rocksdb/utilities
Maysam Yabandeh 54d94e9c2c PinnableSlice
Summary:
Currently the point lookup values are copied to a string provided by the user.
This incures an extra memcpy cost. This patch allows doing point lookup
via a PinnableSlice which pins the source memory location (instead of
copying their content) and releases them after the content is consumed
by the user. The old API of Get(string) is translated to the new API
underneath.

 Here is the summary for improvements:
 1. value 100 byte: 1.8%  regular, 1.2% merge values
 2. value 1k   byte: 11.5% regular, 7.5% merge values
 3. value 10k byte: 26% regular,    29.9% merge values

 The improvement for merge could be more if we extend this approach to
 pin the merge output and delay the full merge operation until the user
 actually needs it. We have put that for future work.

PS:
Sometimes we observe a small decrease in performance when switching from
t5452014 to this patch but with the old Get(string) API. The difference
is a little and could be noise. More importantly it is safely
cancelled
Closes https://github.com/facebook/rocksdb/pull/1732

Differential Revision: D4374613

Pulled By: maysamyabandeh

fbshipit-source-id: a077f1a
2017-01-08 13:54:13 -08:00
..
backupable Fix backupable db test 2017-01-01 11:24:14 -08:00
blob_db Support SST files with Global sequence numbers [reland] 2016-10-18 16:59:37 -07:00
checkpoint Always fsync the file after file copying 2016-12-28 19:09:16 -08:00
compaction_filters Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
convenience Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
date_tiered DeleteRange user iterator support 2016-11-04 12:09:22 -07:00
document PinnableSlice 2017-01-08 13:54:13 -08:00
geodb Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
leveldb_options Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
lua rocks_lua_compaction_filter: add unused attribute to a variable 2016-11-21 14:54:14 -08:00
memory Disable auto compactions in memory_test and re-enable the test (#1408) 2016-10-19 18:18:42 -07:00
merge_operators Introduce FullMergeV2 (eliminate memcpy from merge operators) 2016-07-20 09:49:03 -07:00
option_change_migration option_change_migration_test: force full compaction when needed 2016-11-15 22:09:34 -08:00
options Only cache level 0 indexes and filter when opening table reader 2016-07-20 11:23:31 -07:00
persistent_cache persistent_cache: fix two timer 2016-12-21 13:39:16 -08:00
redis Eliminate use of 'using namespace std'. Also remove a number of ADL references to std functions. 2016-05-20 07:42:18 -07:00
simulator_cache Print cache options to info log 2016-12-22 14:54:19 -08:00
spatialdb fix wrong assignment of level0_stop_writes_trigger in spatialdb (#1061) 2016-04-07 09:02:28 -07:00
table_properties_collectors Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
transactions gcc-7 requires include <functional> for std::function 2016-12-16 11:24:18 -08:00
ttl PinnableSlice 2017-01-08 13:54:13 -08:00
write_batch_with_index Avoid calling GetDBOptions() inside GetFromBatchAndDB() 2016-10-18 13:19:26 -07:00
col_buf_decoder.cc Fix clang on macOS 2016-08-03 10:41:27 -07:00
col_buf_decoder.h Fix clang build failure and refactor unit test 2016-08-02 15:16:39 -07:00
col_buf_encoder.cc Fix travis (compile for clang < 3.9) 2016-12-01 10:09:22 -08:00
col_buf_encoder.h Fix clang build failure and refactor unit test 2016-08-02 15:16:39 -07:00
column_aware_encoding_exp.cc Support ZSTD with finalized format 2016-09-06 12:22:16 -07:00
column_aware_encoding_test.cc Fix clang build failure and refactor unit test 2016-08-02 15:16:39 -07:00
column_aware_encoding_util.cc Fix Windows build issues (#1253) 2016-08-02 17:15:18 -07:00
column_aware_encoding_util.h Remove ImmutableCFOptions from public API 2016-09-02 14:16:31 -07:00
env_librados.cc Add EnvLibrados - RocksDB Env of RADOS (#1222) 2016-07-21 11:16:34 -07:00
env_librados.md Add EnvLibrados - RocksDB Env of RADOS (#1222) 2016-07-21 11:16:34 -07:00
env_librados_test.cc Add EnvLibrados - RocksDB Env of RADOS (#1222) 2016-07-21 11:16:34 -07:00
env_mirror.cc direct io write support 2016-12-22 13:09:19 -08:00
env_mirror_test.cc env: add EnvMirror 2015-12-10 21:32:45 -05:00
env_registry.cc Env registry for URI-based Env selection [pluggable Env part 1] 2016-06-03 08:15:16 -07:00
env_registry_test.cc Env registry for URI-based Env selection [pluggable Env part 1] 2016-06-03 08:15:16 -07:00
merge_operators.h Introduce FullMergeV2 (eliminate memcpy from merge operators) 2016-07-20 09:49:03 -07:00
util_merge_operators_test.cc Introduce FullMergeV2 (eliminate memcpy from merge operators) 2016-07-20 09:49:03 -07:00