Struct pingora_cache::VarianceBuilder

pub struct VarianceBuilder<'a> { /* private fields */ }

A builder for variance keys, used for distinguishing multiple cached assets at the same URL. This is intended to be easily passed to helper functions, which can each populate a portion of the variance.

Implementations

impl<'a> VarianceBuilder<'a>

pub fn new() -> Self

Create an empty variance key. Has no variance by default - add some variance using Self::add_value.

pub fn add_value( &mut self, name: &'a str, value: &'a (impl AsRef<[u8]> + ?Sized) )

Add a byte string to the variance key. Not sensitive to insertion order. value is intended to take either &str or &[u8].

pub fn add_owned_value(&mut self, name: &'a str, value: Vec<u8>)

Move a byte string to the variance key. Not sensitive to insertion order. Useful when writing helper functions which generate a value then add said value to the VarianceBuilder. Without this, the helper function would have to move the value to the calling function to extend its lifetime to at least match the VarianceBuilder.

pub fn has_variance(&self) -> bool

Check whether this variance key actually has variance, or just refers to the root asset

pub fn finalize(self) -> Option<HashBinary>

Hash this variance key. Returns None if Self::has_variance is false.