Enum casper_node::utils::External

pub enum External<T> {
    Path(PathBuf),
    Loaded(T),
    Missing,
}

External resource.

An External resource can be given in two ways: Either as an immediate value, or through a path, provided the value implements Loadable.

Serializing and deserializing an External value is only possible if it is in path form. This is especially useful when writing structure configurations.

An External also always provides a default, which will always result in an error when load is called. Should the underlying type T implement Default, the with_default can be used instead.

Variants

Path(PathBuf)

Value that should be loaded from an external path.

Loaded(T)

Loaded or immediate value.

Missing

The value has not been specified, but a default has been requested.

Implementations

impl<T> External<T>

pub fn from_value(value: T) -> Self

Creates an external from a value.

pub fn from_path<P: AsRef<Path>>(path: P) -> Self

Creates an external referencing a path.

impl<T> External<T> where
    T: Loadable, 

pub fn load<P: AsRef<Path>>(self, root: P) -> Result<T, LoadError<T::Error>>

Loads the value if not loaded already, resolving relative paths from root or returns available value. If the value is Missing, returns an error.

pub fn full_path<P: AsRef<Path>>(&self, root: P) -> Option<PathBuf>

Returns the full path to the external item, or None if the type is Loaded or Missing.

impl<T> External<T> where
    T: Loadable + Default, 

pub fn with_default(self) -> Self

Insert a default value if missing.

Trait Implementations

impl<T: Clone> Clone for External<T>

fn clone(&self) -> External<T>

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> DataSize for External<T> where
    PathBuf: DataSize,
    T: DataSize, 

const IS_DYNAMIC: bool

If true, the type has a heap size that can vary at runtime, depending on the actual value.

const STATIC_HEAP_SIZE: usize

The amount of space a value of the type always occupies. If IS_DYNAMIC is false, this is the total amount of heap memory occupied by the value. Otherwise this is a lower bound.

fn estimate_heap_size(&self) -> usize

Estimates the size of heap memory taken up by this value.

pub fn estimate_detailed_heap_size(&self) -> MemUsageNode

Create a tree of memory estimations.

impl<T: Debug> Debug for External<T>

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

Formats the value using the given formatter.

impl<T> Default for External<T>

fn default() -> Self

Returns the "default value" for a type.

impl<'de, T> Deserialize<'de> for External<T>

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<T: Eq> Eq for External<T>

impl<T: PartialEq> PartialEq<External<T>> for External<T>

fn eq(&self, other: &External<T>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &External<T>) -> bool

This method tests for !=.

impl<T> Serialize for External<T>

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error> where
    __S: Serializer, 

Serialize this value into the given Serde serializer.

impl<T> StructuralEq for External<T>

impl<T> StructuralPartialEq for External<T>