Add a benchmark for CIDR parsing

Also optimise the cidr_parts implementation

Cargo.toml

@@ -17,6 +17,7 @@ serde = ">=0.8.0, <2.0"
 [dev-dependencies]
 serde_json = "1.0"
 serde_derive = ">=0.8.0, <2.0"
+criterion = "0.2.9"
 
 [badges]
 travis-ci = { repository = "achanda/ipnetwork" }
@@ -24,3 +25,7 @@ travis-ci = { repository = "achanda/ipnetwork" }
 [features]
 default = []
 dev = ["clippy"]
+
+[[bench]]
+name = "parse_bench"
+harness = false

benches/parse_bench.rs

@@ -0,0 +1,21 @@
+#[macro_use]
+extern crate criterion;
+extern crate ipnetwork;
+
+use ipnetwork::{Ipv4Network, Ipv6Network};
+use criterion::Criterion;
+
+fn parse_ipv4_benchmark(c: &mut Criterion) {
+    c.bench_function("parse ipv4", |b| b.iter(|| {
+        "127.1.0.0/24".parse::<Ipv4Network>().unwrap()
+    }));
+}
+
+fn parse_ipv6_benchmark(c: &mut Criterion) {
+    c.bench_function("parse ipv6", |b| b.iter(|| {
+        "FF01:0:0:17:0:0:0:2/64".parse::<Ipv6Network>().unwrap()
+    }));
+}
+
+criterion_group!(benches, parse_ipv4_benchmark, parse_ipv6_benchmark);
+criterion_main!(benches);

src/common.rs

@@ -32,16 +32,23 @@ impl Error for IpNetworkError {
 }
 
 pub fn cidr_parts(cidr: &str) -> Result<(&str, Option<&str>), IpNetworkError> {
-    let parts = cidr.split('/').collect::<Vec<&str>>();
-    if parts.len() == 1 {
-        Ok((parts[0], None))
-    } else if parts.len() == 2 {
-        Ok((parts[0], Some(parts[1])))
-    } else {
-        Err(IpNetworkError::InvalidCidrFormat(format!(
+    // Try to find a single slash
+    if let Some(sep) = cidr.find('/') {
+        let (ip, prefix) = cidr.split_at(sep);
+        // Error if cidr has multiple slashes
+        if prefix[1..].find('/').is_some() {
+            return Err(IpNetworkError::InvalidCidrFormat(format!(
             "CIDR must contain a single '/': {}",
             cidr
-        )))
+            )));
+        }
+        else {
+            // Handle the case when cidr has exactly one slash
+            return Ok((ip, Some(&prefix[1..])));
+        }
+    } else {
+        // Handle the case when cidr does not have a slash
+        return Ok((cidr, None));
     }
 }