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Alter Riak HEAD

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Change the extract of Riak metadata.

In Riak-based volume tests hte writing of SFT files is tanking.  Could
this be the "extra" metadata.  i.e. There are only current plans to look
at the vclock.  Sibling count is free to fetch, what if we just get
these two items, will it be less CPU to extract the metadata, but also
will the reduced weight reduce the downstream impact?
This commit is contained in:
martinsumner 2016-12-08 23:38:50 +00:00
parent 2f4013f430
commit 5bdb7fd7fa
1 changed files with 9 additions and 40 deletions
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49
src/leveled_codec.erl
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@ -331,8 +331,8 @@ build_metadata_object(PrimaryKey, MD) ->
{Tag, _Bucket, _Key, null} = PrimaryKey,
case Tag of
?RIAK_TAG ->
{SibMetaBinList, Vclock, _Hash, _Size} = MD,
riak_metadata_to_binary(Vclock, SibMetaBinList);
{SibCount, Vclock, _Hash, _Size} = MD,
riak_metadata_to_binary(Vclock, SibCount);
?STD_TAG ->
MD
end.
@ -341,55 +341,24 @@ build_metadata_object(PrimaryKey, MD) ->
riak_extract_metadata(delete, Size) ->
{delete, null, null, Size};
riak_extract_metadata(ObjBin, Size) ->
{Vclock, SibMetaBinList} = riak_metadata_from_binary(ObjBin),
{SibMetaBinList, Vclock, erlang:phash2(ObjBin), Size}.
{Vclock, SibCount} = riak_metadata_from_binary(ObjBin),
{SibCount, Vclock, erlang:phash2(ObjBin), Size}.
%% <<?MAGIC:8/integer, ?V1_VERS:8/integer, VclockLen:32/integer,
%%% VclockBin/binary, SibCount:32/integer, SibsBin/binary>>.
riak_metadata_to_binary(Vclock, SibMetaBinList) ->
riak_metadata_to_binary(Vclock, SibCount) ->
VclockBin = term_to_binary(Vclock),
VclockLen = byte_size(VclockBin),
SibCount = length(SibMetaBinList),
SibsBin = slimbin_contents(SibMetaBinList),
<<?MAGIC:8/integer, ?V1_VERS:8/integer, VclockLen:32/integer,
VclockBin:VclockLen/binary, SibCount:32/integer, SibsBin/binary>>.
VclockBin:VclockLen/binary, SibCount:32/integer>>.
% Fixes the value length for each sibling to be zero, and so includes no value
slimbin_content(MetaBin) ->
MetaLen = byte_size(MetaBin),
<<0:32/integer, MetaLen:32/integer, MetaBin:MetaLen/binary>>.
slimbin_contents(SibMetaBinList) ->
F = fun(MetaBin, Acc) ->
<<Acc/binary, (slimbin_content(MetaBin))/binary>>
end,
lists:foldl(F, <<>>, SibMetaBinList).
riak_metadata_from_binary(V1Binary) ->
<<?MAGIC:8/integer, ?V1_VERS:8/integer, VclockLen:32/integer,
Rest/binary>> = V1Binary,
<<VclockBin:VclockLen/binary, SibCount:32/integer, SibsBin/binary>> = Rest,
SibMetaBinList =
case SibCount of
0 ->
[];
SC when is_integer(SC) ->
get_metadata_from_siblings(SibsBin, SibCount, [])
end,
{binary_to_term(VclockBin), SibMetaBinList}.
get_metadata_from_siblings(<<>>, 0, SibMetaBinList) ->
SibMetaBinList;
get_metadata_from_siblings(<<ValLen:32/integer, Rest0/binary>>,
SibCount,
SibMetaBinList) ->
<<_ValBin:ValLen/binary, MetaLen:32/integer, Rest1/binary>> = Rest0,
<<MetaBin:MetaLen/binary, Rest2/binary>> = Rest1,
get_metadata_from_siblings(Rest2,
SibCount - 1,
[MetaBin|SibMetaBinList]).
<<VclockBin:VclockLen/binary, SibCount:32/integer, _Rest/binary>> = Rest,
{binary_to_term(VclockBin), SibCount}.