%% %% %CopyrightBegin% %% %% Copyright Ericsson AB 2004-2010. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in %% compliance with the License. You should have received a copy of the %% Erlang Public License along with this software. If not, it can be %% retrieved online at http://www.erlang.org/. %% %% Software distributed under the License is distributed on an "AS IS" %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See %% the License for the specific language governing rights and limitations %% under the License. %% %% %CopyrightEnd% %% -module(qlc). %%% Purpose: Main API module qlc. Functions for evaluation. %%% Other files: %%% qlc_pt. Implements the parse transform. %% External exports -export([parse_transform/2, transform_from_evaluator/2]). -export([q/1, q/2]). -export([eval/1, e/1, eval/2, e/2, fold/3, fold/4]). -export([cursor/1, cursor/2, next_answers/1, next_answers/2, delete_cursor/1]). -export([append/1, append/2]). -export([sort/1, sort/2, keysort/2, keysort/3]). -export([table/2]). -export([info/1, info/2]). -export([string_to_handle/1, string_to_handle/2, string_to_handle/3]). -export([format_error/1]). %% Exported to qlc_pt.erl only: -export([template_state/0, aux_name/3, name_suffix/2, vars/1, var_ufold/2, var_fold/3, all_selections/1]). %% When cache=list lists bigger than ?MAX_LIST_SIZE bytes are put on %% file. Also used when merge join finds big equivalence classes. -define(MAX_LIST_SIZE, 512*1024). -record(qlc_append, % qlc:append/1,2 {hl }). -record(qlc_table, % qlc:table/2 {trav_fun, % traverse fun trav_MS, % bool(); true iff traverse fun takes a match spec pre_fun, post_fun, info_fun, format_fun, lookup_fun, parent_fun, key_equality, % '==' | '=:=' | undefined (--R12B-5) lu_vals, % undefined | {Position,Values}; values to be looked up ms = no_match_spec % match specification; [T || P <- Tab, Fs] }). -record(qlc_sort, % qlc:sort/1,2 and qlc:keysort/2,3 {h, keypos, % sort | {keysort, KeyPos} unique, compressed, % [] | [compressed] order, fs_opts, % file_sorter options tmpdir_usage = allowed, % allowed | not_allowed % | warning_msg | error_msg | info_msg tmpdir }). %% Also in qlc_pt.erl. -record(qlc_lc, % qlc:q/1,2 {lc, opt % #qlc_opt }). -record(qlc_list, % a prepared list {l, ms = no_match_spec }). -record(qlc_join, % a prepared join {kind, % {merge, KeyEquality} | % {lookup, KeyEquality, LookupFun} opt, % #qlc_opt from q/2. h1, q1, c1, % to be traversed by "lookup join" h2, q2, c2 % to be looked up by "lookup join" }). %%% A query cursor is a tuple {qlc_cursor, Cursor} where Cursor is a pair %%% {CursorPid, OwnerPid}. -record(qlc_cursor, {c}). -record(qlc_opt, {unique = false, % bool() cache = false, % bool() | list (true~ets, false~no) max_lookup = -1, % int() >= 0 | -1 (represents infinity) join = any, % any | nested_loop | merge | lookup tmpdir = "", % global tmpdir lookup = any, % any | bool() max_list = ?MAX_LIST_SIZE, % int() >= 0 tmpdir_usage = allowed % allowed | not_allowed % | warning_msg | error_msg | info_msg }). -record(setup, {parent}). -define(THROWN_ERROR, {?MODULE, throw_error, _}). %%% A query handle is a tuple {qlc_handle, Handle} where Handle is one %%% of #qlc_append, #qlc_table, #qlc_sort, and #qlc_lc. -record(qlc_handle, {h}). get_handle(#qlc_handle{h = #qlc_lc{opt = {qlc_opt, U, C, M}}=H}) -> %% R11B-0. H#qlc_lc{opt = #qlc_opt{unique = U, cache = C, max_lookup = M}}; get_handle(#qlc_handle{h = H}) -> H; get_handle(L) when is_list(L) -> L; get_handle(_) -> badarg. %%% %%% Exported functions %%% append(QHs) -> Hs = [case get_handle(QH) of badarg -> erlang:error(badarg, [QHs]); H -> H end || QH <- QHs], #qlc_handle{h = #qlc_append{hl = Hs}}. append(QH1, QH2) -> Hs = [case get_handle(QH) of badarg -> erlang:error(badarg, [QH1, QH2]); H -> H end || QH <- [QH1, QH2]], #qlc_handle{h = #qlc_append{hl = Hs}}. cursor(QH) -> cursor(QH, []). cursor(QH, Options) -> case {options(Options, [unique_all, cache_all, tmpdir, spawn_options, max_list_size, tmpdir_usage]), get_handle(QH)} of {B1, B2} when B1 =:= badarg; B2 =:= badarg -> erlang:error(badarg, [QH, Options]); {[GUnique, GCache, TmpDir, SpawnOptions0, MaxList, TmpUsage], H} -> SpawnOptions = spawn_options(SpawnOptions0), case cursor_process(H, GUnique, GCache, TmpDir, SpawnOptions, MaxList, TmpUsage) of Pid when is_pid(Pid) -> #qlc_cursor{c = {Pid, self()}}; Error -> Error end end. delete_cursor(#qlc_cursor{c = {_, Owner}}=C) when Owner =/= self() -> erlang:error(not_cursor_owner, [C]); delete_cursor(#qlc_cursor{c = {Pid, _}}) -> stop_cursor(Pid); delete_cursor(T) -> erlang:error(badarg, [T]). e(QH) -> eval(QH, []). e(QH, Options) -> eval(QH, Options). eval(QH) -> eval(QH, []). eval(QH, Options) -> case {options(Options, [unique_all, cache_all, tmpdir, max_list_size, tmpdir_usage]), get_handle(QH)} of {B1, B2} when B1 =:= badarg; B2 =:= badarg -> erlang:error(badarg, [QH, Options]); {[GUnique, GCache, TmpDir, MaxList, TmpUsage], Handle} -> try Prep = prepare_qlc(Handle, [], GUnique, GCache, TmpDir, MaxList, TmpUsage), case setup_qlc(Prep, #setup{parent = self()}) of {L, Post, _LocalPost} when is_list(L) -> post_funs(Post), L; {Objs, Post, _LocalPost} when is_function(Objs) -> try collect(Objs) after post_funs(Post) end end catch Term -> case erlang:get_stacktrace() of [?THROWN_ERROR | _] -> Term; Stacktrace -> erlang:raise(throw, Term, Stacktrace) end end end. fold(Fun, Acc0, QH) -> fold(Fun, Acc0, QH, []). fold(Fun, Acc0, QH, Options) -> case {options(Options, [unique_all, cache_all, tmpdir, max_list_size, tmpdir_usage]), get_handle(QH)} of {B1, B2} when B1 =:= badarg; B2 =:= badarg -> erlang:error(badarg, [Fun, Acc0, QH, Options]); {[GUnique, GCache, TmpDir, MaxList, TmpUsage], Handle} -> try Prep = prepare_qlc(Handle, not_a_list, GUnique, GCache, TmpDir, MaxList, TmpUsage), case setup_qlc(Prep, #setup{parent = self()}) of {Objs, Post, _LocalPost} when is_function(Objs); is_list(Objs) -> try fold_loop(Fun, Objs, Acc0) after post_funs(Post) end end catch Term -> case erlang:get_stacktrace() of [?THROWN_ERROR | _] -> Term; Stacktrace -> erlang:raise(throw, Term, Stacktrace) end end end. format_error(not_a_query_list_comprehension) -> io_lib:format("argument is not a query list comprehension", []); format_error({used_generator_variable, V}) -> io_lib:format("generated variable ~w must not be used in list expression", [V]); format_error(binary_generator) -> io_lib:format("cannot handle binary generators", []); format_error(too_complex_join) -> io_lib:format("cannot handle join of three or more generators efficiently", []); format_error(too_many_joins) -> io_lib:format("cannot handle more than one join efficiently", []); format_error(nomatch_pattern) -> io_lib:format("pattern cannot possibly match", []); format_error(nomatch_filter) -> io_lib:format("filter evaluates to 'false'", []); format_error({Line, Mod, Reason}) when is_integer(Line) -> io_lib:format("~p: ~s~n", [Line, lists:flatten(Mod:format_error(Reason))]); %% file_sorter errors format_error({bad_object, FileName}) -> io_lib:format("the temporary file \"~s\" holding answers is corrupt", [FileName]); format_error(bad_object) -> io_lib:format("the keys could not be extracted from some term", []); format_error({file_error, FileName, Reason}) -> io_lib:format("\"~s\": ~p~n",[FileName, file:format_error(Reason)]); format_error({premature_eof, FileName}) -> io_lib:format("\"~s\": end-of-file was encountered inside some binary term", [FileName]); format_error({tmpdir_usage, Why}) -> io_lib:format("temporary file was needed for ~w~n", [Why]); format_error({error, Module, Reason}) -> Module:format_error(Reason); format_error(E) -> io_lib:format("~p~n", [E]). info(QH) -> info(QH, []). info(QH, Options) -> case {options(Options, [unique_all, cache_all, flat, format, n_elements, depth, tmpdir, max_list_size, tmpdir_usage]), get_handle(QH)} of {B1, B2} when B1 =:= badarg; B2 =:= badarg -> erlang:error(badarg, [QH, Options]); {[GUnique, GCache, Flat, Format, NElements, Depth, TmpDir, MaxList, TmpUsage], H} -> try Prep = prepare_qlc(H, [], GUnique, GCache, TmpDir, MaxList, TmpUsage), Info = le_info(Prep, {NElements,Depth}), AbstractCode = abstract(Info, Flat, NElements, Depth), case Format of abstract_code -> abstract_code(AbstractCode); string -> Hook = fun({special, _Line, String}, _I, _P, _F) -> String end, lists:flatten(erl_pp:expr(AbstractCode, 0, Hook)); debug -> % Not documented. Intended for testing only. Info end catch Term -> case erlang:get_stacktrace() of [?THROWN_ERROR | _] -> Term; Stacktrace -> erlang:raise(throw, Term, Stacktrace) end end end. keysort(KeyPos, QH) -> keysort(KeyPos, QH, []). keysort(KeyPos, QH, Options) -> case {is_keypos(KeyPos), options(Options, [tmpdir, order, unique, compressed, size, no_files]), get_handle(QH)} of {true, [TmpDir, Order, Unique,Compressed | _], H} when H =/= badarg -> #qlc_handle{h = #qlc_sort{h = H, keypos = {keysort,KeyPos}, unique = Unique, compressed = Compressed, order = Order, fs_opts = listify(Options), tmpdir = TmpDir}}; _ -> erlang:error(badarg, [KeyPos, QH, Options]) end. -define(DEFAULT_NUM_OF_ANSWERS, 10). next_answers(C) -> next_answers(C, ?DEFAULT_NUM_OF_ANSWERS). next_answers(#qlc_cursor{c = {_, Owner}}=C, NumOfAnswers) when Owner =/= self() -> erlang:error(not_cursor_owner, [C, NumOfAnswers]); next_answers(#qlc_cursor{c = {Pid, _}}=C, NumOfAnswers) -> N = case NumOfAnswers of all_remaining -> -1; _ when is_integer(NumOfAnswers), NumOfAnswers > 0 -> NumOfAnswers; _ -> erlang:error(badarg, [C, NumOfAnswers]) end, next_loop(Pid, [], N); next_answers(T1, T2) -> erlang:error(badarg, [T1, T2]). parse_transform(Forms, Options) -> qlc_pt:parse_transform(Forms, Options). %% The funcspecs qlc:q/1 and qlc:q/2 are known by erl_eval.erl and %% erl_lint.erl. q(QLC_lc) -> q(QLC_lc, []). q(#qlc_lc{}=QLC_lc, Options) -> case options(Options, [unique, cache, max_lookup, join, lookup]) of [Unique, Cache, Max, Join, Lookup] -> Opt = #qlc_opt{unique = Unique, cache = Cache, max_lookup = Max, join = Join, lookup = Lookup}, #qlc_handle{h = QLC_lc#qlc_lc{opt = Opt}}; _ -> erlang:error(badarg, [QLC_lc, Options]) end; q(T1, T2) -> erlang:error(badarg, [T1, T2]). sort(QH) -> sort(QH, []). sort(QH, Options) -> case {options(Options, [tmpdir, order, unique, compressed, size, no_files]), get_handle(QH)} of {B1, B2} when B1 =:= badarg; B2 =:= badarg -> erlang:error(badarg, [QH, Options]); {[TD, Order, Unique, Compressed | _], H} -> #qlc_handle{h = #qlc_sort{h = H, keypos = sort, unique = Unique, compressed = Compressed, order = Order, fs_opts = listify(Options), tmpdir = TD}} end. %% Note that the generated code is evaluated by (the slow) erl_eval. string_to_handle(Str) -> string_to_handle(Str, []). string_to_handle(Str, Options) -> string_to_handle(Str, Options, []). string_to_handle(Str, Options, Bindings) when is_list(Str), is_list(Bindings) -> case options(Options, [unique, cache, max_lookup, join, lookup]) of badarg -> erlang:error(badarg, [Str, Options, Bindings]); [Unique, Cache, MaxLookup, Join, Lookup] -> case erl_scan:string(Str) of {ok, Tokens, _} -> case erl_parse:parse_exprs(Tokens) of {ok, [Expr]} -> case qlc_pt:transform_expression(Expr, Bindings) of {ok, {call, _, _QlcQ, Handle}} -> {value, QLC_lc, _} = erl_eval:exprs(Handle, Bindings), O = #qlc_opt{unique = Unique, cache = Cache, max_lookup = MaxLookup, join = Join, lookup = Lookup}, #qlc_handle{h = QLC_lc#qlc_lc{opt = O}}; {not_ok, [{error, Error} | _]} -> error(Error) end; {ok, _ExprList} -> erlang:error(badarg, [Str, Options, Bindings]); {error, ErrorInfo} -> error(ErrorInfo) end; {error, ErrorInfo, _EndLine} -> error(ErrorInfo) end end; string_to_handle(T1, T2, T3) -> erlang:error(badarg, [T1, T2, T3]). table(TraverseFun, Options) when is_function(TraverseFun) -> case {is_function(TraverseFun, 0), IsFun1 = is_function(TraverseFun, 1)} of {false, false} -> erlang:error(badarg, [TraverseFun, Options]); _ -> case options(Options, [pre_fun, post_fun, info_fun, format_fun, lookup_fun, parent_fun, key_equality]) of [PreFun, PostFun, InfoFun, FormatFun, LookupFun, ParentFun, KeyEquality] -> T = #qlc_table{trav_fun = TraverseFun, pre_fun = PreFun, post_fun = PostFun, info_fun = InfoFun, parent_fun = ParentFun, trav_MS = IsFun1, format_fun = FormatFun, lookup_fun = LookupFun, key_equality = KeyEquality}, #qlc_handle{h = T}; badarg -> erlang:error(badarg, [TraverseFun, Options]) end end; table(T1, T2) -> erlang:error(badarg, [T1, T2]). transform_from_evaluator(LC, Bs0) -> qlc_pt:transform_from_evaluator(LC, Bs0). -define(TEMPLATE_STATE, 1). template_state() -> ?TEMPLATE_STATE. aux_name(Name, N, AllNames) -> {VN, _} = aux_name1(Name, N, AllNames), VN. name_suffix(A, Suff) -> list_to_atom(lists:concat([A, Suff])). vars(E) -> var_ufold(fun({var,_L,V}) -> V end, E). var_ufold(F, E) -> ordsets:from_list(var_fold(F, [], E)). all_selections([]) -> [[]]; all_selections([{I,Cs} | ICs]) -> [[{I,C} | L] || C <- Cs, L <- all_selections(ICs)]. %%% %%% Local functions %%% aux_name1(Name, N, AllNames) -> SN = name_suffix(Name, N), case sets:is_element(SN, AllNames) of true -> aux_name1(Name, N + 1, AllNames); false -> {SN, N} end. var_fold(F, A, {var,_,V}=Var) when V =/= '_' -> [F(Var) | A]; var_fold(F, A, T) when is_tuple(T) -> var_fold(F, A, tuple_to_list(T)); var_fold(F, A, [E | Es]) -> var_fold(F, var_fold(F, A, E), Es); var_fold(_F, A, _T) -> A. options(Options, Keys) when is_list(Options) -> options(Options, Keys, []); options(Option, Keys) -> options([Option], Keys, []). options(Options0, [Key | Keys], L) when is_list(Options0) -> Options = case lists:member(Key, Options0) of true -> [atom_option(Key) | lists:delete(Key, Options0)]; false -> Options0 end, V = case lists:keyfind(Key, 1, Options) of {format_fun, U=undefined} -> {ok, U}; {info_fun, U=undefined} -> {ok, U}; {lookup_fun, U=undefined} -> {ok, U}; {parent_fun, U=undefined} -> {ok, U}; {post_fun, U=undefined} -> {ok, U}; {pre_fun, U=undefined} -> {ok, U}; {info_fun, Fun} when is_function(Fun), is_function(Fun, 1) -> {ok, Fun}; {pre_fun, Fun} when is_function(Fun), is_function(Fun, 1) -> {ok, Fun}; {post_fun, Fun} when is_function(Fun), is_function(Fun, 0) -> {ok, Fun}; {lookup_fun, Fun} when is_function(Fun), is_function(Fun, 2) -> {ok, Fun}; {max_lookup, Max} when is_integer(Max), Max >= 0 -> {ok, Max}; {max_lookup, infinity} -> {ok, -1}; {format_fun, Fun} when is_function(Fun), is_function(Fun, 1) -> {ok, Fun}; {parent_fun, Fun} when is_function(Fun), is_function(Fun, 0) -> {ok, Fun}; {key_equality, KE='=='} -> {ok, KE}; {key_equality, KE='=:='} -> {ok, KE}; {join, J=any} -> {ok, J}; {join, J=nested_loop} -> {ok, J}; {join, J=merge} -> {ok, J}; {join, J=lookup} -> {ok, J}; {lookup, LookUp} when is_boolean(LookUp); LookUp =:= any -> {ok, LookUp}; {max_list_size, Max} when is_integer(Max), Max >= 0 -> {ok, Max}; {tmpdir_usage, TmpUsage} when TmpUsage =:= allowed; TmpUsage =:= not_allowed; TmpUsage =:= info_msg; TmpUsage =:= warning_msg; TmpUsage =:= error_msg -> {ok, TmpUsage}; {unique, Unique} when is_boolean(Unique) -> {ok, Unique}; {cache, Cache} when is_boolean(Cache); Cache =:= list -> {ok, Cache}; {cache, ets} -> {ok, true}; {cache, no} -> {ok, false}; {unique_all, UniqueAll} when is_boolean(UniqueAll) -> {ok, UniqueAll}; {cache_all, CacheAll} when is_boolean(CacheAll); CacheAll =:= list -> {ok, CacheAll}; {cache_all, ets} -> {ok, true}; {cache_all, no} -> {ok, false}; {spawn_options, default} -> {ok, default}; {spawn_options, SpawnOptions} -> case is_proper_list(SpawnOptions) of true -> {ok, SpawnOptions}; false -> badarg end; {flat, Flat} when is_boolean(Flat) -> {ok, Flat}; {format, Format} when Format =:= string; Format =:= abstract_code; Format =:= debug -> {ok, Format}; {n_elements, NElements} when NElements =:= infinity; is_integer(NElements), NElements > 0 -> {ok, NElements}; {depth, Depth} when Depth =:= infinity; is_integer(Depth), Depth >= 0 -> {ok, Depth}; {order, Order} when is_function(Order), is_function(Order, 2); (Order =:= ascending); (Order =:= descending) -> {ok, Order}; {compressed, Comp} when Comp -> {ok, [compressed]}; {compressed, Comp} when not Comp -> {ok, []}; {tmpdir, T} -> {ok, T}; {size, Size} when is_integer(Size), Size > 0 -> {ok, Size}; {no_files, NoFiles} when is_integer(NoFiles), NoFiles > 1 -> {ok, NoFiles}; {Key, _} -> badarg; false -> Default = default_option(Key), {ok, Default} end, case V of badarg -> badarg; {ok, Value} -> NewOptions = lists:keydelete(Key, 1, Options), options(NewOptions, Keys, [Value | L]) end; options([], [], L) -> lists:reverse(L); options(_Options, _, _L) -> badarg. default_option(pre_fun) -> undefined; default_option(post_fun) -> undefined; default_option(info_fun) -> undefined; default_option(format_fun) -> undefined; default_option(lookup_fun) -> undefined; default_option(max_lookup) -> -1; default_option(join) -> any; default_option(lookup) -> any; default_option(parent_fun) -> undefined; default_option(key_equality) -> '=:='; default_option(spawn_options) -> default; default_option(flat) -> true; default_option(format) -> string; default_option(n_elements) -> infinity; default_option(depth) -> infinity; default_option(max_list_size) -> ?MAX_LIST_SIZE; default_option(tmpdir_usage) -> allowed; default_option(cache) -> false; default_option(cache_all) -> false; default_option(unique) -> false; default_option(unique_all) -> false; default_option(order) -> ascending; % default values from file_sorter.erl default_option(compressed) -> []; default_option(tmpdir) -> ""; default_option(size) -> 524288; default_option(no_files) -> 16. atom_option(cache) -> {cache, true}; atom_option(unique) -> {unique, true}; atom_option(cache_all) -> {cache_all, true}; atom_option(unique_all) -> {unique_all, true}; atom_option(lookup) -> {lookup, true}; atom_option(flat) -> {flat, true}; atom_option(Key) -> Key. is_proper_list([_ | L]) -> is_proper_list(L); is_proper_list(L) -> L =:= []. spawn_options(default) -> [link]; spawn_options(SpawnOptions) -> lists:delete(monitor, case lists:member(link, SpawnOptions) of true -> SpawnOptions; false -> [link | SpawnOptions] end). is_keypos(Keypos) when is_integer(Keypos), Keypos > 0 -> true; is_keypos([]) -> false; is_keypos(L) -> is_keyposs(L). is_keyposs([Kp | Kps]) when is_integer(Kp), Kp > 0 -> is_keyposs(Kps); is_keyposs(Kps) -> Kps =:= []. listify(L) when is_list(L) -> L; listify(T) -> [T]. %% Optimizations to be carried out. -record(optz, {unique = false, % bool() cache = false, % bool() | list join_option = any, % constraint set by the 'join' option fast_join = no, % no | #qlc_join. 'no' means nested loop. opt % #qlc_opt }). %% Prepared #qlc_lc. -record(qlc, {lcf, % fun() -> Val codef, qdata, % with evaluated list expressions init_value, optz % #optz }). %% Prepared simple #qlc_lc. -record(simple_qlc, {p, % atom(), pattern variable le, line, init_value, optz % #optz }). -record(prepared, {qh, % #qlc_append | #qlc_table | #qlc | #simple_qlc | % #qlc_sort | list() sorted = no, % yes | no | ascending | descending sort_info = [], % sort_info2 = [], % 'sort_info' updated with pattern info; qh is LE lu_skip_quals = [], % qualifiers to skip due to lookup join = {[],[]}, % {Lookup, Merge} n_objs = undefined, % for join (not used yet) is_unique_objects = false, % bool() is_cached = false % bool() (true means 'ets' or 'list') }). %%% Cursor process functions. cursor_process(H, GUnique, GCache, TmpDir, SpawnOptions, MaxList, TmpUsage) -> Parent = self(), Setup = #setup{parent = Parent}, CF = fun() -> %% Unless exit/2 is trapped no cleanup can be done. %% The user is assumed not to set the flag to false. process_flag(trap_exit, true), MonRef = erlang:monitor(process, Parent), {Objs, Post, _LocalPost} = try Prep = prepare_qlc(H, not_a_list, GUnique, GCache, TmpDir, MaxList, TmpUsage), setup_qlc(Prep, Setup) catch Class:Reason -> Parent ! {self(), {caught, Class, Reason, erlang:get_stacktrace()}}, exit(normal) end, Parent ! {self(), ok}, wait_for_request(Parent, MonRef, Post), reply(Parent, MonRef, Post, Objs) end, Pid = spawn_opt(CF, SpawnOptions), parent_fun(Pid, Parent). %% Expect calls from tables calling the parent_fun and finally an 'ok'. parent_fun(Pid, Parent) -> receive {Pid, ok} -> Pid; {TPid, {parent_fun, Fun}} -> V = try {value, Fun()} catch Class:Reason -> {parent_fun_caught, Class, Reason, erlang:get_stacktrace()} end, TPid ! {Parent, V}, parent_fun(Pid, Parent); {Pid, {caught, throw, Error, [?THROWN_ERROR | _]}} -> Error; {Pid, {caught, Class, Reason, Stacktrace}} -> erlang:raise(Class, Reason, Stacktrace) end. reply(Parent, MonRef, Post, []) -> no_more(Parent, MonRef, Post); reply(Parent, MonRef, Post, [Answer | Cont]) -> Parent ! {self(), {answer, Answer}}, wait_for_request(Parent, MonRef, Post), reply(Parent, MonRef, Post, Cont); reply(Parent, MonRef, Post, Cont) -> Reply = try if is_function(Cont) -> Cont(); true -> throw_error(Cont) end catch Class:Reason -> post_funs(Post), Message = {caught, Class, Reason, erlang:get_stacktrace()}, Parent ! {self(), Message}, exit(normal) end, reply(Parent, MonRef, Post, Reply). no_more(Parent, MonRef, Post) -> Parent ! {self(), no_more}, wait_for_request(Parent, MonRef, Post), no_more(Parent, MonRef, Post). wait_for_request(Parent, MonRef, Post) -> receive {Parent, stop} -> post_funs(Post), exit(normal); {Parent, more} -> ok; {'EXIT', Parent, _Reason} -> post_funs(Post), exit(normal); {'DOWN', MonRef, process, Parent, _Info} -> post_funs(Post), exit(normal); {'EXIT', Pid, _Reason} when Pid =:= self() -> %% Trapped signal. The cursor ignores it... wait_for_request(Parent, MonRef, Post); Other -> error_logger:error_msg( "The qlc cursor ~w received an unexpected message:\n~p\n", [self(), Other]), wait_for_request(Parent, MonRef, Post) end. %%% End of cursor process functions. abstract_code({special, Line, String}) -> {string, Line, String}; abstract_code(Tuple) when is_tuple(Tuple) -> list_to_tuple(abstract_code(tuple_to_list(Tuple))); abstract_code([H | T]) -> [abstract_code(H) | abstract_code(T)]; abstract_code(Term) -> Term. %% Also in qlc_pt.erl. -define(Q, q). -define(QLC_Q(L1, L2, L3, L4, LC, Os), {call,L1,{remote,L2,{atom,L3,?MODULE},{atom,L4,?Q}},[LC | Os]}). abstract(Info, false=_Flat, NElements, Depth) -> abstract(Info, NElements, Depth); abstract(Info, true=_Flat, NElements, Depth) -> Abstract = abstract(Info, NElements, Depth), Vars = abstract_vars(Abstract), {_, Body0, Expr} = flatten_abstr(Abstract, 1, Vars, []), case Body0 of [] -> Expr; [{match,_,Expr,Q}] -> Q; [{match,_,Expr,Q} | Body] -> {block, 0, lists:reverse(Body, [Q])}; _ -> {block, 0, lists:reverse(Body0, [Expr])} end. abstract({qlc, E0, Qs0, Opt}, NElements, Depth) -> Qs = lists:map(fun({generate, P, LE}) -> {generate, 1, binary_to_term(P), abstract(LE, NElements, Depth)}; (F) -> binary_to_term(F) end, Qs0), E = binary_to_term(E0), Os = case Opt of [] -> []; _ -> [abstract_term(Opt, 1)] end, ?QLC_Q(1, 1, 1, 1, {lc,1,E,Qs}, Os); abstract({table, {M, F, As0}}, _NElements, _Depth) when is_atom(M), is_atom(F), is_list(As0) -> As = [abstract_term(A, 1) || A <- As0], {call, 1, {remote, 1, {atom, 1, M}, {atom, 1, F}}, As}; abstract({table, TableDesc}, _NElements, _Depth) -> case io_lib:deep_char_list(TableDesc) of true -> {ok, Tokens, _} = erl_scan:string(lists:flatten(TableDesc++".")), {ok, [Expr]} = erl_parse:parse_exprs(Tokens), Expr; false -> % abstract expression TableDesc end; abstract({append, Infos}, NElements, Depth) -> As = lists:foldr(fun(Info, As0) -> {cons,1,abstract(Info, NElements, Depth),As0} end, {nil, 1}, Infos), {call, 1, {remote, 1, {atom, 1, ?MODULE}, {atom, 1, append}}, [As]}; abstract({sort, Info, SortOptions}, NElements, Depth) -> {call, 1, {remote, 1, {atom, 1, ?MODULE}, {atom, 1, sort}}, [abstract(Info, NElements, Depth), abstract_term(SortOptions, 1)]}; abstract({keysort, Info, Kp, SortOptions}, NElements, Depth) -> {call, 1, {remote, 1, {atom, 1, ?MODULE}, {atom, 1, keysort}}, [abstract_term(Kp, 1), abstract(Info, NElements, Depth), abstract_term(SortOptions, 1)]}; abstract({list,L,MS}, NElements, Depth) -> {call, 1, {remote, 1, {atom, 1, ets}, {atom, 1, match_spec_run}}, [abstract(L, NElements, Depth), {call, 1, {remote, 1, {atom, 1, ets}, {atom, 1, match_spec_compile}}, [abstract_term(depth(MS, Depth), 1)]}]}; abstract({list, L}, NElements, Depth) when NElements =:= infinity; NElements >= length(L) -> abstract_term(depth(L, Depth), 1); abstract({list, L}, NElements, Depth) -> abstract_term(depth(lists:sublist(L, NElements), Depth) ++ '...', 1). depth(List, infinity) -> List; depth(List, Depth) -> [depth1(E, Depth) || E <- List]. depth_fun(infinity = _Depth) -> fun(E) -> E end; depth_fun(Depth) -> fun(E) -> depth1(E, Depth) end. depth1([]=L, _D) -> L; depth1(_Term, 0) -> '...'; depth1(Tuple, D) when is_tuple(Tuple) -> depth_tuple(Tuple, tuple_size(Tuple), 1, D - 1, []); depth1(List, D) when is_list(List) -> if D =:= 1 -> ['...']; true -> depth_list(List, D - 1) end; depth1(Binary, D) when byte_size(Binary) > D - 1 -> D1 = D - 1, <<Bin:D1/bytes,_/bytes>> = Binary, <<Bin/bytes,"...">>; depth1(T, _Depth) -> T. depth_list([]=L, _D) -> L; depth_list(_L, 0) -> '...'; depth_list([E | Es], D) -> [depth1(E, D) | depth_list(Es, D - 1)]. depth_tuple(_Tuple, Sz, I, _D, L) when I > Sz -> list_to_tuple(lists:reverse(L)); depth_tuple(_L, _Sz, _I, 0, L) -> list_to_tuple(lists:reverse(L, ['...'])); depth_tuple(Tuple, Sz, I, D, L) -> E = depth1(element(I, Tuple), D), depth_tuple(Tuple, Sz, I + 1, D - 1, [E | L]). abstract_term(Term) -> abstract_term(Term, 0). abstract_term(Term, Line) -> abstr_term(Term, Line). abstr_term(Tuple, Line) when is_tuple(Tuple) -> {tuple,Line,[abstr_term(E, Line) || E <- tuple_to_list(Tuple)]}; abstr_term([_ | _]=L, Line) -> case io_lib:char_list(L) of true -> erl_parse:abstract(L, Line); false -> abstr_list(L, Line) end; abstr_term(Fun, Line) when is_function(Fun) -> case erl_eval:fun_data(Fun) of {fun_data, _Bs, Cs} -> {'fun', Line, {clauses, Cs}}; false -> {name, Name} = erlang:fun_info(Fun, name), {arity, Arity} = erlang:fun_info(Fun, arity), case erlang:fun_info(Fun, type) of {type, external} -> {module, Module} = erlang:fun_info(Fun, module), {'fun', Line, {function,Module,Name,Arity}}; {type, local} -> {'fun', Line, {function,Name,Arity}} end end; abstr_term(PPR, Line) when is_pid(PPR); is_port(PPR); is_reference(PPR) -> {special, Line, lists:flatten(io_lib:write(PPR))}; abstr_term(Simple, Line) -> erl_parse:abstract(Simple, Line). abstr_list([H | T], Line) -> {cons, Line, abstr_term(H, Line), abstr_list(T, Line)}; abstr_list(T, Line) -> abstr_term(T, Line). %% Since generator pattern variables cannot be used in list %% expressions, it is OK to flatten out QLCs using temporary %% variables. flatten_abstr(?QLC_Q(L1, L2, L3, L4, LC0, Os), VN0, Vars, Body0) -> {lc,L,E,Qs0} = LC0, F = fun({generate,Ln,P,LE0}, {VN1,Body1}) -> {VN2,Body2,LE} = flatten_abstr(LE0, VN1, Vars, Body1), {{generate,Ln,P,LE}, {VN2,Body2}}; (Fil, VN_Body) -> {Fil, VN_Body} end, {Qs, {VN3,Body}} = lists:mapfoldl(F, {VN0,Body0}, Qs0), LC = {lc,L,E,Qs}, {V, VN} = aux_name1('V', VN3, Vars), Var = {var, L1, V}, QLC = ?QLC_Q(L1, L2, L3, L4, LC, Os), {VN + 1, [{match, L1, Var, QLC} | Body], Var}; flatten_abstr(T0, VN0, Vars, Body0) when is_tuple(T0) -> {VN, Body, L} = flatten_abstr(tuple_to_list(T0), VN0, Vars, Body0), {VN, Body, list_to_tuple(L)}; flatten_abstr([E0 | Es0], VN0, Vars, Body0) -> {VN1, Body1, E} = flatten_abstr(E0, VN0, Vars, Body0), {VN, Body, Es} = flatten_abstr(Es0, VN1, Vars, Body1), {VN, Body, [E | Es]}; flatten_abstr(E, VN, _Vars, Body) -> {VN, Body, E}. abstract_vars(Abstract) -> sets:from_list(ordsets:to_list(vars(Abstract))). collect([]=L) -> L; collect([Answer | Cont]) -> [Answer | collect(Cont)]; collect(Cont) -> case Cont() of Answers when is_list(Answers) -> collect(Answers); Term -> throw_error(Term) end. fold_loop(Fun, [Obj | Cont], Acc) -> fold_loop(Fun, Cont, Fun(Obj, Acc)); fold_loop(_Fun, [], Acc) -> Acc; fold_loop(Fun, Cont, Acc) -> case Cont() of Objects when is_list(Objects) -> fold_loop(Fun, Objects, Acc); Term -> Term end. next_loop(Pid, L, N) when N =/= 0 -> case monitor_request(Pid, more) of no_more -> lists:reverse(L); {answer, Answer} -> next_loop(Pid, [Answer | L], N - 1); {caught, throw, Error, [?THROWN_ERROR | _]} -> Error; {caught, Class, Reason, Stacktrace} -> _ = (catch erlang:error(foo)), erlang:raise(Class, Reason, Stacktrace ++ erlang:get_stacktrace()); error -> erlang:error({qlc_cursor_pid_no_longer_exists, Pid}) end; next_loop(_Pid, L, _N) -> lists:reverse(L). stop_cursor(Pid) -> erlang:monitor(process, Pid), unlink(Pid), receive {'EXIT',Pid,_Reason} -> % Simply ignore the error. receive {'DOWN',_,process,Pid,_} -> ok end after 0 -> Pid ! {self(),stop}, receive {'DOWN',_,process,Pid,_} -> ok end end. monitor_request(Pid, Req) -> Ref = erlang:monitor(process, Pid), Pid ! {self(), Req}, receive {'DOWN', Ref, process, Pid, _Info} -> receive {'EXIT', Pid, _Reason} -> ok after 1 -> ok end, error; {'EXIT', Pid, _Reason} -> receive {'DOWN', _, process, Pid, _} -> error end; {Pid, Reply} -> erlang:demonitor(Ref, [flush]), Reply end. %% Marker for skipped filter or unused generator. -define(SKIP, (-1)). %% Qual = {gen, LE} | fil -define(qual_data(QNum, GoToIndex, State, Qual), {QNum, GoToIndex, State, Qual}). -record(join, % generated by qlc_pt {op, q1, q2, wh1, wh2, cs_fun}). % op is unused %% le_info/1 returns an intermediate information format only used for %% testing purposes. Changes will happen without notice. %% %% QueryDesc = {qlc, TemplateDesc, [QualDesc], [QueryOpt]} %% | {table, TableDesc} %% | {append, [QueryDesc]} %% | {sort, QueryDesc, [SortOption]} %% | {keysort, KeyPos, QueryDesc, [SortOption]} %% | {list, list()} %% | {list, QueryDesc, MatchExpression} %% TableDesc = {Mod, Fun, Args} %% | AbstractExpression %% | character_list() %% Mod = module() %% Fun = atom() %% Args = [term()] %% QualDesc = FilterDesc %% | {generate, PatternDesc, QueryDesc} %% QueryOpt = {cache, bool()} | cache %% | {unique, bool()} | unique %% FilterDesc = PatternDesc = TemplateDesc = binary() le_info(#prepared{qh = #simple_qlc{le = LE, p = P, line = L, optz = Optz}}, InfOpt) -> QVar = term_to_binary({var, L, P}), {qlc, QVar, [{generate, QVar, le_info(LE, InfOpt)}], opt_info(Optz)}; le_info(#prepared{qh = #qlc{codef = CodeF, qdata = Qdata, optz = Optz}}, InfOpt) -> Code = CodeF(), TemplateState = template_state(), E = element(TemplateState, Code), QualInfo0 = qual_info(Qdata, Code, InfOpt), QualInfo1 = case Optz#optz.fast_join of #qlc_join{} = Join -> join_info(Join, QualInfo0, Qdata, Code); no -> QualInfo0 end, QualInfo = [I || I <- QualInfo1, I =/= skip], {qlc, E, QualInfo, opt_info(Optz)}; le_info(#prepared{qh = #qlc_table{format_fun = FormatFun, trav_MS = TravMS, ms = MS, lu_vals = LuVals}}, InfOpt) -> {NElements, Depth} = InfOpt, %% The 'depth' option applies to match specifications as well. %% This is for limiting imported variables (parameters). DepthFun = depth_fun(Depth), case LuVals of _ when FormatFun =:= undefined -> {table, {'$MOD', '$FUN', []}}; {Pos, Vals} -> Formated = try FormatFun({lookup, Pos, Vals, NElements, DepthFun}) catch _:_ -> FormatFun({lookup, Pos, Vals}) end, if MS =:= no_match_spec -> {table, Formated}; true -> {list, {table, Formated}, depth(MS, Depth)} end; _ when TravMS, is_list(MS) -> {table, FormatFun({match_spec, depth(MS, Depth)})}; _ when MS =:= no_match_spec -> try {table, FormatFun({all, NElements, DepthFun})} catch _:_ -> {table, FormatFun(all)} end end; le_info(#prepared{qh = #qlc_append{hl = HL}}, InfOpt) -> {append, [le_info(H, InfOpt) || H <- HL]}; le_info(#prepared{qh = #qlc_sort{h = H, keypos = sort, fs_opts = SortOptions0, tmpdir = TmpDir}}, InfOpt) -> SortOptions = sort_options_global_tmp(SortOptions0, TmpDir), {sort, le_info(H, InfOpt), SortOptions}; le_info(#prepared{qh = #qlc_sort{h = H, keypos = {keysort, Kp}, fs_opts = SortOptions0, tmpdir = TmpDir}}, InfOpt) -> SortOptions = sort_options_global_tmp(SortOptions0, TmpDir), {keysort, le_info(H, InfOpt), Kp, SortOptions}; le_info(#prepared{qh = #qlc_list{l = L, ms = no_match_spec}}, _InfOpt) -> {list, L}; le_info(#prepared{qh = #qlc_list{l = L, ms = MS}},_InfOpt) when is_list(L) -> {list, {list, L}, MS}; le_info(#prepared{qh = #qlc_list{l = L, ms = MS}}, InfOpt) -> {list, le_info(L, InfOpt), MS}. qual_info([?qual_data(_QNum, _GoI, ?SKIP, fil) | Qdata], Code, InfOpt) -> %% see skip_lookup_filters() [skip | qual_info(Qdata, Code, InfOpt)]; qual_info([?qual_data(QNum, _GoI, _SI, fil) | Qdata], Code, InfOpt) -> [element(QNum + 1, Code) | qual_info(Qdata, Code, InfOpt)]; qual_info([?qual_data(_QNum, _GoI, _SI, {gen,#join{}}) | Qdata], Code, InfOpt) -> [skip | qual_info(Qdata, Code, InfOpt)]; qual_info([?qual_data(QNum, _GoI, _SI, {gen,LE}) | Qdata], Code, InfOpt) -> [{generate,element(QNum + 1, Code),le_info(LE, InfOpt)} | qual_info(Qdata, Code, InfOpt)]; qual_info([], _Code, _InfOpt) -> []. join_info(Join, QInfo, Qdata, Code) -> #qlc_join{kind = Kind, q1 = QNum1a, c1 = C1, q2 = QNum2a, c2 = C2, opt = Opt} = Join, {?qual_data(JQNum,_,_,_), Rev, QNum1, QNum2, _WH1, _WH2, CsFun} = find_join_data(Qdata, QNum1a, QNum2a), {Cs1_0, Cs2_0, Compat} = CsFun(), [Cs1, Cs2] = case Compat of [] -> % --R12B-5 [[{C,[{V,'=:='} || V <- Vs]} || {C,Vs} <- CVs] || CVs <- [Cs1_0, Cs2_0]]; _ -> % 'v1', R13A -- %% Only compared constants (==). [Cs1_0, Cs2_0] end, L = 0, G1_0 = {var,L,'G1'}, G2_0 = {var,L,'G2'}, JP = element(JQNum + 1, Code), %% Create code for wh1 and wh2 in #join{}: {{I1,G1}, {I2,G2}, QInfoL} = case Kind of {merge, _} -> {JG1,QInfo1} = join_merge_info(QNum1, QInfo, Code, G1_0, Cs1), {JG2,QInfo2} = join_merge_info(QNum2, QInfo, Code, G2_0, Cs2), {JG1, JG2, QInfo1 ++ QInfo2}; _ when Rev -> {JG2,QInfo2} = join_merge_info(QNum2, QInfo, Code, G2_0, Cs2), {J1, QInfo1} = join_lookup_info(QNum1, QInfo, G1_0), {{J1,G1_0}, JG2, QInfo2 ++ [QInfo1]}; _ -> {JG1,QInfo1} = join_merge_info(QNum1, QInfo, Code, G1_0, Cs1), {J2, QInfo2} = join_lookup_info(QNum2, QInfo, G2_0), {JG1, {J2,G2_0}, QInfo1 ++ [QInfo2]} end, {JOptVal, JOp} = kind2op(Kind), JOpt = [{join, JOptVal}] ++ opt_info(join_unique_cache(Opt)), JFil = term_to_binary({op,L,JOp, {call,L,{atom,L,element},[{integer,L,C1},G1]}, {call,L,{atom,L,element},[{integer,L,C2},G2]}}), P = term_to_binary({cons, L, G1, G2}), JInfo = {generate, JP, {qlc, P, QInfoL ++ [JFil], JOpt}}, {Before, [I1 | After]} = lists:split(QNum1 - 1, QInfo), Before ++ [JInfo] ++ lists:delete(I2, After). kind2op({merge, _KE}) -> {merge, '=='}; kind2op({lookup, KE, _LU_fun}) -> {lookup, KE}. %% qlc:q(P0 || P0 = Pattern <- H1, ConstFilters), %% where "P0" is a fresh variable and ConstFilters are filters that %% test constant values of pattern columns. join_merge_info(QNum, QInfo, Code, G, ExtraConstants) -> {generate, _, LEInfo}=I = lists:nth(QNum, QInfo), P = binary_to_term(element(QNum + 1, Code)), case {P, ExtraConstants} of {{var, _, _}, []} -> %% No need to introduce a QLC. TP = term_to_binary(G), I2 = {generate, TP, LEInfo}, {{I,G}, [I2]}; _ -> {EPV, M} = case P of {var, _, _} -> %% No need to introduce a pattern variable. {P, P}; _ -> {PV, _} = aux_name1('P', 0, abstract_vars(P)), L = 0, V = {var, L, PV}, {V, {match, L, V, P}} end, DQP = term_to_binary(EPV), LEI = {generate, term_to_binary(M), LEInfo}, TP = term_to_binary(G), CFs = [begin Call = {call,0,{atom,0,element},[{integer,0,Col},EPV]}, F = list2op([{op,0,Op,abstract_term(Con),Call} || {Con,Op} <- ConstOps], 'or'), term_to_binary(F) end || {Col,ConstOps} <- ExtraConstants], {{I,G}, [{generate, TP, {qlc, DQP, [LEI | CFs], []}}]} end. list2op([E], _Op) -> E; list2op([E | Es], Op) -> {op,0,Op,E,list2op(Es, Op)}. join_lookup_info(QNum, QInfo, G) -> {generate, _, LEInfo}=I = lists:nth(QNum, QInfo), TP = term_to_binary(G), {I, {generate, TP, LEInfo}}. opt_info(#optz{unique = Unique, cache = Cache0, join_option = JoinOption}) -> %% No 'nested_loop' options are added here, even if there are %% nested loops to carry out, unless a 'nested_loop' was given as %% option. The reason is that the qlc module does not know about %% all instances of nested loops. Cache = if Cache0 -> ets; true -> Cache0 end, [{T,V} || {T,V} <- [{cache,Cache},{unique,Unique}], V =/= default_option(T)] ++ [{T,V} || {T,V} <- [{join,JoinOption}], V =:= nested_loop]. prepare_qlc(H, InitialValue, GUnique, GCache, TmpDir, MaxList, TmpUsage) -> GOpt = #qlc_opt{unique = GUnique, cache = GCache, tmpdir = TmpDir, max_list = MaxList, tmpdir_usage = TmpUsage}, case opt_le(prep_le(H, GOpt), 1) of #prepared{qh = #qlc{} = QLC}=Prep -> Prep#prepared{qh = QLC#qlc{init_value = InitialValue}}; #prepared{qh = #simple_qlc{}=SimpleQLC}=Prep -> Prep#prepared{qh = SimpleQLC#simple_qlc{init_value = InitialValue}}; Prep -> Prep end. %%% The options given to append, q and table (unique and cache) as well %%% as the type of expression (list, table, append, qlc...) are %%% analyzed by prep_le. The results are is_unique_objects and %%% is_cached. It is checked that the evaluation (in the Erlang sense) %%% of list expressions yields qlc handles. prep_le(#qlc_lc{lc = LC_fun, opt = #qlc_opt{} = Opt0}=H, GOpt) -> #qlc_opt{unique = GUnique, cache = GCache, tmpdir = TmpDir, max_list = MaxList, tmpdir_usage = TmpUsage} = GOpt, Unique = Opt0#qlc_opt.unique or GUnique, Cache = if not GCache -> Opt0#qlc_opt.cache; true -> GCache end, Opt = Opt0#qlc_opt{unique = Unique, cache = Cache, tmpdir = TmpDir, max_list = MaxList, tmpdir_usage = TmpUsage}, prep_qlc_lc(LC_fun(), Opt, GOpt, H); prep_le(#qlc_table{info_fun = IF}=T, GOpt) -> {SortInfo, Sorted} = table_sort_info(T), IsUnique = grd(IF, is_unique_objects), Prep = #prepared{qh = T, sort_info = SortInfo, sorted = Sorted, is_unique_objects = IsUnique}, Opt = if IsUnique or not GOpt#qlc_opt.unique, T#qlc_table.ms =:= no_match_spec -> GOpt#qlc_opt{cache = false}; true -> GOpt end, may_create_simple(Opt, Prep); prep_le(#qlc_append{hl = HL}, GOpt) -> case lists:flatmap(fun(#prepared{qh = #qlc_list{l = []}}) -> []; (#prepared{qh = #qlc_append{hl = HL1}}) -> HL1; (H) -> [H] end, [prep_le(H, GOpt) || H <- HL]) of []=Nil -> short_list(Nil); [Prep] -> Prep; PrepL -> Cache = lists:all(fun(#prepared{is_cached = IsC}) -> IsC =/= false end, PrepL), %% The handles in hl are replaced by prepared handles: Prep = #prepared{qh = #qlc_append{hl = PrepL}, is_cached = Cache}, may_create_simple(GOpt, Prep) end; prep_le(#qlc_sort{h = H0}=Q0, GOpt) -> %% The handle h is replaced by a prepared handle: Q = Q0#qlc_sort{h = prep_le(H0, GOpt)}, prep_sort(Q, GOpt); prep_le([_, _ | _]=L, GOpt) -> Prep = #prepared{qh = #qlc_list{l = L}, is_cached = true}, Opt = if not GOpt#qlc_opt.unique -> GOpt#qlc_opt{cache = false}; true -> GOpt end, may_create_simple(Opt, Prep); prep_le(L, _GOpt) when is_list(L) -> short_list(L); prep_le(T, _GOpt) -> erlang:error({unsupported_qlc_handle, #qlc_handle{h = T}}). eval_le(LE_fun, GOpt) -> case LE_fun() of {error, ?MODULE, _} = Error -> throw_error(Error); R -> case get_handle(R) of badarg -> erlang:error(badarg, [R]); H -> prep_le(H, GOpt) end end. prep_qlc_lc({simple_v1, PVar, LE_fun, L}, Opt, GOpt, _H) -> check_lookup_option(Opt, false), prep_simple_qlc(PVar, L, eval_le(LE_fun, GOpt), Opt); prep_qlc_lc({qlc_v1, QFun, CodeF, Qdata0, QOpt}, Opt, GOpt, _H) -> F = fun(?qual_data(_QNum, _GoI, _SI, fil)=QualData, ModGens) -> {QualData, ModGens}; (?qual_data(_QNum, _GoI, _SI, {gen, #join{}})=QualData, ModGens) -> {QualData, ModGens}; (?qual_data(QNum, GoI, SI, {gen, LE_fun}), ModGens0) -> Prep1 = eval_le(LE_fun, GOpt), {Prep, ModGens} = prep_generator(QNum, Prep1, QOpt, Opt, ModGens0), {?qual_data(QNum, GoI, SI, {gen, Prep}), ModGens} end, {Qdata, ModGens} = lists:mapfoldl(F, [], Qdata0), SomeLookUp = lists:keymember(true, 2, ModGens), check_lookup_option(Opt, SomeLookUp), case ModGens of [{_QNum, _LookUp, all, OnePrep}] -> check_join_option(Opt), OnePrep; _ -> Prep0 = prep_qlc(QFun, CodeF, Qdata, QOpt, Opt), LU_SkipQuals = lists:flatmap(fun({QNum,_LookUp,Fs,_Prep}) -> [{QNum,Fs}] end, ModGens), Prep1 = Prep0#prepared{lu_skip_quals = LU_SkipQuals}, prep_join(Prep1, QOpt, Opt) end; prep_qlc_lc(_, _Opt, _GOpt, H) -> erlang:error({unsupported_qlc_handle, #qlc_handle{h = H}}). prep_generator(QNum, Prep0, QOpt, Opt, ModGens) -> PosFun = fun(KeyEquality) -> pos_fun(KeyEquality, QOpt, QNum) end, MSFs = case match_specs(QOpt, QNum) of undefined -> {no_match_spec, []}; {_, _}=MSFs0 -> MSFs0 end, #prepared{qh = LE} = Prep0, case prep_gen(LE, Prep0, PosFun, MSFs, Opt) of {replace, Fs, LookUp, Prep} -> {Prep, [{QNum,LookUp,Fs,Prep} | ModGens]}; {skip, SkipFils, LookUp, Prep} -> {Prep, [{QNum,LookUp,SkipFils,Prep} | ModGens]}; {no, _Fs, _LookUp, Prep} -> {Prep, ModGens} end. pos_fun(undefined, QOpt, QNum) -> {'=:=', constants(QOpt, QNum)}; %% --R12B-5 pos_fun('=:=', QOpt, QNum) -> {'=:=', constants(QOpt, QNum)}; pos_fun('==', QOpt, QNum) -> try {'==', equal_constants(QOpt, QNum)} % R13A-- catch _:_ -> {'=:=', constants(QOpt, QNum)} end. prep_gen(#qlc_table{lu_vals = LuV0, ms = MS0, trav_MS = TravMS, info_fun = IF, lookup_fun = LU_fun, key_equality = KeyEquality}=LE0, Prep0, PosFun0, {MS, Fs}, Opt) -> PosFun = PosFun0(KeyEquality), {LuV, {STag,SkipFils}} = find_const_positions(IF, LU_fun, PosFun, Opt), LU = LuV =/= false, if LuV0 =/= undefined; MS0 =/= no_match_spec -> {no, [], false, Prep0}; MS =/= no_match_spec, LU -> MS1 = if Fs =:= SkipFils; STag =:= Fs -> %% The guard of the match specification %% is covered by the lookup. case MS of [{'$1',_Guard,['$1']}] -> % no transformation no_match_spec; [{Head,_Guard,Body}] -> [{Head,[],Body}] % true guard end; true -> MS end, Prep = Prep0#prepared{qh = LE0#qlc_table{lu_vals = LuV,ms = MS1}}, {replace, Fs, LU, Prep}; LU -> Prep = Prep0#prepared{qh = LE0#qlc_table{lu_vals = LuV}}, {skip, SkipFils, LU, Prep}; TravMS, MS =/= no_match_spec -> Prep = Prep0#prepared{qh = LE0#qlc_table{ms = MS}, is_unique_objects = false}, {replace, Fs, false, may_create_simple(Opt, Prep)}; true -> {no, [], false, Prep0} end; prep_gen(#qlc_list{l = []}, Prep0, _PosFun, {_MS, Fs}, _Opt) -> %% unique and cached {replace, Fs, false, Prep0}; prep_gen(#qlc_list{ms = no_match_spec}=LE0, Prep0, _PosFun, {MS, Fs}, Opt) when MS =/= no_match_spec -> Prep = Prep0#prepared{qh = LE0#qlc_list{ms = MS}, is_cached = false}, {replace, Fs, false, may_create_simple(Opt, Prep)}; prep_gen(#qlc_list{}, Prep0, _PosFun, {MS, Fs}, Opt) when MS =/= no_match_spec -> ListMS = #qlc_list{l = Prep0, ms = MS}, LE = #prepared{qh = ListMS, is_cached = false}, {replace, Fs, false, may_create_simple(Opt, LE)}; prep_gen(_LE0, Prep0, _PosFun, _MSFs, _Opt) -> {no, [], false, Prep0}. -define(SIMPLE_QVAR, 'SQV'). may_create_simple(#qlc_opt{unique = Unique, cache = Cache} = Opt, #prepared{is_cached = IsCached, is_unique_objects = IsUnique} = Prep) -> if Unique and not IsUnique; (Cache =/= false) and not IsCached -> prep_simple_qlc(?SIMPLE_QVAR, 1, Prep, Opt); true -> Prep end. prep_simple_qlc(PVar, Line, LE, Opt) -> check_join_option(Opt), #prepared{is_cached = IsCached, sort_info = SortInfo, sorted = Sorted, is_unique_objects = IsUnique} = LE, #qlc_opt{unique = Unique, cache = Cache} = Opt, Cachez = if Unique -> Cache; not IsCached -> Cache; true -> false end, Optz = #optz{unique = Unique and not IsUnique, cache = Cachez, opt = Opt}, QLC = #simple_qlc{p = PVar, le = LE, line = Line, init_value = not_a_list, optz = Optz}, %% LE#prepared.join is not copied #prepared{qh = QLC, is_unique_objects = IsUnique or Unique, sort_info = SortInfo, sorted = Sorted, is_cached = IsCached or (Cachez =/= false)}. prep_sort(#qlc_sort{h = #prepared{sorted = yes}=Prep}, _GOpt) -> Prep; prep_sort(#qlc_sort{h = #prepared{is_unique_objects = IsUniqueObjs}}=Q, GOpt) -> S1 = sort_unique(IsUniqueObjs, Q), S2 = sort_tmpdir(S1, GOpt), S = S2#qlc_sort{tmpdir_usage = GOpt#qlc_opt.tmpdir_usage}, {SortInfo, Sorted} = sort_sort_info(S), #prepared{qh = S, is_cached = true, sort_info = SortInfo, sorted = Sorted, is_unique_objects = S#qlc_sort.unique or IsUniqueObjs}. prep_qlc(QFun, CodeF, Qdata0, QOpt, Opt) -> #qlc_opt{unique = Unique, cache = Cache, join = Join} = Opt, Optz = #optz{unique = Unique, cache = Cache, join_option = Join, opt = Opt}, {Qdata, SortInfo} = qlc_sort_info(Qdata0, QOpt), QLC = #qlc{lcf = QFun, codef = CodeF, qdata = Qdata, init_value = not_a_list, optz = Optz}, #prepared{qh = QLC, sort_info = SortInfo, is_unique_objects = Unique, is_cached = Cache =/= false}. %% 'sorted', 'sorted_info', and 'sorted_info2' are used to avoid %% sorting on a key when there is no need to sort on the key. 'sorted' %% is set by qlc:sort() only; its purpose is to assure that if columns %% 1 to i are constant, then column i+1 is key-sorted (always true if %% the tuples are sorted). Note: the implementation is (too?) simple. %% For instance, each column is annotated with 'ascending' or %% 'descending' (not yet). More exact would be, as examples, 'always %% ascending' and 'ascending if all preceding columns are constant'. %% %% The 'size' of the template is not used (size_of_qualifier(QOpt, 0)). qlc_sort_info(Qdata0, QOpt) -> F = fun(?qual_data(_QNum, _GoI, _SI, fil)=Qd, Info) -> {Qd, Info}; (?qual_data(_QNum, _GoI, _SI, {gen, #join{}})=Qd, Info) -> {Qd, Info}; (?qual_data(QNum, GoI, SI, {gen, PrepLE0}), Info) -> PrepLE = sort_info(PrepLE0, QNum, QOpt), Qd = ?qual_data(QNum, GoI, SI, {gen, PrepLE}), I = [{{Column,Order}, [{traverse,QNum,C}]} || {{C,Order},What} <- PrepLE#prepared.sort_info2, What =:= [], % Something else later... Column <- equal_template_columns(QOpt, {QNum,C})], {Qd, [I | Info]} end, {Qdata, SortInfoL} = lists:mapfoldl(F, [], Qdata0), SortInfo0 = [{{Pos,Ord}, [template]} || Pos <- constant_columns(QOpt, 0), Ord <- orders(yes)] ++ lists:append(SortInfoL), SortInfo = family_union(SortInfo0), {Qdata, SortInfo}. sort_info(#prepared{sort_info = SI, sorted = S} = Prep, QNum, QOpt) -> SI1 = [{{C,Ord},[]} || S =/= no, is_integer(Sz = size_of_qualifier(QOpt, QNum)), Sz > 0, % the size of the pattern (NConstCols = size_of_constant_prefix(QOpt, QNum)) < Sz, C <- [NConstCols+1], Ord <- orders(S)] ++ [{{Pos,Ord},[]} || Pos <- constant_columns(QOpt, QNum), Ord <- orders(yes)] ++ [{PosOrd,[]} || {PosOrd,_} <- SI], SI2 = lists:usort(SI1), Prep#prepared{sort_info2 = SI2}. %orders(descending=O) -> % [O]; orders(ascending=O) -> [O]; orders(yes) -> [ascending % ,descending ]. sort_unique(true, #qlc_sort{fs_opts = SortOptions, keypos = sort}=Sort) -> Sort#qlc_sort{unique = false, fs_opts = lists:keydelete(unique, 1, lists:delete(unique, SortOptions))}; sort_unique(_, Sort) -> Sort. sort_tmpdir(S, #qlc_opt{tmpdir = ""}) -> S; sort_tmpdir(S, Opt) -> S#qlc_sort{tmpdir = Opt#qlc_opt.tmpdir}. short_list(L) -> %% length(L) < 2: all elements are known be equal #prepared{qh = #qlc_list{l = L}, sorted = yes, is_unique_objects = true, is_cached = true}. find_const_positions(IF, LU_fun, {KeyEquality, PosFun}, #qlc_opt{max_lookup = Max, lookup = Lookup}) when is_function(LU_fun), is_function(PosFun), is_function(IF), Lookup =/= false -> case call(IF, keypos, undefined, []) of undefined -> Indices = call(IF, indices, undefined, []), find_const_position_idx(Indices, KeyEquality, PosFun, Max, []); KeyPos -> case pos_vals(KeyPos, KeyEquality, PosFun(KeyPos), Max) of false -> find_const_position_idx(IF(indices), KeyEquality, PosFun, Max, []); PosValuesSkip -> PosValuesSkip end end; find_const_positions(_IF, _LU_fun, _KE_PosFun, _Opt0) -> {false, {some,[]}}. find_const_position_idx([I | Is], KeyEquality, PosFun, Max, L0) -> case pos_vals(I, KeyEquality, PosFun(I), Max) of false -> find_const_position_idx(Is, KeyEquality, PosFun, Max, L0); {{_Pos, Values}, _SkipFils}=PosValuesFils -> L = [{length(Values), PosValuesFils} | L0], find_const_position_idx(Is, KeyEquality, PosFun, Max, L) end; find_const_position_idx(_, _KeyEquality, _PosFun, _Max, []) -> {false, {some,[]}}; find_const_position_idx(_, _KeyEquality, _PosFun, _Max, L) -> [{_,PVF} | _] = lists:sort(L), PVF. pos_vals(Pos, '==', {usort_needed, Values, SkipFils}, Max) -> pos_vals_max(Pos, lists:usort(Values), SkipFils, Max); pos_vals(Pos, '=:=', {usort_needed, Values, SkipFils}, Max) -> pos_vals_max(Pos, lists:sort(nub(Values)), SkipFils, Max); pos_vals(Pos, _KeyEquality, {values, Values, SkipFils}, Max) -> pos_vals_max(Pos, Values, SkipFils, Max); pos_vals(_Pos, _KeyEquality, _T, _Max) -> false. nub([]) -> []; nub([E | L]) -> case lists:member(E, Es=nub(L)) of true -> Es; false -> [E | Es] end. %% length(Values) >= 1 pos_vals_max(Pos, Values, Skip, Max) when Max =:= -1; Max >= length(Values) -> {{Pos, Values}, Skip}; pos_vals_max(_Pos, _Value, _Skip, _Max) -> false. prep_join(Prep, QOpt, Opt) -> case join_opt(QOpt) of undefined -> check_join_option(Opt), Prep; EqualMatch -> {Ix, M} = case EqualMatch of {NEqual, NMatch} -> pref_join(NEqual, NMatch, Prep, QOpt, Opt); EM -> pref_join(EM, EM, Prep, QOpt, Opt) end, SI = family_union(Prep#prepared.sort_info ++ M), Prep#prepared{join = {Ix, M}, sort_info = SI} end. %% The parse transform ensures that only two tables are involved. pref_join(Equal, Match, Prep, QOpt, #qlc_opt{join = JoinOpt}) -> JQs = [{KeyEquality, QCs} || {KeyEquality, QCsL} <- [{'==',Equal}, {'=:=',Match}], QCs <- QCsL], IxL = [pref_lookup_join(KE, QCs, Prep, QOpt) || JoinOpt =:= any orelse JoinOpt =:= lookup, {KE, QCs} <- JQs], ML = [pref_merge_join(KE, QCs, Prep, QOpt) || JoinOpt =:= any orelse JoinOpt =:= merge, {KE, QCs} <- JQs], {lists:usort(lists:append(IxL)), lists:usort(lists:append(ML))}. pref_lookup_join(KeyEquality, {[{Q1,C1},{Q2,C2}],Skip}, Prep, QOpt) when is_integer(C1), is_integer(C2) -> #prepared{qh = #qlc{qdata = QData}} = Prep, Is1 = lookup_qual_data(QData, Q1, KeyEquality), Lu2 = [pref_lookup_join2(Q2, C2, Q1, C1, Skip, QOpt, KeyEquality) || IC1 <- Is1, IC1 =:= C1], Is2 = lookup_qual_data(QData, Q2, KeyEquality), Lu1 = [pref_lookup_join2(Q1, C1, Q2, C2, Skip, QOpt, KeyEquality) || IC2 <- Is2, IC2 =:= C2], family(Lu1 ++ Lu2); pref_lookup_join(KE, [{_,Cs1},{_,Cs2}]=L, Prep, QOpt) when is_list(Cs1), is_list(Cs2) -> %% --R12B-5 lists:append([pref_lookup_join(KE, QC,Prep,QOpt) || QC <- selections_no_skip(L)]). lookup_qual_data(QData, QNum, KeyEquality) -> case lists:keysearch(QNum, 1, QData) of {value, ?qual_data(QNum, _, _, {gen, PrepLE})} -> join_indices(PrepLE, KeyEquality) end. %% If the table has a match specification (ms =/= no_match_spec) that %% has _not_ been derived from a filter but from a query handle then %% the lookup join cannot be done. This particular case has not been %% excluded here but is taken care of in opt_join(). join_indices(#prepared{qh = #qlc_table{info_fun = IF, lookup_fun = LU_fun, key_equality = KeyEquality, lu_vals = undefined}}, KE) when is_function(LU_fun), KE =:= KeyEquality orelse KE =:= '=:=' andalso KeyEquality =:= undefined -> % --R12B-5 KpL = case call(IF, keypos, undefined, []) of undefined -> []; Kp -> [Kp] end, case call(IF, indices, undefined, []) of undefined -> KpL; Is0 -> lists:usort(KpL ++ Is0) end; join_indices(_Prep, _KeyEquality) -> []. pref_lookup_join2(Q1, C1, Q2, C2, Skip, QOpt, KeyEquality) -> TemplCols = compared_template_columns(QOpt, {Q1,C1}, KeyEquality), {{Q1,C1,Q2,C2},{lookup_join,TemplCols,KeyEquality,Skip}}. pref_merge_join(KE, {[{Q1,C1},{Q2,C2}],Skip}, Prep, QOpt) when is_integer(C1), is_integer(C2) -> #prepared{qh = #qlc{qdata = QData}} = Prep, Sort1 = merge_qual_data(QData, Q1), Sort2 = merge_qual_data(QData, Q2), Merge = pref_merge(KE, Q1, C1, Q2, C2, Skip, Sort1, Sort2, QOpt), family_union(Merge); pref_merge_join(KE, [{_,Cs1},{_,Cs2}]=L, Prep, QOpt) when is_list(Cs1), is_list(Cs2) -> %% --R12B-5 lists:append([pref_merge_join(KE, QC, Prep, QOpt) || QC <- selections_no_skip(L)]). selections_no_skip(L) -> [{C,{some,[]}} || C <- all_selections(L)]. merge_qual_data(QData, QNum) -> case lists:keysearch(QNum, 1, QData) of {value, ?qual_data(QNum, _, _, {gen, PrepLE})} -> #prepared{sort_info2 = SortInfo} = PrepLE, SortInfo end. pref_merge(KE, Q1, C1, Q2, C2, Skip, Sort1, Sort2, QOpt) -> Col1 = {Q1,C1}, Col2 = {Q2,C2}, DoSort = [QC || {{_QNum,Col}=QC,SortL} <- [{Col1,Sort1}, {Col2,Sort2}], lists:keymember({Col, ascending}, 1, SortL) =:= false], J = [{{Q1,C1,Q2,C2}, {merge_join,DoSort,KE,Skip}}], %% true = (QOpt(template))(Col1, '==') =:= (QOpt(template))(Col2, '==') [{{Column, ascending}, J} || Column <- equal_template_columns(QOpt, Col1)] ++ [{other, J}]. table_sort_info(#qlc_table{info_fun = IF}) -> case call(IF, is_sorted_key, undefined, []) of undefined -> {[], no}; false -> {[], no}; true -> case call(IF, keypos, undefined, []) of undefined -> % strange {[], no}; KeyPos -> {[{{KeyPos,ascending},[]}], no} end end. sort_sort_info(#qlc_sort{keypos = sort, order = Ord0}) -> {[], sort_order(Ord0)}; sort_sort_info(#qlc_sort{keypos = {keysort,Kp0}, order = Ord0}) -> Kp = case Kp0 of [Pos | _] -> Pos; _ -> Kp0 end, {[{{Kp,sort_order(Ord0)},[]}], no}. sort_order(F) when is_function(F) -> no; sort_order(Order) -> Order. check_join_option(#qlc_opt{join = any}) -> ok; check_join_option(#qlc_opt{join = Join}) -> erlang:error(no_join_to_carry_out, [{join,Join}]). check_lookup_option(#qlc_opt{lookup = true}, false) -> erlang:error(no_lookup_to_carry_out, [{lookup,true}]); check_lookup_option(_QOpt, _LuV) -> ok. compared_template_columns(QOpt, QNumColumn, KeyEquality) -> (QOpt(template))(QNumColumn, KeyEquality). equal_template_columns(QOpt, QNumColumn) -> (QOpt(template))(QNumColumn, '=='). %eq_template_columns(QOpt, QNumColumn) -> % (QOpt(template))(QNumColumn, '=:='). size_of_constant_prefix(QOpt, QNum) -> (QOpt(n_leading_constant_columns))(QNum). constants(QOpt, QNum) -> (QOpt(constants))(QNum). equal_constants(QOpt, QNum) -> (QOpt(equal_constants))(QNum). join_opt(QOpt) -> QOpt(join). match_specs(QOpt, QNum) -> (QOpt(match_specs))(QNum). constant_columns(QOpt, QNum) -> (QOpt(constant_columns))(QNum). size_of_qualifier(QOpt, QNum) -> (QOpt(size))(QNum). %% Two optimizations are carried out: %% 1. The first generator is never cached if the QLC itself is cached. %% Since the answers do not need to be cached, the top-most QLC is %% never cached either. Simple QLCs not holding any options are %% removed. Simple QLCs are coalesced when possible. %% 2. Merge join and lookup join is done if possible. opt_le(#prepared{qh = #simple_qlc{le = LE0, optz = Optz0}=QLC}=Prep0, GenNum) -> case LE0 of #prepared{qh = #simple_qlc{p = LE_Pvar, le = LE2, optz = Optz2}} -> %% Coalesce two simple QLCs. Cachez = case Optz2#optz.cache of false -> Optz0#optz.cache; Cache2 -> Cache2 end, Optz = Optz0#optz{cache = Cachez, unique = Optz0#optz.unique or Optz2#optz.unique}, PVar = if LE_Pvar =:= ?SIMPLE_QVAR -> QLC#simple_qlc.p; true -> LE_Pvar end, Prep = Prep0#prepared{qh = QLC#simple_qlc{p = PVar, le = LE2, optz = Optz}}, opt_le(Prep, GenNum); _ -> Optz1 = no_cache_of_first_generator(Optz0, GenNum), case {opt_le(LE0, 1), Optz1} of {LE, #optz{unique = false, cache = false}} -> LE; {LE, _} -> Prep0#prepared{qh = QLC#simple_qlc{le = LE, optz = Optz1}} end end; opt_le(#prepared{qh = #qlc{}, lu_skip_quals = LU_SkipQuals0}=Prep0, GenNum) -> #prepared{qh = #qlc{qdata = Qdata0, optz = Optz0}=QLC} = Prep0, #optz{join_option = JoinOption, opt = Opt} = Optz0, JoinOption = Optz0#optz.join_option, {LU_QNum, Join, JoinSkipFs, DoSort} = opt_join(Prep0#prepared.join, JoinOption, Qdata0, Opt, LU_SkipQuals0), {LU_Skip, LU_SkipQuals} = lists:partition(fun({QNum,_Fs}) -> QNum =:= LU_QNum end, LU_SkipQuals0), LU_SkipFs = lists:flatmap(fun({_QNum,Fs}) -> Fs end, LU_SkipQuals), %% If LU_QNum has a match spec it must be applied _after_ the %% lookup join (the filter must not be skipped!). Qdata1 = if LU_Skip =:= [] -> Qdata0; true -> activate_join_lookup_filter(LU_QNum, Qdata0) end, Qdata2 = skip_lookup_filters(Qdata1, LU_SkipFs ++ JoinSkipFs), F = fun(?qual_data(QNum, GoI, SI, {gen, #prepared{}=PrepLE}), GenNum1) -> NewPrepLE = maybe_sort(PrepLE, QNum, DoSort, Opt), {?qual_data(QNum, GoI, SI, {gen, opt_le(NewPrepLE, GenNum1)}), GenNum1 + 1}; (Qd, GenNum1) -> {Qd, GenNum1} end, {Qdata, _} = lists:mapfoldl(F, 1, Qdata2), Optz1 = no_cache_of_first_generator(Optz0, GenNum), Optz = Optz1#optz{fast_join = Join}, Prep0#prepared{qh = QLC#qlc{qdata = Qdata, optz = Optz}}; opt_le(#prepared{qh = #qlc_append{hl = HL}}=Prep, GenNum) -> Hs = [opt_le(H, GenNum) || H <- HL], Prep#prepared{qh = #qlc_append{hl = Hs}}; opt_le(#prepared{qh = #qlc_sort{h = H}=Sort}=Prep, GenNum) -> Prep#prepared{qh = Sort#qlc_sort{h = opt_le(H, GenNum)}}; opt_le(Prep, _GenNum) -> Prep. no_cache_of_first_generator(Optz, GenNum) when GenNum > 1 -> Optz; no_cache_of_first_generator(Optz, 1) -> Optz#optz{cache = false}. maybe_sort(LE, QNum, DoSort, Opt) -> case lists:keyfind(QNum, 1, DoSort) of {QNum, Col} -> #qlc_opt{tmpdir = TmpDir, tmpdir_usage = TmpUsage} = Opt, SortOpts = [{tmpdir,Dir} || Dir <- [TmpDir], Dir =/= ""], Sort = #qlc_sort{h = LE, keypos = {keysort, Col}, unique = false, compressed = [], order = ascending, fs_opts = SortOpts, tmpdir_usage = TmpUsage, tmpdir = TmpDir}, #prepared{qh = Sort, sorted = no, join = no}; false -> LE end. skip_lookup_filters(Qdata, []) -> Qdata; skip_lookup_filters(Qdata0, LU_SkipFs) -> [case lists:member(QNum, LU_SkipFs) of true -> ?qual_data(QNum, GoI, ?SKIP, fil); false -> Qd end || ?qual_data(QNum, GoI, _, _)=Qd <- Qdata0]. %% If the qualifier used for lookup by the join (QNum) has a match %% specification it must be applied _after_ the lookup join (the %% filter must not be skipped!). activate_join_lookup_filter(QNum, Qdata) -> {_,GoI2,SI2,{gen,Prep2}} = lists:keyfind(QNum, 1, Qdata), Table2 = Prep2#prepared.qh, NPrep2 = Prep2#prepared{qh = Table2#qlc_table{ms = no_match_spec}}, %% Table2#qlc_table.ms has been reset; the filter will be run. lists:keyreplace(QNum, 1, Qdata, ?qual_data(QNum,GoI2,SI2,{gen,NPrep2})). opt_join(Join, JoinOption, Qdata, Opt, LU_SkipQuals) -> %% prep_qlc_lc() assures that no unwanted join is carried out {Ix0, M0} = Join, Ix1 = opt_join_lu(Ix0, Qdata, LU_SkipQuals), Ix = lists:reverse(lists:keysort(2, Ix1)), % prefer to skip case Ix of [{{Q1,C1,Q2,C2},Skip,KE,LU_fun} | _] -> J = #qlc_join{kind = {lookup, KE, LU_fun}, q1 = Q1, c1 = C1, q2 = Q2, c2 = C2, opt = Opt}, {Q2, J, Skip, []}; [] -> M = opt_join_merge(M0), case M of [{{Q1,C1,Q2,C2},{merge_join,DoSort,KE,Skip}}|_] -> J = #qlc_join{kind = {merge, KE}, opt = Opt, q1 = Q1, c1 = C1, q2 = Q2, c2 = C2}, {not_a_qnum, J, Skip, DoSort}; [] when JoinOption =:= nested_loop -> {not_a_qnum, no, [], []}; _ when JoinOption =/= any -> erlang:error(cannot_carry_out_join, [JoinOption]); _ -> {not_a_qnum, no, [], []} end end. opt_join_lu([{{_Q1,_C1,Q2,_C2}=J,[{lookup_join,_KEols,JKE,Skip0} | _]} | LJ], Qdata, LU_SkipQuals) -> {Q2,_,_,{gen,Prep2}} = lists:keyfind(Q2, 1, Qdata), #qlc_table{ms = MS, key_equality = KE, lookup_fun = LU_fun} = Prep2#prepared.qh, %% If there is no filter to skip (the match spec was derived %% from a query handle) then the lookup join cannot be done. case MS =/= no_match_spec andalso lists:keymember(Q2, 1, LU_SkipQuals) =:= false of true -> opt_join_lu(LJ, Qdata, LU_SkipQuals); false -> %% The join is preferred before evaluating the match spec %% (if there is one). Skip = skip_if_possible(JKE, KE, Skip0), [{J,Skip,KE,LU_fun} | opt_join_lu(LJ, Qdata, LU_SkipQuals)] end; opt_join_lu([], _Qdata, _LU_SkipQuals) -> []. opt_join_merge(M) -> %% Prefer not to sort arguments. Prefer to skip join filter. L = [{-length(DoSort),length(Skip), {QCs,{merge_join,DoSort,KE,Skip}}} || {_KpOrder_or_other,MJ} <- M, {QCs,{merge_join,DoSort,KE,Skip0}} <- MJ, Skip <- [skip_if_possible(KE, '==', Skip0)]], lists:reverse([J || {_,_,J} <- lists:sort(L)]). %% Cannot skip the join filter the join operator is '=:=' and the join %% is performed using '=='. Note: the tag 'some'/'all' is not used. skip_if_possible('=:=', '==', _) -> []; skip_if_possible(_, _, {_SkipTag, Skip}) -> Skip. %% -> {Objects, Post, LocalPost} | throw() %% Post is a list of funs (closures) to run afterwards. %% LocalPost should be run when all objects have been found (optimization). %% LocalPost will always be a subset of Post. %% List expressions are evaluated, resulting in lists of objects kept in %% RAM or on disk. %% An error term is thrown as soon as cleanup according Post has been %% done. (This is opposed to errors during evaluation; such errors are %% returned as terms.) setup_qlc(Prep, Setup) -> Post0 = [], setup_le(Prep, Post0, Setup). setup_le(#prepared{qh = #simple_qlc{le = LE, optz = Optz}}, Post0, Setup) -> {Objs, Post, LocalPost} = setup_le(LE, Post0, Setup), unique_cache(Objs, Post, LocalPost, Optz); setup_le(#prepared{qh = #qlc{lcf = QFun, qdata = Qdata, init_value = V, optz = Optz}}, Post0, Setup) -> {GoTo, FirstState, Post, LocalPost} = setup_quals(Qdata, Post0, Setup, Optz), Objs = fun() -> QFun(FirstState, V, GoTo) end, unique_cache(Objs, Post, LocalPost, Optz); setup_le(#prepared{qh = #qlc_table{post_fun = PostFun}=Table}, Post, Setup) -> H = table_handle(Table, Post, Setup), %% The pre fun has been called from table_handle(): {H, [PostFun | Post], []}; setup_le(#prepared{qh = #qlc_append{hl = PrepL}}, Post0, Setup) -> F = fun(Prep, {Post1, LPost1}) -> {Objs, Post2, LPost2} = setup_le(Prep, Post1, Setup), {Objs, {Post2, LPost1++LPost2}} end, {ObjsL, {Post, LocalPost}} = lists:mapfoldl(F, {Post0,[]}, PrepL), {fun() -> append_loop(ObjsL, 0) end, Post, LocalPost}; setup_le(#prepared{qh = #qlc_sort{h = Prep, keypos = Kp, unique = Unique, compressed = Compressed, order = Order, fs_opts = SortOptions0, tmpdir_usage = TmpUsage,tmpdir = TmpDir}}, Post0, Setup) -> SortOptions = sort_options_global_tmp(SortOptions0, TmpDir), LF = fun(Objs) -> sort_list(Objs, Order, Unique, Kp, SortOptions, Post0) end, case setup_le(Prep, Post0, Setup) of {L, Post, LocalPost} when is_list(L) -> {LF(L), Post, LocalPost}; {Objs, Post, LocalPost} -> FF = fun(Objs1) -> file_sort_handle(Objs1, Kp, SortOptions, TmpDir, Compressed, Post, LocalPost) end, sort_handle(Objs, LF, FF, SortOptions, Post, LocalPost, {TmpUsage, sorting}) end; setup_le(#prepared{qh = #qlc_list{l = L, ms = MS}}, Post, _Setup) when (no_match_spec =:= MS); L =:= [] -> {L, Post, []}; setup_le(#prepared{qh = #qlc_list{l = L, ms = MS}}, Post, _Setup) when is_list(L) -> {ets:match_spec_run(L, ets:match_spec_compile(MS)), Post, []}; setup_le(#prepared{qh = #qlc_list{l = H0, ms = MS}}, Post0, Setup) -> {Objs0, Post, LocalPost} = setup_le(H0, Post0, Setup), Objs = ets:match_spec_run(Objs0, ets:match_spec_compile(MS)), {Objs, Post, LocalPost}. %% The goto table (a tuple) is created at runtime. It is accessed by %% the generated code in order to find next clause to execute. For %% generators there is also a fun; calling the fun runs the list %% expression of the generator. There are two elements for a filter: %% the first one is the state to go when the filter is false; the %% other the state when the filter is true. There are three elements %% for a generator G: the first one is the state of the generator %% before G (or the stop state if there is no generator); the second %% one is the state of the qualifier following the generator (or the %% template if there is no next generator); the third one is the list %% expression fun. %% There are also join generators which are "activated" when it is %% possbible to do a join. setup_quals(Qdata, Post0, Setup, Optz) -> {GoTo0, Post1, LocalPost0} = setup_quals(0, Qdata, [], Post0, [], Setup), GoTo1 = lists:keysort(1, GoTo0), FirstState0 = next_state(Qdata), {GoTo2, FirstState, Post, LocalPost1} = case Optz#optz.fast_join of #qlc_join{kind = {merge,_KE}, c1 = C1, c2 = C2, opt = Opt} = MJ -> MF = fun(_Rev, {H1, WH1}, {H2, WH2}) -> fun() -> merge_join(WH1(H1), C1, WH2(H2), C2, Opt) end end, setup_join(MJ, Qdata, GoTo1, FirstState0, MF, Post1); #qlc_join{kind = {lookup,_KE,LuF}, c1 = C1, c2 = C2} = LJ -> LF = fun(Rev, {H1, WH1}, {H2, WH2}) -> {H, W} = if Rev -> {H2, WH2}; true -> {H1, WH1} end, fun() -> lookup_join(W(H), C1, LuF, C2, Rev) end end, setup_join(LJ, Qdata, GoTo1, FirstState0, LF, Post1); no -> {flat_goto(GoTo1), FirstState0, Post1, []} end, GoTo = list_to_tuple(GoTo2), {GoTo, FirstState, Post, LocalPost0 ++ LocalPost1}. setup_quals(GenLoopS, [?qual_data(_QNum,GoI,?SKIP,fil) | Qdata], Gs, P, LP, Setup) -> %% ?SKIP causes runtime error. See also skip_lookup_filters(). setup_quals(GenLoopS, Qdata, [{GoI,[?SKIP,?SKIP]} | Gs], P, LP, Setup); setup_quals(GenLoopS, [?qual_data(_QNum,GoI,_SI,fil) | Qdata], Gs, P, LP, Setup) -> setup_quals(GenLoopS, Qdata, [{GoI,[GenLoopS,next_state(Qdata)]} | Gs], P, LP, Setup); setup_quals(GenLoopS, [?qual_data(_QNum,GoI,_SI, {gen,#join{}}) | Qdata], Gs, P, LP, Setup) -> setup_quals(GenLoopS, Qdata, [{GoI,[?SKIP,?SKIP,?SKIP]} | Gs],P,LP,Setup); setup_quals(GenLoopS, [?qual_data(_QNum,GoI,SI,{gen,LE}) | Qdata], Gs, P, LP, Setup) -> {V, NP, LP1} = setup_le(LE, P, Setup), setup_quals(SI + 1, Qdata, [{GoI, [GenLoopS,next_state(Qdata),V]} | Gs], NP, LP ++ LP1, Setup); setup_quals(GenLoopS, [], Gs, P, LP, _Setup) -> {[{1,[GenLoopS]} | Gs], P, LP}. %% Finds the qualifier in Qdata that performs the join between Q1 and %% Q2, and sets it up using the handles already set up for Q1 and Q2. %% Removes Q1 and Q2 from GoTo0 and updates the join qualifier in GoTo0. %% Note: the parse transform has given each generator three slots %% in the GoTo table. The position of these slots within the GoTo table %% is fixed (at runtime). %% (Assumes there is only one join-generator in Qdata.) setup_join(J, Qdata, GoTo0, FirstState0, JoinFun, Post0) -> #qlc_join{q1 = QNum1a, q2 = QNum2a, opt = Opt} = J, {?qual_data(_QN,JGoI,JSI,_), Rev, QNum1, QNum2, WH1, WH2, _CsFun} = find_join_data(Qdata, QNum1a, QNum2a), [{GoI1,SI1}] = [{GoI,SI} || ?qual_data(QNum,GoI,SI,_) <- Qdata, QNum =:= QNum1], [{GoI2,SI2}] = [{GoI,SI} || ?qual_data(QNum,GoI,SI,_) <- Qdata, QNum =:= QNum2], [H1] = [H || {GoI,[_Back,_Forth,H]} <- GoTo0, GoI =:= GoI1], [{BackH2,H2}] = [{Back,H} || {GoI,[Back,_Forth,H]} <- GoTo0, GoI =:= GoI2], H0 = JoinFun(Rev, {H1,WH1}, {H2,WH2}), %% The qlc expression options apply to the introduced qlc expr as well. {H, Post, LocalPost} = unique_cache(H0, Post0, [], join_unique_cache(Opt)), [JBack] = [Back || {GoI,[Back,_,_]} <- GoTo0, GoI =:= GoI1], JForth = next_after(Qdata, SI1, QNum2), GoTo1 = lists:map(fun({GoI,_}) when GoI =:= JGoI -> {JGoI, [JBack, JForth, H]}; ({GoI,_}) when GoI =:= GoI1; GoI =:= GoI2 -> {GoI, [?SKIP,?SKIP,?SKIP]}; % not necessary (Go) -> Go end, GoTo0), GoTo = lists:map(fun(S) when S =:= SI1 -> JSI; (S) when S =:= SI2 -> next_after(Qdata, S, QNum2); (S) when S =:= SI1+1 -> JSI+1; (S) when S =:= SI2+1, SI1 + 1 =:= BackH2 -> JSI+1; (S) when S =:= SI2+1 -> BackH2; (S) -> S end, flat_goto(GoTo1)), FirstState = if SI1 =:= FirstState0 -> JSI; true -> FirstState0 end, {GoTo, FirstState, Post, LocalPost}. join_unique_cache(#qlc_opt{cache = Cache, unique = Unique}=Opt) -> #optz{cache = Cache, unique = Unique, opt = Opt}. flat_goto(GoTo) -> lists:flatmap(fun({_,L}) -> L end, GoTo). next_after([?qual_data(_, _, S, _) | Qdata], S, QNum2) -> case Qdata of [?qual_data(QNum2, _, _, _) | Qdata1] -> next_state(Qdata1); _ -> next_state(Qdata) end; next_after([_ | Qdata], S, QNum2) -> next_after(Qdata, S, QNum2). next_state([?qual_data(_,_,_,{gen,#join{}}) | Qdata]) -> next_state(Qdata); next_state([?qual_data(_,_,?SKIP,fil) | Qdata]) -> %% see skip_lookup_filters() next_state(Qdata); next_state([?qual_data(_,_,S,_) | _]) -> S; next_state([]) -> template_state(). find_join_data(Qdata, QNum1, QNum2) -> [QRev] = [{Q,Rev,QN1,QN2,H1,H2,CsF} || ?qual_data(_QN,_GoI,_SI, {gen,#join{q1 = QN1,q2 = QN2, wh1 = H1, wh2 = H2, cs_fun = CsF}})= Q <- Qdata, if QN1 =:= QNum1, QN2 =:= QNum2 -> not (Rev = false); QN1 =:= QNum2, QN2 =:= QNum1 -> Rev = true; true -> Rev = false end], QRev. table_handle(#qlc_table{trav_fun = TraverseFun, trav_MS = TravMS, pre_fun = PreFun, lookup_fun = LuF, parent_fun = ParentFun, lu_vals = LuVals, ms = MS}, Post, Setup) -> #setup{parent = Parent} = Setup, ParentValue = if ParentFun =:= undefined -> undefined; Parent =:= self() -> try ParentFun() catch Class:Reason -> post_funs(Post), erlang:raise(Class, Reason, erlang:get_stacktrace()) end; true -> case monitor_request(Parent, {parent_fun, ParentFun}) of error -> % parent has died post_funs(Post), exit(normal); {value, Value} -> Value; {parent_fun_caught, Class, Reason, Stacktrace} -> %% No use augmenting Stacktrace here. post_funs(Post), erlang:raise(Class, Reason, Stacktrace) end end, StopFun = if Parent =:= self() -> undefined; true -> Cursor = #qlc_cursor{c = {self(), Parent}}, fun() -> delete_cursor(Cursor) end end, PreFunArgs = [{parent_value, ParentValue}, {stop_fun, StopFun}], _ = call(PreFun, PreFunArgs, ok, Post), case LuVals of {Pos, Vals} when MS =:= no_match_spec -> LuF(Pos, Vals); {Pos, Vals} -> case LuF(Pos, Vals) of [] -> []; Objs when is_list(Objs) -> ets:match_spec_run(Objs, ets:match_spec_compile(MS)); Error -> post_funs(Post), throw_error(Error) end; _ when not TravMS -> MS = no_match_spec, % assertion TraverseFun; _ when MS =:= no_match_spec -> fun() -> TraverseFun([{'$1',[],['$1']}]) end; _ -> fun() -> TraverseFun(MS) end end. -define(CHUNK_SIZE, 64*1024). open_file(FileName, Extra, Post) -> case file:open(FileName, [read, raw, binary | Extra]) of {ok, Fd} -> {fun() -> case file:position(Fd, bof) of {ok, 0} -> TF = fun([], _) -> []; (Ts, C) when is_list(Ts) -> lists:reverse(Ts, C) end, file_loop_read(<<>>, ?CHUNK_SIZE, {Fd,FileName}, TF); Error -> file_error(FileName, Error) end end, Fd}; Error -> post_funs(Post), throw_file_error(FileName, Error) end. file_loop(Bin0, Fd_FName, Ts0, TF) -> case try file_loop2(Bin0, Ts0) catch _:_ -> {_Fd, FileName} = Fd_FName, error({bad_object, FileName}) end of {terms, <<Size:4/unit:8, B/bytes>>=Bin, []} -> file_loop_read(Bin, Size - byte_size(B) + 4, Fd_FName, TF); {terms, <<Size:4/unit:8, _/bytes>>=Bin, Ts} -> C = fun() -> file_loop_read(Bin, Size+4, Fd_FName, TF) end, TF(Ts, C); {terms, B, Ts} -> C = fun() -> file_loop_read(B, ?CHUNK_SIZE, Fd_FName, TF) end, TF(Ts, C); Error -> Error end. file_loop2(<<Size:4/unit:8, B:Size/bytes, Bin/bytes>>, Ts) -> file_loop2(Bin, [binary_to_term(B) | Ts]); file_loop2(Bin, Ts) -> {terms, Bin, Ts}. %% After power failures (and only then) files with corrupted Size %% fields have been observed in a disk_log file. If file:read/2 is %% asked to read a huge amount of data the emulator may crash. Nothing %% has been done here to prevent such crashes (by inspecting %% BytesToRead in some way) since temporary files will never be read %% after a power failure. file_loop_read(B, MinBytesToRead, {Fd, FileName}=Fd_FName, TF) -> BytesToRead = erlang:max(?CHUNK_SIZE, MinBytesToRead), case file:read(Fd, BytesToRead) of {ok, Bin} when byte_size(B) =:= 0 -> file_loop(Bin, Fd_FName, [], TF); {ok, Bin} -> case B of <<Size:4/unit:8, Tl/bytes>> when byte_size(Bin) + byte_size(Tl) >= Size -> {B1, B2} = split_binary(Bin, Size - byte_size(Tl)), Foo = fun([T], Fun) -> [T | Fun] end, %% TF should be applied exactly once. case file_loop(list_to_binary([B, B1]), Fd_FName, [], Foo) of [T | Fun] -> true = is_function(Fun), file_loop(B2, Fd_FName, [T], TF); Error -> Error end; _ -> file_loop(list_to_binary([B, Bin]), Fd_FName, [], TF) end; eof when byte_size(B) =:= 0 -> TF([], foo); eof -> error({bad_object, FileName}); Error -> file_error(FileName, Error) end. sort_cursor_input(H, NoObjects) -> fun(close) -> ok; (read) -> sort_cursor_input_read(H, NoObjects) end. sort_cursor_list_output(TmpDir, Z, Unique) -> fun(close) -> {terms, []}; ({value, NoObjects}) -> fun(BTerms) when Unique; length(BTerms) =:= NoObjects -> fun(close) -> {terms, BTerms}; (BTerms1) -> sort_cursor_file(BTerms ++ BTerms1, TmpDir, Z) end; (BTerms) -> sort_cursor_file(BTerms, TmpDir, Z) end end. sort_cursor_file(BTerms, TmpDir, Z) -> FName = tmp_filename(TmpDir), case file:open(FName, [write, raw, binary | Z]) of {ok, Fd} -> WFun = write_terms(FName, Fd), WFun(BTerms); Error -> throw_file_error(FName, Error) end. sort_options_global_tmp(S, "") -> S; sort_options_global_tmp(S, TmpDir) -> [{tmpdir,TmpDir} | lists:keydelete(tmpdir, 1, S)]. tmp_filename(TmpDirOpt) -> U = "_", Node = node(), Pid = os:getpid(), {MSecs,Secs,MySecs} = erlang:now(), F = lists:concat([?MODULE,U,Node,U,Pid,U,MSecs,U,Secs,U,MySecs]), TmpDir = case TmpDirOpt of "" -> {ok, CurDir} = file:get_cwd(), CurDir; TDir -> TDir end, filename:join(filename:absname(TmpDir), F). write_terms(FileName, Fd) -> fun(close) -> _ = file:close(Fd), {file, FileName}; (BTerms) -> case file:write(Fd, size_bin(BTerms, [])) of ok -> write_terms(FileName, Fd); Error -> _ = file:close(Fd), throw_file_error(FileName, Error) end end. size_bin([], L) -> L; size_bin([BinTerm | BinTerms], L) -> size_bin(BinTerms, [L, <<(byte_size(BinTerm)):4/unit:8>> | BinTerm]). sort_cursor_input_read([], NoObjects) -> {end_of_input, NoObjects}; sort_cursor_input_read([Object | Cont], NoObjects) -> {[term_to_binary(Object)], sort_cursor_input(Cont, NoObjects + 1)}; sort_cursor_input_read(F, NoObjects) -> case F() of Objects when is_list(Objects) -> sort_cursor_input_read(Objects, NoObjects); Term -> throw_error(Term) end. unique_cache(L, Post, LocalPost, Optz) when is_list(L) -> case Optz#optz.unique of true -> {unique_sort_list(L), Post, LocalPost}; false -> %% If Optz#optz.cache then an ETS table could be used. {L, Post, LocalPost} end; unique_cache(H, Post, LocalPost, #optz{unique = false, cache = false}) -> {H, Post, LocalPost}; unique_cache(H, Post, LocalPost, #optz{unique = true, cache = false}) -> E = ets:new(qlc, [set, private]), {fun() -> no_dups(H, E) end, [del_table(E) | Post], LocalPost}; unique_cache(H, Post, LocalPost, #optz{unique = false, cache = true}) -> E = ets:new(qlc, [set, private]), {L, P} = unique_cache_post(E), {fun() -> cache(H, E, LocalPost) end, [P | Post], [L]}; unique_cache(H, Post, LocalPost, #optz{unique = true, cache = true}) -> UT = ets:new(qlc, [bag, private]), MT = ets:new(qlc, [set, private]), {L1, P1} = unique_cache_post(UT), {L2, P2} = unique_cache_post(MT), {fun() -> ucache(H, UT, MT, LocalPost) end, [P1, P2 | Post], [L1, L2]}; unique_cache(H, Post, LocalPost, #optz{unique = false, cache = list}=Optz) -> Ref = make_ref(), F = del_lcache(Ref), #qlc_opt{tmpdir = TmpDir, max_list = MaxList, tmpdir_usage = TmpUsage} = Optz#optz.opt, {fun() -> lcache(H, Ref, LocalPost, TmpDir, MaxList, TmpUsage) end, [F | Post], [F]}; unique_cache(H, Post0, LocalPost0, #optz{unique = true, cache = list}=Optz) -> #qlc_opt{tmpdir = TmpDir, max_list = MaxList, tmpdir_usage = TmpUsage} = Optz#optz.opt, Size = if MaxList >= 1 bsl 31 -> (1 bsl 31) - 1; MaxList =:= 0 -> 1; true -> MaxList end, SortOptions = [{size, Size}, {tmpdir, TmpDir}], USortOptions = [{unique, true} | SortOptions], TmpUsageM = {TmpUsage, caching}, LF1 = fun(Objs) -> lists:ukeysort(1, Objs) end, FF1 = fun(Objs) -> file_sort_handle(Objs, {keysort, 1}, USortOptions, TmpDir, [], Post0, LocalPost0) end, {UH, Post1, LocalPost1} = sort_handle(tag_objects(H, 1), LF1, FF1, USortOptions, Post0, LocalPost0, TmpUsageM), LF2 = fun(Objs) -> lists:keysort(2, Objs) end, FF2 = fun(Objs) -> file_sort_handle(Objs, {keysort, 2}, SortOptions, TmpDir, [], Post1, LocalPost1) end, {SH, Post, LocalPost} = sort_handle(UH, LF2, FF2, SortOptions, Post1, LocalPost1, TmpUsageM), if is_list(SH) -> %% Remove the tag once and for all. {untag_objects2(SH), Post, LocalPost}; true -> %% Every traversal untags the objects... {fun() -> untag_objects(SH) end, Post, LocalPost} end. unique_cache_post(E) -> {empty_table(E), del_table(E)}. unique_sort_list(L) -> E = ets:new(qlc, [set, private]), unique_list(L, E). unique_list([], E) -> true = ets:delete(E), []; unique_list([Object | Objects], E) -> case ets:member(E, Object) of false -> true = ets:insert(E, {Object}), [Object | unique_list(Objects, E)]; true -> unique_list(Objects, E) end. sort_list(L, CFun, true, sort, _SortOptions, _Post) when is_function(CFun) -> lists:usort(CFun, L); sort_list(L, CFun, false, sort, _SortOptions, _Post) when is_function(CFun) -> lists:sort(CFun, L); sort_list(L, ascending, true, sort, _SortOptions, _Post) -> lists:usort(L); sort_list(L, descending, true, sort, _SortOptions, _Post) -> lists:reverse(lists:usort(L)); sort_list(L, ascending, false, sort, _SortOptions, _Post) -> lists:sort(L); sort_list(L, descending, false, sort, _SortOptions, _Post) -> lists:reverse(lists:sort(L)); sort_list(L, Order, Unique, {keysort, Kp}, _SortOptions, _Post) when is_integer(Kp), is_atom(Order) -> case {Order, Unique} of {ascending, true} -> lists:ukeysort(Kp, L); {ascending, false} -> lists:keysort(Kp, L); {descending, true} -> lists:reverse(lists:ukeysort(Kp, L)); {descending, false} -> lists:reverse(lists:keysort(Kp, L)) end; sort_list(L, _Order, _Unique, Sort, SortOptions, Post) -> In = fun(_) -> {L, fun(_) -> end_of_input end} end, Out = sort_list_output([]), TSortOptions = [{format,term} | SortOptions], do_sort(In, Out, Sort, TSortOptions, Post). sort_list_output(L) -> fun(close) -> lists:append(lists:reverse(L)); (Terms) when is_list(Terms) -> sort_list_output([Terms | L]) end. %% Don't use the file_sorter unless it is known that objects will be %% put on a temporary file (optimization). sort_handle(H, ListFun, FileFun, SortOptions, Post, LocalPost, TmpUsageM) -> Size = case lists:keyfind(size, 1, SortOptions) of {size, Size0} -> Size0; false -> default_option(size) end, sort_cache(H, [], Size, {ListFun, FileFun, Post, LocalPost, TmpUsageM}). sort_cache([], CL, _Sz, {LF, _FF, Post, LocalPost, _TmpUsageM}) -> {LF(lists:reverse(CL)), Post, LocalPost}; sort_cache(Objs, CL, Sz, C) when Sz < 0 -> sort_cache2(Objs, CL, false, C); sort_cache([Object | Cont], CL, Sz0, C) -> Sz = decr_list_size(Sz0, Object), sort_cache(Cont, [Object | CL], Sz, C); sort_cache(F, CL, Sz, C) -> case F() of Objects when is_list(Objects) -> sort_cache(Objects, CL, Sz, C); Term -> {_LF, _FF, Post, _LocalPost, _TmpUsageM} = C, post_funs(Post), throw_error(Term) end. sort_cache2([], CL, _X, {LF, _FF, Post, LocalPost, _TmpUsageM}) -> {LF(lists:reverse(CL)), Post, LocalPost}; sort_cache2([Object | Cont], CL, _, C) -> sort_cache2(Cont, [Object | CL], true, C); sort_cache2(F, CL, false, C) -> %% Find one extra object to be sure that temporary file(s) will be %% used when calling the file_sorter. This works even if %% duplicates are removed. case F() of Objects when is_list(Objects) -> sort_cache2(Objects, CL, true, C); Term -> {_LF, _FF, Post, _LocalPost, _TmpUsageM} = C, post_funs(Post), throw_error(Term) end; sort_cache2(_Cont, _CL, true, {_LF,_FF,Post,_LocalPost, {not_allowed,M}}) -> post_funs(Post), throw_reason({tmpdir_usage, M}); sort_cache2(Cont, CL, true, {_LF, FF, _Post, _LocalPost, {TmpUsage, M}}) -> maybe_error_logger(TmpUsage, M), FF(lists:reverse(CL, Cont)). file_sort_handle(H, Kp, SortOptions, TmpDir, Compressed, Post, LocalPost) -> In = sort_cursor_input(H, 0), Unique = lists:member(unique, SortOptions) orelse lists:keymember(unique, 1, SortOptions), Out = sort_cursor_list_output(TmpDir, Compressed, Unique), Reply = do_sort(In, Out, Kp, SortOptions, Post), case Reply of {file, FileName} -> {F, Fd} = open_file(FileName, Compressed, Post), P = fun() -> _ = file:close(Fd), _ = file:delete(FileName) end, {F, [P | Post], LocalPost}; {terms, BTerms} -> try {[binary_to_term(B) || B <- BTerms], Post, LocalPost} catch Class:Reason -> post_funs(Post), erlang:raise(Class, Reason, erlang:get_stacktrace()) end end. do_sort(In, Out, Sort, SortOptions, Post) -> try case do_sort(In, Out, Sort, SortOptions) of {error, Reason} -> throw_reason(Reason); Reply -> Reply end catch Class:Term -> post_funs(Post), erlang:raise(Class, Term, erlang:get_stacktrace()) end. do_sort(In, Out, sort, SortOptions) -> file_sorter:sort(In, Out, SortOptions); do_sort(In, Out, {keysort, KeyPos}, SortOptions) -> file_sorter:keysort(KeyPos, In, Out, SortOptions). del_table(Ets) -> fun() -> true = ets:delete(Ets) end. empty_table(Ets) -> fun() -> true = ets:delete_all_objects(Ets) end. append_loop([[_ | _]=L], _N) -> L; append_loop([F], _N) -> F(); append_loop([L | Hs], N) -> append_loop(L, N, Hs). append_loop([], N, Hs) -> append_loop(Hs, N); append_loop([Object | Cont], N, Hs) -> [Object | append_loop(Cont, N + 1, Hs)]; append_loop(F, 0, Hs) -> case F() of [] -> append_loop(Hs, 0); [Object | Cont] -> [Object | append_loop(Cont, 1, Hs)]; Term -> Term end; append_loop(F, _N, Hs) -> % when _N > 0 fun() -> append_loop(F, 0, Hs) end. no_dups([]=Cont, UTab) -> true = ets:delete_all_objects(UTab), Cont; no_dups([Object | Cont], UTab) -> case ets:member(UTab, Object) of false -> true = ets:insert(UTab, {Object}), %% A fun is created here, even if Cont is a list; objects %% will not be copied to the ETS table unless requested. [Object | fun() -> no_dups(Cont, UTab) end]; true -> no_dups(Cont, UTab) end; no_dups(F, UTab) -> case F() of Objects when is_list(Objects) -> no_dups(Objects, UTab); Term -> Term end. %% When all objects have been returned from a cached QLC, the %% generators of the expression will never be called again, and so the %% tables used by the generators (LocalPost) can be emptied. cache(H, MTab, LocalPost) -> case ets:member(MTab, 0) of false -> true = ets:insert(MTab, {0}), cache(H, MTab, 1, LocalPost); true -> cache_recall(MTab, 1) end. cache([]=Cont, _MTab, _SeqNo, LocalPost) -> local_post(LocalPost), Cont; cache([Object | Cont], MTab, SeqNo, LocalPost) -> true = ets:insert(MTab, {SeqNo, Object}), %% A fun is created here, even if Cont is a list; objects %% will not be copied to the ETS table unless requested. [Object | fun() -> cache(Cont, MTab, SeqNo + 1, LocalPost) end]; cache(F, MTab, SeqNo, LocalPost) -> case F() of Objects when is_list(Objects) -> cache(Objects, MTab, SeqNo, LocalPost); Term -> Term end. cache_recall(MTab, SeqNo) -> case ets:lookup(MTab, SeqNo) of []=Cont -> Cont; [{SeqNo, Object}] -> [Object | fun() -> cache_recall(MTab, SeqNo + 1) end] end. ucache(H, UTab, MTab, LocalPost) -> case ets:member(MTab, 0) of false -> true = ets:insert(MTab, {0}), ucache(H, UTab, MTab, 1, LocalPost); true -> ucache_recall(UTab, MTab, 1) end. ucache([]=Cont, _UTab, _MTab, _SeqNo, LocalPost) -> local_post(LocalPost), Cont; ucache([Object | Cont], UTab, MTab, SeqNo, LocalPost) -> %% Always using 28 bits hash value... Hash = erlang:phash2(Object), case ets:lookup(UTab, Hash) of [] -> ucache3(Object, Cont, Hash, UTab, MTab, SeqNo, LocalPost); HashSeqObjects -> case lists:keymember(Object, 3, HashSeqObjects) of true -> ucache(Cont, UTab, MTab, SeqNo, LocalPost); false -> ucache3(Object, Cont, Hash, UTab, MTab, SeqNo, LocalPost) end end; ucache(F, UTab, MTab, SeqNo, LocalPost) -> case F() of Objects when is_list(Objects) -> ucache(Objects, UTab, MTab, SeqNo, LocalPost); Term -> Term end. ucache3(Object, Cont, Hash, UTab, MTab, SeqNo, LocalPost) -> true = ets:insert(UTab, {Hash, SeqNo, Object}), true = ets:insert(MTab, {SeqNo, Hash}), %% A fun is created here, even if Cont is a list; objects %% will not be copied to the ETS table unless requested. [Object | fun() -> ucache(Cont, UTab, MTab, SeqNo+1, LocalPost) end]. ucache_recall(UTab, MTab, SeqNo) -> case ets:lookup(MTab, SeqNo) of []=Cont -> Cont; [{SeqNo, Hash}] -> Object = case ets:lookup(UTab, Hash) of [{Hash, SeqNo, Object0}] -> Object0; HashSeqObjects -> {Hash, SeqNo, Object0} = lists:keyfind(SeqNo, 2, HashSeqObjects), Object0 end, [Object | fun() -> ucache_recall(UTab, MTab, SeqNo + 1) end] end. -define(LCACHE_FILE(Ref), {Ref, '$_qlc_cache_tmpfiles_'}). lcache(H, Ref, LocalPost, TmpDir, MaxList, TmpUsage) -> Key = ?LCACHE_FILE(Ref), case get(Key) of undefined -> lcache1(H, {Key, LocalPost, TmpDir, MaxList, TmpUsage}, MaxList, []); {file, _Fd, _TmpFile, F} -> F(); L when is_list(L) -> L end. lcache1([]=Cont, {Key, LocalPost, _TmpDir, _MaxList, _TmpUsage}, _Sz, Acc) -> local_post(LocalPost), case get(Key) of undefined -> put(Key, lists:reverse(Acc)), Cont; {file, Fd, TmpFile, _F} -> case lcache_write(Fd, TmpFile, Acc) of ok -> Cont; Error -> Error end end; lcache1(H, State, Sz, Acc) when Sz < 0 -> {Key, LocalPost, TmpDir, MaxList, TmpUsage} = State, GetFile = case get(Key) of {file, Fd0, TmpFile, _F} -> {TmpFile, Fd0}; undefined when TmpUsage =:= not_allowed -> error({tmpdir_usage, caching}); undefined -> maybe_error_logger(TmpUsage, caching), FName = tmp_filename(TmpDir), {F, Fd0} = open_file(FName, [write], LocalPost), put(Key, {file, Fd0, FName, F}), {FName, Fd0} end, case GetFile of {FileName, Fd} -> case lcache_write(Fd, FileName, Acc) of ok -> lcache1(H, State, MaxList, []); Error -> Error end; Error -> Error end; lcache1([Object | Cont], State, Sz0, Acc) -> Sz = decr_list_size(Sz0, Object), [Object | lcache2(Cont, State, Sz, [Object | Acc])]; lcache1(F, State, Sz, Acc) -> case F() of Objects when is_list(Objects) -> lcache1(Objects, State, Sz, Acc); Term -> Term end. lcache2([Object | Cont], State, Sz0, Acc) when Sz0 >= 0 -> Sz = decr_list_size(Sz0, Object), [Object | lcache2(Cont, State, Sz, [Object | Acc])]; lcache2(Cont, State, Sz, Acc) -> fun() -> lcache1(Cont, State, Sz, Acc) end. lcache_write(Fd, FileName, L) -> write_binary_terms(t2b(L, []), Fd, FileName). t2b([], Bs) -> Bs; t2b([T | Ts], Bs) -> t2b(Ts, [term_to_binary(T) | Bs]). del_lcache(Ref) -> fun() -> Key = ?LCACHE_FILE(Ref), case get(Key) of undefined -> ok; {file, Fd, TmpFile, _F} -> _ = file:close(Fd), _ = file:delete(TmpFile), erase(Key); _L -> erase(Key) end end. tag_objects([Object | Cont], T) -> [{Object, T} | tag_objects2(Cont, T + 1)]; tag_objects([]=Cont, _T) -> Cont; tag_objects(F, T) -> case F() of Objects when is_list(Objects) -> tag_objects(Objects, T); Term -> Term end. tag_objects2([Object | Cont], T) -> [{Object, T} | tag_objects2(Cont, T + 1)]; tag_objects2(Objects, T) -> fun() -> tag_objects(Objects, T) end. untag_objects([]=Objs) -> Objs; untag_objects([{Object, _N} | Cont]) -> [Object | untag_objects2(Cont)]; untag_objects(F) -> case F() of Objects when is_list(Objects) -> untag_objects(Objects); Term -> % Cannot happen Term end. untag_objects2([{Object, _N} | Cont]) -> [Object | untag_objects2(Cont)]; untag_objects2([]=Cont) -> Cont; untag_objects2(Objects) -> fun() -> untag_objects(Objects) end. %%% Merge join. %%% Temporary files are used when many objects have the same key. -define(JWRAP(E1, E2), [E1 | E2]). -record(m, {id, tmpdir, max_list, tmp_usage}). merge_join([]=Cont, _C1, _T2, _C2, _Opt) -> Cont; merge_join([E1 | L1], C1, L2, C2, Opt) -> #qlc_opt{tmpdir = TmpDir, max_list = MaxList, tmpdir_usage = TmpUsage} = Opt, M = #m{id = merge_join_id(), tmpdir = TmpDir, max_list = MaxList, tmp_usage = TmpUsage}, merge_join2(E1, element(C1, E1), L1, C1, L2, C2, M); merge_join(F1, C1, L2, C2, Opt) -> case F1() of L1 when is_list(L1) -> merge_join(L1, C1, L2, C2, Opt); T1 -> T1 end. merge_join1(_E2, _K2, []=Cont, _C1, _L2, _C2, M) -> end_merge_join(Cont, M); merge_join1(E2, K2, [E1 | L1], C1, L2, C2, M) -> K1 = element(C1, E1), if K1 == K2 -> same_keys2(E1, K1, L1, C1, L2, C2, E2, M); K1 > K2 -> merge_join2(E1, K1, L1, C1, L2, C2, M); true -> % K1 < K2 merge_join1(E2, K2, L1, C1, L2, C2, M) end; merge_join1(E2, K2, F1, C1, L2, C2, M) -> case F1() of L1 when is_list(L1) -> merge_join1(E2, K2, L1, C1, L2, C2, M); T1 -> T1 end. merge_join2(_E1, _K1, _L1, _C1, []=Cont, _C2, M) -> end_merge_join(Cont, M); merge_join2(E1, K1, L1, C1, [E2 | L2], C2, M) -> K2 = element(C2, E2), if K1 == K2 -> same_keys2(E1, K1, L1, C1, L2, C2, E2, M); K1 > K2 -> merge_join2(E1, K1, L1, C1, L2, C2, M); true -> % K1 < K2 merge_join1(E2, K2, L1, C1, L2, C2, M) end; merge_join2(E1, K1, L1, C1, F2, C2, M) -> case F2() of L2 when is_list(L2) -> merge_join2(E1, K1, L1, C1, L2, C2, M); T2 -> T2 end. %% element(C2, E2_0) == K1 same_keys2(E1, K1, L1, C1, [], _C2, E2_0, M) -> Cont = fun(_L1b) -> end_merge_join([], M) end, loop_same_keys(E1, K1, L1, C1, [E2_0], Cont, M); same_keys2(E1, K1, L1, C1, [E2 | L2]=L2_0, C2, E2_0, M) -> K2 = element(C2, E2), if K1 == K2 -> same_keys1(E1, K1, L1, C1, E2, C2, E2_0, L2, M); K1 < K2 -> [?JWRAP(E1, E2_0) | fun() -> same_loop1(L1, K1, C1, E2_0, L2_0, C2, M) end] end; same_keys2(E1, K1, L1, C1, F2, C2, E2_0, M) -> case F2() of L2 when is_list(L2) -> same_keys2(E1, K1, L1, C1, L2, C2, E2_0, M); T2 -> Cont = fun(_L1b) -> T2 end, loop_same_keys(E1, K1, L1, C1, [E2_0], Cont, M) end. same_loop1([], _K1_0, _C1, _E2_0, _L2, _C2, M) -> end_merge_join([], M); same_loop1([E1 | L1], K1_0, C1, E2_0, L2, C2, M) -> K1 = element(C1, E1), if K1 == K1_0 -> [?JWRAP(E1, E2_0) | fun() -> same_loop1(L1, K1_0, C1, E2_0, L2, C2, M) end]; K1_0 < K1 -> merge_join2(E1, K1, L1, C1, L2, C2, M) end; same_loop1(F1, K1_0, C1, E2_0, L2, C2, M) -> case F1() of L1 when is_list(L1) -> same_loop1(L1, K1_0, C1, E2_0, L2, C2, M); T1 -> T1 end. %% element(C2, E2_0) == K1, element(C2, E2) == K1_0 same_keys1(E1_0, K1_0, []=L1, C1, E2, C2, E2_0, L2, M) -> [?JWRAP(E1_0, E2_0), ?JWRAP(E1_0, E2) | fun() -> same_keys(K1_0, E1_0, L1, C1, L2, C2, M) end]; same_keys1(E1_0, K1_0, [E1 | _]=L1, C1, E2, C2, E2_0, L2, M) -> K1 = element(C1, E1), if K1_0 == K1 -> E2s = [E2, E2_0], Sz0 = decr_list_size(M#m.max_list, E2s), same_keys_cache(E1_0, K1_0, L1, C1, L2, C2, E2s, Sz0, M); K1_0 < K1 -> [?JWRAP(E1_0, E2_0), ?JWRAP(E1_0, E2) | fun() -> same_keys(K1_0, E1_0, L1, C1, L2, C2, M) end] end; same_keys1(E1_0, K1_0, F1, C1, E2, C2, E2_0, L2, M) -> case F1() of L1 when is_list(L1) -> same_keys1(E1_0, K1_0, L1, C1, E2, C2, E2_0, L2, M); T1 -> Cont = fun() -> T1 end, loop_same(E1_0, [E2, E2_0], Cont) end. %% There is no such element E in L1 such that element(C1, E) == K1. same_keys(_K1, _E1, _L1, _C1, []=Cont, _C2, M) -> end_merge_join(Cont, M); same_keys(K1, E1, L1, C1, [E2 | L2], C2, M) -> K2 = element(C2, E2), if K1 == K2 -> [?JWRAP(E1, E2) | fun() -> same_keys(K1, E1, L1, C1, L2, C2, M) end]; K1 < K2 -> merge_join1(E2, K2, L1, C1, L2, C2, M) end; same_keys(K1, E1, L1, C1, F2, C2, M) -> case F2() of L2 when is_list(L2) -> same_keys(K1, E1, L1, C1, L2, C2, M); T2 -> T2 end. %% There are at least two elements in [E1 | L1] that are to be combined %% with the elements in E2s (length(E2s) > 1). This loop covers the case %% when all elements in E2 with key K1 can be kept in RAM. same_keys_cache(E1, K1, L1, C1, [], _C2, E2s, _Sz, M) -> Cont = fun(_L1b) -> end_merge_join([], M) end, loop_same_keys(E1, K1, L1, C1, E2s, Cont, M); same_keys_cache(E1, K1, L1, C1, L2, C2, E2s, Sz0, M) when Sz0 < 0 -> case init_merge_join(M) of ok -> Sz = M#m.max_list, C = fun() -> same_keys_file(E1, K1, L1, C1, L2, C2, [], Sz, M) end, write_same_keys(E1, E2s, M, C); Error -> Error end; same_keys_cache(E1, K1, L1, C1, [E2 | L2], C2, E2s, Sz0, M) -> K2 = element(C2, E2), if K1 == K2 -> Sz = decr_list_size(Sz0, E2), same_keys_cache(E1, K1, L1, C1, L2, C2, [E2 | E2s], Sz, M); K1 < K2 -> Cont = fun(L1b) -> merge_join1(E2, K2, L1b, C1, L2, C2, M) end, loop_same_keys(E1, K1, L1, C1, E2s, Cont, M) end; same_keys_cache(E1, K1, L1, C1, F2, C2, E2s, Sz, M) -> case F2() of L2 when is_list(L2) -> same_keys_cache(E1, K1, L1, C1, L2, C2, E2s, Sz, M); T2 -> Cont = fun(_L1b) -> T2 end, loop_same_keys(E1, K1, L1, C1, E2s, Cont, M) end. %% E2s holds all elements E2 in L2 such that element(E2, C2) == K1. loop_same_keys(E1, _K1, [], _C1, E2s, _Cont, M) -> end_merge_join(loop_same(E1, E2s, []), M); loop_same_keys(E1, K1, L1, C1, E2s, Cont, M) -> loop_same(E1, E2s, fun() -> loop_keys(K1, L1, C1, E2s, Cont, M) end). loop_same(_E1, [], L) -> L; loop_same(E1, [E2 | E2s], L) -> loop_same(E1, E2s, [?JWRAP(E1, E2) | L]). loop_keys(K, [E1 | L1]=L1_0, C1, E2s, Cont, M) -> K1 = element(C1, E1), if K1 == K -> loop_same_keys(E1, K1, L1, C1, E2s, Cont, M); K1 > K -> Cont(L1_0) end; loop_keys(_K, []=L1, _C1, _Es2, Cont, _M) -> Cont(L1); loop_keys(K, F1, C1, E2s, Cont, M) -> case F1() of L1 when is_list(L1) -> loop_keys(K, L1, C1, E2s, Cont, M); T1 -> T1 end. %% This is for the case when a temporary file has to be used. same_keys_file(E1, K1, L1, C1, [], _C2, E2s, _Sz, M) -> Cont = fun(_L1b) -> end_merge_join([], M) end, same_keys_file_write(E1, K1, L1, C1, E2s, M, Cont); same_keys_file(E1, K1, L1, C1, L2, C2, E2s, Sz0, M) when Sz0 < 0 -> Sz = M#m.max_list, C = fun() -> same_keys_file(E1, K1, L1, C1, L2, C2, [], Sz, M) end, write_same_keys(E1, E2s, M, C); same_keys_file(E1, K1, L1, C1, [E2 | L2], C2, E2s, Sz0, M) -> K2 = element(C2, E2), if K1 == K2 -> Sz = decr_list_size(Sz0, E2), same_keys_file(E1, K1, L1, C1, L2, C2, [E2 | E2s], Sz, M); K1 < K2 -> Cont = fun(L1b) -> %% The temporary file could be truncated here. merge_join1(E2, K2, L1b, C1, L2, C2, M) end, same_keys_file_write(E1, K1, L1, C1, E2s, M, Cont) end; same_keys_file(E1, K1, L1, C1, F2, C2, E2s, Sz, M) -> case F2() of L2 when is_list(L2) -> same_keys_file(E1, K1, L1, C1, L2, C2, E2s, Sz, M); T2 -> Cont = fun(_L1b) -> T2 end, same_keys_file_write(E1, K1, L1, C1, E2s, M, Cont) end. same_keys_file_write(E1, K1, L1, C1, E2s, M, Cont) -> C = fun() -> loop_keys_file(K1, L1, C1, Cont, M) end, write_same_keys(E1, E2s, M, C). write_same_keys(_E1, [], _M, Cont) -> Cont(); write_same_keys(E1, Es2, M, Cont) -> write_same_keys(E1, Es2, M, [], Cont). %% Avoids one (the first) traversal of the temporary file. write_same_keys(_E1, [], M, E2s, Objs) -> case write_merge_join(M, E2s) of ok -> Objs; Error -> Error end; write_same_keys(E1, [E2 | E2s0], M, E2s, Objs) -> BE2 = term_to_binary(E2), write_same_keys(E1, E2s0, M, [BE2 | E2s], [?JWRAP(E1, E2) | Objs]). loop_keys_file(K, [E1 | L1]=L1_0, C1, Cont, M) -> K1 = element(C1, E1), if K1 == K -> C = fun() -> loop_keys_file(K1, L1, C1, Cont, M) end, read_merge_join(M, E1, C); K1 > K -> Cont(L1_0) end; loop_keys_file(_K, []=L1, _C1, Cont, _M) -> Cont(L1); loop_keys_file(K, F1, C1, Cont, M) -> case F1() of L1 when is_list(L1) -> loop_keys_file(K, L1, C1, Cont, M); T1 -> T1 end. end_merge_join(Reply, M) -> end_merge_join(M), Reply. %% Normally post_funs() cleans up temporary files by calling funs in %% Post. It seems impossible to do that with the temporary file(s) %% used when many objects have the same key--such a file is created %% after the setup when Post is prepared. There seems to be no real %% alternative to using the process dictionary, at least as things %% have been implemented so far. Probably all of Post could have been %% put in the process dictionary... -define(MERGE_JOIN_FILE, '$_qlc_merge_join_tmpfiles_'). init_merge_join(#m{id = MergeId, tmpdir = TmpDir, tmp_usage = TmpUsage}) -> case tmp_merge_file(MergeId) of {Fd, FileName} -> case file:position(Fd, bof) of {ok, 0} -> case file:truncate(Fd) of ok -> ok; Error -> file_error(FileName, Error) end; Error -> file_error(FileName, Error) end; none when TmpUsage =:= not_allowed -> error({tmpdir_usage, joining}); none -> maybe_error_logger(TmpUsage, joining), FName = tmp_filename(TmpDir), case file:open(FName, [raw, binary, read, write]) of {ok, Fd} -> TmpFiles = get(?MERGE_JOIN_FILE), put(?MERGE_JOIN_FILE, [{MergeId, Fd, FName} | TmpFiles]), ok; Error -> file_error(FName, Error) end end. write_merge_join(#m{id = MergeId}, BTerms) -> {Fd, FileName} = tmp_merge_file(MergeId), write_binary_terms(BTerms, Fd, FileName). read_merge_join(#m{id = MergeId}, E1, Cont) -> {Fd, FileName} = tmp_merge_file(MergeId), case file:position(Fd, bof) of {ok, 0} -> Fun = fun([], _) -> Cont(); (Ts, C) when is_list(Ts) -> join_read_terms(E1, Ts, C) end, file_loop_read(<<>>, ?CHUNK_SIZE, {Fd, FileName}, Fun); Error -> file_error(FileName, Error) end. join_read_terms(_E1, [], Objs) -> Objs; join_read_terms(E1, [E2 | E2s], Objs) -> join_read_terms(E1, E2s, [?JWRAP(E1, E2) | Objs]). end_merge_join(#m{id = MergeId}) -> case tmp_merge_file(MergeId) of none -> ok; {Fd, FileName} -> _ = file:close(Fd), _ = file:delete(FileName), put(?MERGE_JOIN_FILE, lists:keydelete(MergeId, 1, get(?MERGE_JOIN_FILE))) end. end_all_merge_joins() -> lists:foreach( fun(Id) -> end_merge_join(#m{id = Id}) end, [Id || {Id, _Fd, _FileName} <- lists:flatten([get(?MERGE_JOIN_FILE)])]), erase(?MERGE_JOIN_FILE). merge_join_id() -> case get(?MERGE_JOIN_FILE) of undefined -> put(?MERGE_JOIN_FILE, []); _ -> ok end, make_ref(). tmp_merge_file(MergeId) -> TmpFiles = get(?MERGE_JOIN_FILE), case lists:keyfind(MergeId, 1, TmpFiles) of {MergeId, Fd, FileName} -> {Fd, FileName}; false -> none end. decr_list_size(Sz0, E) when is_integer(Sz0) -> Sz0 - erlang:external_size(E). %%% End of merge join. lookup_join([E1 | L1], C1, LuF, C2, Rev) -> K1 = element(C1, E1), case LuF(C2, [K1]) of [] -> lookup_join(L1, C1, LuF, C2, Rev); [E2] when Rev -> [?JWRAP(E2, E1) | fun() -> lookup_join(L1, C1, LuF, C2, Rev) end]; [E2] -> [?JWRAP(E1, E2) | fun() -> lookup_join(L1, C1, LuF, C2, Rev) end]; E2s when is_list(E2s), Rev -> [?JWRAP(E2, E1) || E2 <- E2s] ++ fun() -> lookup_join(L1, C1, LuF, C2, Rev) end; E2s when is_list(E2s) -> [?JWRAP(E1, E2) || E2 <- E2s] ++ fun() -> lookup_join(L1, C1, LuF, C2, Rev) end; Term -> Term end; lookup_join([]=Cont, _C1, _LuF, _C2, _Rev) -> Cont; lookup_join(F1, C1, LuF, C2, Rev) -> case F1() of L1 when is_list(L1) -> lookup_join(L1, C1, LuF, C2, Rev); T1 -> T1 end. maybe_error_logger(allowed, _) -> ok; maybe_error_logger(Name, Why) -> [_, _, {?MODULE,maybe_error_logger,_} | Stacktrace] = expand_stacktrace(), Trimmer = fun(M, _F, _A) -> M =:= erl_eval end, Formater = fun(Term, I) -> io_lib:print(Term, I, 80, -1) end, X = lib:format_stacktrace(1, Stacktrace, Trimmer, Formater), error_logger:Name("qlc: temporary file was needed for ~w\n~s\n", [Why, lists:flatten(X)]). expand_stacktrace() -> D = erlang:system_flag(backtrace_depth, 8), try %% Compensate for a bug in erlang:system_flag/2: expand_stacktrace(erlang:max(1, D)) after erlang:system_flag(backtrace_depth, D) end. expand_stacktrace(D) -> _ = erlang:system_flag(backtrace_depth, D), {'EXIT', {foo, Stacktrace}} = (catch erlang:error(foo)), L = lists:takewhile(fun({M,_,_}) -> M =/= ?MODULE end, lists:reverse(Stacktrace)), if length(L) < 3 andalso length(Stacktrace) =:= D -> expand_stacktrace(D + 5); true -> Stacktrace end. write_binary_terms(BTerms, Fd, FileName) -> case file:write(Fd, size_bin(BTerms, [])) of ok -> ok; Error -> file_error(FileName, Error) end. post_funs(L) -> end_all_merge_joins(), local_post(L). local_post(L) -> lists:foreach(fun(undefined) -> ok; (F) -> catch (F)() end, L). call(undefined, _Arg, Default, _Post) -> Default; call(Fun, Arg, _Default, Post) -> try Fun(Arg) catch Class:Reason -> post_funs(Post), erlang:raise(Class, Reason, erlang:get_stacktrace()) end. grd(undefined, _Arg) -> false; grd(Fun, Arg) -> case Fun(Arg) of true -> true; _ -> false end. family(L) -> sofs:to_external(sofs:relation_to_family(sofs:relation(L))). family_union(L) -> R = sofs:relation(L,[{atom,[atom]}]), sofs:to_external(sofs:family_union(sofs:relation_to_family(R))). file_error(File, {error, Reason}) -> error({file_error, File, Reason}). -spec throw_file_error(string(), {'error',atom()}) -> no_return(). throw_file_error(File, {error, Reason}) -> throw_reason({file_error, File, Reason}). -spec throw_reason(term()) -> no_return(). throw_reason(Reason) -> throw_error(error(Reason)). -spec throw_error(term()) -> no_return(). throw_error(Error) -> throw(Error). error(Reason) -> {error, ?MODULE, Reason}.