Trait disk::Empty

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pub unsafe trait Empty {
    const OS_DIRECTORY: Dir;
    const PROJECT_DIRECTORY: &'static str;
    const SUB_DIRECTORIES: &'static str;
    const FILE: &'static str;
    const FILE_EXT: &'static str;
    const FILE_NAME: &'static str;
    const FILE_NAME_GZIP: &'static str;
    const FILE_NAME_TMP: &'static str;
    const FILE_NAME_GZIP_TMP: &'static str;
Show 15 methods
    // Provided methods
    fn mkdir() -> Result<(), Error> { ... }
    fn rm_rf() -> Result<(), Error> { ... }
    fn rm() -> Result<(), Error> { ... }
    fn exists() -> Result<bool, Error> { ... }
    fn project_dir() -> &'static str { ... }
    fn sub_dirs() -> &'static str { ... }
    fn file_name() -> &'static str { ... }
    fn file_ext() -> &'static str { ... }
    fn file() -> &'static str { ... }
    fn file_gzip() -> &'static str { ... }
    fn file_tmp() -> &'static str { ... }
    fn file_gzip_tmp() -> &'static str { ... }
    fn base_path() -> Result<PathBuf, Error> { ... }
    fn absolute_path() -> Result<PathBuf, Error> { ... }
    fn touch() -> Result<(), Error> { ... }
}

Expand description

Empty file

This is a an empty file that

Contains no data
Doesn’t need serde
Inherits useful PATH methods.

Typically used for file-based signals.

If you implement this on a struct that contains data, the data will be ignored and an empty file will always be created.

The file created will have no file extension, e.g:

disk::empty!(Hello, Dir::Data, "disk_test", "signal", "hello");
#[derive(Serialize, Deserialize)]
struct Hello {
    data: bool,
}

// The filename should be "hello".
assert!(Hello::file_name() == "hello");

// Create the file.
Hello::touch().unwrap();

// Make sure it (and the directories) exist.
assert!(Hello::exists().unwrap());

// Delete the project directory.
Hello::rm_rf().unwrap();

// Make sure the file no longer exist.
assert!(!Hello::exists().unwrap());

This creates a file called hello, containing no data. The bool is ignored.

The PATH on Linux would be: ~/.local/share/disk_test/signal/hello.

Safety

When manually implementing, you are promising that the PATH’s manually specified are correct.

Required Associated Constants§

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const OS_DIRECTORY: Dir

Which OS directory it will be saved in.

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const PROJECT_DIRECTORY: &'static str

What the main project directory will be.

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const SUB_DIRECTORIES: &'static str

Optional sub directories in between the project directory and file.

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const FILE: &'static str

What the raw file name will be (no extension).

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const FILE_EXT: &'static str

What the file extension will be.

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const FILE_NAME: &'static str

What the full filename + extension will be.

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const FILE_NAME_GZIP: &'static str

What the gzip variant of the filename will be.

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const FILE_NAME_TMP: &'static str

What the tmp variant of the filename will be.

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const FILE_NAME_GZIP_TMP: &'static str

What the gzip + tmp variant of the filename will be.

Provided Methods§

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fn mkdir() -> Result<(), Error>

Create the directories leading up-to the file.

This is not necessary when using any variant of Self::save() as the directories are created implicitly.

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fn rm_rf() -> Result<(), Error>

Recursively remove this file’s project directory.

This deletes all directories starting from Self::PROJECT_DIRECTORY. For example:

disk::toml!(State, disk::Dir::Data, "MyProject", "sub_dir", "state");

This project’s file would be located at ~/.local/share/myproject. This is the PATH that gets removed recursively.

This is akin to running:

rm -rf ~/.local/share/myproject

The input to all disk macros are sanity checked. The worst you can do with this function is delete your project’s directory.

This function calls std::fs::remove_dir_all, which does not follow symlinks.

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fn rm() -> Result<(), Error>

Try deleting the file.

This will return success if the file doesn’t exist or if deleted.

It will return failure if the file existed but could not be deleted or if any other error occurs.

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fn exists() -> Result<bool, Error>

Check if the file exists.

true == The file exists.
false == The file does not exist.
anyhow::Error == There was an error, existance is unknown.

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