From 8719ea0b7fac77846c5882ac64f3dc7136089b66 Mon Sep 17 00:00:00 2001
From: Robert Debug <robertt.debug@gmail.com>
Date: Mon, 10 Aug 2020 18:03:27 +0200
Subject: [PATCH] remove metrics feature from macro

---
 rust/Cargo.lock                      |  4 +-
 rust/Cargo.toml                      |  2 +-
 rust/xaynet-metrics-macro/Cargo.toml |  5 +-
 rust/xaynet-metrics-macro/src/lib.rs | 81 +++++++++++++---------------
 4 files changed, 41 insertions(+), 51 deletions(-)

diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index 063b423d6..700623cd2 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -1953,9 +1953,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.37"
+version = "1.0.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "239f255b9e3429350f188c27b807fc9920a15eb9145230ff1a7d054c08fec319"
+checksum = "e69abc24912995b3038597a7a593be5053eb0fb44f3cc5beec0deb421790c1f4"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index e386c8ec9..53cc57d5e 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -60,4 +60,4 @@ path = "src/bin/main.rs"
 [features]
 default = ["reqwest/default-tls"]
 rustls = ["reqwest/rustls-tls"]
-metrics = ["influxdb", "chrono", "xaynet-metrics-macro/metrics"]
+metrics = ["influxdb", "chrono"]
diff --git a/rust/xaynet-metrics-macro/Cargo.toml b/rust/xaynet-metrics-macro/Cargo.toml
index 274df6303..632cc249e 100644
--- a/rust/xaynet-metrics-macro/Cargo.toml
+++ b/rust/xaynet-metrics-macro/Cargo.toml
@@ -5,11 +5,8 @@ authors = ["Xayn Engineering <engineering@xaynet.dev>"]
 edition = "2018"
 
 [dependencies]
-syn = "1.0.37"
+syn = "1.0.38"
 quote = "1.0"
 
 [lib]
 proc-macro = true
-
-[features]
-metrics = []
diff --git a/rust/xaynet-metrics-macro/src/lib.rs b/rust/xaynet-metrics-macro/src/lib.rs
index 7fc22a660..02f5b964b 100644
--- a/rust/xaynet-metrics-macro/src/lib.rs
+++ b/rust/xaynet-metrics-macro/src/lib.rs
@@ -1,60 +1,53 @@
 extern crate proc_macro;
-use proc_macro::TokenStream;
 
-#[cfg(feature = "metrics")]
-pub(crate) mod metric {
-    use syn::{
-        parse::{Parse, ParseStream, Result},
-        Expr,
-        Token,
-    };
-    pub struct Send {
-        pub sender: Expr,
-        pub metrics: Vec<Expr>,
-    }
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{
+    parse::{Parse, ParseStream, Result},
+    parse_macro_input,
+    Expr,
+    Token,
+};
+struct Send {
+    sender: Expr,
+    metrics: Vec<Expr>,
+}
 
-    impl Parse for Send {
-        fn parse(input: ParseStream) -> Result<Self> {
-            // metrics!(expr, expr);
-            let sender = input.parse()?; // expr
-            let mut metrics = Vec::new();
+impl Parse for Send {
+    fn parse(input: ParseStream) -> Result<Self> {
+        // metrics!(sender, metric);
+        let sender = input.parse()?; // expr
+        let mut metrics = Vec::new();
+
+        // at least one metric is required
+        input.parse::<Token![,]>()?; // ,
+        let metric = input.parse()?; // expr
+        metrics.push(metric);
+
+        // metrics!(sender, metric, metric, ...);
+        loop {
+            if input.is_empty() {
+                break;
+            }
 
-            // at least one metric is required
             input.parse::<Token![,]>()?; // ,
             let metric = input.parse()?; // expr
-            metrics.push(metric);
-
-            loop {
-                if input.is_empty() {
-                    break;
-                }
-
-                input.parse::<Token![,]>()?; // ,
-                let metric = input.parse()?; // expr
 
-                metrics.push(metric);
-            }
-
-            Ok(Send { sender, metrics })
+            metrics.push(metric);
         }
+
+        Ok(Send { sender, metrics })
     }
 }
 
-#[allow(unused_variables)]
 #[proc_macro]
 pub fn metrics(input: TokenStream) -> TokenStream {
-    #[cfg(not(feature = "metrics"))]
-    return TokenStream::new();
+    let Send { sender, metrics } = parse_macro_input!(input as Send);
 
-    #[cfg(feature = "metrics")]
-    {
-        use quote::quote;
-        use syn::parse_macro_input;
-        let metric::Send { sender, metrics } = parse_macro_input!(input as metric::Send);
-
-        let gen = quote! {
+    TokenStream::from(quote! {
+            #[cfg(feature = "metrics")]
+            {
                 #(#sender.send(#metrics);)*
-        };
-        gen.into()
-    }
+            }
+    })
 }