base/values.cc

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/values.h"

#include <cmath>
#include <ostream>
#include <tuple>
#include <utility>

#include "base/bit_cast.h"
#include "base/check.h"
#include "base/check_op.h"
#include "base/containers/checked_iterators.h"
#include "base/containers/cxx20_erase_vector.h"
#include "base/cxx17_backports.h"
#include "base/cxx20_to_address.h"
#include "base/json/json_writer.h"
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/notreached.h"
#include "base/ranges/algorithm.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/trace_event/base_tracing.h"
#include "base/tracing_buildflags.h"
#include "third_party/abseil-cpp/absl/types/optional.h"
#include "third_party/abseil-cpp/absl/types/variant.h"

#if BUILDFLAG(ENABLE_BASE_TRACING)
#include "base/trace_event/memory_usage_estimator.h"  // no-presubmit-check
#endif  // BUILDFLAG(ENABLE_BASE_TRACING)

namespace base {

namespace {

const char* const kTypeNames[] = {"null",   "boolean", "integer",    "double",
                                  "string", "binary",  "dictionary", "list"};
static_assert(std::size(kTypeNames) ==
                  static_cast<size_t>(Value::Type::LIST) + 1,
              "kTypeNames Has Wrong Size");

// Helper class to enumerate the path components from a StringPiece
// without performing heap allocations. Components are simply separated
// by single dots (e.g. "foo.bar.baz"  -> ["foo", "bar", "baz"]).
//
// Usage example:
//    PathSplitter splitter(some_path);
//    while (splitter.HasNext()) {
//       StringPiece component = splitter.Next();
//       ...
//    }
//
class PathSplitter {
 public:
  explicit PathSplitter(StringPiece path) : path_(path) {}

  bool HasNext() const { return pos_ < path_.size(); }

  StringPiece Next() {
    DCHECK(HasNext());
    size_t start = pos_;
    size_t pos = path_.find('.', start);
    size_t end;
    if (pos == path_.npos) {
      end = path_.size();
      pos_ = end;
    } else {
      end = pos;
      pos_ = pos + 1;
    }
    return path_.substr(start, end - start);
  }

 private:
  StringPiece path_;
  size_t pos_ = 0;
};

std::string DebugStringImpl(ValueView value) {
  std::string json;
  JSONWriter::WriteWithOptions(value, JSONWriter::OPTIONS_PRETTY_PRINT, &json);
  return json;
}

}  // namespace

// A helper used to provide templated functions for cloning to Value, and
// ValueView. This private class is used so the cloning method may have access
// to the special private constructors in Value, created specifically for
// cloning.
class Value::CloningHelper {
 public:
  // This set of overloads are used to unwrap the reference wrappers, which are
  // presented when cloning a ValueView.
  template <typename T>
  static const T& UnwrapReference(std::reference_wrapper<const T> value) {
    return value.get();
  }

  template <typename T>
  static const T& UnwrapReference(const T& value) {
    return value;
  }

  // Returns a new Value object using the contents of the |storage| variant.
  template <typename Storage>
  static Value Clone(const Storage& storage) {
    return absl::visit(
        [](const auto& member) {
          const auto& value = UnwrapReference(member);
          using T = std::decay_t<decltype(value)>;
          if constexpr (std::is_same_v<T, Value::Dict> ||
                        std::is_same_v<T, Value::List>) {
            return Value(value.Clone());
          } else {
            return Value(value);
          }
        },
        storage);
  }
};

// static
Value Value::FromUniquePtrValue(std::unique_ptr<Value> val) {
  return std::move(*val);
}

// static
std::unique_ptr<Value> Value::ToUniquePtrValue(Value val) {
  return std::make_unique<Value>(std::move(val));
}

Value::Value() noexcept = default;

Value::Value(Value&&) noexcept = default;

Value& Value::operator=(Value&&) noexcept = default;

Value::Value(Type type) {
  // Initialize with the default value.
  switch (type) {
    case Type::NONE:
      return;

    case Type::BOOLEAN:
      data_.emplace<bool>(false);
      return;
    case Type::INTEGER:
      data_.emplace<int>(0);
      return;
    case Type::DOUBLE:
      data_.emplace<DoubleStorage>(0.0);
      return;
    case Type::STRING:
      data_.emplace<std::string>();
      return;
    case Type::BINARY:
      data_.emplace<BlobStorage>();
      return;
    case Type::DICT:
      data_.emplace<Dict>();
      return;
    case Type::LIST:
      data_.emplace<List>();
      return;
  }

  CHECK(false);
}

Value::Value(bool value) : data_(value) {}

Value::Value(int value) : data_(value) {}

Value::Value(double value)
    : data_(absl::in_place_type_t<DoubleStorage>(), value) {}

Value::Value(StringPiece value) : Value(std::string(value)) {}

Value::Value(StringPiece16 value) : Value(UTF16ToUTF8(value)) {}

Value::Value(const char* value) : Value(std::string(value)) {}

Value::Value(const char16_t* value) : Value(UTF16ToUTF8(value)) {}

Value::Value(std::string&& value) noexcept : data_(std::move(value)) {
  DCHECK(IsStringUTF8AllowingNoncharacters(GetString()));
}

Value::Value(const std::vector<char>& value)
    : data_(absl::in_place_type_t<BlobStorage>(), value.begin(), value.end()) {}

Value::Value(base::span<const uint8_t> value)
    : data_(absl::in_place_type_t<BlobStorage>(), value.size()) {
  // This is 100x faster than using the "range" constructor for a 512k blob:
  // crbug.com/1343636
  ranges::copy(value, absl::get<BlobStorage>(data_).data());
}

Value::Value(BlobStorage&& value) noexcept : data_(std::move(value)) {}

Value::Value(Dict&& value) noexcept : data_(std::move(value)) {}

Value::Value(List&& value) noexcept : data_(std::move(value)) {}

Value::Value(absl::monostate) {}

Value::Value(DoubleStorage storage) : data_(std::move(storage)) {}

Value::DoubleStorage::DoubleStorage(double v) : v_(bit_cast<decltype(v_)>(v)) {
  if (!std::isfinite(v)) {
    NOTREACHED() << "Non-finite (i.e. NaN or positive/negative infinity) "
                 << "values cannot be represented in JSON";
    v_ = bit_cast<decltype(v_)>(0.0);
  }
}

Value Value::Clone() const {
  return CloningHelper::Clone(data_);
}

Value::~Value() = default;

// static
const char* Value::GetTypeName(Value::Type type) {
  DCHECK_GE(static_cast<int>(type), 0);
  DCHECK_LT(static_cast<size_t>(type), std::size(kTypeNames));
  return kTypeNames[static_cast<size_t>(type)];
}

absl::optional<bool> Value::GetIfBool() const {
  return is_bool() ? absl::make_optional(GetBool()) : absl::nullopt;
}

absl::optional<int> Value::GetIfInt() const {
  return is_int() ? absl::make_optional(GetInt()) : absl::nullopt;
}

absl::optional<double> Value::GetIfDouble() const {
  return (is_int() || is_double()) ? absl::make_optional(GetDouble())
                                   : absl::nullopt;
}

const std::string* Value::GetIfString() const {
  return absl::get_if<std::string>(&data_);
}

std::string* Value::GetIfString() {
  return absl::get_if<std::string>(&data_);
}

const Value::BlobStorage* Value::GetIfBlob() const {
  return absl::get_if<BlobStorage>(&data_);
}

const Value::Dict* Value::GetIfDict() const {
  return absl::get_if<Dict>(&data_);
}

Value::Dict* Value::GetIfDict() {
  return absl::get_if<Dict>(&data_);
}

const Value::List* Value::GetIfList() const {
  return absl::get_if<List>(&data_);
}

Value::List* Value::GetIfList() {
  return absl::get_if<List>(&data_);
}

bool Value::GetBool() const {
  DCHECK(is_bool());
  return absl::get<bool>(data_);
}

int Value::GetInt() const {
  DCHECK(is_int());
  return absl::get<int>(data_);
}

double Value::GetDouble() const {
  if (is_double()) {
    return absl::get<DoubleStorage>(data_);
  }
  if (is_int()) {
    return GetInt();
  }
  CHECK(false);
  return 0.0;
}

const std::string& Value::GetString() const {
  DCHECK(is_string());
  return absl::get<std::string>(data_);
}

std::string& Value::GetString() {
  DCHECK(is_string());
  return absl::get<std::string>(data_);
}

const Value::BlobStorage& Value::GetBlob() const {
  DCHECK(is_blob());
  return absl::get<BlobStorage>(data_);
}

const Value::Dict& Value::GetDict() const {
  DCHECK(is_dict());
  return absl::get<Dict>(data_);
}

Value::Dict& Value::GetDict() {
  DCHECK(is_dict());
  return absl::get<Dict>(data_);
}

const Value::List& Value::GetList() const {
  DCHECK(is_list());
  return absl::get<List>(data_);
}

Value::List& Value::GetList() {
  DCHECK(is_list());
  return absl::get<List>(data_);
}

std::string Value::TakeString() && {
  return std::move(GetString());
}

Value::Dict Value::TakeDict() && {
  return std::move(GetDict());
}

Value::List Value::TakeList() && {
  return std::move(GetList());
}

Value::Dict::Dict() = default;

Value::Dict::Dict(Dict&&) noexcept = default;

Value::Dict& Value::Dict::operator=(Dict&&) noexcept = default;

Value::Dict::~Dict() = default;

bool Value::Dict::empty() const {
  return storage_.empty();
}

size_t Value::Dict::size() const {
  return storage_.size();
}

Value::Dict::iterator Value::Dict::begin() {
  return iterator(storage_.begin());
}

Value::Dict::const_iterator Value::Dict::begin() const {
  return const_iterator(storage_.begin());
}

Value::Dict::const_iterator Value::Dict::cbegin() const {
  return const_iterator(storage_.cbegin());
}

Value::Dict::iterator Value::Dict::end() {
  return iterator(storage_.end());
}

Value::Dict::const_iterator Value::Dict::end() const {
  return const_iterator(storage_.end());
}

Value::Dict::const_iterator Value::Dict::cend() const {
  return const_iterator(storage_.cend());
}

bool Value::Dict::contains(base::StringPiece key) const {
  DCHECK(IsStringUTF8AllowingNoncharacters(key));

  return storage_.contains(key);
}

void Value::Dict::clear() {
  return storage_.clear();
}

Value::Dict::iterator Value::Dict::erase(iterator pos) {
  return iterator(storage_.erase(pos.GetUnderlyingIteratorDoNotUse()));
}

Value::Dict::iterator Value::Dict::erase(const_iterator pos) {
  return iterator(storage_.erase(pos.GetUnderlyingIteratorDoNotUse()));
}

Value::Dict Value::Dict::Clone() const {
  return Dict(storage_);
}

void Value::Dict::Merge(Dict dict) {
  for (const auto [key, value] : dict) {
    if (Dict* nested_dict = value.GetIfDict()) {
      if (Dict* current_dict = FindDict(key)) {
        // If `key` is a nested dictionary in this dictionary and the dictionary
        // being merged, recursively merge the two dictionaries.
        current_dict->Merge(std::move(*nested_dict));
        continue;
      }
    }

    // Otherwise, unconditionally set the value, overwriting any value that may
    // already be associated with the key.
    Set(key, std::move(value));
  }
}

const Value* Value::Dict::Find(StringPiece key) const {
  DCHECK(IsStringUTF8AllowingNoncharacters(key));

  auto it = storage_.find(key);
  return it != storage_.end() ? it->second.get() : nullptr;
}

Value* Value::Dict::Find(StringPiece key) {
  auto it = storage_.find(key);
  return it != storage_.end() ? it->second.get() : nullptr;
}

absl::optional<bool> Value::Dict::FindBool(StringPiece key) const {
  const Value* v = Find(key);
  return v ? v->GetIfBool() : absl::nullopt;
}

absl::optional<int> Value::Dict::FindInt(StringPiece key) const {
  const Value* v = Find(key);
  return v ? v->GetIfInt() : absl::nullopt;
}

absl::optional<double> Value::Dict::FindDouble(StringPiece key) const {
  const Value* v = Find(key);
  return v ? v->GetIfDouble() : absl::nullopt;
}

const std::string* Value::Dict::FindString(StringPiece key) const {
  const Value* v = Find(key);
  return v ? v->GetIfString() : nullptr;
}

std::string* Value::Dict::FindString(StringPiece key) {
  Value* v = Find(key);
  return v ? v->GetIfString() : nullptr;
}

const Value::BlobStorage* Value::Dict::FindBlob(StringPiece key) const {
  const Value* v = Find(key);
  return v ? v->GetIfBlob() : nullptr;
}

const Value::Dict* Value::Dict::FindDict(StringPiece key) const {
  const Value* v = Find(key);
  return v ? v->GetIfDict() : nullptr;
}

Value::Dict* Value::Dict::FindDict(StringPiece key) {
  Value* v = Find(key);
  return v ? v->GetIfDict() : nullptr;
}

const Value::List* Value::Dict::FindList(StringPiece key) const {
  const Value* v = Find(key);
  return v ? v->GetIfList() : nullptr;
}

Value::List* Value::Dict::FindList(StringPiece key) {
  Value* v = Find(key);
  return v ? v->GetIfList() : nullptr;
}

Value::Dict* Value::Dict::EnsureDict(StringPiece key) {
  Value::Dict* dict = FindDict(key);
  if (dict) {
    return dict;
  }
  return &Set(key, base::Value::Dict())->GetDict();
}

Value::List* Value::Dict::EnsureList(StringPiece key) {
  Value::List* list = FindList(key);
  if (list) {
    return list;
  }
  return &Set(key, base::Value::List())->GetList();
}

Value* Value::Dict::Set(StringPiece key, Value&& value) & {
  DCHECK(IsStringUTF8AllowingNoncharacters(key));

  auto wrapped_value = std::make_unique<Value>(std::move(value));
  auto* raw_value = wrapped_value.get();
  storage_.insert_or_assign(key, std::move(wrapped_value));
  return raw_value;
}

Value* Value::Dict::Set(StringPiece key, bool value) & {
  return Set(key, Value(value));
}

Value* Value::Dict::Set(StringPiece key, int value) & {
  return Set(key, Value(value));
}

Value* Value::Dict::Set(StringPiece key, double value) & {
  return Set(key, Value(value));
}

Value* Value::Dict::Set(StringPiece key, StringPiece value) & {
  return Set(key, Value(value));
}

Value* Value::Dict::Set(StringPiece key, StringPiece16 value) & {
  return Set(key, Value(value));
}

Value* Value::Dict::Set(StringPiece key, const char* value) & {
  return Set(key, Value(value));
}

Value* Value::Dict::Set(StringPiece key, const char16_t* value) & {
  return Set(key, Value(value));
}

Value* Value::Dict::Set(StringPiece key, std::string&& value) & {
  return Set(key, Value(std::move(value)));
}

Value* Value::Dict::Set(StringPiece key, BlobStorage&& value) & {
  return Set(key, Value(std::move(value)));
}

Value* Value::Dict::Set(StringPiece key, Dict&& value) & {
  return Set(key, Value(std::move(value)));
}

Value* Value::Dict::Set(StringPiece key, List&& value) & {
  return Set(key, Value(std::move(value)));
}

Value::Dict&& Value::Dict::Set(StringPiece key, Value&& value) && {
  DCHECK(IsStringUTF8AllowingNoncharacters(key));
  storage_.insert_or_assign(key, std::make_unique<Value>(std::move(value)));
  return std::move(*this);
}

Value::Dict&& Value::Dict::Set(StringPiece key, bool value) && {
  return std::move(*this).Set(key, Value(value));
}

Value::Dict&& Value::Dict::Set(StringPiece key, int value) && {
  return std::move(*this).Set(key, Value(value));
}

Value::Dict&& Value::Dict::Set(StringPiece key, double value) && {
  return std::move(*this).Set(key, Value(value));
}

Value::Dict&& Value::Dict::Set(StringPiece key, StringPiece value) && {
  return std::move(*this).Set(key, Value(value));
}

Value::Dict&& Value::Dict::Set(StringPiece key, StringPiece16 value) && {
  return std::move(*this).Set(key, Value(value));
}

Value::Dict&& Value::Dict::Set(StringPiece key, const char* value) && {
  return std::move(*this).Set(key, Value(value));
}

Value::Dict&& Value::Dict::Set(StringPiece key, const char16_t* value) && {
  return std::move(*this).Set(key, Value(value));
}

Value::Dict&& Value::Dict::Set(StringPiece key, std::string&& value) && {
  return std::move(*this).Set(key, Value(std::move(value)));
}

Value::Dict&& Value::Dict::Set(StringPiece key, BlobStorage&& value) && {
  return std::move(*this).Set(key, Value(std::move(value)));
}

Value::Dict&& Value::Dict::Set(StringPiece key, Dict&& value) && {
  return std::move(*this).Set(key, Value(std::move(value)));
}

Value::Dict&& Value::Dict::Set(StringPiece key, List&& value) && {
  return std::move(*this).Set(key, Value(std::move(value)));
}

bool Value::Dict::Remove(StringPiece key) {
  DCHECK(IsStringUTF8AllowingNoncharacters(key));

  return storage_.erase(key) > 0;
}

absl::optional<Value> Value::Dict::Extract(StringPiece key) {
  DCHECK(IsStringUTF8AllowingNoncharacters(key));

  auto it = storage_.find(key);
  if (it == storage_.end()) {
    return absl::nullopt;
  }
  Value v = std::move(*it->second);
  storage_.erase(it);
  return v;
}

const Value* Value::Dict::FindByDottedPath(StringPiece path) const {
  DCHECK(!path.empty());
  DCHECK(IsStringUTF8AllowingNoncharacters(path));

  const Dict* current_dict = this;
  const Value* current_value = nullptr;
  PathSplitter splitter(path);
  while (true) {
    current_value = current_dict->Find(splitter.Next());
    if (!splitter.HasNext()) {
      return current_value;
    }
    if (!current_value) {
      return nullptr;
    }
    current_dict = current_value->GetIfDict();
    if (!current_dict) {
      return nullptr;
    }
  }
}

Value* Value::Dict::FindByDottedPath(StringPiece path) {
  return const_cast<Value*>(std::as_const(*this).FindByDottedPath(path));
}

absl::optional<bool> Value::Dict::FindBoolByDottedPath(StringPiece path) const {
  const Value* v = FindByDottedPath(path);
  return v ? v->GetIfBool() : absl::nullopt;
}

absl::optional<int> Value::Dict::FindIntByDottedPath(StringPiece path) const {
  const Value* v = FindByDottedPath(path);
  return v ? v->GetIfInt() : absl::nullopt;
}

absl::optional<double> Value::Dict::FindDoubleByDottedPath(
    StringPiece path) const {
  const Value* v = FindByDottedPath(path);
  return v ? v->GetIfDouble() : absl::nullopt;
}

const std::string* Value::Dict::FindStringByDottedPath(StringPiece path) const {
  const Value* v = FindByDottedPath(path);
  return v ? v->GetIfString() : nullptr;
}

std::string* Value::Dict::FindStringByDottedPath(StringPiece path) {
  Value* v = FindByDottedPath(path);
  return v ? v->GetIfString() : nullptr;
}

const Value::BlobStorage* Value::Dict::FindBlobByDottedPath(
    StringPiece path) const {
  const Value* v = FindByDottedPath(path);
  return v ? v->GetIfBlob() : nullptr;
}

const Value::Dict* Value::Dict::FindDictByDottedPath(StringPiece path) const {
  const Value* v = FindByDottedPath(path);
  return v ? v->GetIfDict() : nullptr;
}

Value::Dict* Value::Dict::FindDictByDottedPath(StringPiece path) {
  Value* v = FindByDottedPath(path);
  return v ? v->GetIfDict() : nullptr;
}

const Value::List* Value::Dict::FindListByDottedPath(StringPiece path) const {
  const Value* v = FindByDottedPath(path);
  return v ? v->GetIfList() : nullptr;
}

Value::List* Value::Dict::FindListByDottedPath(StringPiece path) {
  Value* v = FindByDottedPath(path);
  return v ? v->GetIfList() : nullptr;
}

Value* Value::Dict::SetByDottedPath(StringPiece path, Value&& value) {
  DCHECK(!path.empty());
  DCHECK(IsStringUTF8AllowingNoncharacters(path));

  Dict* current_dict = this;
  Value* current_value = nullptr;
  PathSplitter splitter(path);
  while (true) {
    StringPiece next_key = splitter.Next();
    if (!splitter.HasNext()) {
      return current_dict->Set(next_key, std::move(value));
    }
    // This could be clever to avoid a double-lookup via use of lower_bound(),
    // but for now, just implement it the most straightforward way.
    current_value = current_dict->Find(next_key);
    if (current_value) {
      // Unlike the legacy DictionaryValue API, encountering an intermediate
      // node that is not a `Value::Type::DICT` is an error.
      current_dict = current_value->GetIfDict();
      if (!current_dict) {
        return nullptr;
      }
    } else {
      current_dict = &current_dict->Set(next_key, Dict())->GetDict();
    }
  }
}

Value* Value::Dict::SetByDottedPath(StringPiece path, bool value) {
  return SetByDottedPath(path, Value(value));
}

Value* Value::Dict::SetByDottedPath(StringPiece path, int value) {
  return SetByDottedPath(path, Value(value));
}

Value* Value::Dict::SetByDottedPath(StringPiece path, double value) {
  return SetByDottedPath(path, Value(value));
}

Value* Value::Dict::SetByDottedPath(StringPiece path, StringPiece value) {
  return SetByDottedPath(path, Value(value));
}

Value* Value::Dict::SetByDottedPath(StringPiece path, StringPiece16 value) {
  return SetByDottedPath(path, Value(value));
}

Value* Value::Dict::SetByDottedPath(StringPiece path, const char* value) {
  return SetByDottedPath(path, Value(value));
}

Value* Value::Dict::SetByDottedPath(StringPiece path, const char16_t* value) {
  return SetByDottedPath(path, Value(value));
}

Value* Value::Dict::SetByDottedPath(StringPiece path, std::string&& value) {
  return SetByDottedPath(path, Value(std::move(value)));
}

Value* Value::Dict::SetByDottedPath(StringPiece path, BlobStorage&& value) {
  return SetByDottedPath(path, Value(std::move(value)));
}

Value* Value::Dict::SetByDottedPath(StringPiece path, Dict&& value) {
  return SetByDottedPath(path, Value(std::move(value)));
}

Value* Value::Dict::SetByDottedPath(StringPiece path, List&& value) {
  return SetByDottedPath(path, Value(std::move(value)));
}

bool Value::Dict::RemoveByDottedPath(StringPiece path) {
  return ExtractByDottedPath(path).has_value();
}

absl::optional<Value> Value::Dict::ExtractByDottedPath(StringPiece path) {
  DCHECK(!path.empty());
  DCHECK(IsStringUTF8AllowingNoncharacters(path));

  // Use recursion instead of PathSplitter here, as it simplifies code for
  // removing dictionaries that become empty if a value matching `path` is
  // extracted.
  size_t dot_index = path.find('.');
  if (dot_index == StringPiece::npos) {
    return Extract(path);
  }
  // This could be clever to avoid a double-lookup by using storage_ directly,
  // but for now, just implement it in the most straightforward way.
  StringPiece next_key = path.substr(0, dot_index);
  auto* next_dict = FindDict(next_key);
  if (!next_dict) {
    return absl::nullopt;
  }
  absl::optional<Value> extracted =
      next_dict->ExtractByDottedPath(path.substr(dot_index + 1));
  if (extracted && next_dict->empty()) {
    Remove(next_key);
  }
  return extracted;
}

size_t Value::Dict::EstimateMemoryUsage() const {
#if BUILDFLAG(ENABLE_BASE_TRACING)
  return base::trace_event::EstimateMemoryUsage(storage_);
#else   // BUILDFLAG(ENABLE_BASE_TRACING)
  return 0;
#endif  // BUILDFLAG(ENABLE_BASE_TRACING)
}

std::string Value::Dict::DebugString() const {
  return DebugStringImpl(*this);
}

#if BUILDFLAG(ENABLE_BASE_TRACING)
void Value::Dict::WriteIntoTrace(perfetto::TracedValue context) const {
  perfetto::TracedDictionary dict = std::move(context).WriteDictionary();
  for (auto kv : *this) {
    dict.Add(perfetto::DynamicString(kv.first), kv.second);
  }
}
#endif  // BUILDFLAG(ENABLE_BASE_TRACING)

Value::Dict::Dict(
    const flat_map<std::string, std::unique_ptr<Value>>& storage) {
  storage_.reserve(storage.size());
  for (const auto& [key, value] : storage) {
    Set(key, value->Clone());
  }
}

bool operator==(const Value::Dict& lhs, const Value::Dict& rhs) {
  auto deref_2nd = [](const auto& p) { return std::tie(p.first, *p.second); };
  return ranges::equal(lhs.storage_, rhs.storage_, {}, deref_2nd, deref_2nd);
}

bool operator!=(const Value::Dict& lhs, const Value::Dict& rhs) {
  return !(lhs == rhs);
}

bool operator<(const Value::Dict& lhs, const Value::Dict& rhs) {
  auto deref_2nd = [](const auto& p) { return std::tie(p.first, *p.second); };
  return ranges::lexicographical_compare(lhs.storage_, rhs.storage_, {},
                                         deref_2nd, deref_2nd);
}

bool operator>(const Value::Dict& lhs, const Value::Dict& rhs) {
  return rhs < lhs;
}

bool operator<=(const Value::Dict& lhs, const Value::Dict& rhs) {
  return !(rhs < lhs);
}

bool operator>=(const Value::Dict& lhs, const Value::Dict& rhs) {
  return !(lhs < rhs);
}

// static
Value::List Value::List::with_capacity(size_t capacity) {
  Value::List result;
  result.reserve(capacity);
  return result;
}

Value::List::List() = default;

Value::List::List(List&&) noexcept = default;

Value::List& Value::List::operator=(List&&) noexcept = default;

Value::List::~List() = default;

bool Value::List::empty() const {
  return storage_.empty();
}

size_t Value::List::size() const {
  return storage_.size();
}
// TODO: b/326979654 -- Remove this when we have -stdlib=libc++ defined in
// all Cobalt toolchains.
#if defined(COBALT_PENDING_CLEAN_UP)
Value::List::iterator Value::List::begin() {
  return iterator(storage_.data(), storage_.data() + storage_.size());
}

Value::List::const_iterator Value::List::begin() const {
  return const_iterator(storage_.data(), storage_.data() + storage_.size());
}

Value::List::const_iterator Value::List::cbegin() const {
  return const_iterator(storage_.data(), storage_.data() + storage_.size());
}

Value::List::iterator Value::List::end() {
    return iterator(storage_.data(), storage_.data() + storage_.size(), storage_.data() + storage_.size());

}

Value::List::const_iterator Value::List::end() const {
  return const_iterator(storage_.data(),
                        storage_.data() + storage_.size(),
                        storage_.data() + storage_.size());
}

Value::List::const_iterator Value::List::cend() const {
  return const_iterator(storage_.data(),
                        storage_.data() + storage_.size(),
                        storage_.data() + storage_.size());
}
#else
Value::List::iterator Value::List::begin() {
  return iterator(base::to_address(storage_.begin()),
                  base::to_address(storage_.end()));
}

Value::List::const_iterator Value::List::begin() const {
  return const_iterator(base::to_address(storage_.begin()),
                        base::to_address(storage_.end()));
}

Value::List::const_iterator Value::List::cbegin() const {
  return const_iterator(base::to_address(storage_.cbegin()),
                        base::to_address(storage_.cend()));
}

Value::List::iterator Value::List::end() {
  return iterator(base::to_address(storage_.begin()),
                  base::to_address(storage_.end()),
                  base::to_address(storage_.end()));
}

Value::List::const_iterator Value::List::end() const {
  return const_iterator(base::to_address(storage_.begin()),
                        base::to_address(storage_.end()),
                        base::to_address(storage_.end()));
}

Value::List::const_iterator Value::List::cend() const {
  return const_iterator(base::to_address(storage_.cbegin()),
                        base::to_address(storage_.cend()),
                        base::to_address(storage_.cend()));
}
#endif

const Value& Value::List::front() const {
  CHECK(!storage_.empty());
  return storage_.front();
}

Value& Value::List::front() {
  CHECK(!storage_.empty());
  return storage_.front();
}

const Value& Value::List::back() const {
  CHECK(!storage_.empty());
  return storage_.back();
}

Value& Value::List::back() {
  CHECK(!storage_.empty());
  return storage_.back();
}

void Value::List::reserve(size_t capacity) {
  storage_.reserve(capacity);
}

const Value& Value::List::operator[](size_t index) const {
  CHECK_LT(index, storage_.size());
  return storage_[index];
}

Value& Value::List::operator[](size_t index) {
  CHECK_LT(index, storage_.size());
  return storage_[index];
}

void Value::List::clear() {
  storage_.clear();
}

// TODO: b/326979654 -- Remove this when we have -stdlib=libc++ defined in
// all Cobalt toolchains.
#if defined(COBALT_PENDING_CLEAN_UP)
Value::List::iterator Value::List::erase(iterator pos) {
  auto next_it = storage_.erase(storage_.begin() + (pos - begin()));
  return iterator(storage_.data(),
                  storage_.data() + (next_it - storage_.begin()),
                  storage_.data() + storage_.size());
}

Value::List::const_iterator Value::List::erase(const_iterator pos) {
  auto next_it = storage_.erase(storage_.begin() + (pos - begin()));
  return const_iterator(storage_.data(),
                  storage_.data() + (next_it - storage_.begin()),
                  storage_.data() + storage_.size());
}

Value::List::iterator Value::List::erase(iterator first, iterator last) {
  auto next_it = storage_.erase(storage_.begin() + (first - begin()),
                                storage_.begin() + (last - begin()));
  return iterator(storage_.data(),
                  storage_.data() + (next_it - storage_.begin()),
                  storage_.data() + storage_.size());
}

Value::List::const_iterator Value::List::erase(const_iterator first,
                                               const_iterator last) {
  auto next_it = storage_.erase(storage_.begin() + (first - begin()),
                                storage_.begin() + (last - begin()));
  return const_iterator(storage_.data(),
                  storage_.data() + (next_it - storage_.begin()),
                  storage_.data() + storage_.size());
}
#else
Value::List::iterator Value::List::erase(iterator pos) {
  auto next_it = storage_.erase(storage_.begin() + (pos - begin()));
  return iterator(base::to_address(storage_.begin()), base::to_address(next_it),
                  base::to_address(storage_.end()));
}

Value::List::const_iterator Value::List::erase(const_iterator pos) {
  auto next_it = storage_.erase(storage_.begin() + (pos - begin()));
  return const_iterator(base::to_address(storage_.begin()),
                        base::to_address(next_it),
                        base::to_address(storage_.end()));
}

Value::List::iterator Value::List::erase(iterator first, iterator last) {
  auto next_it = storage_.erase(storage_.begin() + (first - begin()),
                                storage_.begin() + (last - begin()));
  return iterator(base::to_address(storage_.begin()), base::to_address(next_it),
                  base::to_address(storage_.end()));
}

Value::List::const_iterator Value::List::erase(const_iterator first,
                                               const_iterator last) {
  auto next_it = storage_.erase(storage_.begin() + (first - begin()),
                                storage_.begin() + (last - begin()));
  return const_iterator(base::to_address(storage_.begin()),
                        base::to_address(next_it),
                        base::to_address(storage_.end()));
}
#endif

Value::List Value::List::Clone() const {
  return List(storage_);
}

void Value::List::Append(Value&& value) & {
  storage_.emplace_back(std::move(value));
}

void Value::List::Append(bool value) & {
  storage_.emplace_back(value);
}

void Value::List::Append(int value) & {
  storage_.emplace_back(value);
}

void Value::List::Append(double value) & {
  storage_.emplace_back(value);
}

void Value::List::Append(StringPiece value) & {
  Append(Value(value));
}

void Value::List::Append(StringPiece16 value) & {
  storage_.emplace_back(value);
}

void Value::List::Append(const char* value) & {
  storage_.emplace_back(value);
}

void Value::List::Append(const char16_t* value) & {
  storage_.emplace_back(value);
}

void Value::List::Append(std::string&& value) & {
  storage_.emplace_back(std::move(value));
}

void Value::List::Append(BlobStorage&& value) & {
  storage_.emplace_back(std::move(value));
}

void Value::List::Append(Dict&& value) & {
  storage_.emplace_back(std::move(value));
}

void Value::List::Append(List&& value) & {
  storage_.emplace_back(std::move(value));
}

Value::List&& Value::List::Append(Value&& value) && {
  storage_.emplace_back(std::move(value));
  return std::move(*this);
}

Value::List&& Value::List::Append(bool value) && {
  storage_.emplace_back(value);
  return std::move(*this);
}

Value::List&& Value::List::Append(int value) && {
  storage_.emplace_back(value);
  return std::move(*this);
}

Value::List&& Value::List::Append(double value) && {
  storage_.emplace_back(value);
  return std::move(*this);
}

Value::List&& Value::List::Append(StringPiece value) && {
  Append(Value(value));
  return std::move(*this);
}

Value::List&& Value::List::Append(StringPiece16 value) && {
  storage_.emplace_back(value);
  return std::move(*this);
}

Value::List&& Value::List::Append(const char* value) && {
  storage_.emplace_back(value);
  return std::move(*this);
}

Value::List&& Value::List::Append(const char16_t* value) && {
  storage_.emplace_back(value);
  return std::move(*this);
}

Value::List&& Value::List::Append(std::string&& value) && {
  storage_.emplace_back(std::move(value));
  return std::move(*this);
}

Value::List&& Value::List::Append(BlobStorage&& value) && {
  storage_.emplace_back(std::move(value));
  return std::move(*this);
}

Value::List&& Value::List::Append(Dict&& value) && {
  storage_.emplace_back(std::move(value));
  return std::move(*this);
}

Value::List&& Value::List::Append(List&& value) && {
  storage_.emplace_back(std::move(value));
  return std::move(*this);
}

// TODO: b/326979654 -- Remove this when we have -stdlib=libc++ defined in
// all Cobalt toolchains.
#if defined(COBALT_PENDING_CLEAN_UP)
Value::List::iterator Value::List::Insert(const_iterator pos, Value&& value) {
  auto inserted_it =
      storage_.insert(storage_.begin() + (pos - begin()), std::move(value));
  return iterator(storage_.data(),
                  storage_.data() + (inserted_it - storage_.begin()),
                  storage_.data() + storage_.size());
}
#else
Value::List::iterator Value::List::Insert(const_iterator pos, Value&& value) {
  auto inserted_it =
      storage_.insert(storage_.begin() + (pos - begin()), std::move(value));
  return iterator(base::to_address(storage_.begin()),
                  base::to_address(inserted_it),
                  base::to_address(storage_.end()));
}
#endif

size_t Value::List::EraseValue(const Value& value) {
  return Erase(storage_, value);
}

size_t Value::List::EstimateMemoryUsage() const {
#if BUILDFLAG(ENABLE_BASE_TRACING)
  return base::trace_event::EstimateMemoryUsage(storage_);
#else   // BUILDFLAG(ENABLE_BASE_TRACING)
  return 0;
#endif  // BUILDFLAG(ENABLE_BASE_TRACING)
}

std::string Value::List::DebugString() const {
  return DebugStringImpl(*this);
}

#if BUILDFLAG(ENABLE_BASE_TRACING)
void Value::List::WriteIntoTrace(perfetto::TracedValue context) const {
  perfetto::TracedArray array = std::move(context).WriteArray();
  for (const auto& item : *this) {
    array.Append(item);
  }
}
#endif  // BUILDFLAG(ENABLE_BASE_TRACING)

Value::List::List(const std::vector<Value>& storage) {
  storage_.reserve(storage.size());
  for (const auto& value : storage) {
    storage_.push_back(value.Clone());
  }
}

bool operator==(const Value::List& lhs, const Value::List& rhs) {
  return lhs.storage_ == rhs.storage_;
}

bool operator!=(const Value::List& lhs, const Value::List& rhs) {
  return !(lhs == rhs);
}

bool operator<(const Value::List& lhs, const Value::List& rhs) {
  return lhs.storage_ < rhs.storage_;
}

bool operator>(const Value::List& lhs, const Value::List& rhs) {
  return rhs < lhs;
}

bool operator<=(const Value::List& lhs, const Value::List& rhs) {
  return !(rhs < lhs);
}

bool operator>=(const Value::List& lhs, const Value::List& rhs) {
  return !(lhs < rhs);
}

absl::optional<bool> Value::FindBoolKey(StringPiece key) const {
  return GetDict().FindBool(key);
}

absl::optional<int> Value::FindIntKey(StringPiece key) const {
  return GetDict().FindInt(key);
}

const std::string* Value::FindStringKey(StringPiece key) const {
  return GetDict().FindString(key);
}

std::string* Value::FindStringKey(StringPiece key) {
  return GetDict().FindString(key);
}

const Value* Value::FindListKey(StringPiece key) const {
  const Value* result = GetDict().Find(key);
  if (!result || result->type() != Type::LIST) {
    return nullptr;
  }
  return result;
}

Value* Value::FindListKey(StringPiece key) {
  return const_cast<Value*>(std::as_const(*this).FindListKey(key));
}

Value* Value::SetKey(StringPiece key, Value&& value) {
  return GetDict().Set(key, std::move(value));
}

Value* Value::SetBoolKey(StringPiece key, bool value) {
  return GetDict().Set(key, value);
}

Value* Value::SetIntKey(StringPiece key, int value) {
  return GetDict().Set(key, value);
}

Value* Value::SetDoubleKey(StringPiece key, double value) {
  return GetDict().Set(key, value);
}

Value* Value::SetStringKey(StringPiece key, StringPiece value) {
  return GetDict().Set(key, value);
}

Value* Value::SetStringKey(StringPiece key, StringPiece16 value) {
  return GetDict().Set(key, value);
}

Value* Value::SetStringKey(StringPiece key, const char* value) {
  return GetDict().Set(key, value);
}

Value* Value::SetStringKey(StringPiece key, std::string&& value) {
  return GetDict().Set(key, std::move(value));
}

bool Value::RemoveKey(StringPiece key) {
  return GetDict().Remove(key);
}

Value* Value::FindPath(StringPiece path) {
  return GetDict().FindByDottedPath(path);
}

const Value* Value::FindPath(StringPiece path) const {
  return GetDict().FindByDottedPath(path);
}

absl::optional<bool> Value::FindBoolPath(StringPiece path) const {
  return GetDict().FindBoolByDottedPath(path);
}

absl::optional<int> Value::FindIntPath(StringPiece path) const {
  return GetDict().FindIntByDottedPath(path);
}

absl::optional<double> Value::FindDoublePath(StringPiece path) const {
  return GetDict().FindDoubleByDottedPath(path);
}

const std::string* Value::FindStringPath(StringPiece path) const {
  return GetDict().FindStringByDottedPath(path);
}

std::string* Value::FindStringPath(StringPiece path) {
  return GetDict().FindStringByDottedPath(path);
}

const Value* Value::FindDictPath(StringPiece path) const {
  const Value* cur = GetDict().FindByDottedPath(path);
  if (!cur || cur->type() != Type::DICT) {
    return nullptr;
  }
  return cur;
}

Value* Value::FindDictPath(StringPiece path) {
  return const_cast<Value*>(std::as_const(*this).FindDictPath(path));
}

const Value* Value::FindListPath(StringPiece path) const {
  const Value* cur = GetDict().FindByDottedPath(path);
  if (!cur || cur->type() != Type::LIST) {
    return nullptr;
  }
  return cur;
}

Value* Value::FindListPath(StringPiece path) {
  return const_cast<Value*>(std::as_const(*this).FindListPath(path));
}

size_t Value::DictSize() const {
  return GetDict().size();
}

bool operator==(const Value& lhs, const Value& rhs) {
  return lhs.data_ == rhs.data_;
}

bool operator!=(const Value& lhs, const Value& rhs) {
  return !(lhs == rhs);
}

bool operator<(const Value& lhs, const Value& rhs) {
  return lhs.data_ < rhs.data_;
}

bool operator>(const Value& lhs, const Value& rhs) {
  return rhs < lhs;
}

bool operator<=(const Value& lhs, const Value& rhs) {
  return !(rhs < lhs);
}

bool operator>=(const Value& lhs, const Value& rhs) {
  return !(lhs < rhs);
}

bool operator==(const Value& lhs, bool rhs) {
  return lhs.is_bool() && lhs.GetBool() == rhs;
}

bool operator==(const Value& lhs, int rhs) {
  return lhs.is_int() && lhs.GetInt() == rhs;
}

bool operator==(const Value& lhs, double rhs) {
  return lhs.is_double() && lhs.GetDouble() == rhs;
}

bool operator==(const Value& lhs, StringPiece rhs) {
  return lhs.is_string() && lhs.GetString() == rhs;
}

bool operator==(const Value& lhs, const Value::Dict& rhs) {
  return lhs.is_dict() && lhs.GetDict() == rhs;
}

bool operator==(const Value& lhs, const Value::List& rhs) {
  return lhs.is_list() && lhs.GetList() == rhs;
}

size_t Value::EstimateMemoryUsage() const {
  switch (type()) {
#if BUILDFLAG(ENABLE_BASE_TRACING)
    case Type::STRING:
      return base::trace_event::EstimateMemoryUsage(GetString());
    case Type::BINARY:
      return base::trace_event::EstimateMemoryUsage(GetBlob());
    case Type::DICT:
      return GetDict().EstimateMemoryUsage();
    case Type::LIST:
      return GetList().EstimateMemoryUsage();
#endif  // BUILDFLAG(ENABLE_BASE_TRACING)
    default:
      return 0;
  }
}

std::string Value::DebugString() const {
  return DebugStringImpl(*this);
}

#if BUILDFLAG(ENABLE_BASE_TRACING)
void Value::WriteIntoTrace(perfetto::TracedValue context) const {
  Visit([&](const auto& member) {
    using T = std::decay_t<decltype(member)>;
    if constexpr (std::is_same_v<T, absl::monostate>) {
      std::move(context).WriteString("<none>");
    } else if constexpr (std::is_same_v<T, bool>) {
      std::move(context).WriteBoolean(member);
    } else if constexpr (std::is_same_v<T, int>) {
      std::move(context).WriteInt64(member);
    } else if constexpr (std::is_same_v<T, DoubleStorage>) {
      std::move(context).WriteDouble(member);
    } else if constexpr (std::is_same_v<T, std::string>) {
      std::move(context).WriteString(member);
    } else if constexpr (std::is_same_v<T, BlobStorage>) {
      std::move(context).WriteString("<binary data not supported>");
    } else if constexpr (std::is_same_v<T, Dict>) {
      member.WriteIntoTrace(std::move(context));
    } else if constexpr (std::is_same_v<T, List>) {
      member.WriteIntoTrace(std::move(context));
    }
  });
}
#endif  // BUILDFLAG(ENABLE_BASE_TRACING)

ValueView::ValueView(const Value& value)
    : data_view_(
          value.Visit([](const auto& member) { return ViewType(member); })) {}

Value ValueView::ToValue() const {
  return Value::CloningHelper::Clone(data_view_);
}

ValueSerializer::~ValueSerializer() = default;

ValueDeserializer::~ValueDeserializer() = default;

std::ostream& operator<<(std::ostream& out, const Value& value) {
  return out << value.DebugString();
}

std::ostream& operator<<(std::ostream& out, const Value::Dict& dict) {
  return out << dict.DebugString();
}

std::ostream& operator<<(std::ostream& out, const Value::List& list) {
  return out << list.DebugString();
}

std::ostream& operator<<(std::ostream& out, const Value::Type& type) {
  if (static_cast<int>(type) < 0 ||
      static_cast<size_t>(type) >= std::size(kTypeNames)) {
    return out << "Invalid Type (index = " << static_cast<int>(type) << ")";
  }
  return out << Value::GetTypeName(type);
}

}  // namespace base