Added raw_values to SliceMut

odbc-api/src/buffers/column_with_indicator.rs

@@ -229,6 +229,37 @@ impl<'a, T> NullableSliceMut<'a, T> {
     pub fn len(&self) -> usize {
         self.values.len()
     }
+
+    /// Write access to the underlying raw value and indicator buffer.
+    ///
+    /// The number of elements in the buffer is equal to `len`.
+    ///
+    /// This method is useful for writing performant bindings to datastructures with similar binary
+    /// layout, as it allows for using memcopy rather than iterating over individual values.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use odbc_api::{buffers::NullableSliceMut, sys::NULL_DATA};
+    ///
+    /// // Memcopy the values into the buffer, and set indicators according to mask
+    /// // values.
+    /// fn copy_values_and_make_mask(new_values: &[i32], mask: &[bool], odbc_slice: &mut NullableSliceMut<i32>) {
+    ///     let (values, indicators) = odbc_slice.raw_values();
+    ///     values.copy_from_slice(new_values);
+    ///     // Create array of bools indicating null values.
+    ///     indicators.iter_mut().zip(mask.iter()).for_each(|(indicator, &mask)| {
+    ///         *indicator = if mask {
+    ///             1
+    ///         } else {
+    ///             NULL_DATA
+    ///         }
+    ///     });
+    /// }
+    /// ```
+    pub fn raw_values(&mut self) -> (&mut [T], &mut [isize]) {
+        (&mut self.values, &mut self.indicators)
+    }
 }
 
 impl<'a, T> NullableSliceMut<'a, T> {

odbc-api/tests/integration.rs

@@ -1,6 +1,7 @@
 mod common;
 
 use odbc_sys::{SqlDataType, Timestamp};
+use sys::NULL_DATA;
 use tempfile::NamedTempFile;
 use test_case::test_case;
 
@@ -769,6 +770,51 @@ fn columnar_insert_timestamp(profile: &Profile) {
     assert_eq!(expected, actual);
 }
 
+/// Insert values into a i32 column using a columnar buffer's raw values
+#[test_case(MSSQL; "Microsoft SQL Server")]
+// #[test_case(MARIADB; "Maria DB")] No DATEIME2 type
+// #[test_case(SQLITE_3; "SQLite 3")] default precision of 3 instead 7
+fn columnar_insert_int_raw(profile: &Profile) {
+    let table_name = "Int";
+    // Setup
+    let conn = profile.setup_empty_table(table_name, &["INT"]).unwrap();
+
+    // Fill buffer with values
+    let desc = BufferDescription {
+        kind: BufferKind::I32,
+        nullable: true,
+    };
+    let mut buffer = buffer_from_description(10, iter::once(desc));
+
+    // Input values to insert.
+    let input_values = [1, 0, 3];
+    let mask = [true, false, true];
+
+    buffer.set_num_rows(input_values.len());
+    if let AnyColumnViewMut::NullableI32(mut writer) = buffer.column_mut(0) {
+        let (values, indicators) = writer.raw_values();
+        values.copy_from_slice(&input_values);
+        indicators
+            .iter_mut()
+            .zip(mask.iter())
+            .for_each(|(indicator, &mask)| *indicator = if mask { 1 } else { NULL_DATA })
+    } else {
+        panic!("Expected i32 column writer");
+    };
+
+    // Bind buffer and insert values.
+    conn.execute(
+        &format!("INSERT INTO {} (a) VALUES (?)", table_name),
+        &buffer,
+    )
+    .unwrap();
+
+    // Query values and compare with expectation
+    let actual = table_to_string(&conn, table_name, &["a"]);
+    let expected = "1\nNULL\n3";
+    assert_eq!(expected, actual);
+}
+
 /// Insert values into a DATETIME2(3) column using a columnar buffer. Milliseconds precision is
 /// different from the default precision 7 (100ns).
 #[test_case(MSSQL; "Microsoft SQL Server")]