Revert "Move to async I/O with Tokio"

This reverts commit e1dbfd7.

Author: afilini

.travis.yml

@@ -8,11 +8,12 @@ before_script:
 script:
   - cargo fmt -- --check --verbose
   - cargo test --verbose --all
+  - cargo check --verbose --features=use-openssl
   - cargo check --verbose --no-default-features --features=proxy
-  - cargo check --verbose --no-default-features --features=tls
   - cargo check --verbose --no-default-features --features=minimal
   - cargo check --verbose --no-default-features --features=minimal,debug-calls
-  - cargo check --verbose --no-default-features --features=minimal,no-sync
+  - cargo check --verbose --no-default-features --features=proxy,use-openssl
+  - cargo check --verbose --no-default-features --features=proxy,use-rustls
 
 before_cache:
   - rm -rf "$TRAVIS_HOME/.cargo/registry/src"

Cargo.toml

@@ -1,5 +1,4 @@
 [package]
-edition = "2018"
 name = "electrum-client"
 version = "0.1.0-beta.6"
 authors = ["Alekos Filini <[email protected]>"]
@@ -23,23 +22,20 @@ path = "src/lib.rs"
 [dependencies]
 log = "^0.4"
 bitcoin = { version = "0.23", features = ["use-serde"] }
-tokio = { version = "0.2", features = ["net", "io-util"] }
-futures = "0.3"
 serde = { version = "^1.0", features = ["derive"] }
 serde_json = { version = "^1.0" }
 
 # Optional dependencies
-tokio-tls = { version = "0.3", optional = true }
-native-tls = { version = "0.2.4", optional = true }
-tokio-socks = { version = "0.2", optional = true }
-
-[dev-dependencies]
-tokio = { version = "0.2", features = ["net", "io-util", "macros"] }
+socks = { version = "^0.3", optional = true }
+openssl = { version = "^0.10", optional = true }
+rustls = { version = "0.16.0", optional = true, features = ["dangerous_configuration"] }
+webpki = { version = "0.21.0", optional = true }
+webpki-roots = { version = "^0.19", optional = true }
 
 [features]
-default = ["tokio-tls", "native-tls", "tokio-socks"]
-no-sync = []
+default = ["socks", "webpki", "webpki-roots", "rustls"]
 minimal = []
 debug-calls = []
-proxy = ["tokio-socks"]
-tls = ["tokio-tls", "native-tls"]
+proxy = ["socks"]
+use-rustls = ["webpki", "webpki-roots", "rustls"]
+use-openssl = ["openssl"]

examples/plaintext.rs

@@ -2,9 +2,8 @@ extern crate electrum_client;
 
 use electrum_client::Client;
 
-#[tokio::main]
-async fn main() {
-    let mut client = Client::new("kirsche.emzy.de:50001").await.unwrap();
-    let res = client.server_features().await;
+fn main() {
+    let mut client = Client::new("kirsche.emzy.de:50001").unwrap();
+    let res = client.server_features();
     println!("{:#?}", res);
 }

examples/ssl.rs

@@ -0,0 +1,9 @@
+extern crate electrum_client;
+
+use electrum_client::Client;
+
+fn main() {
+    let mut client = Client::new_ssl("electrum2.hodlister.co:50002", true).unwrap();
+    let res = client.server_features();
+    println!("{:#?}", res);
+}

examples/tls.rs

@@ -2,24 +2,20 @@ extern crate electrum_client;
 
 use electrum_client::Client;
 
-#[tokio::main]
-async fn main() {
+fn main() {
     // NOTE: This assumes Tor is running localy, with an unauthenticated Socks5 listening at
     // localhost:9050
 
-    let mut client = Client::new_proxy("ozahtqwp25chjdjd.onion:50001", "127.0.0.1:9050")
-        .await
-        .unwrap();
-    let res = client.server_features().await;
+    let mut client = Client::new_proxy("ozahtqwp25chjdjd.onion:50001", "127.0.0.1:9050").unwrap();
+    let res = client.server_features();
     println!("{:#?}", res);
 
     // works both with onion v2/v3 (if your Tor supports them)
     let mut client = Client::new_proxy(
         "v7gtzf7nua6hdmb2wtqaqioqmesdb4xrlly4zwr7bvayxv2bpg665pqd.onion:50001",
         "127.0.0.1:9050",
     )
-    .await
     .unwrap();
-    let res = client.server_features().await;
+    let res = client.server_features();
     println!("{:#?}", res);
 }

examples/tor.rs

@@ -5,7 +5,7 @@
 use bitcoin::hashes::hex::ToHex;
 use bitcoin::{Script, Txid};
 
-use crate::types::{Param, ToElectrumScriptHash};
+use types::{Param, ToElectrumScriptHash};
 
 /// Helper structure that caches all the requests before they are actually sent to the server.
 ///