Struct FileSystemCapabilities 

pub struct FileSystemCapabilities { /* private fields */ }

Stable typed capability support for one configured filesystem.

Capabilities have one of two support strengths: conditional capabilities may be attempted and can still be rejected for an individual request, while guaranteed capabilities are promised for every valid request in scope. Derived capabilities must not be stronger than their base capability.

Examples

use qubit_fs::metadata::{FileSystemCapabilities, FileSystemCapability,
    FileSystemCapabilitySupport};

let capabilities = FileSystemCapabilities::new()
    .with_conditional(FileSystemCapability::Read)
    .with_conditional(FileSystemCapability::RangeRead);
assert_eq!(capabilities.support(FileSystemCapability::RangeRead),
    FileSystemCapabilitySupport::Conditional);
assert_eq!(capabilities.support(FileSystemCapability::Write),
    FileSystemCapabilitySupport::Unsupported);
assert!(capabilities.missing_dependency().is_none());

let invalid = FileSystemCapabilities::new()
    .with_guaranteed(FileSystemCapability::RangeRead)
    .with_conditional(FileSystemCapability::Read);
assert_eq!(invalid.missing_dependency(), Some((
    FileSystemCapability::RangeRead, FileSystemCapability::Read)));

Implementations

impl FileSystemCapabilities

pub const fn new() -> Self

Creates an empty capability set.

pub const fn with_conditional(self, capability: FileSystemCapability) -> Self

Returns a copy with one additional conditional capability.

pub const fn with_guaranteed(self, capability: FileSystemCapability) -> Self

Returns a copy with one additional guaranteed capability.

pub const fn set_support( self, capability: FileSystemCapability, support: FileSystemCapabilitySupport, ) -> Self

Replaces the support status of one capability.

pub const fn support( &self, capability: FileSystemCapability, ) -> FileSystemCapabilitySupport

Returns the support status of capability.

pub const fn supports(&self, capability: FileSystemCapability) -> bool

Returns whether the provider can attempt capability.

pub const fn guarantees(&self, capability: FileSystemCapability) -> bool

Returns whether capability is guaranteed in this filesystem scope.

pub const fn len(&self) -> usize

Returns the number of advertised capabilities.

Returns

Number of set capability flags.

pub const fn is_empty(&self) -> bool

Returns whether no capability is advertised.

Returns

true when the set contains no capability.

pub fn iter(&self) -> impl Iterator<Item = FileSystemCapability> + '_

Iterates advertised capabilities in stable discriminant order.

Returns

An iterator over every capability contained in this set.

pub fn iter_with_support( &self, ) -> impl Iterator<Item = (FileSystemCapability, FileSystemCapabilitySupport)> + '_

Iterates advertised capabilities with their support status.

pub fn missing_dependency( &self, ) -> Option<(FileSystemCapability, FileSystemCapability)>

Returns the first advertised capability whose required base capability is absent.

None means that every advertised derived capability has its required base capability. The returned pair contains the derived capability followed by the missing base capability.

Returns

Some with the first derived capability and missing base capability, or None when no advertised dependency is missing.

Trait Implementations

impl Clone for FileSystemCapabilities

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FileSystemCapabilities

impl Debug for FileSystemCapabilities

fn fmt(&self, formatter: &mut Formatter<'_>) -> FmtResult

Formats the value using the given formatter.

impl Default for FileSystemCapabilities

fn default() -> Self

Creates an empty capability set.

impl Eq for FileSystemCapabilities

impl PartialEq for FileSystemCapabilities

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for FileSystemCapabilities