Add compression flag to benchmarks.

benchmarks/db_bench.cc

@@ -118,6 +118,9 @@ static bool FLAGS_use_existing_db = false;
 // If true, reuse existing log/MANIFEST files when re-opening a database.
 static bool FLAGS_reuse_logs = false;
 
+// If true, use compression.
+static bool FLAGS_compression = true;
+
 // Use the db with the following name.
 static const char* FLAGS_db = nullptr;
 
@@ -771,6 +774,8 @@ class Benchmark {
     options.max_open_files = FLAGS_open_files;
     options.filter_policy = filter_policy_;
     options.reuse_logs = FLAGS_reuse_logs;
+    options.compression = FLAGS_compression ? kSnappyCompression
+                                            : kNoCompression;
     Status s = DB::Open(options, FLAGS_db, &db_);
     if (!s.ok()) {
       std::fprintf(stderr, "open error: %s\n", s.ToString().c_str());
@@ -1045,6 +1050,9 @@ int main(int argc, char** argv) {
     } else if (sscanf(argv[i], "--reuse_logs=%d%c", &n, &junk) == 1 &&
                (n == 0 || n == 1)) {
       FLAGS_reuse_logs = n;
+    } else if (sscanf(argv[i], "--compression=%d%c", &n, &junk) == 1 &&
+               (n == 0 || n == 1)) {
+      FLAGS_compression = n;
     } else if (sscanf(argv[i], "--num=%d%c", &n, &junk) == 1) {
       FLAGS_num = n;
     } else if (sscanf(argv[i], "--reads=%d%c", &n, &junk) == 1) {