C API: support total_order_mode

Summary: Closes https://github.com/facebook/rocksdb/pull/1687

Differential Revision: D4349210

Pulled By: IslamAbdelRahman

fbshipit-source-id: 32d0fbd

db/c.cc

@@ -2256,6 +2256,11 @@ void rocksdb_readoptions_set_pin_data(rocksdb_readoptions_t* opt,
   opt->rep.pin_data = v;
 }
 
+void rocksdb_readoptions_set_total_order_seek(rocksdb_readoptions_t* opt,
+                                              unsigned char v) {
+  opt->rep.total_order_seek = v;
+}
+
 rocksdb_writeoptions_t* rocksdb_writeoptions_create() {
   return new rocksdb_writeoptions_t;
 }

db/c_test.c

@@ -989,6 +989,19 @@ int main(int argc, char** argv) {
     CheckNoError(err);
     rocksdb_iter_destroy(iter);
 
+    rocksdb_readoptions_set_total_order_seek(roptions, 1);
+    iter = rocksdb_create_iterator(db, roptions);
+    CheckCondition(!rocksdb_iter_valid(iter));
+
+    rocksdb_iter_seek(iter, "ba", 2);
+    rocksdb_iter_get_error(iter, &err);
+    CheckNoError(err);
+    CheckCondition(rocksdb_iter_valid(iter));
+    CheckIter(iter, "bar1", "bar");
+
+    rocksdb_iter_destroy(iter);
+    rocksdb_readoptions_set_total_order_seek(roptions, 0);
+
     rocksdb_close(db);
     rocksdb_destroy_db(options, dbname, &err);
   }

include/rocksdb/c.h

@@ -879,6 +879,8 @@ extern ROCKSDB_LIBRARY_API void rocksdb_readoptions_set_readahead_size(
     rocksdb_readoptions_t*, size_t);
 extern ROCKSDB_LIBRARY_API void rocksdb_readoptions_set_pin_data(
     rocksdb_readoptions_t*, unsigned char);
+extern ROCKSDB_LIBRARY_API void rocksdb_readoptions_set_total_order_seek(
+    rocksdb_readoptions_t*, unsigned char);
 
 /* Write options */