Struct pearl::Storage

pub struct Storage<K> { /* fields omitted */ }

A main storage struct.

This type is clonable, cloning it will only create a new reference, not a new storage. Storage has a type parameter K. To perform read/write operations K must implement Key trait.

Examples

use pearl::{Storage, Builder, Key};

#[tokio::main]
async fn main() {
    let mut storage: Storage<String> = Builder::new()
        .work_dir("/tmp/pearl/")
        .max_blob_size(1_000_000)
        .max_data_in_blob(1_000_000_000)
        .blob_file_name_prefix("pearl-test")
        .build()
        .unwrap();
    storage.init().await.unwrap();
}

Methods

impl<K> Storage<K>

pub async fn init<'_>(&'_ mut self) -> Result<()>

init() used to prepare all environment to further work.

Storage works in directory provided to builder. If directory don't exist, storage creates it, otherwise tries to init existing storage.

pub async fn write<'_>(&'_ self, key: impl Key, value: Vec<u8>) -> Result<()>

Writes data to active blob asyncronously. If active blob reaches it limit, creates new and closes old.

Examples

async fn write_data() {
    let key = 42u64.to_be_bytes().to_vec();
    let data = b"async written to blob".to_vec();
    storage.write(key, data).await
}

pub async fn write_with<'_>(
    &'_ self,
    key: impl Key,
    value: Vec<u8>,
    meta: Meta
) -> Result<()>

Similar to [write()] but with metadata

Examples

async fn write_data() {
    let key = 42u64.to_be_bytes().to_vec();
    let data = b"async written to blob".to_vec();
    let meta = Meta::new();
    meta.insert("version".to_string(), b"1.0".to_vec());
    storage.write_with(&key, data, meta).await
}

pub async fn read<'_>(&'_ self, key: impl Key) -> Result<Vec<u8>>

Reads the first found data matching given key, if are no records with matching key, returns Error::RecordNotFound

Examples

async fn read_data() {
    let key = 42u64.to_be_bytes().to_vec();
    let data = storage.read(key).await;
}

pub async fn read_with<'_, '_>(
    &'_ self,
    key: impl Key,
    meta: &'_ Meta
) -> Result<Vec<u8>>

Reads data matching given key and metadata, if are no records with matching key, returns Error::RecordNotFound

Examples

async fn read_data() {
    let key = 42u64.to_be_bytes().to_vec();
    let meta = Meta::new();
    meta.insert("version".to_string(), b"1.0".to_vec());
    let data = storage.read(&key, &meta).await;
}

pub fn read_all<'a>(&'a self, key: &'a impl Key) -> ReadAll<'a, K>

Returns stream producing entries with matching key

pub async fn close<'_>(&'_ self) -> Result<()>

Stop blob updater and release lock file

#[must_use] pub fn blobs_count(&self) -> usize

blob_count returns number of closed blobs plus one active, if there is some.

Examples

use pearl::Builder;

let mut storage = Builder::new().work_dir("/tmp/pearl/").build::<f64>();
storage.init().await;
assert_eq!(storage.blobs_count(), 1);

Trait Implementations

impl<K> Drop for Storage<K>

fn drop(&mut self)

Executes the destructor for this type.

impl<K> Clone for Storage<K>

#[must_use] fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<K: Debug> Debug for Storage<K>

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

Formats the value using the given formatter.