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gdss-brick >> gh24 'reversed' option for get_many/5
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- Update brick_ets:get_many/5 to handle 'reversed' option.
- Minor refactoring in get_many/5.
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@tatsuya6502
tatsuya6502 committed Aug 7, 2015
1 parent 0202a8c commit f38dfec
Showing 1 changed file with 71 additions and 44 deletions.
115 changes: 71 additions & 44 deletions src/brick_ets.erl
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Original file line number Diff line number Diff line change
Expand Up @@ -1201,11 +1201,6 @@ get_key(Key, Flags, State) ->
key_not_exist
end.

ets_next_wrapper(Tab, ?BRICK__GET_MANY_FIRST) ->
ets:first(Tab);
ets_next_wrapper(Tab, Key) ->
ets:next(Tab, Key).

%% @spec (term(), list(), boolean(), proplist(), state_r()) ->
%% {{list(), true | false}, state_r()}
%% @doc Get a list of keys, starting with Key, in order specified by
Expand Down Expand Up @@ -1291,31 +1286,31 @@ get_many1b(Key, Flags, IncreasingOrderP, State) ->
DoWitnessP =
case check_flaglist(witness, Flags) of
{true, true} ->
true;
witness;
_ ->
false
undefined
end,
DoAllAttrP =
case check_flaglist(get_all_attribs, Flags) of
{true, true} ->
true;
all_attribs;
_ ->
false
undefined
end,
RawStoreTupleP =
case check_flaglist(get_many_raw_storetuples, Flags) of
{true, true} ->
true;
raw_storetuples;
_ ->
false
undefined
end,
ResultFlavor = {DoWitnessP, DoAllAttrP, RawStoreTupleP},
BinPrefix =
case proplists:get_value(binary_prefix, Flags) of
Prefix when is_binary(Prefix) ->
{size(Prefix), Prefix};
_ ->
0
undefined
end,
MaxBytes =
case proplists:get_value(max_bytes, Flags) of
Expand All @@ -1324,14 +1319,24 @@ get_many1b(Key, Flags, IncreasingOrderP, State) ->
_ ->
2 * 1024 * 1024 * 1024
end,
Res = get_many2(ets_next_wrapper(State#state.ctab, Key),
MaxNum, MaxBytes, ResultFlavor, BinPrefix, [], State),
ScanDirection =
case check_flaglist(reversed, Flags) of
{true, true} ->
backward;
_ ->
forward
end,

Res = get_many2(ets_start_key(State#state.ctab, Key, ScanDirection),
MaxNum, MaxBytes, ResultFlavor,
BinPrefix, ScanDirection, [], State),

if IncreasingOrderP -> %% dialyzer: can never succeed
if
IncreasingOrderP -> %% dialyzer: can never succeed
%% ManyList is backward, must reverse it.
{{ManyList, TorF}, State2} = Res,
{{lists:reverse(ManyList), TorF}, State2};
true ->
true ->
%% Result list is backward, that's OK.
Res
end.
Expand All @@ -1342,40 +1347,61 @@ get_many1b(Key, Flags, IncreasingOrderP, State) ->
%%
%% NOTE: We are *supposed* to return our results in reversed order.

-spec get_many2(key(), any(), any(), any(), any(), any(), any())
-> {{list(extern_tuple()), boolean()}, any()}.
get_many2('$end_of_table', _MaxNum, _MaxBytes, _ResultFlavor, _BPref, Acc, State) ->
-spec get_many2(key() | '$end_of_table',
non_neg_integer(), non_neg_integer(),
{'witness'|'undefined', 'all_attribs'|'undefined', 'raw_storetuples'|'undefined'},
{non_neg_integer(), binary()}|'undefined', 'forward'|'backward',
[extern_tuple()], term()) ->
{{[extern_tuple()], boolean()}, term()}.
get_many2('$end_of_table', _MaxNum, _MaxBytes, _ResultFlavor, _BPref, _ScanDirection, Acc, State) ->
{{Acc, false}, State};
get_many2(_Key, 0, _MaxBytes, _ResultFlavor, _BPref, Acc, State) ->
get_many2(_Key, 0, _MaxBytes, _ResultFlavor, _BPref, _ScanDirection, Acc, State) ->
{{Acc, true}, State};
get_many2(Key, MaxNum, MaxBytes, ResultFlavor, BPref, Acc, State)
get_many2(Key, MaxNum, MaxBytes, ResultFlavor, BPref, ScanDirection, Acc, State)
when MaxBytes > 0 ->
Cont = case BPref of
0 ->
undefined ->
ok;
{PrefixLen, Prefix} ->
case Key of
<<Prefix:PrefixLen/binary, _Rest/binary>> ->
ok;
_ ->
skip %{{lists:reverse(Acc), false}, State}
skip
end
end,
if
Cont =:= ok ->
[Tuple] = ets:lookup(State#state.ctab, Key),
case Cont of
ok ->
CTab = State#state.ctab,
[Tuple] = ets:lookup(CTab, Key),
Bytes = storetuple_vallen(Tuple),
Item = make_many_result(Tuple, ResultFlavor, State),
get_many2(ets:next(State#state.ctab, Key), MaxNum - 1,
MaxBytes - Bytes,
ResultFlavor, BPref, [Item|Acc], State);
Cont =:= skip ->
get_many2('$end_of_table', MaxNum, MaxBytes, ResultFlavor, BPref,
Acc, State)
get_many2(ets_next_key(CTab, Key, ScanDirection), MaxNum - 1,
MaxBytes - Bytes, ResultFlavor,
BPref, ScanDirection, [Item|Acc], State);
skip ->
get_many2('$end_of_table', MaxNum, MaxBytes, ResultFlavor,
BPref, ScanDirection, Acc, State)
end;
get_many2(_Key, _MaxNum, _MaxBytes, _ResultFlavor, _BPref, Acc, State) ->
get_many2(_Key, _MaxNum, _MaxBytes, _ResultFlavor, _BPref, _ScanDirection, Acc, State) ->
{{Acc, true}, State}.

-spec ets_start_key(atom(), key(), 'forward' | 'backward') -> key().
ets_start_key(Tab, ?BRICK__GET_MANY_FIRST, forward) ->
ets:first(Tab);
ets_start_key(Tab, Key, forward) ->
ets:next(Tab, Key);
ets_start_key(Tab, ?BRICK__GET_MANY_FIRST, backward) ->
ets:last(Tab);
ets_start_key(Tab, Key, backward) ->
ets:prev(Tab, Key).

-spec ets_next_key(atom(), key(), 'forward' | 'backword') -> key() | '$end_of_table'.
ets_next_key(Tab, Key, forward) ->
ets:next(Tab, Key);
ets_next_key(Tab, Key, backward) ->
ets:prev(Tab, Key).

%% @doc Create the result tuple for a single get_many result.
%%
%% Note about separation of ETS and disk storage:
Expand All @@ -1386,32 +1412,33 @@ get_many2(_Key, _MaxNum, _MaxBytes, _ResultFlavor, _BPref, Acc, State) ->
%%
%% Arg note: (StoreTuple, {DoWitnessP, DoAllAttrP, RawStoreTupleP}, State).

-spec make_many_result(store_tuple(), {boolean(), boolean(), boolean()}, any()) ->
extern_tuple().
make_many_result(StoreTuple, {true, false, false}, _S) ->
-spec make_many_result(store_tuple(),
{'witness'|'undefined', 'all_attribs'|'undefined', 'raw_storetuples'|'undefined'},
State::term()) -> extern_tuple().
make_many_result(StoreTuple, {witness, undefined, undefined}, _S) ->
{storetuple_key(StoreTuple), storetuple_ts(StoreTuple)};
make_many_result(StoreTuple, {true, true, false}, S) ->
make_many_result(StoreTuple, {witness, all_attribs, undefined}, S) ->
{storetuple_key(StoreTuple), storetuple_ts(StoreTuple),
make_extern_flags(storetuple_val(StoreTuple),
storetuple_vallen(StoreTuple),
storetuple_flags(StoreTuple), S)};
make_many_result(StoreTuple, {false, false, false}, S) ->
make_many_result(StoreTuple, {undefined, undefined, undefined}, S) ->
make_many_result2(StoreTuple, S);
make_many_result(StoreTuple, {false, true, false}, S) ->
make_many_result(StoreTuple, {undefined, all_attribs, undefined}, S) ->
make_many_result3(StoreTuple, S);
make_many_result(StoreTuple, {_DoWitness, _DoAllAttr, true}, _S) ->
make_many_result(StoreTuple, {_DoWitness, _DoAllAttr, raw_storetuples}, _S) ->
StoreTuple.

make_many_result2(StoreTuple, S) ->
{Key, TStamp, Val0, _ExpTime, _Flags} = storetuple_to_externtuple(
StoreTuple, S),
{Key, TStamp, Val0, _ExpTime, _Flags} =
storetuple_to_externtuple(StoreTuple, S),
ValLen = storetuple_vallen(StoreTuple),
Val = bigdata_dir_get_val(Key, Val0, ValLen, S),
{Key, TStamp, Val}.

make_many_result3(StoreTuple, S) ->
{Key, TStamp, Val0, ExpTime, Flags} = storetuple_to_externtuple(
StoreTuple, S),
{Key, TStamp, Val0, ExpTime, Flags} =
storetuple_to_externtuple(StoreTuple, S),
ValLen = storetuple_vallen(StoreTuple),
Val = bigdata_dir_get_val(Key, Val0, ValLen, S),
{Key, TStamp, Val, ExpTime, Flags}.
Expand Down

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