Expose flush_cfs_opt to flush multiple column families (#793)

src/db.rs

@@ -915,6 +915,28 @@ impl<T: ThreadMode, D: DBInner> DBCommon<T, D> {
         Ok(())
     }
 
+    /// Flushes multiple column families.
+    ///
+    /// If atomic flush is not enabled, it is equivalent to calling flush_cf multiple times.
+    /// If atomic flush is enabled, it will flush all column families specified in `cfs` up to the latest sequence
+    /// number at the time when flush is requested.
+    pub fn flush_cfs_opt(
+        &self,
+        cfs: &[&impl AsColumnFamilyRef],
+        opts: &FlushOptions,
+    ) -> Result<(), Error> {
+        let mut cfs = cfs.iter().map(|cf| cf.inner()).collect::<Vec<_>>();
+        unsafe {
+            ffi_try!(ffi::rocksdb_flush_cfs(
+                self.inner.inner(),
+                opts.inner,
+                cfs.as_mut_ptr(),
+                cfs.len() as libc::c_int,
+            ));
+        }
+        Ok(())
+    }
+
     /// Flushes database memtables to SST files on the disk for a given column family using default
     /// options.
     pub fn flush_cf(&self, cf: &impl AsColumnFamilyRef) -> Result<(), Error> {

tests/test_db.rs

@@ -1397,3 +1397,48 @@ fn cuckoo() {
         assert!(db.get(b"k1").unwrap().is_none());
     }
 }
+
+#[test]
+fn test_atomic_flush_cfs() {
+    let n = DBPath::new("_rust_rocksdb_atomic_flush_cfs");
+    {
+        let mut opts = Options::default();
+        opts.create_if_missing(true);
+        opts.create_missing_column_families(true);
+        opts.set_atomic_flush(true);
+
+        let db = DB::open_cf(&opts, &n, ["cf1", "cf2"]).unwrap();
+        let cf1 = db.cf_handle("cf1").unwrap();
+        let cf2 = db.cf_handle("cf2").unwrap();
+
+        let mut write_options = rocksdb::WriteOptions::new();
+        write_options.disable_wal(true);
+
+        db.put_cf_opt(&cf1, "k11", "v11", &write_options).unwrap();
+        db.put_cf_opt(&cf2, "k21", "v21", &write_options).unwrap();
+
+        let mut opts = rocksdb::FlushOptions::new();
+        opts.set_wait(true);
+        db.flush_cfs_opt(&[&cf1, &cf2], &opts).unwrap();
+    }
+
+    {
+        let mut opts = Options::default();
+        opts.create_if_missing(true);
+        opts.create_missing_column_families(true);
+        opts.set_atomic_flush(true);
+
+        let db = DB::open_cf(&opts, &n, ["cf1", "cf2"]).unwrap();
+        let cf1 = db.cf_handle("cf1").unwrap();
+        let cf2 = db.cf_handle("cf2").unwrap();
+
+        assert_eq!(
+            db.get_cf(&cf1, "k11").unwrap(),
+            Some("v11".as_bytes().to_vec())
+        );
+        assert_eq!(
+            db.get_cf(&cf2, "k21").unwrap(),
+            Some("v21".as_bytes().to_vec())
+        );
+    }
+}