Add AsyncClient

sdk/src/async_client.rs

@@ -0,0 +1,35 @@
+//! Defines a trait for non-blocking (asynchronous) communication with a Solana server.
+//! Implementations are expected to create tranasctions, sign them, and send
+//! them but without waiting to see if the server accepted it.
+
+use crate::instruction::Instruction;
+use crate::message::Message;
+use crate::pubkey::Pubkey;
+use crate::signature::{Keypair, Signature};
+use crate::transaction::Transaction;
+use std::io;
+
+pub trait AsyncClient {
+    /// Send a signed transaction, but don't wait to see if the server accepted it.
+    fn async_send_transaction(&self, transaction: Transaction) -> io::Result<Signature>;
+
+    /// Create a transaction from the given message, and send it to the
+    /// server, but don't wait for to see if the server accepted it.
+    fn async_send_message(&self, keypairs: &[&Keypair], message: Message) -> io::Result<Signature>;
+
+    /// Create a transaction from a single instruction that only requires
+    /// a single signer. Then send it to the server, but don't wait for a reply.
+    fn async_send_instruction(
+        &self,
+        keypair: &Keypair,
+        instruction: Instruction,
+    ) -> io::Result<Signature>;
+
+    /// Attempt to transfer lamports from `keypair` to `pubkey`, but don't wait to confirm.
+    fn async_transfer(
+        &self,
+        lamports: u64,
+        keypair: &Keypair,
+        pubkey: &Pubkey,
+    ) -> io::Result<Signature>;
+}

sdk/src/lib.rs

@@ -1,4 +1,5 @@
 pub mod account;
+pub mod async_client;
 pub mod bpf_loader;
 pub mod fee_calculator;
 pub mod genesis_block;