Fix the error of duplicate signing within multiple threads

src/signer.rs

@@ -133,7 +133,7 @@ impl Signer {
         F: FnOnce(&str) -> T,
     {
         if self.is_expired() {
-            self.renew()?;
+            self.renew_if_expired()?;
         }
 
         let signature = self.signature.read();
@@ -175,7 +175,9 @@ impl Signer {
         ))
     }
 
-    fn renew(&self) -> Result<(), Error> {
+    fn renew_if_expired(&self) -> Result<(), Error> {
+        let mut signature = self.signature.write();
+
         let issued_at = get_time();
 
         #[cfg(feature = "tracing")]
@@ -189,12 +191,12 @@ impl Signer {
             );
         }
 
-        let mut signature = self.signature.write();
-
-        *signature = Signature {
-            key: Self::create_signature(&self.secret, &self.key_id, &self.team_id, issued_at)?,
-            issued_at,
-        };
+        if issued_at - signature.issued_at >= self.expire_after_s.as_secs() as i64 {
+            *signature = Signature {
+                key: Self::create_signature(&self.secret, &self.key_id, &self.team_id, issued_at)?,
+                issued_at,
+            };
+        }
 
         Ok(())
     }
@@ -248,6 +250,8 @@ fn get_time() -> i64 {
 
 #[cfg(test)]
 mod tests {
+    use std::{collections::HashSet, sync::Mutex, time::Instant};
+
     use super::*;
 
     const PRIVATE_KEY: &str = "-----BEGIN PRIVATE KEY-----
@@ -293,4 +297,50 @@ jDwmlD1Gg0yJt1e38djFwsxsfr5q2hv0Rj9fTEqAPr8H7mGm0wKxZ7iQ
 
         assert_ne!(sig1, sig2);
     }
+
+    #[test]
+    fn test_signature_caching_in_multithreads() {
+        let signer = Signer::new(
+            PRIVATE_KEY.as_bytes(),
+            "89AFRD1X22",
+            "ASDFQWERTY",
+            Duration::from_secs(3),
+        )
+        .unwrap();
+
+        let signer = Arc::new(signer);
+
+        let created_sign: Arc<Mutex<HashSet<String>>> = Arc::new(Mutex::new(HashSet::new()));
+        let mut threads = Vec::new();
+        let now = Instant::now();
+
+        for _ in 0..100 {
+            let created_sign = created_sign.clone();
+            let now = now.clone();
+            let signer = signer.clone();
+            threads.push(std::thread::spawn(move || {
+                let mut sig = String::new();
+                loop {
+                    let mut sig1 = String::new();
+                    signer.with_signature(|sig| sig1.push_str(sig)).unwrap();
+
+                    if sig1 != sig {
+                        sig = sig1.clone();
+                        let mut created_sign = created_sign.lock().unwrap();
+                        created_sign.insert(sig1);
+                    }
+
+                    if now.elapsed() > Duration::from_secs(4) {
+                        break;
+                    }
+                }
+            }));
+        }
+
+        for th in threads {
+            let _ = th.join();
+        }
+
+        assert_eq!(created_sign.lock().unwrap().len(), 2);
+    }
 }