Trait Host 

pub trait Host {
    // Required methods
    fn read_classified(
        &self,
        label: &str,
        max: usize,
    ) -> Result<Option<Vec<u8>>, ReadFail>;
    fn ensure_absent(&self, label: &str) -> Result<(), IoFail>;
    fn create(&self, label: &str, bytes: &[u8]) -> Result<(), IoFail>;
    fn write_all(&self, files: &[(String, Vec<u8>)]) -> Result<(), IoFail>;
    fn join(&self, dir: &str, name: &str) -> String;

    // Provided methods
    fn read(&self, label: &str, limit: usize) -> Result<Vec<u8>, IoFail> { ... }
    fn read_bounded(
        &self,
        label: &str,
        max: usize,
    ) -> Result<Option<Vec<u8>>, IoFail> { ... }
}

The host of one command.

Required Methods

fn read_classified( &self, label: &str, max: usize, ) -> Result<Option<Vec<u8>>, ReadFail>

Read label, at most max bytes of it; None when it does not exist. A failure of the input is told from an exhausted command budget, which depends on read order rather than on the input.

fn ensure_absent(&self, label: &str) -> Result<(), IoFail>

Refuse an output that already exists, before any work. A pure check that changes nothing, so calling it again for the same label gives the same answer: commands check every output up front and again just before writing.

fn create(&self, label: &str, bytes: &[u8]) -> Result<(), IoFail>

Publish one output, never overwriting.

fn write_all(&self, files: &[(String, Vec<u8>)]) -> Result<(), IoFail>

Publish every (label, bytes), all or none.

fn join(&self, dir: &str, name: &str) -> String

The label of name inside the output or input directory dir.

Provided Methods

fn read(&self, label: &str, limit: usize) -> Result<Vec<u8>, IoFail>

Read label up to its document limit plus one byte, so an oversized input reaches the parser and is refused by the document’s own bound.

fn read_bounded( &self, label: &str, max: usize, ) -> Result<Option<Vec<u8>>, IoFail>

Like Host::read with an explicit maximum, returning None for an input that does not exist.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl Host for Memory