Struct opendal::layers::CacheLayer

pub struct CacheLayer { /* private fields */ }

ContentCacheLayer will add content data cache support for OpenDAL.

Notes

This layer only maintains its own states. Users should care about the cache consistency by themselves. For example, in the following situations, users could get out-dated metadata cache:

• Users have operations on underlying operator directly.
• Other nodes have operations on underlying storage directly.
• Concurrent read/write/delete on the same path.

To make sure content cache consistent across the cluster, please make sure all nodes in the cluster use the same cache services like redis or tikv.

Examples

Use memory as cache.

use std::sync::Arc;

use anyhow::Result;
use opendal::layers::CacheLayer;
use opendal::services::memory;
use opendal::Operator;
use opendal::Scheme;

let _ = Operator::from_env(Scheme::Fs)
    .expect("must init")
    .layer(CacheLayer::new(
        Operator::from_env(Scheme::Memory).expect("must init"),
    ));

Use memory and fs as a two level cache.

use std::sync::Arc;

use anyhow::Result;
use opendal::layers::CacheLayer;
use opendal::services::memory;
use opendal::Operator;
use opendal::Scheme;

let _ = Operator::from_env(Scheme::Fs)
    .expect("must init")
    .layer(CacheLayer::new(
        Operator::from_env(Scheme::Fs).expect("must init"),
    ))
    .layer(CacheLayer::new(
        Operator::from_env(Scheme::Memory).expect("must init"),
    ));

Implementations

impl CacheLayer

pub fn new(cache: Operator) -> Self

Create a new metadata cache layer.

pub fn with_policy(self, policy: impl CachePolicy) -> Self

Update the cache layer’s logic.

Trait Implementations

impl Clone for CacheLayer

fn clone(&self) -> CacheLayer

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for CacheLayer

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

Formats the value using the given formatter.

impl Layer for CacheLayer

fn layer(&self, inner: Arc<dyn Accessor>) -> Arc<dyn Accessor>

Intercept the operations on the underlying storage.