Struct Protocol

pub struct Protocol<S> { /* private fields */ }

Memcache ASCII protocol implementation.

Implementations

impl<S> Protocol<S>

where S: AsyncRead + AsyncWrite + Unpin,

pub fn new(io: S) -> Self

Creates the ASCII protocol on a stream.

Examples found in repository

examples/tcp-simple.rs (line 25)

fn main() {
    let args: Vec<String> = env::args().collect();
    if args.len() < 2 {
        eprintln!("{} <addr>", args[0]);
        return;
    }

    let addr = &args[1];

    block_on(async move {
        let (key, val) = ("foo", "bar");
        let stream = TcpStream::connect(addr).expect("Failed to create stream");

        // "futures::io::AllowStdIo" is used here to make the stream
        // work with AsyncIO. This shouldn't be used in production
        // since it will block current thread. Use something like
        // romio or tokio instead.
        let mut cache = Protocol::new(AllowStdIo::new(stream));
        cache
            .set(&key, val.as_bytes(), 0)
            .await
            .expect("Failed to set key");

        let v = cache.get(&key).await.expect("Failed to get key");
        assert_eq!(v, val.as_bytes());
    });
}

pub async fn get<K: AsRef<[u8]>>(&mut self, key: K) -> Result<Vec<u8>, Error>

Returns the value for given key as bytes. If the value doesn’t exist, ErrorKind::NotFound is returned.

Examples found in repository

examples/tcp-simple.rs (line 31)

fn main() {
    let args: Vec<String> = env::args().collect();
    if args.len() < 2 {
        eprintln!("{} <addr>", args[0]);
        return;
    }

    let addr = &args[1];

    block_on(async move {
        let (key, val) = ("foo", "bar");
        let stream = TcpStream::connect(addr).expect("Failed to create stream");

        // "futures::io::AllowStdIo" is used here to make the stream
        // work with AsyncIO. This shouldn't be used in production
        // since it will block current thread. Use something like
        // romio or tokio instead.
        let mut cache = Protocol::new(AllowStdIo::new(stream));
        cache
            .set(&key, val.as_bytes(), 0)
            .await
            .expect("Failed to set key");

        let v = cache.get(&key).await.expect("Failed to get key");
        assert_eq!(v, val.as_bytes());
    });
}

pub async fn get_multi<K: AsRef<[u8]>>( &mut self, keys: &[K], ) -> Result<HashMap<String, Vec<u8>>, Error>

Returns values for multiple keys in a single call as a HashMap from keys to found values. If a key is not present in memcached it will be absent from returned map.

pub async fn get_prefix<K: Display>( &mut self, key_prefix: K, limit: Option<usize>, ) -> Result<HashMap<String, Vec<u8>>, Error>

Get up to limit keys which match the given prefix. Returns a HashMap from keys to found values. This is not part of the Memcached standard, but some servers implement it nonetheless.

pub async fn add<K: Display>( &mut self, key: K, val: &[u8], expiration: u32, ) -> Result<(), Error>

Add a key. If the value exists, ErrorKind::AlreadyExists is returned.

pub async fn set<K: Display>( &mut self, key: K, val: &[u8], expiration: u32, ) -> Result<(), Error>

Set key to given value and don’t wait for response.

Examples found in repository

examples/tcp-simple.rs (line 27)

fn main() {
    let args: Vec<String> = env::args().collect();
    if args.len() < 2 {
        eprintln!("{} <addr>", args[0]);
        return;
    }

    let addr = &args[1];

    block_on(async move {
        let (key, val) = ("foo", "bar");
        let stream = TcpStream::connect(addr).expect("Failed to create stream");

        // "futures::io::AllowStdIo" is used here to make the stream
        // work with AsyncIO. This shouldn't be used in production
        // since it will block current thread. Use something like
        // romio or tokio instead.
        let mut cache = Protocol::new(AllowStdIo::new(stream));
        cache
            .set(&key, val.as_bytes(), 0)
            .await
            .expect("Failed to set key");

        let v = cache.get(&key).await.expect("Failed to get key");
        assert_eq!(v, val.as_bytes());
    });
}

pub async fn append<K: Display>( &mut self, key: K, val: &[u8], ) -> Result<(), Error>

Append bytes to the value in memcached and don’t wait for response.

pub async fn delete<K: Display>(&mut self, key: K) -> Result<(), Error>

Delete a key and don’t wait for response.

pub async fn version(&mut self) -> Result<String, Error>

Return the version of the remote server.

pub async fn flush(&mut self) -> Result<(), Error>

Delete all keys from the cache.

pub async fn increment<K: AsRef<[u8]>>( &mut self, key: K, amount: u64, ) -> Result<u64, Error>

Increment a specific integer stored with a key by a given value. If the value doesn’t exist, ErrorKind::NotFound is returned. Otherwise the new value is returned

pub async fn decrement<K: AsRef<[u8]>>( &mut self, key: K, amount: u64, ) -> Result<u64, Error>

Decrement a specific integer stored with a key by a given value. If the value doesn’t exist, ErrorKind::NotFound is returned. Otherwise the new value is returned

pub async fn gets_cas<K: AsRef<[u8]>>( &mut self, key: K, ) -> Result<(Vec<u8>, u64), Error>

Call gets to also return CAS id, which can be used to run a second CAS command

pub async fn cas<K: Display>( &mut self, key: K, val: &[u8], cas_id: u64, expiration: u32, ) -> Result<bool, Error>

pub async fn append_or_vivify<K: Display>( &mut self, key: K, val: &[u8], ttl: u32, ) -> Result<(), Error>

Append bytes to the value in memcached, and creates the key if it is missing instead of failing compared to simple append