Huisheng Liu 904a60ff63 return timestamp from get (#6409) ... Summary: Added new Get() methods that return timestamp. Dummy implementation is given so that classes derived from DB don't need to be touched to provide their implementation. MultiGet is not included. ReadRandom perf test (10 minutes) on the same development machine ram drive with the same DB data shows no regression (within marge of error). The test is adapted from https://github.com/facebook/rocksdb/wiki/RocksDB-In-Memory-Workload-Performance-Benchmarks. base line (commit 72ee067b9): 101.712 micros/op 314602 ops/sec; 36.0 MB/s (5658999 of 5658999 found) This PR: 100.288 micros/op 319071 ops/sec; 36.5 MB/s (5674999 of 5674999 found) ./db_bench --db=r:\rocksdb.github --num_levels=6 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --cache_size=2147483648 --cache_numshardbits=6 --compression_type=none --compression_ratio=1 --min_level_to_compress=-1 --disable_seek_compaction=1 --hard_rate_limit=2 --write_buffer_size=134217728 --max_write_buffer_number=2 --level0_file_num_compaction_trigger=8 --target_file_size_base=134217728 --max_bytes_for_level_base=1073741824 --disable_wal=0 --wal_dir=r:\rocksdb.github\WAL_LOG --sync=0 --verify_checksum=1 --delete_obsolete_files_period_micros=314572800 --max_background_compactions=4 --max_background_flushes=0 --level0_slowdown_writes_trigger=16 --level0_stop_writes_trigger=24 --statistics=0 --stats_per_interval=0 --stats_interval=1048576 --histogram=0 --use_plain_table=1 --open_files=-1 --mmap_read=1 --mmap_write=0 --memtablerep=prefix_hash --bloom_bits=10 --bloom_locality=1 --duration=600 --benchmarks=readrandom --use_existing_db=1 --num=25000000 --threads=32 Pull Request resolved: https://github.com/facebook/rocksdb/pull/6409 Differential Revision: D20200086 Pulled By: riversand963 fbshipit-source-id: 490edd74d924f62bd8ae9c29c2a6bbbb8410ca50		2020-03-02 16:01:00 -08:00
..
adaptive
block_based
cuckoo
plain
block_fetcher.cc
block_fetcher.h
cleanable_test.cc
format.cc
format.h
get_context.cc
get_context.h
internal_iterator.h
iter_heap.h
iterator.cc
iterator_wrapper.h
merger_test.cc
merging_iterator.cc
merging_iterator.h
meta_blocks.cc
meta_blocks.h
mock_table.cc
mock_table.h
multiget_context.h
persistent_cache_helper.cc
persistent_cache_helper.h
persistent_cache_options.h
scoped_arena_iterator.h
sst_file_reader.cc
sst_file_reader_test.cc
sst_file_writer.cc
sst_file_writer_collectors.h
table_builder.h
table_properties.cc
table_properties_internal.h
table_reader.h
table_reader_bench.cc
table_reader_caller.h
table_test.cc
two_level_iterator.cc
two_level_iterator.h