Struct hyperbee::prefixed::Prefixed

pub struct Prefixed<M: CoreMem> {
    pub prefix: Vec<u8>,
    /* private fields */
}

A “sub” Hyperbee, which can be used for grouping data. get, put, del, traverse operations are automatically prefixed with Prefixed::prefix + PrefixedConfig::seperator where appropriate.

Fields

prefix: Vec<u8>

All keys inserted with Prefixed::put are prefixed with this value

Implementations

impl<M: CoreMem> Prefixed<M>

pub async fn get( &self, key: &[u8] ) -> Result<Option<(u64, Option<Vec<u8>>)>, HyperbeeError>

Get the value corresponding to the provided key from the Hyperbee

Errors

When Hyperbee.get_root fails

pub async fn put( &self, key: &[u8], value: Option<&[u8]> ) -> Result<(Option<u64>, u64), HyperbeeError>

Insert the given key and value into the tree Returs the seq of the new key, and Option<u64> which contains the seq of the old key if it was replaced.

pub async fn put_compare_and_swap( &self, key: &[u8], value: Option<&[u8]>, cas: impl FnOnce(Option<&KeyValueData>, &KeyValueData) -> bool ) -> Result<(Option<u64>, Option<u64>), HyperbeeError>

Like Prefixed::put but takes a compare_and_swap function. The compared_and_swap function is called with the old key (if present), and the new key. The new key is only inserted if compare_and_swap returns true. Returs two Option<u64>s. The first is the old key, the second is the new key.

pub async fn del(&self, key: &[u8]) -> Result<Option<u64>, HyperbeeError>

Delete the given key from the tree Returns the seq from the key if it was deleted.

pub async fn del_compare_and_swap( &self, key: &[u8], cas: impl FnOnce(&KeyValueData) -> bool ) -> Result<Option<(bool, u64)>, HyperbeeError>

Like Prefixed::del but takes a compare_and_swap function. Before deleting the function is called with existing key’s KeyValueData. The key is only deleted if compare_and_swap returs true. Returns the bool representing the result of compare_and_swap, and the seq for the key.

pub async fn traverse<'a>( &self, conf: &TraverseConfig ) -> Result<impl Stream<Item = KeyDataResult> + 'a, HyperbeeError>

where M: 'a,

Travese prefixed keys. If you provide TraverseConfig::min_value or TraverseConfig::max_value it should not include the prefix. Note that the key that is yielded has Self::prefix + PrefixedConfig::seperator stripped (which is the same behavior as JavaScript Hyperbee’s method .sub