/*
 * Copyright (C) 2017 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.
 */

#ifndef ART_LIBDEXFILE_DEX_ART_DEX_FILE_LOADER_H_
#define ART_LIBDEXFILE_DEX_ART_DEX_FILE_LOADER_H_

#include <cstdint>
#include <memory>
#include <string>
#include <vector>

#include "base/macros.h"
#include "dex/dex_file_loader.h"

namespace art {

class DexFile;
class DexFileContainer;
class MemMap;
class OatDexFile;
class ZipArchive;

// Class that is used to open dex files and deal with corresponding multidex and location logic.
class ArtDexFileLoader : public DexFileLoader {
 public:
  virtual ~ArtDexFileLoader() { }

  // Returns the checksums of a file for comparison with GetLocationChecksum().
  // For .dex files, this is the single header checksum.
  // For zip files, this is the zip entry CRC32 checksum for classes.dex and
  // each additional multidex entry classes2.dex, classes3.dex, etc.
  // If a valid zip_fd is provided the file content will be read directly from
  // the descriptor and `filename` will be used as alias for error logging. If
  // zip_fd is -1, the method will try to open the `filename` and read the
  // content from it.
  //
  // The dex_locations vector will be populated with the corresponding multidex
  // locations.
  //
  // Return true if the checksums could be found, false otherwise.
  bool GetMultiDexChecksums(const char* filename,
                            std::vector<uint32_t>* checksums,
                            std::vector<std::string>* dex_locations,
                            std::string* error_msg,
                            int zip_fd = -1,
                            bool* only_contains_uncompressed_dex = nullptr) const override;

  // Opens .dex file, backed by existing memory
  std::unique_ptr<const DexFile> Open(
      const uint8_t* base,
      size_t size,
      const std::string& location,
      uint32_t location_checksum,
      const OatDexFile* oat_dex_file,
      bool verify,
      bool verify_checksum,
      std::string* error_msg,
      std::unique_ptr<DexFileContainer> container = nullptr) const override;

  // Opens .dex file that has been memory-mapped by the caller.
  std::unique_ptr<const DexFile> Open(const std::string& location,
                                      uint32_t location_checkum,
                                      MemMap&& mem_map,
                                      bool verify,
                                      bool verify_checksum,
                                      std::string* error_msg) const;

  // Opens all .dex files found in the file, guessing the container format based on file magic.
  bool Open(const char* filename,
            const std::string& location,
            bool verify,
            bool verify_checksum,
            std::string* error_msg,
            std::vector<std::unique_ptr<const DexFile>>* dex_files) const;
  bool Open(int fd,
            const std::string& location,
            bool verify,
            bool verify_checksum,
            std::string* error_msg,
            std::vector<std::unique_ptr<const DexFile>>* dex_files) const;
  // Opens all .dex files found in the file, guessing the container format based on file magic.
  // If the fd is -1 then the dex files are opened using the filename; otherwise they are
  // opened using the fd.
  bool Open(const char* filename,
            int fd,
            const std::string& location,
            bool verify,
            bool verify_checksum,
            std::string* error_msg,
            std::vector<std::unique_ptr<const DexFile>>* dex_files) const;

  // Open a single dex file from an fd. This function closes the fd.
  std::unique_ptr<const DexFile> OpenDex(int fd,
                                         const std::string& location,
                                         bool verify,
                                         bool verify_checksum,
                                         bool mmap_shared,
                                         std::string* error_msg) const;

  // Opens dex files from within a .jar, .zip, or .apk file
  bool OpenZip(int fd,
               const std::string& location,
               bool verify,
               bool verify_checksum,
               std::string* error_msg,
               std::vector<std::unique_ptr<const DexFile>>* dex_files) const;

 private:
  bool OpenWithMagic(uint32_t magic,
                     int fd,
                     const std::string& location,
                     bool verify,
                     bool verify_checksum,
                     std::string* error_msg,
                     std::vector<std::unique_ptr<const DexFile>>* dex_files) const;

  std::unique_ptr<const DexFile> OpenFile(int fd,
                                          const std::string& location,
                                          bool verify,
                                          bool verify_checksum,
                                          bool mmap_shared,
                                          std::string* error_msg) const;

  // Open all classesXXX.dex files from a zip archive.
  bool OpenAllDexFilesFromZip(const ZipArchive& zip_archive,
                              const std::string& location,
                              bool verify,
                              bool verify_checksum,
                              std::string* error_msg,
                              std::vector<std::unique_ptr<const DexFile>>* dex_files) const;

  // Opens .dex file from the entry_name in a zip archive. error_code is undefined when non-null
  // return.
  std::unique_ptr<const DexFile> OpenOneDexFileFromZip(const ZipArchive& zip_archive,
                                                       const char* entry_name,
                                                       const std::string& location,
                                                       bool verify,
                                                       bool verify_checksum,
                                                       std::string* error_msg,
                                                       DexFileLoaderErrorCode* error_code) const;

  static std::unique_ptr<DexFile> OpenCommon(const uint8_t* base,
                                             size_t size,
                                             const uint8_t* data_base,
                                             size_t data_size,
                                             const std::string& location,
                                             uint32_t location_checksum,
                                             const OatDexFile* oat_dex_file,
                                             bool verify,
                                             bool verify_checksum,
                                             std::string* error_msg,
                                             std::unique_ptr<DexFileContainer> container,
                                             VerifyResult* verify_result);
};

}  // namespace art

#endif  // ART_LIBDEXFILE_DEX_ART_DEX_FILE_LOADER_H_