Struct git_features::fs::MutableSnapshot

pub struct MutableSnapshot<T: Debug>(pub MutableOnDemand<Option<SharedSnapshot<T>>>);

Use this type for fields in structs that are to store the Snapshot, typically behind an OwnShared.

Note that the resource itself is behind another OwnShared to allow it to be used without holding any kind of lock, hence without blocking updates while it is used.

Tuple Fields

0: MutableOnDemand<Option<SharedSnapshot<T>>>

Implementations

impl<T: Debug> MutableSnapshot<T>

pub fn new() -> Self

Create a new instance of this type.

Useful in case Default::default() isn’t working for some reason.

pub fn force_refresh<E>(
    &self,
    open: impl FnOnce() -> Result<Option<(SystemTime, T)>, E>
) -> Result<(), E>

Refresh state forcefully by re-opening the resource. Note that open() returns None if the resource isn’t present on disk, and that it’s critical that the modified time is obtained before opening the resource.

pub fn recent_snapshot<E>(
    &self,
    current_modification_time: impl FnMut() -> Option<SystemTime>,
    open: impl FnOnce() -> Result<Option<T>, E>
) -> Result<Option<SharedSnapshot<T>>, E>

Assure that the resource in state is up-to-date by comparing the current_modification_time with the one we know in state and by acting accordingly. Returns the potentially updated/reloaded resource if it is still present on disk, which then represents a snapshot that is up-to-date in that very moment, or None if the underlying file doesn’t exist.

Note that even though this is racy, each time a request is made there is a chance to see the actual state.

Trait Implementations

impl<T: Debug + Debug> Debug for MutableSnapshot<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Default + Debug> Default for MutableSnapshot<T>

fn default() -> MutableSnapshot<T>

Returns the “default value” for a type.

impl<T: Debug> Deref for MutableSnapshot<T>

type Target = RwLock<RawRwLock, Option<Arc<Snapshot<T>>>>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.