Add Row::get_bytes

Useful for things like postgres_large_object to avoid some allocation

Author: sfackler

src/lib.rs

@@ -1693,6 +1693,18 @@ impl<'stmt> Row<'stmt> {
             Err(err) => panic!("error retrieving column {:?}: {:?}", idx, err)
         }
     }
+
+    /// Retrieves the specified field as a raw buffer of Postgres data.
+    ///
+    /// ## Panics
+    ///
+    /// Panics if the index does not references a column.
+    pub fn get_bytes<I>(&self, idx: I) -> Option<&[u8]> where I: RowIndex + fmt::Debug {
+        match idx.idx(self.stmt) {
+            Some(idx) => self.data[idx].as_ref().map(|e| &**e),
+            None => panic!("invalid index {:?}", idx),
+        }
+    }
 }
 
 /// A trait implemented by types that can index into columns of a row.

tests/test.rs

@@ -917,3 +917,11 @@ fn test_parameter() {
     assert_eq!(Some("UTF8".to_string()), conn.parameter("client_encoding"));
     assert_eq!(None, conn.parameter("asdf"));
 }
+
+#[test]
+fn test_get_bytes() {
+    let conn = or_panic!(Connection::connect("postgres://postgres@localhost", &SslMode::None));
+    let stmt = or_panic!(conn.prepare("SELECT '\\x00010203'::BYTEA"));
+    let mut result = or_panic!(stmt.query(&[]));
+    assert_eq!(b"\x00\x01\x02\x03", result.next().unwrap().get_bytes(0).unwrap());
+}