Struct hyperbee::Hyperbee

pub struct Hyperbee<M: CoreMem> { /* private fields */ }

An append only B-Tree built on Hypercore. It provides a key-value store API, with methods for inserting, getting, and deleting key-value pair. As well as creating sorted iterators, and “sub” B-Trees for grouping related data.

Implementations

impl<M: CoreMem> Hyperbee<M>

pub async fn version(&self) -> u64

The number of blocks in the hypercore. The first block is always the header block so: version would be the seq of the next block version - 1 is most recent block

pub async fn get_root( &self, ensure_header: bool ) -> Result<Option<Arc<RwLock<Node<M>>>>, HyperbeeError>

Gets the root of the tree. When ensure_header == true write the hyperbee header onto the hypercore if it does not exist.

pub async fn create_header( &self, metadata: Option<Metadata> ) -> Result<AppendOutcome, HyperbeeError>

Create the header for the Hyperbee. This must be done before writing anything else to the tree.

pub async fn print(&self) -> Result<String, HyperbeeError>

Returs a string representing the structure of the tree showing the keys in each node

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 Hyperbee::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 Hyperbee::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 fn sub(&self, prefix: &[u8]) -> Prefixed<M>

Create a new tree with all it’s operation’s prefixed by the provided prefix.

pub async fn traverse<'a>( &self, conf: TraverseConfig ) -> Result<Traverse<'a, M>, HyperbeeError>

Traverse the tree based on the given TraverseConfig

impl Hyperbee<RandomAccessDisk>

pub async fn from_storage_dir<T: AsRef<Path>>( path_to_storage_dir: T ) -> Result<Hyperbee<RandomAccessDisk>, HyperbeeError>

Helper for creating a Hyperbee

Panics

when storage path is incorrect when Hypercore failse to build when Blocks fails to build

Errors

when Hyperbee fails to build

impl Hyperbee<RandomAccessMemory>

pub async fn from_ram() -> Result<Hyperbee<RandomAccessMemory>, HyperbeeError>

Helper for creating a Hyperbee in RAM

Trait Implementations

impl<M: Debug + CoreMem> Debug for Hyperbee<M>

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

Formats the value using the given formatter.