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7555243bcf
Summary: The motivations for this change include * Free up space in ClockHandle so that we can add data for secondary cache handling while still keeping within single cache line (64 byte) size. * This change frees up space by eliminating the need for the `hash` field by making the fixed-size key itself a hash, using a 128-bit bijective (lossless) hash. * Generally more customizability of ShardedCache (such as hashing) without worrying about virtual call overheads * ShardedCache now uses static polymorphism (template) instead of dynamic polymorphism (virtual overrides) for the CacheShard. No obvious performance benefit is seen from the change (as mostly expected; most calls to virtual functions in CacheShard could already be optimized to static calls), but offers more flexibility without incurring the runtime cost of adhering to a common interface (without type parameters or static callbacks). * You'll also notice less `reinterpret_cast`ing and other boilerplate in the Cache implementations, as this can go in ShardedCache. More detail: * Don't have LRUCacheShard maintain `std::shared_ptr<SecondaryCache>` copies (extra refcount) when LRUCache can be in charge of keeping a `shared_ptr`. * Renamed `capacity_mutex_` to `config_mutex_` to better represent the scope of what it guards. * Some preparation for 64-bit hash and indexing in LRUCache, but didn't include the full change because of slight performance regression. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10801 Test Plan: Unit test updates were non-trivial because of major changes to the ClockCacheShard interface in handling of key vs. hash. Performance: Create with `TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=30000000 -disable_wal=1 -bloom_bits=16` Test with ``` TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=readrandom[-X1000] -readonly -num=30000000 -bloom_bits=16 -cache_index_and_filter_blocks=1 -cache_size=610000000 -duration 20 -threads=16 ``` Before: `readrandom [AVG 150 runs] : 321147 (± 253) ops/sec` After: `readrandom [AVG 150 runs] : 321530 (± 326) ops/sec` So possibly ~0.1% improvement. And with `-cache_type=hyper_clock_cache`: Before: `readrandom [AVG 30 runs] : 614126 (± 7978) ops/sec` After: `readrandom [AVG 30 runs] : 645349 (± 8087) ops/sec` So roughly 5% improvement! Reviewed By: anand1976 Differential Revision: D40252236 Pulled By: pdillinger fbshipit-source-id: ff8fc70ef569585edc95bcbaaa0386f61355ae5b |
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| .. | ||
| binary_search_index_reader.cc | ||
| binary_search_index_reader.h | ||
| block.cc | ||
| block.h | ||
| block_based_table_builder.cc | ||
| block_based_table_builder.h | ||
| block_based_table_factory.cc | ||
| block_based_table_factory.h | ||
| block_based_table_iterator.cc | ||
| block_based_table_iterator.h | ||
| block_based_table_reader.cc | ||
| block_based_table_reader.h | ||
| block_based_table_reader_impl.h | ||
| block_based_table_reader_sync_and_async.h | ||
| block_based_table_reader_test.cc | ||
| block_builder.cc | ||
| block_builder.h | ||
| block_like_traits.h | ||
| block_prefetcher.cc | ||
| block_prefetcher.h | ||
| block_prefix_index.cc | ||
| block_prefix_index.h | ||
| block_test.cc | ||
| block_type.h | ||
| cachable_entry.h | ||
| data_block_footer.cc | ||
| data_block_footer.h | ||
| data_block_hash_index.cc | ||
| data_block_hash_index.h | ||
| data_block_hash_index_test.cc | ||
| filter_block.h | ||
| filter_block_reader_common.cc | ||
| filter_block_reader_common.h | ||
| filter_policy.cc | ||
| filter_policy_internal.h | ||
| flush_block_policy.cc | ||
| flush_block_policy.h | ||
| full_filter_block.cc | ||
| full_filter_block.h | ||
| full_filter_block_test.cc | ||
| hash_index_reader.cc | ||
| hash_index_reader.h | ||
| index_builder.cc | ||
| index_builder.h | ||
| index_reader_common.cc | ||
| index_reader_common.h | ||
| mock_block_based_table.h | ||
| parsed_full_filter_block.cc | ||
| parsed_full_filter_block.h | ||
| partitioned_filter_block.cc | ||
| partitioned_filter_block.h | ||
| partitioned_filter_block_test.cc | ||
| partitioned_index_iterator.cc | ||
| partitioned_index_iterator.h | ||
| partitioned_index_reader.cc | ||
| partitioned_index_reader.h | ||
| reader_common.cc | ||
| reader_common.h | ||
| uncompression_dict_reader.cc | ||
| uncompression_dict_reader.h | ||