build: Clean up "proxy" feature

Before, the the `client` module was gated on the "proxy"
feature, which caused unnecessary coupling since proxy is only
required for the Socks5 client type.

This commit removes feature gating of the `client` module in favor
of more precise feature gating of the Socks5 client type as well
as functions which call into the `socks` module.

Author: ValuedMammal

src/client.rs

@@ -17,13 +17,14 @@ use std::convert::TryFrom;
 /// [`RawClient`](client/struct.RawClient.html) and provides a more user-friendly
 /// constructor that can choose the right backend based on the url prefix.
 ///
-/// **This is available only with the `default` features, or if `proxy` and one ssl implementation are enabled**
+/// **Note the `Socks5` client type requires the "proxy" feature to be enabled.
 pub enum ClientType {
     #[allow(missing_docs)]
     TCP(RawClient<ElectrumPlaintextStream>),
     #[allow(missing_docs)]
     SSL(RawClient<ElectrumSslStream>),
     #[allow(missing_docs)]
+    #[cfg(feature = "proxy")]
     Socks5(RawClient<ElectrumProxyStream>),
 }
 
@@ -44,6 +45,7 @@ macro_rules! impl_inner_call {
             let res = match &*read_client {
                 ClientType::TCP(inner) => inner.$name( $($args, )* ),
                 ClientType::SSL(inner) => inner.$name( $($args, )* ),
+                #[cfg(feature = "proxy")]
                 ClientType::Socks5(inner) => inner.$name( $($args, )* ),
             };
             drop(read_client);
@@ -110,6 +112,7 @@ impl ClientType {
     pub fn from_config(url: &str, config: &Config) -> Result<Self, Error> {
         if url.starts_with("ssl://") {
             let url = url.replacen("ssl://", "", 1);
+            #[cfg(feature = "proxy")]
             let client = match config.socks5() {
                 Some(socks5) => RawClient::new_proxy_ssl(
                     url.as_str(),
@@ -121,19 +124,28 @@ impl ClientType {
                     RawClient::new_ssl(url.as_str(), config.validate_domain(), config.timeout())?
                 }
             };
+            #[cfg(not(feature = "proxy"))]
+            let client =
+                RawClient::new_ssl(url.as_str(), config.validate_domain(), config.timeout())?;
 
             Ok(ClientType::SSL(client))
         } else {
             let url = url.replacen("tcp://", "", 1);
 
-            Ok(match config.socks5().as_ref() {
-                None => ClientType::TCP(RawClient::new(url.as_str(), config.timeout())?),
+            #[cfg(feature = "proxy")]
+            let client = match config.socks5() {
                 Some(socks5) => ClientType::Socks5(RawClient::new_proxy(
                     url.as_str(),
                     socks5,
                     config.timeout(),
                 )?),
-            })
+                None => ClientType::TCP(RawClient::new(url.as_str(), config.timeout())?),
+            };
+
+            #[cfg(not(feature = "proxy"))]
+            let client = ClientType::TCP(RawClient::new(url.as_str(), config.timeout())?);
+
+            Ok(client)
         }
     }
 }

src/lib.rs

@@ -43,25 +43,20 @@ extern crate serde_json;
 ))]
 extern crate webpki_roots;
 
-#[cfg(any(feature = "default", feature = "proxy"))]
+#[cfg(feature = "proxy")]
 extern crate byteorder;
 
-#[cfg(all(unix, any(feature = "default", feature = "proxy")))]
+#[cfg(all(unix, feature = "proxy"))]
 extern crate libc;
-#[cfg(all(windows, any(feature = "default", feature = "proxy")))]
+#[cfg(all(windows, feature = "proxy"))]
 extern crate winapi;
 
-#[cfg(any(feature = "default", feature = "proxy"))]
+#[cfg(feature = "proxy")]
 pub mod socks;
 
 mod api;
 mod batch;
 
-#[cfg(any(
-    all(feature = "proxy", feature = "use-openssl"),
-    all(feature = "proxy", feature = "use-rustls"),
-    all(feature = "proxy", feature = "use-rustls-ring")
-))]
 pub mod client;
 
 mod config;
@@ -73,11 +68,6 @@ pub mod utils;
 
 pub use api::ElectrumApi;
 pub use batch::Batch;
-#[cfg(any(
-    all(feature = "proxy", feature = "use-openssl"),
-    all(feature = "proxy", feature = "use-rustls"),
-    all(feature = "proxy", feature = "use-rustls-ring")
-))]
 pub use client::*;
 pub use config::{Config, ConfigBuilder, Socks5Config};
 pub use types::*;

src/raw_client.rs

@@ -470,10 +470,10 @@ impl RawClient<ElectrumSslStream> {
     }
 }
 
-#[cfg(any(feature = "default", feature = "proxy"))]
+#[cfg(feature = "proxy")]
 /// Transport type used to establish a connection to a server through a socks proxy
 pub type ElectrumProxyStream = Socks5Stream;
-#[cfg(any(feature = "default", feature = "proxy"))]
+#[cfg(feature = "proxy")]
 impl RawClient<ElectrumProxyStream> {
     /// Creates a new socks client and tries to connect to `target_addr` using `proxy_addr` as a
     /// socks proxy server. The DNS resolution of `target_addr`, if required, is done
@@ -499,10 +499,13 @@ impl RawClient<ElectrumProxyStream> {
         Ok(stream.into())
     }
 
-    #[cfg(any(
-        feature = "use-openssl",
-        feature = "use-rustls",
-        feature = "use-rustls-ring"
+    #[cfg(all(
+        feature = "proxy",
+        any(
+            feature = "use-openssl",
+            feature = "use-rustls",
+            feature = "use-rustls-ring",
+        )
     ))]
     /// Creates a new TLS client that connects to `target_addr` using `proxy_addr` as a socks proxy
     /// server. The DNS resolution of `target_addr`, if required, is done through the proxy. This