| |
| // DictionaryValue provides a key-value dictionary with (optional) "path" |
| // parsing for recursive access; see the comment at the top of the file. Keys |
| // are |std::string|s and should be UTF-8 encoded. |
| class BASE_EXPORT DictionaryValue : public Value { |
| public: |
| using const_iterator = DictStorage::const_iterator; |
| using iterator = DictStorage::iterator; |
| |
| // Returns |value| if it is a dictionary, nullptr otherwise. |
| static std::unique_ptr<DictionaryValue> From(std::unique_ptr<Value> value); |
| |
| DictionaryValue(); |
| explicit DictionaryValue(const DictStorage& in_dict); |
| explicit DictionaryValue(DictStorage&& in_dict) noexcept; |
| |
| // Returns true if the current dictionary has a value for the given key. |
| // DEPRECATED, use Value::FindKey(key) instead. |
| bool HasKey(StringPiece key) const; |
| |
| // Returns the number of Values in this dictionary. |
| size_t size() const { return dict().size(); } |
| |
| // Returns whether the dictionary is empty. |
| bool empty() const { return dict().empty(); } |
| |
| // Clears any current contents of this dictionary. |
| void Clear(); |
| |
| // Sets the Value associated with the given path starting from this object. |
| // A path has the form "<key>" or "<key>.<key>.[...]", where "." indexes |
| // into the next DictionaryValue down. Obviously, "." can't be used |
| // within a key, but there are no other restrictions on keys. |
| // If the key at any step of the way doesn't exist, or exists but isn't |
| // a DictionaryValue, a new DictionaryValue will be created and attached |
| // to the path in that location. |in_value| must be non-null. |
| // Returns a pointer to the inserted value. |
| // DEPRECATED, use Value::SetPath(path, value) instead. |
| Value* Set(StringPiece path, std::unique_ptr<Value> in_value); |
| |
| // Convenience forms of Set(). These methods will replace any existing |
| // value at that path, even if it has a different type. |
| // DEPRECATED, use Value::SetBoolKey() or Value::SetBoolPath(). |
| Value* SetBoolean(StringPiece path, bool in_value); |
| // DEPRECATED, use Value::SetIntPath(). |
| Value* SetInteger(StringPiece path, int in_value); |
| // DEPRECATED, use Value::SetDoublePath(). |
| Value* SetDouble(StringPiece path, double in_value); |
| // DEPRECATED, use Value::SetStringPath(). |
| Value* SetString(StringPiece path, StringPiece in_value); |
| // DEPRECATED, use Value::SetStringPath(). |
| Value* SetString(StringPiece path, const string16& in_value); |
| // DEPRECATED, use Value::SetPath(). |
| DictionaryValue* SetDictionary(StringPiece path, |
| std::unique_ptr<DictionaryValue> in_value); |
| // DEPRECATED, use Value::SetPath(). |
| ListValue* SetList(StringPiece path, std::unique_ptr<ListValue> in_value); |
| |
| // Like Set(), but without special treatment of '.'. This allows e.g. URLs to |
| // be used as paths. |
| // DEPRECATED, use Value::SetKey(key, value) instead. |
| Value* SetWithoutPathExpansion(StringPiece key, |
| std::unique_ptr<Value> in_value); |
| |
| // Gets the Value associated with the given path starting from this object. |
| // A path has the form "<key>" or "<key>.<key>.[...]", where "." indexes |
| // into the next DictionaryValue down. If the path can be resolved |
| // successfully, the value for the last key in the path will be returned |
| // through the |out_value| parameter, and the function will return true. |
| // Otherwise, it will return false and |out_value| will be untouched. |
| // Note that the dictionary always owns the value that's returned. |
| // |out_value| is optional and will only be set if non-NULL. |
| // DEPRECATED, use Value::FindPath(path) instead. |
| bool Get(StringPiece path, const Value** out_value) const; |
| // DEPRECATED, use Value::FindPath(path) instead. |
| bool Get(StringPiece path, Value** out_value); |
| |
| // These are convenience forms of Get(). The value will be retrieved |
| // and the return value will be true if the path is valid and the value at |
| // the end of the path can be returned in the form specified. |
| // |out_value| is optional and will only be set if non-NULL. |
| // DEPRECATED, use Value::FindBoolPath(path) instead. |
| bool GetBoolean(StringPiece path, bool* out_value) const; |
| // DEPRECATED, use Value::FindIntPath(path) instead. |
| bool GetInteger(StringPiece path, int* out_value) const; |
| // Values of both type Type::INTEGER and Type::DOUBLE can be obtained as |
| // doubles. |
| // DEPRECATED, use Value::FindDoublePath(path). |
| bool GetDouble(StringPiece path, double* out_value) const; |
| // DEPRECATED, use Value::FindStringPath(path) instead. |
| bool GetString(StringPiece path, std::string* out_value) const; |
| // DEPRECATED, use Value::FindStringPath(path) instead. |
| bool GetString(StringPiece path, string16* out_value) const; |
| // DEPRECATED, use Value::FindString(path) and IsAsciiString() instead. |
| bool GetStringASCII(StringPiece path, std::string* out_value) const; |
| // DEPRECATED, use Value::FindBlobPath(path) instead. |
| bool GetBinary(StringPiece path, const Value** out_value) const; |
| // DEPRECATED, use Value::FindBlobPath(path) instead. |
| bool GetBinary(StringPiece path, Value** out_value); |
| // DEPRECATED, use Value::FindPath(path) and Value's Dictionary API instead. |
| bool GetDictionary(StringPiece path, const DictionaryValue** out_value) const; |
| // DEPRECATED, use Value::FindPath(path) and Value's Dictionary API instead. |
| bool GetDictionary(StringPiece path, DictionaryValue** out_value); |
| // DEPRECATED, use Value::FindPath(path) and Value::GetList() instead. |
| bool GetList(StringPiece path, const ListValue** out_value) const; |
| // DEPRECATED, use Value::FindPath(path) and Value::GetList() instead. |
| bool GetList(StringPiece path, ListValue** out_value); |
| |
| // Like Get(), but without special treatment of '.'. This allows e.g. URLs to |
| // be used as paths. |
| // DEPRECATED, use Value::FindKey(key) instead. |
| bool GetWithoutPathExpansion(StringPiece key, const Value** out_value) const; |
| // DEPRECATED, use Value::FindKey(key) instead. |
| bool GetWithoutPathExpansion(StringPiece key, Value** out_value); |
| // DEPRECATED, use Value::FindBoolKey(key) instead. |
| bool GetBooleanWithoutPathExpansion(StringPiece key, bool* out_value) const; |
| // DEPRECATED, use Value::FindIntKey(key) instead. |
| bool GetIntegerWithoutPathExpansion(StringPiece key, int* out_value) const; |
| // DEPRECATED, use Value::FindDoubleKey(key) instead. |
| bool GetDoubleWithoutPathExpansion(StringPiece key, double* out_value) const; |
| // DEPRECATED, use Value::FindStringKey(key) instead. |
| bool GetStringWithoutPathExpansion(StringPiece key, |
| std::string* out_value) const; |
| // DEPRECATED, use Value::FindStringKey(key) and UTF8ToUTF16() instead. |
| bool GetStringWithoutPathExpansion(StringPiece key, |
| string16* out_value) const; |
| // DEPRECATED, use Value::FindDictKey(key) instead. |
| bool GetDictionaryWithoutPathExpansion( |
| StringPiece key, |
| const DictionaryValue** out_value) const; |
| // DEPRECATED, use Value::FindDictKey(key) instead. |
| bool GetDictionaryWithoutPathExpansion(StringPiece key, |
| DictionaryValue** out_value); |
| // DEPRECATED, use Value::FindListKey(key) instead. |
| bool GetListWithoutPathExpansion(StringPiece key, |
| const ListValue** out_value) const; |
| // DEPRECATED, use Value::FindListKey(key) instead. |
| bool GetListWithoutPathExpansion(StringPiece key, ListValue** out_value); |
| |
| // Removes the Value with the specified path from this dictionary (or one |
| // of its child dictionaries, if the path is more than just a local key). |
| // If |out_value| is non-NULL, the removed Value will be passed out via |
| // |out_value|. If |out_value| is NULL, the removed value will be deleted. |
| // This method returns true if |path| is a valid path; otherwise it will |
| // return false and the DictionaryValue object will be unchanged. |
| // DEPRECATED, use Value::RemovePath(path) or Value::ExtractPath(path) |
| // instead. |
| bool Remove(StringPiece path, std::unique_ptr<Value>* out_value); |
| |
| // Like Remove(), but without special treatment of '.'. This allows e.g. URLs |
| // to be used as paths. |
| // DEPRECATED, use Value::RemoveKey(key) or Value::ExtractKey(key) instead. |
| bool RemoveWithoutPathExpansion(StringPiece key, |
| std::unique_ptr<Value>* out_value); |
| |
| // Removes a path, clearing out all dictionaries on |path| that remain empty |
| // after removing the value at |path|. |
| // DEPRECATED, use Value::RemovePath(path) or Value::ExtractPath(path) |
| // instead. |
| bool RemovePath(StringPiece path, std::unique_ptr<Value>* out_value); |
| |
| using Value::RemovePath; // DictionaryValue::RemovePath shadows otherwise. |
| |
| // Makes a copy of |this| but doesn't include empty dictionaries and lists in |
| // the copy. This never returns NULL, even if |this| itself is empty. |
| std::unique_ptr<DictionaryValue> DeepCopyWithoutEmptyChildren() const; |
| |
| // Swaps contents with the |other| dictionary. |
| void Swap(DictionaryValue* other); |
| |
| // This class provides an iterator over both keys and values in the |
| // dictionary. It can't be used to modify the dictionary. |
| // DEPRECATED, use Value::DictItems() instead. |
| class BASE_EXPORT Iterator { |
| public: |
| explicit Iterator(const DictionaryValue& target); |
| Iterator(const Iterator& other); |
| ~Iterator(); |
| |
| bool IsAtEnd() const { return it_ == target_.end(); } |
| void Advance() { ++it_; } |
| |
| const std::string& key() const { return it_->first; } |
| const Value& value() const { return *it_->second; } |
| |
| private: |
| const DictionaryValue& target_; |
| DictStorage::const_iterator it_; |
| }; |
| |
| // Iteration. |
| // DEPRECATED, use Value::DictItems() instead. |
| iterator begin() { return dict().begin(); } |
| iterator end() { return dict().end(); } |
| |
| // DEPRECATED, use Value::DictItems() instead. |
| const_iterator begin() const { return dict().begin(); } |
| const_iterator end() const { return dict().end(); } |
| |
| // DEPRECATED, use Value::Clone() instead. |
| // TODO(crbug.com/646113): Delete this and migrate callsites. |
| DictionaryValue* DeepCopy() const; |
| // DEPRECATED, use Value::Clone() instead. |
| // TODO(crbug.com/646113): Delete this and migrate callsites. |
| std::unique_ptr<DictionaryValue> CreateDeepCopy() const; |
| }; |
| |
| // This type of Value represents a list of other Value values. |
| class BASE_EXPORT ListValue : public Value { |
| public: |
| using const_iterator = ListView::const_iterator; |
| using iterator = ListView::iterator; |
| |
| // Returns |value| if it is a list, nullptr otherwise. |
| static std::unique_ptr<ListValue> From(std::unique_ptr<Value> value); |
| |
| ListValue(); |
| explicit ListValue(span<const Value> in_list); |
| explicit ListValue(ListStorage&& in_list) noexcept; |
| |
| // Clears the contents of this ListValue |
| // DEPRECATED, use ClearList() instead. |
| void Clear(); |
| |
| // Returns the number of Values in this list. |
| // DEPRECATED, use GetList()::size() instead. |
| size_t GetSize() const { return list().size(); } |
| |
| // Returns whether the list is empty. |
| // DEPRECATED, use GetList()::empty() instead. |
| bool empty() const { return list().empty(); } |
| |
| // Sets the list item at the given index to be the Value specified by |
| // the value given. If the index beyond the current end of the list, null |
| // Values will be used to pad out the list. |
| // Returns true if successful, or false if the index was negative or |
| // the value is a null pointer. |
| // DEPRECATED, use GetList()::operator[] instead. |
| bool Set(size_t index, std::unique_ptr<Value> in_value); |
| |
| // Gets the Value at the given index. Modifies |out_value| (and returns true) |
| // only if the index falls within the current list range. |
| // Note that the list always owns the Value passed out via |out_value|. |
| // |out_value| is optional and will only be set if non-NULL. |
| // DEPRECATED, use GetList()::operator[] instead. |
| bool Get(size_t index, const Value** out_value) const; |
| bool Get(size_t index, Value** out_value); |
| |
| // Convenience forms of Get(). Modifies |out_value| (and returns true) |
| // only if the index is valid and the Value at that index can be returned |
| // in the specified form. |
| // |out_value| is optional and will only be set if non-NULL. |
| // DEPRECATED, use GetList()::operator[]::GetBool() instead. |
| bool GetBoolean(size_t index, bool* out_value) const; |
| // DEPRECATED, use GetList()::operator[]::GetInt() instead. |
| bool GetInteger(size_t index, int* out_value) const; |
| // Values of both type Type::INTEGER and Type::DOUBLE can be obtained as |
| // doubles. |
| // DEPRECATED, use GetList()::operator[]::GetDouble() instead. |
| bool GetDouble(size_t index, double* out_value) const; |
| // DEPRECATED, use GetList()::operator[]::GetString() instead. |
| bool GetString(size_t index, std::string* out_value) const; |
| bool GetString(size_t index, string16* out_value) const; |
| |
| bool GetDictionary(size_t index, const DictionaryValue** out_value) const; |
| bool GetDictionary(size_t index, DictionaryValue** out_value); |
| |
| using Value::GetList; |
| // DEPRECATED, use GetList()::operator[]::GetList() instead. |
| bool GetList(size_t index, const ListValue** out_value) const; |
| bool GetList(size_t index, ListValue** out_value); |
| |
| // Removes the Value with the specified index from this list. |
| // If |out_value| is non-NULL, the removed Value AND ITS OWNERSHIP will be |
| // passed out via |out_value|. If |out_value| is NULL, the removed value will |
| // be deleted. This method returns true if |index| is valid; otherwise |
| // it will return false and the ListValue object will be unchanged. |
| // DEPRECATED, use GetList()::erase() instead. |
| bool Remove(size_t index, std::unique_ptr<Value>* out_value); |
| |
| // Removes the first instance of |value| found in the list, if any, and |
| // deletes it. |index| is the location where |value| was found. Returns false |
| // if not found. |
| // DEPRECATED, use GetList()::erase() instead. |
| bool Remove(const Value& value, size_t* index); |
| |
| // Removes the element at |iter|. If |out_value| is NULL, the value will be |
| // deleted, otherwise ownership of the value is passed back to the caller. |
| // Returns an iterator pointing to the location of the element that |
| // followed the erased element. |
| // DEPRECATED, use GetList()::erase() instead. |
| iterator Erase(iterator iter, std::unique_ptr<Value>* out_value); |
| |
| using Value::Append; |
| // Appends a Value to the end of the list. |
| // DEPRECATED, use Value::Append() instead. |
| void Append(std::unique_ptr<Value> in_value); |
| |
| // Convenience forms of Append. |
| // DEPRECATED, use Value::Append() instead. |
| void AppendBoolean(bool in_value); |
| void AppendInteger(int in_value); |
| void AppendDouble(double in_value); |
| void AppendString(StringPiece in_value); |
| void AppendString(const string16& in_value); |
| // DEPRECATED, use Value::Append() in a loop instead. |
| void AppendStrings(const std::vector<std::string>& in_values); |
| |
| // Appends a Value if it's not already present. Returns true if successful, |
| // or false if the value was already |
| // DEPRECATED, use std::find() with Value::Append() instead. |
| bool AppendIfNotPresent(std::unique_ptr<Value> in_value); |
| |
| using Value::Insert; |
| // Insert a Value at index. |
| // Returns true if successful, or false if the index was out of range. |
| // DEPRECATED, use Value::Insert() instead. |
| bool Insert(size_t index, std::unique_ptr<Value> in_value); |
| |
| // Searches for the first instance of |value| in the list using the Equals |
| // method of the Value type. |
| // Returns a const_iterator to the found item or to end() if none exists. |
| // DEPRECATED, use std::find() instead. |
| const_iterator Find(const Value& value) const; |
| |
| // Swaps contents with the |other| list. |
| // DEPRECATED, use GetList()::swap() instead. |
| void Swap(ListValue* other); |
| |
| // Iteration. |
| // DEPRECATED, use GetList()::begin() instead. |
| iterator begin() { return GetList().begin(); } |
| // DEPRECATED, use GetList()::end() instead. |
| iterator end() { return GetList().end(); } |
| |
| // DEPRECATED, use GetList()::begin() instead. |
| const_iterator begin() const { return GetList().begin(); } |
| // DEPRECATED, use GetList()::end() instead. |
| const_iterator end() const { return GetList().end(); } |
| |
| // DEPRECATED, use Value::Clone() instead. |
| // TODO(crbug.com/646113): Delete this and migrate callsites. |
| ListValue* DeepCopy() const; |
| // DEPRECATED, use Value::Clone() instead. |
| // TODO(crbug.com/646113): Delete this and migrate callsites. |
| std::unique_ptr<ListValue> CreateDeepCopy() const; |
| }; |
| |
| // This interface is implemented by classes that know how to serialize |
| // Value objects. |
| class BASE_EXPORT ValueSerializer { |
| public: |
| virtual ~ValueSerializer(); |
| |
| virtual bool Serialize(const Value& root) = 0; |
| }; |
| |
| // This interface is implemented by classes that know how to deserialize Value |
| // objects. |
| class BASE_EXPORT ValueDeserializer { |
| public: |
| virtual ~ValueDeserializer(); |
| |
| // This method deserializes the subclass-specific format into a Value object. |
| // If the return value is non-NULL, the caller takes ownership of returned |
| // Value. |
| // |
| // If the return value is nullptr, and if |error_code| is non-nullptr, |
| // |*error_code| will be set to an integer value representing the underlying |
| // error. See "enum ErrorCode" below for more detail about the integer value. |
| // |
| // If |error_message| is non-nullptr, it will be filled in with a formatted |
| // error message including the location of the error if appropriate. |
| virtual std::unique_ptr<Value> Deserialize(int* error_code, |
| std::string* error_message) = 0; |
| |
| // The integer-valued error codes form four groups: |
| // - The value 0 means no error. |
| // - Values between 1 and 999 inclusive mean an error in the data (i.e. |
| // content). The bytes being deserialized are not in the right format. |
| // - Values 1000 and above mean an error in the metadata (i.e. context). The |
| // file could not be read, the network is down, etc. |
| // - Negative values are reserved. |
| enum ErrorCode { |
| kErrorCodeNoError = 0, |
| // kErrorCodeInvalidFormat is a generic error code for "the data is not in |
| // the right format". Subclasses of ValueDeserializer may return other |
| // values for more specific errors. |
| kErrorCodeInvalidFormat = 1, |
| // kErrorCodeFirstMetadataError is the minimum value (inclusive) of the |
| // range of metadata errors. |
| kErrorCodeFirstMetadataError = 1000, |
| }; |
| |
| // The |error_code| argument can be one of the ErrorCode values, but it is |
| // not restricted to only being 0, 1 or 1000. Subclasses of ValueDeserializer |
| // can define their own error code values. |
| static inline bool ErrorCodeIsDataError(int error_code) { |
| return (kErrorCodeInvalidFormat <= error_code) && |
| (error_code < kErrorCodeFirstMetadataError); |
| } |
| }; |
| |
| // Stream operator so Values can be used in assertion statements. In order that |
| // gtest uses this operator to print readable output on test failures, we must |
| // override each specific type. Otherwise, the default template implementation |
| // is preferred over an upcast. |
| BASE_EXPORT std::ostream& operator<<(std::ostream& out, const Value& value); |
| |
| BASE_EXPORT inline std::ostream& operator<<(std::ostream& out, |
| const DictionaryValue& value) { |
| return out << static_cast<const Value&>(value); |
| } |
| |
| BASE_EXPORT inline std::ostream& operator<<(std::ostream& out, |
| const ListValue& value) { |
| return out << static_cast<const Value&>(value); |
| } |
| |
| // Stream operator so that enum class Types can be used in log statements. |
| BASE_EXPORT std::ostream& operator<<(std::ostream& out, |
| const Value::Type& type); |
| |
| } // namespace base |
| |
| #endif // BASE_VALUES_H_ |