/*

 * Copyright (C) 2016 The Android Open Source Project

 *

 * 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

 *

 *      http://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.

 */

#pragma once

#include <stdint.h>

#include <map>

#include <optional>

#include <string>

#include <unordered_map>

#include <unwindstack/SharedString.h>

namespace unwindstack {

// Forward declaration.

class Memory;

class Symbols {

  struct Info {

    uint32_t size;   // Symbol size in bytes.

    uint32_t index;  // Index into *sorted* symbol table.

    SharedString name;

  };

 public:

  Symbols(uint64_t offset, uint64_t size, uint64_t entry_size, uint64_t str_offset,

          uint64_t str_size);

  virtual ~Symbols() = default;

  template <typename SymType>

  bool GetName(uint64_t addr, Memory* elf_memory, SharedString* name, uint64_t* func_offset);

  template <typename SymType>

  bool GetGlobal(Memory* elf_memory, const std::string& name, uint64_t* memory_address);

  void ClearCache() {

    symbols_.clear();

    remap_.reset();

  }

 private:

  template <typename SymType, bool RemapIndices>

  Info* BinarySearch(uint64_t addr, Memory* elf_memory, uint64_t* func_offset);

  template <typename SymType>

  void BuildRemapTable(Memory* elf_memory);

  const uint64_t offset_;

  const uint64_t count_;

  const uint64_t entry_size_;

  const uint64_t str_offset_;

  uint64_t str_end_;

  std::map<uint64_t, Info> symbols_;  // Cache of read symbols (keyed by function *end* address).

  std::optional<std::vector<uint32_t>> remap_;  // Indices of function symbols sorted by address.

  // Cache of global data (non-function) symbols.

  std::unordered_map<std::string, std::optional<uint64_t>> global_variables_;

  // Do not allow the total number of symbols to go above this.

  constexpr static size_t kMaxSymbols = 1000000;

};

}  // namespace unwindstack