Struct ControlBlockStateHelper 

pub struct ControlBlockStateHelper;

Helper for reading/writing state to/from ControlBlock.

Implementations

impl ControlBlockStateHelper

pub fn write_embedded<S: EmbeddedState>( block: &mut ControlBlock, state: &S, ) -> Result<()>

Write embedded state to ControlBlock’s reserved field.

Errors

Returns error if state doesn’t fit in 24 bytes.

pub fn read_embedded<S: EmbeddedState>(block: &ControlBlock) -> Result<S>

Read embedded state from ControlBlock’s reserved field.

Errors

Returns error if state type size exceeds 24 bytes.

pub fn write_descriptor( block: &mut ControlBlock, descriptor: &StateDescriptor, ) -> Result<()>

Write state descriptor for external state.

pub fn read_descriptor(block: &ControlBlock) -> Option<StateDescriptor>

Read state descriptor from ControlBlock.

Returns None if no valid descriptor is present.

pub fn has_embedded_state(block: &ControlBlock) -> bool

Check if ControlBlock has embedded state (no external pointer).

pub fn has_external_state(block: &ControlBlock) -> bool

Check if ControlBlock references external state.

pub fn clear_state(block: &mut ControlBlock)

Clear all state from ControlBlock.

pub fn raw_bytes(block: &ControlBlock) -> &[u8; 24]

Get raw bytes from reserved field.

pub fn raw_bytes_mut(block: &mut ControlBlock) -> &mut [u8; 24]

Get mutable raw bytes from reserved field.