Support setting options on column families via C bindings (#4785)

Summary:
Currently, it supports setting options only on the default column family.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4785

Differential Revision: D13491819

Pulled By: ajkr

fbshipit-source-id: 75c78bd86222bb05568e538562af84fb53eb4d8d

db/c.cc

@@ -2067,6 +2067,15 @@ void rocksdb_set_options(
             db->rep->SetOptions(options_map));
     }
 
+void rocksdb_set_options_cf(
+    rocksdb_t* db, rocksdb_column_family_handle_t* handle, int count, const char* const keys[], const char* const values[], char** errptr) {
+        std::unordered_map<std::string, std::string> options_map;
+        for (int i=0; i<count; i++)
+            options_map[keys[i]] = values[i];
+        SaveError(errptr,
+            db->rep->SetOptions(handle->rep, options_map));
+    }
+
 rocksdb_options_t* rocksdb_options_create() {
   return new rocksdb_options_t;
 }

include/rocksdb/c.h

@@ -728,6 +728,9 @@ extern ROCKSDB_LIBRARY_API void rocksdb_options_set_cuckoo_table_factory(
 extern ROCKSDB_LIBRARY_API void rocksdb_set_options(
     rocksdb_t* db, int count, const char* const keys[], const char* const values[], char** errptr);
 
+extern ROCKSDB_LIBRARY_API void rocksdb_set_options_cf(
+    rocksdb_t* db, rocksdb_column_family_handle_t* handle, int count, const char* const keys[], const char* const values[], char** errptr);
+
 extern ROCKSDB_LIBRARY_API rocksdb_options_t* rocksdb_options_create();
 extern ROCKSDB_LIBRARY_API void rocksdb_options_destroy(rocksdb_options_t*);
 extern ROCKSDB_LIBRARY_API void rocksdb_options_increase_parallelism(