Add an is_active method

Will be needed when Error::WrongTransaction is removed

Author: sfackler

src/lib.rs

@@ -1109,6 +1109,15 @@ impl Connection {
         self.conn.borrow().is_desynchronized()
     }
 
+    /// Determines if the `Connection` is currently "active", that is, if there
+    /// are no active transactions.
+    ///
+    /// The `transaction` method can only be called on the active `Connection`
+    /// or `Transaction`.
+    pub fn is_active(&self) -> bool {
+        self.conn.borrow().trans_depth == 0
+    }
+
     /// Consumes the connection, closing it.
     ///
     /// Functionally equivalent to the `Drop` implementation for `Connection`
@@ -1234,6 +1243,11 @@ impl<'conn> Transaction<'conn> {
         stmt.lazy_query(self, params, row_limit)
     }
 
+    /// Like `Connection::is_active`.
+    pub fn is_active(&self) -> bool {
+        self.conn.conn.borrow().trans_depth == self.depth
+    }
+
     /// Determines if the transaction is currently set to commit or roll back.
     pub fn will_commit(&self) -> bool {
         self.commit.get()
@@ -1989,6 +2003,9 @@ pub trait GenericConnection {
 
     /// Like `Connection::batch_execute`.
     fn batch_execute(&self, query: &str) -> Result<()>;
+
+    /// Like `Connection::is_active`.
+    fn is_active(&self) -> bool;
 }
 
 impl GenericConnection for Connection {
@@ -2016,6 +2033,10 @@ impl GenericConnection for Connection {
     fn batch_execute(&self, query: &str) -> Result<()> {
         self.batch_execute(query)
     }
+
+    fn is_active(&self) -> bool {
+        self.is_active()
+    }
 }
 
 impl<'a> GenericConnection for Transaction<'a> {
@@ -2043,4 +2064,8 @@ impl<'a> GenericConnection for Transaction<'a> {
     fn batch_execute(&self, query: &str) -> Result<()> {
         self.batch_execute(query)
     }
+
+    fn is_active(&self) -> bool {
+        self.is_active()
+    }
 }

tests/test.rs

@@ -916,3 +916,23 @@ fn test_prepare_cached() {
     assert_eq!(&[2, 1][], or_panic!(stmt.query(&[])).map(|r| r.get(0)).collect::<Vec<i32>>());
     or_panic!(stmt.finish());
 }
+
+#[test]
+fn test_is_active() {
+    let conn = or_panic!(Connection::connect("postgres://postgres@localhost", &SslMode::None));
+    assert!(conn.is_active());
+    let trans = or_panic!(conn.transaction());
+    assert!(!conn.is_active());
+    assert!(trans.is_active());
+    {
+        let trans2 = or_panic!(trans.transaction());
+        assert!(!conn.is_active());
+        assert!(!trans.is_active());
+        assert!(trans2.is_active());
+        or_panic!(trans2.finish());
+    }
+    assert!(!conn.is_active());
+    assert!(trans.is_active());
+    or_panic!(trans.finish());
+    assert!(conn.is_active());
+}