umgeher/leveled
0
Fork 0
Code Issues Pull requests Releases Activity Actions

Add a small cache to SST file

Browse source 
so that a HEAD which folllows a HEAD (e.g. when a GET follows a HEAD) has a chance of avoiding the binary_to_term CPU load
This commit is contained in:
Martin Sumner 2017-11-28 14:56:40 +00:00
parent 7c4e1a5ad9
commit eb90541a85
2 changed files with 52 additions and 15 deletions
Download patch file Download diff file Expand all files Collapse all files

5
src/leveled_log.erl
View file

@ -226,10 +226,11 @@
{"SST12",
{info, "SST Timings for sample_count=~w"
++ " at timing points index_query_time=~w"
++ " lookup_cache_time=~w slot_index_time=~w slot_fetch_time=~w"
++ " lookup_cache_time=~w slot_index_time=~w "
++ " fetch_cache_time=~w slot_fetch_time=~w"
++ " noncached_block_fetch_time=~w"
++ " exiting at points slot_index=~w"
++ " slot_fetch=~w noncached_block_fetch=~w"}},
++ " fetch_cache=~w slot_fetch=~w noncached_block_fetch=~w"}},
{"I0001",

62
src/leveled_sst.erl
View file

@ -78,6 +78,7 @@
-define(TREE_SIZE, 4).
-define(TIMING_SAMPLECOUNTDOWN, 10000).
-define(TIMING_SAMPLESIZE, 100).
-define(CACHE_SIZE, 32).
-include_lib("eunit/include/eunit.hrl").
@ -142,17 +143,20 @@
blockindex_cache,
compression_method = native :: press_methods(),
timings = no_timing :: sst_timings(),
timings_countdown = 0 :: integer()}).
timings_countdown = 0 :: integer(),
fetch_cache = array:new([{size, ?CACHE_SIZE}])}).
-record(sst_timings,
{sample_count = 0 :: integer(),
index_query_time = 0 :: integer(),
lookup_cache_time = 0 :: integer(),
slot_index_time = 0 :: integer(),
fetch_cache_time = 0 :: integer(),
slot_fetch_time = 0 :: integer(),
noncached_block_time = 0 :: integer(),
lookup_cache_count = 0 :: integer(),
slot_index_count = 0 :: integer(),
fetch_cache_count = 0 :: integer(),
slot_fetch_count = 0 :: integer(),
noncached_block_count = 0 :: integer()}).
@ -672,18 +676,37 @@ fetch(LedgerKey, Hash, State, Timings0) ->
_ ->
{SW3, Timings3} =
update_timings(SW2, Timings2, slot_index, true),
StartPos = Slot#slot_index_value.start_position,
Result =
check_blocks(PosList,
State#state.handle,
StartPos,
BlockLengths,
LedgerKey,
PressMethod,
not_present),
{_SW4, Timings4} =
update_timings(SW3, Timings3, slot_fetch, false),
{Result, State, Timings4}
FetchCache = State#state.fetch_cache,
CacheHash = cache_hash(Hash),
case array:get(CacheHash, FetchCache) of
{LedgerKey, V} ->
{_SW4, Timings4} =
update_timings(SW3,
Timings3,
fetch_cache,
false),
{{LedgerKey, V}, State, Timings4};
_ ->
StartPos = Slot#slot_index_value.start_position,
Result =
check_blocks(PosList,
State#state.handle,
StartPos,
BlockLengths,
LedgerKey,
PressMethod,
not_present),
FetchCache0 =
array:set(CacheHash, Result, FetchCache),
{_SW4, Timings4} =
update_timings(SW3,
Timings3,
slot_fetch,
false),
{Result,
State#state{fetch_cache = FetchCache0},
Timings4}
end
end
end.
@ -1471,6 +1494,11 @@ extra_hash({SegHash, _ExtraHash}) when is_integer(SegHash) ->
extra_hash(NotHash) ->
NotHash.
cache_hash({_SegHash, ExtraHash}) when is_integer(ExtraHash) ->
ExtraHash band (?CACHE_SIZE - 1);
cache_hash(_NotHash) ->
0.
tune_hash(SegHash) ->
SegHash band 32767.
@ -1810,9 +1838,11 @@ log_timings(Timings) ->
Timings#sst_timings.index_query_time,
Timings#sst_timings.lookup_cache_time,
Timings#sst_timings.slot_index_time,
Timings#sst_timings.fetch_cache_time,
Timings#sst_timings.slot_fetch_time,
Timings#sst_timings.noncached_block_time,
Timings#sst_timings.slot_index_count,
Timings#sst_timings.fetch_cache_count,
Timings#sst_timings.slot_fetch_count,
Timings#sst_timings.noncached_block_count]).
@ -1832,6 +1862,9 @@ update_timings(SW, Timings, Stage, Continue) ->
slot_index ->
SIT = Timings#sst_timings.slot_index_time,
Timings#sst_timings{slot_index_time = SIT + Timer};
fetch_cache ->
FCT = Timings#sst_timings.fetch_cache_time,
Timings#sst_timings{fetch_cache_time = FCT + Timer};
slot_fetch ->
SFT = Timings#sst_timings.slot_fetch_time,
Timings#sst_timings{slot_fetch_time = SFT + Timer};
@ -1848,6 +1881,9 @@ update_timings(SW, Timings, Stage, Continue) ->
slot_index ->
SIC = Timings#sst_timings.slot_index_count,
Timings0#sst_timings{slot_index_count = SIC + 1};
fetch_cache ->
FCC = Timings#sst_timings.fetch_cache_count,
Timings0#sst_timings{fetch_cache_count = FCC + 1};
slot_fetch ->
SFC = Timings#sst_timings.slot_fetch_count,
Timings0#sst_timings{slot_fetch_count = SFC + 1};