Add missing DataBlock-releated functions to the C-API (facebook#6101)

Summary:
Adds two missing functions to the C-API:

- `rocksdb_block_based_options_set_data_block_index_type`
- `rocksdb_block_based_options_set_data_block_hash_ratio`

This enables users in other languages to enjoy the new(-ish) feature.

The changes here are partially overlapping with [another PR](facebook#5630) but are more focused on the DataBlock indexing options.
Pull Request resolved: facebook#6101

Differential Revision: D18765639

fbshipit-source-id: 4a8947e71b179f26fa1eb83c267dd47ee64ac3b3

db/c.cc

@@ -2032,6 +2032,17 @@ void rocksdb_block_based_options_set_index_type(
   options->rep.index_type = static_cast<BlockBasedTableOptions::IndexType>(v);
 }
 
+void rocksdb_block_based_options_set_data_block_index_type(
+    rocksdb_block_based_table_options_t* options, int v) {
+  options->rep.data_block_index_type =
+          static_cast<BlockBasedTableOptions::DataBlockIndexType>(v);
+}
+
+void rocksdb_block_based_options_set_data_block_hash_ratio(
+    rocksdb_block_based_table_options_t* options, double v) {
+  options->rep.data_block_hash_table_util_ratio = v;
+}
+
 void rocksdb_block_based_options_set_hash_index_allow_collision(
     rocksdb_block_based_table_options_t* options, unsigned char v) {
   options->rep.hash_index_allow_collision = v;

db/c_test.c

@@ -487,8 +487,11 @@ int main(int argc, char** argv) {
   rocksdb_options_set_paranoid_checks(options, 1);
   rocksdb_options_set_max_open_files(options, 10);
   rocksdb_options_set_base_background_compactions(options, 1);
+
   table_options = rocksdb_block_based_options_create();
   rocksdb_block_based_options_set_block_cache(table_options, cache);
+  rocksdb_block_based_options_set_data_block_index_type(table_options, 1);
+  rocksdb_block_based_options_set_data_block_hash_ratio(table_options, 0.75);
   rocksdb_options_set_block_based_table_factory(options, table_options);
 
   rocksdb_options_set_compression(options, rocksdb_no_compression);

include/rocksdb/c.h

@@ -706,6 +706,14 @@ enum {
 };
 extern ROCKSDB_LIBRARY_API void rocksdb_block_based_options_set_index_type(
     rocksdb_block_based_table_options_t*, int);  // uses one of the above enums
+enum {
+  rocksdb_block_based_table_data_block_index_type_binary_search = 0,
+  rocksdb_block_based_table_data_block_index_type_binary_search_and_hash = 1,
+};
+extern ROCKSDB_LIBRARY_API void rocksdb_block_based_options_set_data_block_index_type(
+    rocksdb_block_based_table_options_t*, int);  // uses one of the above enums
+extern ROCKSDB_LIBRARY_API void rocksdb_block_based_options_set_data_block_hash_ratio(
+    rocksdb_block_based_table_options_t* options, double v);
 extern ROCKSDB_LIBRARY_API void
 rocksdb_block_based_options_set_hash_index_allow_collision(
     rocksdb_block_based_table_options_t*, unsigned char);