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Ongoing improvements - in particular CDB now supports general erlang terms not just lists

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This commit is contained in:
Martin Sumner 2015-06-04 21:15:31 +01:00
parent 647a7f44dc
commit c5f50c613d
4 changed files with 412 additions and 159 deletions
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23
src/leveled_bst.erl
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@ -23,16 +23,16 @@
%% There will be up to 4000 blocks in a single bst file
%%
%% The slots is a series of references
%% - 4 byte bloom-filter length
%% - 4 byte bloom-filter length
%% - 4 byte key-helper length
%% - a variable-length compressed bloom filter for all keys in slot (approx 1KB)
%% - 32 ordered variable-length key helpers pointing to first key in each
%% - a variable-length compressed bloom filter for all keys in slot (approx 3KB)
%% - 64 ordered variable-length key helpers pointing to first key in each
%% block (in slot) of the form Key Length, Key, Block Position
%% - 4 byte CRC for the slot
%%
%% The slot index in the footer is made up of 128 keys and pointers at the
%% the start of each slot
%% - 128 Key Length (4 byte), Key, Position (4 byte) indexes
%% - 64 x Key Length (4 byte), Key, Position (4 byte) indexes
%% - 4 bytes CRC for the index
%%
%% The format of the file is intended to support quick lookups, whilst
@ -54,8 +54,9 @@
-record(metadata, {version = ?CURRENT_VERSION :: tuple(),
mutable = false :: true | false,
compressed = true :: tre | false,
slot_list :: list(),
compressed = true :: true | false,
slot_array,
open_slot :: integer(),
cache :: tuple(),
smallest_key :: tuple(),
largest_key :: tuple(),
@ -73,9 +74,9 @@ start_file(Handle) ->
{ok, _} = file:position(Handle, bof),
file:write(Handle, Header),
{Version, {M, C}, _, _} = convert_header(Header),
FileMD = #metadata{version=Version, mutable=M, compressed=C},
SlotArray = array:new(?SLOT_COUNT),
{Handle, FileMD, SlotArray}.
FileMD = #metadata{version = Version, mutable = M, compressed = C,
slot_array = array:new(?SLOT_COUNT), open_slot = 0},
{Handle, FileMD}.
create_header(initial) ->
@ -119,6 +120,8 @@ convert_header_v01(Header) ->
{{0, 1}, {M, C}, {FooterP, SlotLng, HlpLng}, none}.
% add_slot(Handle, FileMD, SlotArray)
%%%%%%%%%%%%%%%%
@ -148,7 +151,7 @@ bad_header_test() ->
?assertMatch(unknown_version, convert_header(NewHdr2)).
record_onstartfile_test() ->
{_, FileMD, _} = start_file("onstartfile.bst"),
{_, FileMD} = start_file("onstartfile.bst"),
?assertMatch({0, 1}, FileMD#metadata.version).