Struct BlobPagerAndVerifier 

pub struct BlobPagerAndVerifier { /* private fields */ }

Coordinates between FxBlob, the block driver, and the kernel to manage pager-backed blobs such that page requests can be handled at the driver instead of the filesystem layer.

BlobPagerAndVerifier uses a dedicated Pager to create pager-backed VMOs for blobs. Kernel page faults on these VMOs are routed directly to the block driver, which reads and decompresses the raw data. The driver then passes this data back to BlobPagerAndVerifier for cryptographic verification and page fault resolution.

Implementations

impl BlobPagerAndVerifier

pub fn delivery_vmo(&self) -> &Vmo

Returns a reference to the shared delivery queue VMO.

pub fn clear_cache(&self)

Evicts all unreferenced blobs from the internal LRU cache.

pub async fn new( mapping_provider: &MappingProviderProxy, mapper: &MapperProxy, ) -> Result<Self, Error>

Creates a new BlobPagerAndVerifier with the default LRU cache capacity.

Establishes a mapping_provider session with FxBlob to receive a shared VMO that will be used to communicate opened blob extent mappings as well as any closed blobs. Then, opens a mapper session with the block driver, forwarding the mapping VMO alongside a Zircon port (for the driver to receive page faults) and a delivery queue VMO (for the driver to emit unverified data for verification).

pub async fn new_with_cache_capacity( mapping_provider: &MappingProviderProxy, mapper: &MapperProxy, cache_capacity: usize, ) -> Result<Self, Error>

Creates a new BlobPagerAndVerifier with the specified unreferenced-blob LRU cache capacity.

pub async fn start_profile( &self, name: impl Into<String>, ) -> Result<ProfileRecording, Status>

Starts recording a profile for name and replaying any existing profile of the same name.

pub async fn record_and_replay_profile( &self, name: impl Into<String>, duration: MonotonicDuration, )

Starts recording and replaying the named profile, stopping and committing the profile in the background after duration elapses.

pub async fn create_vmo(&self, identifier: &[u8; 32]) -> Result<Vmo, Error>

Create pager owned VMO for the blob identified by its Merkle Root Hash.

pub async fn open_child_session( &self, identifier: &[u8; 32], mapping_vmo: Vmo, session: ServerEnd<MapperSessionMarker>, ) -> Result<(), Status>

Opens a child MapperSession backed by the blob identified by its Merkle root hash.

Child VMOs created on session are backed by self.pager and a dedicated child_port passed to the driver. When a child VMO faults, the driver reads the corresponding parent blob chunks and sends DeliveryCommand::ChildData over the shared delivery queue so BlobPagerAndVerifier can verify the parent data before supplying pages to the child VMO.

pub fn get_file_mapper_handler( self: &Arc<Self>, scope: ExecutionScope, ) -> Arc<Service>

Returns a VFS vfs::service::Service that serves fuchsia.storage.mapping/FileMapper by resolving vmo_blob::VmoBlob tokens in scope and opening child mapper sessions on self.