Method OpenAllDexFilesFromZip

Bcore/src/main/cpp/dex/dex_file_loader.cc:447–507

static constexpr size_t kWarnOnManyDexFilesThreshold = 100;

bool DexFileLoader::OpenAllDexFilesFromZip(
    const DexZipArchive& 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 {
  DCHECK(dex_files != nullptr) << "DexFile::OpenFromZip: out-param is nullptr";
  ZipOpenErrorCode error_code;
  std::unique_ptr<const DexFile> dex_file(OpenOneDexFileFromZip(zip_archive,
                                                                kClassesDex,
                                                                location,
                                                                verify,
                                                                verify_checksum,
                                                                error_msg,
                                                                &error_code));
  if (dex_file.get() == nullptr) {
    return false;
  } else {
    // Had at least classes.dex.
    dex_files->push_back(std::move(dex_file));

    // Now try some more.

    // We could try to avoid std::string allocations by working on a char array directly. As we
    // do not expect a lot of iterations, this seems too involved and brittle.

    for (size_t i = 1; ; ++i) {
      std::string name = GetMultiDexClassesDexName(i);
      std::string fake_location = GetMultiDexLocation(i, location.c_str());
      std::unique_ptr<const DexFile> next_dex_file(OpenOneDexFileFromZip(zip_archive,
                                                                         name.c_str(),
                                                                         fake_location,
                                                                         verify,
                                                                         verify_checksum,
                                                                         error_msg,
                                                                         &error_code));
      if (next_dex_file.get() == nullptr) {
        if (error_code != ZipOpenErrorCode::kEntryNotFound) {
          LOG(WARNING) << "Zip open failed: " << *error_msg;
        }
        break;
      } else {
        dex_files->push_back(std::move(next_dex_file));
      }

      if (i == kWarnOnManyDexFilesThreshold) {
        LOG(WARNING) << location << " has in excess of " << kWarnOnManyDexFilesThreshold
                     << " dex files. Please consider coalescing and shrinking the number to "
                        " avoid runtime overhead.";
      }

      if (i == std::numeric_limits<size_t>::max()) {
        LOG(ERROR) << "Overflow in number of dex files!";
        break;
      }
    }