// Copyright 2024 Google LLC

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

// https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include "internal/string_pool.h"

#include <cstring>

#include <string>

#include <utility>

#include "absl/base/optimization.h"

#include "absl/strings/cord.h"

#include "absl/strings/string_view.h"

#include "google/protobuf/arena.h"

namespace cel::internal {

absl::string_view StringPool::InternString(absl::string_view string) {

if (string.empty()) {

return "";

}

return *strings_.lazy_emplace(string, [&](const auto& ctor) {

char* data =

reinterpret_cast<char*>(arena()->AllocateAligned(string.size()));

std::memcpy(data, string.data(), string.size());

ctor(absl::string_view(data, string.size()));

});

}

absl::string_view StringPool::InternString(std::string&& string) {

if (string.empty()) {

return "";

}

return *strings_.lazy_emplace(string, [&](const auto& ctor) {

if (string.size() <= sizeof(std::string)) {

char* data =

reinterpret_cast<char*>(arena()->AllocateAligned(string.size()));

std::memcpy(data, string.data(), string.size());

ctor(absl::string_view(data, string.size()));

} else {

google::protobuf::Arena* arena = this->arena();

ABSL_ASSUME(arena != nullptr);

ctor(absl::string_view(

*google::protobuf::Arena::Create<std::string>(arena, std::move(string))));

}

});

}

absl::string_view StringPool::InternString(const absl::Cord& string) {

if (string.empty()) {

return "";

}

return *strings_.lazy_emplace(string, [&](const auto& ctor) {

char* data =

reinterpret_cast<char*>(arena()->AllocateAligned(string.size()));

absl::Cord::CharIterator string_begin = string.char_begin();

const absl::Cord::CharIterator string_end = string.char_end();

char* p = data;

while (string_begin != string_end) {

absl::string_view chunk = absl::Cord::ChunkRemaining(string_begin);

std::memcpy(p, chunk.data(), chunk.size());

p += chunk.size();

absl::Cord::Advance(&string_begin, chunk.size());

}

ctor(absl::string_view(data, string.size()));

});

}

} // namespace cel::internal