[−][src]Trait caves::Cave

pub trait Cave: Send + Sync {
    fn get(&self, name: &str) -> Res;

    fn set(&self, name: &str, data: &[u8]) -> Res;

    fn delete(&self, name: &str) -> Res;

    fn not_found(&self, name: &str) -> Res { ... }
}

A simple interface for key-value stores.

A Cave object must have support for the following actions:

  • Get a key by name, or return an error if it doesn't exist.
  • Store a key by name; update it if it exists or create it if it doesn't.
  • Delete a key by name, or return an error if it doesn't exist.

These actions must be able to happen concurrently, from any thread. This means that the objects must not rely on exclusive mutability references in order to update their state.

Usage

Here's an example on how one can use a Cave object. In this example, we use a MemoryCave object, but any other Cave object can be used in its place.

use caves::errors::Error;
use caves::{MemoryCave, Cave};

// Initialize a MemoryCave object.
let b = MemoryCave::new();

// Create a new key with an empty value.
b.set("key", b"");

// Override the key's value.
b.set("key", b"value");

// Retrieve the contents of the key.
let res = b.get("key");
assert_eq!(res.unwrap(), b"value");

// Delete the key.
b.delete("key");

// Subsequent attempts to retrieve the contents of the key should return an
// error.
let res = b.get("key");
assert_eq!(res, Err(Error::NotFound("key".to_string())));

Required methods

fn get(&self, name: &str) -> Res

Get a key by its name, and return its contents.

If it does not exist, return an error.

fn set(&self, name: &str, data: &[u8]) -> Res

Create or update a key by its name.

fn delete(&self, name: &str) -> Res

Delete a key by its name.

If it does not exist, return an error.

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Provided methods

fn not_found(&self, name: &str) -> Res

A helper method to return an error for keys that could not be found.

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Implementors

impl Cave for FileCave[src]

impl Cave for MemoryCave[src]

impl Cave for RocksDBCave[src]

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