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Posted to commits@couchdb.apache.org by be...@apache.org on 2014/02/13 17:35:37 UTC
[04/23] goldrush commit: updated refs/heads/import-master to 71e6321
Add event query module.
Project: http://git-wip-us.apache.org/repos/asf/couchdb-goldrush/repo
Commit: http://git-wip-us.apache.org/repos/asf/couchdb-goldrush/commit/2b60b8aa
Tree: http://git-wip-us.apache.org/repos/asf/couchdb-goldrush/tree/2b60b8aa
Diff: http://git-wip-us.apache.org/repos/asf/couchdb-goldrush/diff/2b60b8aa
Branch: refs/heads/import-master
Commit: 2b60b8aa1e7aa2f4a80eaa0146b1fc0b2e1b8efa
Parents: 3ab6e09
Author: Magnus Klaar <kl...@ninenines.fr>
Authored: Mon Apr 23 21:59:09 2012 +0200
Committer: Magnus Klaar <kl...@ninenines.fr>
Committed: Mon Apr 23 21:59:09 2012 +0200
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src/glc.erl | 657 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 657 insertions(+)
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http://git-wip-us.apache.org/repos/asf/couchdb-goldrush/blob/2b60b8aa/src/glc.erl
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diff --git a/src/glc.erl b/src/glc.erl
new file mode 100644
index 0000000..b0e7f40
--- /dev/null
+++ b/src/glc.erl
@@ -0,0 +1,657 @@
+%% Copyright (c) 2012, Magnus Klaar <kl...@ninenines.eu>
+%%
+%% Permission to use, copy, modify, and/or distribute this software for any
+%% purpose with or without fee is hereby granted, provided that the above
+%% copyright notice and this permission notice appear in all copies.
+%%
+%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+
+%% @doc Event filter implementation.
+%%
+%% An event query is constructed using the built in operators exported from
+%% this module. The filtering operators are used to specify which events
+%% should be included in the output of the query. The default output action
+%% is to copy all events matching the input filters associated with a query
+%% to the output. This makes it possible to construct and compose multiple
+%% queries at runtime.
+%%
+%% === Examples of built in filters ===
+%% ```
+%% %% Select all events where 'a' exists and is greater than 0.
+%% glc:gt(a, 0).
+%% %% Select all events where 'a' exists and is equal to 0.
+%% glc:eq(a, 0).
+%% %% Select all events where 'a' exists and is less than 0.
+%% glc:lt(a, 0).
+%%
+%% %% Select no input events. Used as black hole query.
+%% glc:null(false).
+%% %% Select all input events. Used as passthrough query.
+%% glc:null(true).
+%% '''
+%%
+%% === Examples of combining filters ===
+%% ```
+%% %% Select all events where both 'a' and 'b' exists and are greater than 0.
+%% glc:all([glc:gt(a, 0), glc:gt(b, 0)]).
+%% %% Select all events where 'a' or 'b' exists and are greater than 0.
+%% glc:any([glc:get(a, 0), glc:gt(b, 0)]).
+%% '''
+%%
+%% === Handling output events ===
+%%
+%% Once a query has been composed it is possible to override the output action
+%% with an erlang function. The function will be applied to each output event
+%% from the query. The return value from the function will be ignored.
+%%
+%% ```
+%% %% Write all input events as info reports to the error logger.
+%% glc:with(glc:null(true), fun(E) ->
+%% error_logger:info_report(gre:pairs(E)) end).
+%% '''
+%%
+-module(glc).
+
+-export([
+ compile/2,
+ handle/2,
+ delete/1
+]).
+
+-export([
+ lt/2,
+ eq/2,
+ gt/2
+]).
+
+-export([
+ all/1,
+ any/1,
+ null/1,
+ with/2
+]).
+
+-record(module, {
+ 'query' :: term(),
+ tables :: [{atom(), ets:tid()}],
+ qtree :: term()
+}).
+
+-type syntaxTree() :: erl_syntax:syntaxTree().
+
+-record(state, {
+ event = undefined :: syntaxTree(),
+ fields = [] :: [{atom(), syntaxTree()}],
+ fieldc = 0 :: non_neg_integer(),
+ paramvars = [] :: [{term(), syntaxTree()}],
+ paramstab = undefined :: ets:tid()
+}).
+
+-type nextFun() :: fun((#state{}) -> [syntaxTree()]).
+-type q() :: tuple().
+
+-spec lt(atom(), term()) -> q().
+lt(Key, Term) when is_atom(Key) -> {Key, '<', Term}.
+
+-spec eq(atom(), term()) -> q().
+eq(Key, Term) when is_atom(Key) -> {Key, '=', Term}.
+
+-spec gt(atom(), term()) -> q().
+gt(Key, Term) when is_atom(Key) -> {Key, '>', Term}.
+
+
+%% @doc Apply multiple conditions to the input.
+%% For an event to be considered valid output the condition of all filters
+%% specified in the input must hold for the input event.
+-spec all([q()]) -> q().
+all(Conds) when is_list(Conds) ->
+ {all, Conds}.
+
+%% @doc Apply one of multiple conditions to the input.
+-spec any([q()]) -> q().
+any(Conds) when is_list(Conds) ->
+ {any, Conds}.
+
+%% @doc Always return `true' or `false'.
+-spec null(boolean()) -> q().
+null(Result) when is_boolean(Result) ->
+ {null, Result}.
+
+%% @doc Apply a function to each output.
+-spec with(q(), fun((gre:event()) -> term())) -> q().
+with(Query, Fun) when is_function(Fun, 1) ->
+ {with, Query, Fun}.
+
+
+%% @doc Compile a query to a module.
+%%
+%% On success the module representing the query is returned. The module and
+%% data associated with the query must be released using the {@link delete/1}
+%% function. The name of the query module is expected to be unique.
+-spec compile(atom(), list()) -> {ok, atom()}.
+compile(Module, Query) ->
+ {ok, ModuleData} = module_data(Query),
+ {ok, forms, Forms} = abstract_module(Module, ModuleData),
+ {ok, Module, Binary} = compile_forms(Forms, []),
+ {ok, loaded, Module} = load_binary(Module, Binary),
+ {ok, Module}.
+
+%% @doc Handle an event using a compiled query.
+%%
+%% The input event is expected to have been returned from {@link gre:make/2}.
+-spec handle(atom(), gre:event()) -> ok.
+handle(Module, Event) ->
+ Module:handle(Event).
+
+%% @doc Release a compiled query.
+%%
+%% This releases all resources allocated by a compiled query. The query name
+%% is expected to be associated with an existing query module. Calling this
+%% function will result in a runtime error.
+-spec delete(atom()) -> ok.
+delete(_Module) ->
+ ok.
+
+
+%% @private Map a query to a module data term.
+-spec module_data(term()) -> {ok, #module{}}.
+module_data(Query) ->
+ %% terms in the query which are not valid arguments to the
+ %% erl_syntax:abstract/1 functions are stored in ETS.
+ %% the terms are only looked up once they are necessary to
+ %% continue evaluation of the query.
+ Params = ets:new(params, [set,protected]),
+ %% query counters are stored in a shared ETS table. this should
+ %% be an optional feature. enable by defaults to simplify tests.
+ Counters = ets:new(counters, [set,public]),
+ ets:insert(Counters, [{input,0}, {filter,0}, {output,0}]),
+ %% the abstract_tables/1 function expects a list of name-tid pairs.
+ %% tables are referred to by name in the generated code. the table/1
+ %% function maps names to tids.
+ Tables = [{params,Params}, {counters,Counters}],
+ Tree = query_tree(Query),
+ {ok, #module{'query'=Query, tables=Tables, qtree=Tree}}.
+
+
+%% @private Map a query to a simplified query tree term.
+%%
+%% The simplified query tree is used to combine multiple queries into one
+%% query module. The goal of this is to reduce the filtering and dispatch
+%% overhead when multiple concurrent queries are executed.
+%%
+%% A fixed selection condition may be used to specify a property that an event
+%% must have in order to be considered part of the input stream for a query.
+%%
+%% For the sake of simplicity it is only possible to define selection
+%% conditions using the fields present in the context and identifiers
+%% of an event. The fields in the context are bound to the reserved
+%% names:
+%%
+%% - '$n': node name
+%% - '$a': application name
+%% - '$p': process identifier
+%% - '$t': timestamp
+%%
+%%
+%% If an event must be selected based on the runtime state of an event handler
+%% this must be done in the body of the handler.
+-type qcond() ::
+ {atom(), '<', term()} |
+ {atom(), '=', term()} |
+ {atom(), '>', term()} |
+ {any, [qcond()]} |
+ {all, [qcond()]}.
+-type qbody() :: tuple().
+-type qtree() :: [{qcond(), qbody()}].
+-spec query_tree(term()) -> qtree().
+query_tree(Query) ->
+ Query.
+
+%% abstract code geneation functions
+
+%% @private Generate an abstract dispatch module.
+-spec abstract_module(atom(), #module{}) -> {ok, forms, list()}.
+abstract_module(Module, Data) ->
+ Forms = [erl_syntax:revert(E) || E <- abstract_module_(Module, Data)],
+ case lists:keyfind(errors, 1, erl_syntax_lib:analyze_forms(Forms)) of
+ false -> {ok, forms, Forms};
+ {_, []} -> {ok, forms, Forms};
+ {_, [_|_]}=Errors -> Errors
+ end.
+
+%% @private Generate an abstract dispatch module.
+-spec abstract_module_(atom(), #module{}) -> [erl_syntax:syntaxTree()].
+abstract_module_(Module, #module{tables=Tables, qtree=Tree}=Data) ->
+ {_, ParamsTable} = lists:keyfind(params, 1, Tables),
+ AbstractMod = [
+ %% -module(Module)
+ erl_syntax:attribute(erl_syntax:atom(module), [erl_syntax:atom(Module)]),
+ %% -export([
+ erl_syntax:attribute(
+ erl_syntax:atom(export),
+ [erl_syntax:list([
+ %% info/1
+ erl_syntax:arity_qualifier(
+ erl_syntax:atom(info),
+ erl_syntax:integer(1)),
+ %% table/1
+ erl_syntax:arity_qualifier(
+ erl_syntax:atom(table),
+ erl_syntax:integer(1)),
+ %% handle/1
+ erl_syntax:arity_qualifier(
+ erl_syntax:atom(handle),
+ erl_syntax:integer(1))])]),
+ %% ]).
+ %% info(Name) -> Term.
+ erl_syntax:function(
+ erl_syntax:atom(info),
+ abstract_info(Data) ++
+ [erl_syntax:clause(
+ [erl_syntax:underscore()], none,
+ [erl_syntax:application(
+ erl_syntax:atom(erlang),
+ erl_syntax:atom(error),
+ [erl_syntax:atom(badarg)])])]),
+ %% table(Name) -> ets:tid().
+ erl_syntax:function(
+ erl_syntax:atom(table),
+ abstract_tables(Tables) ++
+ [erl_syntax:clause(
+ [erl_syntax:underscore()], none,
+ [erl_syntax:application(
+ erl_syntax:atom(erlang),
+ erl_syntax:atom(error),
+ [erl_syntax:atom(badarg)])])]),
+ %% handle(Event) - entry function
+ erl_syntax:function(
+ erl_syntax:atom(handle),
+ [erl_syntax:clause([erl_syntax:variable("Event")], none,
+ [abstract_count(input),
+ erl_syntax:application(none,
+ erl_syntax:atom(handle_), [erl_syntax:variable("Event")])])]),
+ %% input_(Node, App, Pid, Tags, Values) - filter roots
+ erl_syntax:function(
+ erl_syntax:atom(handle_),
+ [erl_syntax:clause([erl_syntax:variable("Event")], none,
+ abstract_filter(Tree, #state{
+ event=erl_syntax:variable("Event"),
+ paramstab=ParamsTable}))])
+ ],
+ %% Transform Term -> Key to Key -> Term
+ ParamsList = [{K, V} || {V, K} <- ets:tab2list(ParamsTable)],
+ ets:delete_all_objects(ParamsTable),
+ ets:insert(ParamsTable, ParamsList),
+ AbstractMod.
+
+%% @private Return the clauses of the table/1 function.
+abstract_tables(Tables) ->
+ [erl_syntax:clause(
+ [erl_syntax:abstract(K)], none,
+ [erl_syntax:abstract(V)])
+ || {K, V} <- Tables].
+
+%% @private Return the clauses of the info/1 function.
+abstract_info(#module{'query'=Query}) ->
+ [erl_syntax:clause([erl_syntax:abstract(K)], none, V)
+ || {K, V} <- [
+ {'query', abstract_query(Query)},
+ {input, abstract_getcount(input)},
+ {filter, abstract_getcount(filter)},
+ {output, abstract_getcount(output)}
+ ]].
+
+%% @private Return the original query as an expression.
+abstract_query({with, _, _}) ->
+ [erl_syntax:abstract([])];
+abstract_query(Query) ->
+ [erl_syntax:abstract(Query)].
+
+
+%% @private Return a list of expressions to apply a filter.
+%% @todo Allow mulitple functions to be specified using `with/2'.
+-spec abstract_filter(q(), #state{}) -> [syntaxTree()].
+abstract_filter({with, Cond, Fun}, State) ->
+ abstract_filter_(Cond,
+ _OnMatch=fun(State2) ->
+ [abstract_count(output)] ++ abstract_with(Fun, State2) end,
+ _OnNomatch=fun(_State2) -> [abstract_count(filter)] end, State);
+abstract_filter(Cond, State) ->
+ abstract_filter_(Cond,
+ _OnMatch=fun(_State2) -> [abstract_count(output)] end,
+ _OnNomatch=fun(_State2) -> [abstract_count(filter)] end, State).
+
+%% @private Return a list of expressions to apply a filter.
+%% A filter expects two continuation functions which generates the expressions
+%% to apply when the filter matches or fails to match. The state passed to the
+%% functions will be contain all variable bindings to previously accessed
+%% fields and parameters.
+-spec abstract_filter_(qcond(), nextFun(), nextFun(), #state{}) ->
+ syntaxTree().
+abstract_filter_({null, true}, OnMatch, _OnNomatch, State) ->
+ OnMatch(State);
+abstract_filter_({null, false}, _OnMatch, OnNomatch, State) ->
+ OnNomatch(State);
+abstract_filter_({Key, Op, Value}, OnMatch, OnNomatch, State)
+ when Op =:= '>'; Op =:= '='; Op =:= '<' ->
+ Op2 = case Op of '=' -> '=:='; Op -> Op end,
+ abstract_opfilter(Key, Op2, Value, OnMatch, OnNomatch, State);
+abstract_filter_({'any', Conds}, OnMatch, OnNomatch, State) ->
+ abstract_any(Conds, OnMatch, OnNomatch, State);
+abstract_filter_({'all', Conds}, OnMatch, OnNomatch, State) ->
+ abstract_all(Conds, OnMatch, OnNomatch, State).
+
+%% @private Return a branch based on a built in operator.
+-spec abstract_opfilter(atom(), atom(), term(), nextFun(),
+ nextFun(), #state{}) -> [syntaxTree()].
+abstract_opfilter(Key, Opname, Value, OnMatch, OnNomatch, State) ->
+ abstract_getkey(Key,
+ _OnMatch=fun(#state{fields=Fields}=State2) ->
+ {_, Field} = lists:keyfind(Key, 1, Fields),
+ [erl_syntax:case_expr(
+ erl_syntax:application(
+ erl_syntax:atom(erlang), erl_syntax:atom(Opname),
+ [Field, erl_syntax:abstract(Value)]),
+ [erl_syntax:clause([erl_syntax:atom(true)], none,
+ OnMatch(State2)),
+ erl_syntax:clause([erl_syntax:atom(false)], none,
+ OnNomatch(State2))])] end,
+ _OnNomatch=fun(State2) -> OnNomatch(State2) end, State).
+
+
+%% @private Generate an `all' filter.
+%% An `all' filter is evaluated by testing all conditions that must hold. If
+%% any of the conditions does not hold the evaluation is short circuted at that
+%% point. This means that the `OnNomatch' branch is executed once for each
+%% condition. The `OnMatch' branch is only executed once.
+-spec abstract_all([qcond()], nextFun(), nextFun(), #state{}) ->
+ [syntaxTree()].
+abstract_all([H|T], OnMatch, OnNomatch, State) ->
+ abstract_filter_(H,
+ _OnMatch=fun(State2) -> abstract_all(T, OnMatch, OnNomatch, State2)
+ end, OnNomatch, State);
+abstract_all([], OnMatch, _OnNomatch, State) ->
+ OnMatch(State).
+
+%% @private
+-spec abstract_any([qcond()], nextFun(), nextFun(), #state{}) ->
+ [syntaxTree()].
+abstract_any([H|T], OnMatch, OnNomatch, State) ->
+ abstract_filter_(H, OnMatch,
+ _OnNomatch=fun(State2) -> abstract_any(T, OnMatch, OnNomatch, State2)
+ end, State);
+abstract_any([], _OnMatch, OnNomatch, State) ->
+ OnNomatch(State).
+
+%% @private
+-spec abstract_with(fun((gre:event()) -> term()), #state{}) -> [syntaxTree()].
+abstract_with(Fun, State) when is_function(Fun, 1) ->
+ abstract_getparam(Fun, fun(#state{event=Event, paramvars=Params}) ->
+ {_, Fun2} = lists:keyfind(Fun, 1, Params),
+ [erl_syntax:application(none, Fun2, [Event])]
+ end, State).
+
+%% @private Bind the value of a field to a variable.
+%% If the value of a field has already been bound to a variable the previous
+%% binding is reused over re-accessing the value. The `OnMatch' function is
+%% expected to access the variable stored in the state record. The `OnNomatch'
+%% function must not attempt to access the variable.
+-spec abstract_getkey(atom(), nextFun(), nextFun(), #state{}) ->
+ [syntaxTree()].
+abstract_getkey(Key, OnMatch, OnNomatch, #state{fields=Fields}=State) ->
+ case lists:keyfind(Key, 1, Fields) of
+ {Key, _Variable} -> OnMatch(State);
+ false -> abstract_getkey_(Key, OnMatch, OnNomatch, State)
+ end.
+
+
+-spec abstract_getkey_(atom(), nextFun(), nextFun(), #state{}) ->
+ [syntaxTree()].
+abstract_getkey_(Key, OnMatch, OnNomatch, #state{
+ event=Event, fields=Fields}=State) ->
+ [erl_syntax:case_expr(
+ erl_syntax:application(
+ erl_syntax:atom(gre), erl_syntax:atom(find),
+ [erl_syntax:atom(Key), Event]),
+ [erl_syntax:clause([
+ erl_syntax:tuple([
+ erl_syntax:atom(true),
+ field_variable(Key)])], none,
+ OnMatch(State#state{
+ fields=[{Key, field_variable(Key)}|Fields]})),
+ erl_syntax:clause([
+ erl_syntax:atom(false)], none,
+ OnNomatch(State))
+ ]
+ )].
+
+%% @private Bind the value of a parameter to a variable.
+%% During code generation the parameter value is used as the identity of the
+%% parameter. At runtime a unique integer is used as the identity.
+-spec abstract_getparam(term(), nextFun(), #state{}) -> [syntaxTree()].
+abstract_getparam(Term, OnBound, #state{paramvars=Params}=State) ->
+ case lists:keyfind(Term, 1, Params) of
+ {_, _Variable} -> OnBound(State);
+ %% parameter not bound to variable in this scope.
+ false -> abstract_getparam_(Term, OnBound, State)
+ end.
+
+
+-spec abstract_getparam_(term(), nextFun(), #state{}) -> [syntaxTree()].
+abstract_getparam_(Term, OnBound, #state{paramstab=Table,
+ paramvars=Params}=State) ->
+ Key = case ets:lookup(Table, Term) of
+ [{_, Key2}] ->
+ Key2;
+ [] ->
+ Key2 = ets:info(Table, size),
+ ets:insert(Table, {Term, Key2}),
+ Key2
+ end,
+ [erl_syntax:match_expr(
+ param_variable(Key),
+ erl_syntax:application(
+ erl_syntax:atom(ets),
+ erl_syntax:atom(lookup_element),
+ [erl_syntax:application(
+ erl_syntax:atom(table),
+ [erl_syntax:atom(params)]),
+ erl_syntax:abstract(Key),
+ erl_syntax:abstract(2)]))
+ ] ++ OnBound(State#state{paramvars=[{Term, param_variable(Key)}|Params]}).
+
+%% @private Generate a variable name for the value of a field.
+%% @todo Encode non-alphanumeric characters as integer values.
+-spec field_variable(atom()) -> syntaxTree().
+field_variable(Key) ->
+ erl_syntax:variable("Field_" ++ atom_to_list(Key)).
+
+%% @private Generate a variable name for the value of a parameter.
+-spec param_variable(integer()) -> syntaxTree().
+param_variable(Key) ->
+ erl_syntax:variable("Param_" ++ integer_to_list(Key)).
+
+
+%% @private Return an expression to increment a counter.
+%% @todo Pass state record. Only Generate code if `statistics' is enabled.
+-spec abstract_count(atom()) -> syntaxTree().
+abstract_count(Counter) ->
+ erl_syntax:application(
+ erl_syntax:atom(ets),
+ erl_syntax:atom(update_counter),
+ [erl_syntax:application(
+ erl_syntax:atom(table),
+ [erl_syntax:atom(counters)]),
+ erl_syntax:abstract(Counter),
+ erl_syntax:abstract({2,1})]).
+
+
+%% @private Return an expression to get the value of a counter.
+%% @todo Pass state record. Only Generate code if `statistics' is enabled.
+-spec abstract_getcount(atom()) -> [syntaxTree()].
+abstract_getcount(Counter) ->
+ [erl_syntax:application(
+ erl_syntax:atom(ets),
+ erl_syntax:atom(lookup_element),
+ [erl_syntax:application(
+ erl_syntax:atom(table),
+ [erl_syntax:atom(counters)]),
+ erl_syntax:abstract(Counter),
+ erl_syntax:abstract(2)])].
+
+
+%% abstract code util functions
+
+
+%% @private Compile an abstract module.
+-spec compile_forms(term(), [term()]) -> {ok, atom(), binary()}.
+compile_forms(Forms, _Opts) ->
+ case compile:forms(Forms) of
+ {ok, Module, Binary} ->
+ {ok, Module, Binary};
+ {ok, Module, Binary, _Warnings} ->
+ {ok, Module, Binary};
+ Error ->
+ erlang:error({compile_forms, Error})
+ end.
+
+%% @private Load a module binary.
+-spec load_binary(atom(), binary()) -> {ok, loaded, atom()}.
+load_binary(Module, Binary) ->
+ case code:load_binary(Module, "", Binary) of
+ {module, Module} -> {ok, loaded, Module};
+ {error, Reason} -> exit({error_loading_module, Module, Reason})
+ end.
+
+
+-ifdef(TEST).
+-include_lib("eunit/include/eunit.hrl").
+
+setup_query(Module, Query) ->
+ ?assertNot(erlang:module_loaded(Module)),
+ ?assertEqual({ok, Module}, case (catch compile(Module, Query)) of
+ {'EXIT',_}=Error -> ?debugFmt("~p", [Error]), Error; Else -> Else end),
+ ?assert(erlang:function_exported(Module, table, 1)),
+ ?assert(erlang:function_exported(Module, handle, 1)),
+ {compiled, Module}.
+
+nullquery_compiles_test() ->
+ {compiled, Mod} = setup_query(testmod1, glc:null(false)),
+ ?assertError(badarg, Mod:table(noexists)).
+
+params_table_exists_test() ->
+ {compiled, Mod} = setup_query(testmod2, glc:null(false)),
+ ?assert(is_integer(Mod:table(params))),
+ ?assertMatch([_|_], ets:info(Mod:table(params))).
+
+nullquery_exists_test() ->
+ {compiled, Mod} = setup_query(testmod3, glc:null(false)),
+ ?assert(erlang:function_exported(Mod, info, 1)),
+ ?assertError(badarg, Mod:info(invalid)),
+ ?assertEqual({null, false}, Mod:info('query')).
+
+init_counters_test() ->
+ {compiled, Mod} = setup_query(testmod4, glc:null(false)),
+ ?assertEqual(0, Mod:info(input)),
+ ?assertEqual(0, Mod:info(filter)),
+ ?assertEqual(0, Mod:info(output)).
+
+filtered_event_test() ->
+ %% If no selection condition is specified no inputs can match.
+ {compiled, Mod} = setup_query(testmod5, glc:null(false)),
+ glc:handle(Mod, gre:make([], [list])),
+ ?assertEqual(1, Mod:info(input)),
+ ?assertEqual(1, Mod:info(filter)),
+ ?assertEqual(0, Mod:info(output)).
+
+nomatch_event_test() ->
+ %% If a selection condition but no body is specified the event
+ %% is expected to count as filtered out if the condition does
+ %% not hold.
+ {compiled, Mod} = setup_query(testmod6, glc:eq('$n', 'noexists@nohost')),
+ glc:handle(Mod, gre:make([{'$n', 'noexists2@nohost'}], [list])),
+ ?assertEqual(1, Mod:info(input)),
+ ?assertEqual(1, Mod:info(filter)),
+ ?assertEqual(0, Mod:info(output)).
+
+opfilter_eq_test() ->
+ %% If a selection condition but no body is specified the event
+ %% counts as input to the query, but not as filtered out.
+ {compiled, Mod} = setup_query(testmod7, glc:eq('$n', 'noexists@nohost')),
+ glc:handle(Mod, gre:make([{'$n', 'noexists@nohost'}], [list])),
+ ?assertEqual(1, Mod:info(input)),
+ ?assertEqual(0, Mod:info(filter)),
+ ?assertEqual(1, Mod:info(output)),
+ done.
+
+
+opfilter_gt_test() ->
+ {compiled, Mod} = setup_query(testmod8, glc:gt(a, 1)),
+ glc:handle(Mod, gre:make([{'a', 2}], [list])),
+ ?assertEqual(1, Mod:info(input)),
+ ?assertEqual(0, Mod:info(filter)),
+ glc:handle(Mod, gre:make([{'a', 0}], [list])),
+ ?assertEqual(2, Mod:info(input)),
+ ?assertEqual(1, Mod:info(filter)),
+ ?assertEqual(1, Mod:info(output)),
+ done.
+
+opfilter_lt_test() ->
+ {compiled, Mod} = setup_query(testmod9, glc:lt(a, 1)),
+ glc:handle(Mod, gre:make([{'a', 0}], [list])),
+ ?assertEqual(1, Mod:info(input)),
+ ?assertEqual(0, Mod:info(filter)),
+ ?assertEqual(1, Mod:info(output)),
+ glc:handle(Mod, gre:make([{'a', 2}], [list])),
+ ?assertEqual(2, Mod:info(input)),
+ ?assertEqual(1, Mod:info(filter)),
+ ?assertEqual(1, Mod:info(output)),
+ done.
+
+allholds_op_test() ->
+ {compiled, Mod} = setup_query(testmod10,
+ glc:all([glc:eq(a, 1), glc:eq(b, 2)])),
+ glc:handle(Mod, gre:make([{'a', 1}], [list])),
+ glc:handle(Mod, gre:make([{'a', 2}], [list])),
+ ?assertEqual(2, Mod:info(input)),
+ ?assertEqual(2, Mod:info(filter)),
+ glc:handle(Mod, gre:make([{'b', 1}], [list])),
+ glc:handle(Mod, gre:make([{'b', 2}], [list])),
+ ?assertEqual(4, Mod:info(input)),
+ ?assertEqual(4, Mod:info(filter)),
+ glc:handle(Mod, gre:make([{'a', 1},{'b', 2}], [list])),
+ ?assertEqual(5, Mod:info(input)),
+ ?assertEqual(4, Mod:info(filter)),
+ ?assertEqual(1, Mod:info(output)),
+ done.
+
+anyholds_op_test() ->
+ {compiled, Mod} = setup_query(testmod11,
+ glc:any([glc:eq(a, 1), glc:eq(b, 2)])),
+ glc:handle(Mod, gre:make([{'a', 2}], [list])),
+ glc:handle(Mod, gre:make([{'b', 1}], [list])),
+ ?assertEqual(2, Mod:info(input)),
+ ?assertEqual(2, Mod:info(filter)),
+ glc:handle(Mod, gre:make([{'a', 1}], [list])),
+ glc:handle(Mod, gre:make([{'b', 2}], [list])),
+ ?assertEqual(4, Mod:info(input)),
+ ?assertEqual(2, Mod:info(filter)),
+ done.
+
+with_function_test() ->
+ Self = self(),
+ {compiled, Mod} = setup_query(testmod12,
+ glc:with(glc:eq(a, 1), fun(Event) -> Self ! gre:fetch(a, Event) end)),
+ glc:handle(Mod, gre:make([{a,1}], [list])),
+ ?assertEqual(1, Mod:info(output)),
+ ?assertEqual(1, receive Msg -> Msg after 0 -> notcalled end),
+ done.
+
+-endif.