add missing rocksdb_flush_cf in c (#5243)

Summary:
same to #5229
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5243

Differential Revision: D15082800

Pulled By: siying

fbshipit-source-id: f4a68a480db0e40e1ba7cf37e18b88e43dff7c08

db/c.cc

@@ -1183,6 +1183,14 @@ void rocksdb_flush(
   SaveError(errptr, db->rep->Flush(options->rep));
 }
 
+void rocksdb_flush_cf(
+    rocksdb_t* db,
+    const rocksdb_flushoptions_t* options,
+    rocksdb_column_family_handle_t* column_family,
+    char** errptr) {
+  SaveError(errptr, db->rep->Flush(options->rep, column_family->rep));
+}
+
 void rocksdb_disable_file_deletions(
     rocksdb_t* db,
     char** errptr) {

db/c_test.c

@@ -1188,6 +1188,12 @@ int main(int argc, char** argv) {
     rocksdb_put_cf(db, woptions, handles[1], "foo", 3, "hello", 5, &err);
     CheckNoError(err);
 
+    rocksdb_flushoptions_t *flush_options = rocksdb_flushoptions_create();
+    rocksdb_flushoptions_set_wait(flush_options, 1);
+    rocksdb_flush_cf(db, flush_options, handles[1], &err);
+    CheckNoError(err)
+    rocksdb_flushoptions_destroy(flush_options);
+
     CheckGetCF(db, roptions, handles[1], "foo", "hello");
     CheckPinGetCF(db, roptions, handles[1], "foo", "hello");
 

include/rocksdb/c.h

@@ -380,6 +380,10 @@ extern ROCKSDB_LIBRARY_API const rocksdb_livefiles_t* rocksdb_livefiles(
 extern ROCKSDB_LIBRARY_API void rocksdb_flush(
     rocksdb_t* db, const rocksdb_flushoptions_t* options, char** errptr);
 
+extern ROCKSDB_LIBRARY_API void rocksdb_flush_cf(
+    rocksdb_t* db, const rocksdb_flushoptions_t* options,
+    rocksdb_column_family_handle_t* column_family, char** errptr);
+
 extern ROCKSDB_LIBRARY_API void rocksdb_disable_file_deletions(rocksdb_t* db,
                                                                char** errptr);