Struct Versioned

pub struct Versioned<T: DirStructureItem> { /* private fields */ }

A versioned value. This is a wrapper around a value that will keep track of how many times it has been changed. This is useful to not write the value to disk if it hasn’t changed.

You can get a reference to the value via its Deref implementation, and you can get a mutable reference to the value via its DerefMut implementation.

The version is incremented every time DerefMut::deref_mut is called.

Alternatively, for Eq types, you can use the Versioned::edit_eq_check method to edit the value, and it will increment the version if the value has changed.

Example

use dir_structure::VersionedString;

let mut v = VersionedString::new("value".to_owned(), "path");
assert!(v.is_clean());
assert!(!v.is_dirty());

*v = "new value".to_owned();
assert!(v.is_dirty());

Implementations

impl<T: DirStructureItem> Versioned<T>

pub fn new(value: T, path: impl Into<PathBuf>) -> Self

Creates a new Versioned with the specified value.

The version is set to the default value.

pub fn new_dirty(value: T, path: impl Into<PathBuf>) -> Self

Creates a new Versioned with the specified value, and in a dirty state.

Example

use dir_structure::VersionedString;

let v = VersionedString::new_dirty("value".to_owned(), "path");
assert!(v.is_dirty());

pub fn is_dirty(&self) -> bool

Checks if the value has been changed.

pub fn is_clean(&self) -> bool

Checks if the value has not been changed.

pub fn edit_eq_check(&mut self, f: impl FnOnce(&mut T))

where T: Eq + Clone,

Edits the value using the provided closure, and increments the version if the value has changed.

Example

use dir_structure::VersionedString;

let mut v = VersionedString::new("value".to_owned(), "path");

v.edit_eq_check(|s| *s = "value".to_owned());
assert!(v.is_clean());
v.edit_eq_check(|s| *s = "new value".to_owned());
assert!(v.is_dirty());

Trait Implementations

impl<T: Clone + DirStructureItem> Clone for Versioned<T>

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug + DirStructureItem> Debug for Versioned<T>

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

Formats the value using the given formatter.

impl<T: DirStructureItem> Deref for Versioned<T>

type Target = T

The resulting type after dereferencing.

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

Dereferences the value.

impl<T: DirStructureItem> DerefMut for Versioned<T>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<T: Hash + DirStructureItem> Hash for Versioned<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: DirStructureItem> ReadFrom for Versioned<T>

fn read_from(path: &Path) -> Result<Self>

where Self: Sized,

Reads the structure from the specified path, which can be either a file or a directory.

impl<T: DirStructureItem> WriteTo for Versioned<T>

fn write_to(&self, path: &Path) -> Result<()>

Writes the structure to the specified path.