Struct ConnectionPool 

pub struct ConnectionPool { /* private fields */ }

ConnectionPool represents pool of connections to DAPI nodes.

It can be cloned and shared between threads. Cloning the pool will create a new reference to the same pool.

Implementations

impl ConnectionPool

pub fn new(capacity: usize) -> Self

Create a new pool with a given capacity. The pool will evict the least recently used item when the capacity is reached.

Panics

Panics if the capacity is zero.

impl ConnectionPool

pub fn get( &self, prefix: PoolPrefix, uri: &Uri, settings: Option<&AppliedRequestSettings>, ) -> Option<PoolItem>

Get item from the pool for the given uri and settings.

Arguments

• prefix - Prefix for the item in the pool. Used to distinguish between Core and Platform clients.
• uri - URI of the node.
• settings - Applied request settings.

pub fn get_or_create<E>( &self, prefix: PoolPrefix, uri: &Uri, settings: Option<&AppliedRequestSettings>, create: impl FnOnce() -> Result<PoolItem, E>, ) -> Result<PoolItem, E>

Get value from cache or create it using provided closure. If value is already in the cache, it will be returned. If value is not in the cache, it will be created by calling create() and stored in the cache.

Arguments

• prefix - Prefix for the item in the pool. Used to distinguish between Core and Platform clients.
• uri - URI of the node.
• settings - Applied request settings.

pub fn get_or_create_with_generation<E>( &self, prefix: PoolPrefix, uri: &Uri, settings: Option<&AppliedRequestSettings>, create: impl FnOnce() -> Result<PoolItem, E>, ) -> Result<(PoolItem, u64), E>

Like ConnectionPool::get_or_create, and also returns the generation the returned connection was pooled at (see ConnectionPool::generation).

The generation is read under the same lock that finds or stores the connection, so it is the returned connection’s own even when other threads replace it right afterwards.

pub fn put( &self, uri: &Uri, settings: Option<&AppliedRequestSettings>, value: PoolItem, )

Put item into the pool for the given uri and settings.

pub fn generation(&self) -> u64

Generation of the connection pooled most recently. Every connection put into the pool afterwards gets a higher generation.

pub fn remove_uri(&self, uri: &Uri, generation: u64)

Drop every connection to uri pooled at or before generation, whatever its prefix and connection settings.

A request that misses its deadline may have been sent over a half-open connection: the network path died after the request left, and nothing on the idle channel would ever notice. Keeping it pooled would stall the next request sent to the same node, so the executor evicts it and the next request dials a fresh connection.

Connections pooled after generation stay. They were dialed after the timed-out attempt took its connection, for example by a concurrent request that already timed out on the same node and reconnected.

Trait Implementations

impl Clone for ConnectionPool

fn clone(&self) -> ConnectionPool

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ConnectionPool

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

Formats the value using the given formatter.

impl Default for ConnectionPool

fn default() -> Self

Returns the “default value” for a type.