Add DB::open_cf_with_opts method (#689)

src/db.rs

@@ -436,6 +436,22 @@ impl<T: ThreadMode> DBWithThreadMode<T> {
         Self::open_cf_descriptors_internal(opts, path, cfs, &AccessType::ReadWrite)
     }
 
+    /// Opens a database with the given database options and column family names.
+    ///
+    /// Column families opened using given `Options`.
+    pub fn open_cf_with_opts<P, I, N>(opts: &Options, path: P, cfs: I) -> Result<Self, Error>
+    where
+        P: AsRef<Path>,
+        I: IntoIterator<Item = (N, Options)>,
+        N: AsRef<str>,
+    {
+        let cfs = cfs
+            .into_iter()
+            .map(|(name, opts)| ColumnFamilyDescriptor::new(name.as_ref(), opts));
+
+        Self::open_cf_descriptors(opts, path, cfs)
+    }
+
     /// Opens a database for read only with the given database options and column family names.
     pub fn open_cf_for_read_only<P, I, N>(
         opts: &Options,

tests/test_column_family.rs

@@ -156,6 +156,31 @@ fn test_create_missing_column_family() {
     }
 }
 
+#[test]
+fn test_open_column_family_with_opts() {
+    let n = DBPath::new("_rust_rocksdb_open_cf_with_opts");
+
+    {
+        let mut opts = Options::default();
+        opts.create_if_missing(true);
+        opts.create_missing_column_families(true);
+
+        // We can use different parameters for different column family.
+        let mut cf1_opts = Options::default();
+        cf1_opts.set_min_write_buffer_number(2);
+        cf1_opts.set_min_write_buffer_number_to_merge(4);
+        let mut cf2_opts = Options::default();
+        cf2_opts.set_min_write_buffer_number(5);
+        cf2_opts.set_min_write_buffer_number_to_merge(10);
+
+        let cfs = vec![("cf1", cf1_opts), ("cf2", cf2_opts)];
+        match DB::open_cf_with_opts(&opts, &n, cfs) {
+            Ok(_db) => println!("successfully opened column family with the specified options"),
+            Err(e) => panic!("failed to open cf with options: {}", e),
+        }
+    }
+}
+
 #[test]
 #[ignore]
 fn test_merge_operator() {