message: add compression flag.  modify leveldb_memory flag to be megabyte based.
diff: @@ -98,7 +98,10 @@ static int FLAGS_bloom_bits = -1;
  static int FLAGS_bloom2_bits = -1;
  // Riak param for total memory allocation (flex_cache)
  -static int FLAGS_leveldb_memory = -1;
  +static uint64_t FLAGS_leveldb_memory = -1;
  +
  +// Riak param for compression setting
  +static int FLAGS_compression = 2;
  // If true, do not destroy the existing database. If you set this
  // flag and also specify a benchmark that wants a fresh database, that
  @@ -702,6 +705,7 @@ class Benchmark {
  options.block_cache = cache_;
  options.write_buffer_size = FLAGS_write_buffer_size;
  options.filter_policy = filter_policy_;
  + options.compression = (leveldb::CompressionType)FLAGS_compression;
  options.total_leveldb_mem = FLAGS_leveldb_memory;
  Status s = DB::Open(options, FLAGS_db, &db_);
  if (!s.ok()) {
  @@ -934,11 +938,13 @@ class Benchmark {
  int main(int argc, char** argv) {
  FLAGS_write_buffer_size = leveldb::Options().write_buffer_size;
  FLAGS_open_files = leveldb::Options().max_open_files;
  + FLAGS_leveldb_memory = 25000000000LL;
  std::string default_db_path;
  for (int i = 1; i < argc; i++) {
  double d;
  int n;
  + uint64_t u;
  char junk;
  if (leveldb::Slice(argv[i]).starts_with("--benchmarks=")) {
  FLAGS_benchmarks = argv[i] + strlen("--benchmarks=");
  @@ -967,9 +973,11 @@ int main(int argc, char** argv) {
  } else if (sscanf(argv[i], "--bloom_bits2=%d%c", &n, &junk) == 1) {
  FLAGS_bloom2_bits = n;
  } else if (sscanf(argv[i], "--leveldb_memory=%d%c", &n, &junk) == 1) {
  - FLAGS_leveldb_memory = n;
  + FLAGS_leveldb_memory = n * 1024 * 1024LL;
  } else if (sscanf(argv[i], "--open_files=%d%c", &n, &junk) == 1) {
  FLAGS_open_files = n;
  + } else if (sscanf(argv[i], "--compression=%d%c", &n, &junk) == 1) {
  + FLAGS_compression = n;
  } else if (strncmp(argv[i], "--db=", 5) == 0) {
  FLAGS_db = argv[i] + 5;
  } else {
  