Support non-TTL Puts for BlobDB in db_bench (#5921)

Summary:
Currently, db_bench only supports PutWithTTL operations for BlobDB but
not regular Puts. The patch adds support for regular (non-TTL) Puts and also
changes the default for blob_db_max_ttl_range to zero, which corresponds
to no TTL.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5921

Test Plan:
make check

./db_bench -benchmarks=fillrandom -statistics -stats_interval_seconds=1
-duration=90 -num=500000 -use_blob_db=1 -blob_db_file_size=1000000
-target_file_size_base=1000000 (issues Put operations with no TTL)

./db_bench -benchmarks=fillrandom -statistics -stats_interval_seconds=1
-duration=90 -num=500000 -use_blob_db=1 -blob_db_file_size=1000000
-target_file_size_base=1000000 -blob_db_max_ttl_range=86400 (issues
PutWithTTL operations with random TTLs in the [0, blob_db_max_ttl_range)
interval, as before)

Differential Revision: D17919798

Pulled By: ltamasi

fbshipit-source-id: b946c3522b836b92b4c157ffbad24f92ba2b0a16

tools/db_bench_tool.cc

@@ -757,8 +757,9 @@ DEFINE_bool(blob_db_is_fifo, false, "Enable FIFO eviction strategy in BlobDB.");
 DEFINE_uint64(blob_db_max_db_size, 0,
               "Max size limit of the directory where blob files are stored.");
 
-DEFINE_uint64(blob_db_max_ttl_range, 86400,
-              "TTL range to generate BlobDB data (in seconds).");
+DEFINE_uint64(
+    blob_db_max_ttl_range, 0,
+    "TTL range to generate BlobDB data (in seconds). 0 means no TTL.");
 
 DEFINE_uint64(blob_db_ttl_range_secs, 3600,
               "TTL bucket size to use when creating blob files.");
@@ -4188,10 +4189,14 @@ class Benchmark {
         if (use_blob_db_) {
 #ifndef ROCKSDB_LITE
           Slice val = gen.Generate(value_size_);
-          int ttl = rand() % FLAGS_blob_db_max_ttl_range;
           blob_db::BlobDB* blobdb =
               static_cast<blob_db::BlobDB*>(db_with_cfh->db);
-          s = blobdb->PutWithTTL(write_options_, key, val, ttl);
+          if (FLAGS_blob_db_max_ttl_range > 0) {
+            int ttl = rand() % FLAGS_blob_db_max_ttl_range;
+            s = blobdb->PutWithTTL(write_options_, key, val, ttl);
+          } else {
+            s = blobdb->Put(write_options_, key, val);
+          }
 #endif  //  ROCKSDB_LITE
         } else if (FLAGS_num_column_families <= 1) {
           batch.Put(key, gen.Generate(value_size_));