flutter::DirectoryAssetBundle Class Reference

#include <directory_asset_bundle.h>

Inheritance diagram for flutter::DirectoryAssetBundle:

Public Member Functions
	DirectoryAssetBundle (fml::UniqueFD descriptor, bool is_valid_after_asset_manager_change)
	~DirectoryAssetBundle () override
Public Member Functions inherited from flutter::AssetResolver
	AssetResolver ()=default
virtual	~AssetResolver ()=default
virtual const AssetManager *	as_asset_manager () const
virtual const APKAssetProvider *	as_apk_asset_provider () const
bool	operator!= (const AssetResolver &other) const

Private Member Functions
bool	IsValid () const override
bool	IsValidAfterAssetManagerChange () const override
	Certain asset resolvers are still valid after the asset manager is replaced before a hot reload, or after a new run configuration is created during a hot restart. By preserving these resolvers and re-inserting them into the new resolver or run configuration, the tooling can avoid needing to sync all application assets through the Dart devFS upon connecting to the VM Service. Besides improving the startup performance of running a Flutter application, it also reduces the occurrence of tool failures due to repeated network flakes caused by damaged cables or hereto unknown bugs in the Dart HTTP server implementation.
AssetResolver::AssetResolverType	GetType () const override
	Gets the type of AssetResolver this is. Types are defined in AssetResolverType.
std::unique_ptr< fml::Mapping >	GetAsMapping (const std::string &asset_name) const override
std::vector< std::unique_ptr< fml::Mapping > >	GetAsMappings (const std::string &asset_pattern, const std::optional< std::string > &subdir) const override
	Same as GetAsMapping() but returns mappings for all files who's name matches a given pattern. Returns empty vector if no matching assets are found.
bool	operator== (const AssetResolver &other) const override
const DirectoryAssetBundle *	as_directory_asset_bundle () const override

Additional Inherited Members
Public Types inherited from flutter::AssetResolver
enum	AssetResolverType { kAssetManager , kApkAssetProvider , kDirectoryAssetBundle }
	Identifies the type of AssetResolver an instance is. More...

Detailed Description

Definition at line 16 of file directory_asset_bundle.h.

Constructor & Destructor Documentation

DirectoryAssetBundle()

flutter::DirectoryAssetBundle::DirectoryAssetBundle	(	fml::UniqueFD	descriptor,
		bool	is_valid_after_asset_manager_change
	)

Definition at line 17 of file directory_asset_bundle.cc.

    : descriptor_(std::move(descriptor)) {
  if (!fml::IsDirectory(descriptor_)) {
    return;
  }
  is_valid_after_asset_manager_change_ = is_valid_after_asset_manager_change;
  is_valid_ = true;
}

~DirectoryAssetBundle()

flutter::DirectoryAssetBundle::~DirectoryAssetBundle ( )

overridedefault

Member Function Documentation

as_directory_asset_bundle()

const DirectoryAssetBundle * flutter::DirectoryAssetBundle::as_directory_asset_bundle ( ) const

inlineoverrideprivatevirtual

Reimplemented from flutter::AssetResolver.

Definition at line 50 of file directory_asset_bundle.h.

                                                                         {
    return this;
  }

GetAsMapping()

std::unique_ptr< fml::Mapping > flutter::DirectoryAssetBundle::GetAsMapping ( const std::string &  asset_name ) const

overrideprivatevirtual

Implements flutter::AssetResolver.

Definition at line 46 of file directory_asset_bundle.cc.

                                       {
  if (!is_valid_) {
    FML_DLOG(WARNING) << "Asset bundle was not valid.";
    return nullptr;
  }
 
  auto mapping = std::make_unique<fml::FileMapping>(fml::OpenFile(
      descriptor_, asset_name.c_str(), false, fml::FilePermission::kRead));
 
  if (!mapping->IsValid()) {
    return nullptr;
  }
 
  return mapping;
}

GetAsMappings()

std::vector< std::unique_ptr< fml::Mapping > > flutter::DirectoryAssetBundle::GetAsMappings ( const std::string &  asset_pattern, const std::optional< std::string > &  subdir  ) const

overrideprivatevirtual

Same as GetAsMapping() but returns mappings for all files who's name matches a given pattern. Returns empty vector if no matching assets are found.

Parameters

[in]	asset_pattern	The pattern to match file names against.
[in]	subdir	Optional subdirectory in which to search for files. If supplied this function does a flat search within the subdirectory instead of a recursive search through the entire assets directory.

Returns

Returns a vector of mappings of files which match the search parameters.

Reimplemented from flutter::AssetResolver.

Definition at line 63 of file directory_asset_bundle.cc.

                                                {
  std::vector<std::unique_ptr<fml::Mapping>> mappings;
  if (!is_valid_) {
    FML_DLOG(WARNING) << "Asset bundle was not valid.";
    return mappings;
  }
 
  std::regex asset_regex(asset_pattern);
  fml::FileVisitor visitor = [&](const fml::UniqueFD& directory,
                                 const std::string& filename) {
    TRACE_EVENT0("flutter", "DirectoryAssetBundle::GetAsMappings FileVisitor");
 
    if (std::regex_match(filename, asset_regex)) {
      TRACE_EVENT0("flutter", "Matched File");
 
      fml::UniqueFD fd = fml::OpenFile(directory, filename.c_str(), false,
                                       fml::FilePermission::kRead);
 
      if (fml::IsDirectory(fd)) {
        return true;
      }
 
      auto mapping = std::make_unique<fml::FileMapping>(fd);
 
      if (mapping && mapping->IsValid()) {
        mappings.push_back(std::move(mapping));
      } else {
        FML_LOG(ERROR) << "Mapping " << filename << " failed";
      }
    }
    return true;
  };
  if (!subdir) {
    fml::VisitFilesRecursively(descriptor_, visitor);
  } else {
    fml::UniqueFD subdir_fd =
        fml::OpenFileReadOnly(descriptor_, subdir.value().c_str());
    if (!fml::IsDirectory(subdir_fd)) {
      FML_LOG(ERROR) << "Subdirectory path " << subdir.value()
                     << " is not a directory";
      return mappings;
    }
    fml::VisitFiles(subdir_fd, visitor);
  }
 
  return mappings;
}

GetType()

AssetResolver::AssetResolverType flutter::DirectoryAssetBundle::GetType ( ) const

overrideprivatevirtual

Gets the type of AssetResolver this is. Types are defined in AssetResolverType.

Returns

Returns the AssetResolverType that this resolver is.

Implements flutter::AssetResolver.

Definition at line 41 of file directory_asset_bundle.cc.

                                                                   {
  return AssetResolver::AssetResolverType::kDirectoryAssetBundle;
}

IsValid()

bool flutter::DirectoryAssetBundle::IsValid ( ) const

overrideprivatevirtual

Implements flutter::AssetResolver.

Definition at line 31 of file directory_asset_bundle.cc.

                                         {
  return is_valid_;
}

IsValidAfterAssetManagerChange()

bool flutter::DirectoryAssetBundle::IsValidAfterAssetManagerChange ( ) const

overrideprivatevirtual

Certain asset resolvers are still valid after the asset manager is replaced before a hot reload, or after a new run configuration is created during a hot restart. By preserving these resolvers and re-inserting them into the new resolver or run configuration, the tooling can avoid needing to sync all application assets through the Dart devFS upon connecting to the VM Service. Besides improving the startup performance of running a Flutter application, it also reduces the occurrence of tool failures due to repeated network flakes caused by damaged cables or hereto unknown bugs in the Dart HTTP server implementation.

Returns

Returns whether this resolver is valid after the asset manager or run configuration is updated.

Implements flutter::AssetResolver.

Definition at line 36 of file directory_asset_bundle.cc.

                                                                {
  return is_valid_after_asset_manager_change_;
}

operator==()

bool flutter::DirectoryAssetBundle::operator== ( const AssetResolver &  other ) const

overrideprivatevirtual

Implements flutter::AssetResolver.

Definition at line 113 of file directory_asset_bundle.cc.

                                                                      {
  auto other_bundle = other.as_directory_asset_bundle();
  if (!other_bundle) {
    return false;
  }
  return is_valid_after_asset_manager_change_ ==
             other_bundle->is_valid_after_asset_manager_change_ &&
         descriptor_.get() == other_bundle->descriptor_.get();
}

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The documentation for this class was generated from the following files:

• assets/directory_asset_bundle.h
• assets/directory_asset_bundle.cc