add more options to db_ben

Summary: as subject

Test Plan: run db_bench with new options

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D4677

db/db_bench.cc

@@ -120,9 +120,26 @@ static class leveldb::DBStatistics* dbstats = NULL;
 // Number of write operations to do.  If negative, do FLAGS_num reads.
 static long FLAGS_writes = -1;
 
+// These default values might change if the hardcoded
+
 // Sync all writes to disk
 static bool FLAGS_sync = false;
 
+// If true, do not wait until data is synced to disk.
+static bool FLAGS_disable_data_sync = false;
+
+// Target level-0 file size for compaction
+static int FLAGS_target_file_size_base = 2 * 1048576;
+
+// A multiplier to compute targe level-N file size
+static int FLAGS_target_file_size_multiplier = 1;
+
+// Max bytes for level-0
+static int FLAGS_max_bytes_for_level_base = 10 * 1048576;
+
+// A multiplier to compute max bytes for level-N
+static int FLAGS_max_bytes_for_level_multiplier = 10;
+
 // posix or hdfs environment
 static leveldb::Env* FLAGS_env = leveldb::Env::Default();
 
@@ -745,6 +762,12 @@ class Benchmark {
     options.max_open_files = FLAGS_open_files;
     options.statistics = dbstats;
     options.env = FLAGS_env;
+    options.disableDataSync = FLAGS_disable_data_sync;
+    options.target_file_size_base = FLAGS_target_file_size_base;
+    options.target_file_size_multiplier = FLAGS_target_file_size_multiplier;
+    options.max_bytes_for_level_base = FLAGS_max_bytes_for_level_base;
+    options.max_bytes_for_level_multiplier =
+        FLAGS_max_bytes_for_level_multiplier;
     Status s = DB::Open(options, FLAGS_db, &db_);
     if (!s.ok()) {
       fprintf(stderr, "open error: %s\n", s.ToString().c_str());
@@ -1030,8 +1053,23 @@ int main(int argc, char** argv) {
     } else if (sscanf(argv[i], "--sync=%d%c", &n, &junk) == 1 &&
                (n == 0 || n == 1)) {
       FLAGS_sync = n;
+    } else if (sscanf(argv[i], "--disable_data_sync=%d%c", &n, &junk) == 1 &&
+        (n == 0 || n == 1)) {
+      FLAGS_disable_data_sync = n;
     } else if (sscanf(argv[i], "--hdfs=%s", &hdfsname) == 1) {
       FLAGS_env  = new leveldb::HdfsEnv(hdfsname);
+    } else if (sscanf(argv[i], "--target_file_size_base=%d%c",
+        &n, &junk) == 1) {
+      FLAGS_target_file_size_base = n;
+    } else if ( sscanf(argv[i], "--target_file_size_multiplier=%d%c",
+        &n, &junk) == 1) {
+      FLAGS_target_file_size_multiplier = n;
+    } else if (
+        sscanf(argv[i], "--max_bytes_for_level_base=%d%c", &n, &junk) == 1) {
+      FLAGS_max_bytes_for_level_base = n;
+    } else if (sscanf(argv[i], "--max_bytes_for_level_multiplier=%d%c",
+        &n, &junk) == 1) {
+      FLAGS_max_bytes_for_level_multiplier = n;
     } else {
       fprintf(stderr, "Invalid flag '%s'\n", argv[i]);
       exit(1);