feat: Attempt ipinfo.io if ipapi.co returns no results (#204)

* feat: Attempt ipinfo.io if ipapi.co returns no results

* fix: Use the GET method

* feat: Added tests

* chore: DRY

backend/src/util/location.rs

@@ -4,6 +4,7 @@ use std::sync::Arc;
 use actix::prelude::*;
 use rustc_hash::FxHashMap;
 use parking_lot::RwLock;
+use serde::Deserialize;
 
 use crate::chain::{Chain, LocateNode};
 use crate::types::{NodeId, NodeLocation};
@@ -52,6 +53,34 @@ pub struct LocateRequest {
     pub chain: Addr<Chain>,
 }
 
+#[derive(Deserialize)]
+pub struct IPApiLocate {
+    city: Box<str>,
+    loc: Box<str>,
+}
+
+impl IPApiLocate {
+    fn into_node_location(self) -> Option<NodeLocation> {
+        let IPApiLocate { city, loc } = self;
+
+        let mut loc = loc.split(",").map(|n| n.parse());
+
+        let latitude = loc.next()?.ok()?;
+        let longitude = loc.next()?.ok()?;
+
+        // Guarantee that the iterator has been exhausted
+        if loc.next().is_some() {
+            return None;
+        }
+
+        Some(NodeLocation {
+            latitude,
+            longitude,
+            city,
+        })
+    }
+}
+
 impl Handler<LocateRequest> for Locator {
     type Result = ();
 
@@ -66,18 +95,9 @@ impl Handler<LocateRequest> for Locator {
             return
         }
 
-        let ip_req = format!("https://ipapi.co/{}/json", ip);
-        let mut response = match self.client.post(&ip_req).send() {
-            Ok(response) => response,
-            Err(err) => return debug!("POST error for ip location: {:?}", err),
-        };
-
-        let location = match response.json::<NodeLocation>() {
-            Ok(location) => Some(Arc::new(location)),
-            Err(err) => {
-                debug!("JSON error for ip location: {:?}", err);
-                None
-            }
+        let location = match self.iplocate(ip) {
+            Ok(location) => location,
+            Err(err) => return debug!("GET error for ip location: {:?}", err),
         };
 
         self.cache.write().insert(ip, location.clone());
@@ -87,3 +107,72 @@ impl Handler<LocateRequest> for Locator {
         }
     }
 }
+
+impl Locator {
+    fn iplocate(&self, ip: Ipv4Addr) -> Result<Option<Arc<NodeLocation>>, reqwest::Error> {
+        let location = self.iplocate_ipapi_co(ip)?;
+
+        match location {
+            Some(location) => Ok(Some(location)),
+            None => self.iplocate_ipinfo_io(ip),
+        }
+    }
+
+    fn iplocate_ipapi_co(&self, ip: Ipv4Addr) -> Result<Option<Arc<NodeLocation>>, reqwest::Error> {
+        let location = self.query(&format!("https://ipapi.co/{}/json", ip))?.map(Arc::new);
+
+        Ok(location)
+    }
+
+    fn iplocate_ipinfo_io(&self, ip: Ipv4Addr) -> Result<Option<Arc<NodeLocation>>, reqwest::Error> {
+        let location = self.query(&format!("https://ipinfo.io/{}/json", ip))?.and_then(|loc: IPApiLocate| {
+            loc.into_node_location().map(Arc::new)
+        });
+
+        Ok(location)
+    }
+
+    fn query<T>(&self, url: &str) -> Result<Option<T>, reqwest::Error>
+    where
+        for<'de> T: Deserialize<'de>,
+    {
+        match self.client.get(url).send()?.json::<T>() {
+            Ok(result) => Ok(Some(result)),
+            Err(err) => {
+                debug!("JSON error for ip location: {:?}", err);
+                Ok(None)
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ipapi_locate_to_node_location() {
+        let ipapi = IPApiLocate {
+            loc: "12.5,56.25".into(),
+            city: "Foobar".into(),
+        };
+
+        let location = ipapi.into_node_location().unwrap();
+
+        assert_eq!(location.latitude, 12.5);
+        assert_eq!(location.longitude, 56.25);
+        assert_eq!(&*location.city, "Foobar");
+    }
+
+    #[test]
+    fn ipapi_locate_to_node_location_too_many() {
+        let ipapi = IPApiLocate {
+            loc: "12.5,56.25,1.0".into(),
+            city: "Foobar".into(),
+        };
+
+        let location = ipapi.into_node_location();
+
+        assert!(location.is_none());
+    }
+}

backend/src/util/num_stats.rs

@@ -1,4 +1,4 @@
-use num_traits::{Zero, NumOps, Bounded, ops::saturating::Saturating};
+use num_traits::{Zero, NumOps, Bounded};
 use std::iter::Sum;
 use std::convert::TryFrom;
 
@@ -10,7 +10,7 @@ pub struct NumStats<T> {
     sum: T,
 }
 
-impl<T: Saturating + NumOps + Zero + Bounded + Copy + Sum + TryFrom<usize>> NumStats<T> {
+impl<T: NumOps + Zero + Bounded + Copy + Sum + TryFrom<usize>> NumStats<T> {
     pub fn new(size: usize) -> Self {
         NumStats {
             stack: vec![T::zero(); size].into_boxed_slice(),