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%% The contents of this file are subject to the Mozilla Public License
%% Version 1.1 (the "License"); you may not use this file except in
%% compliance with the License. You may obtain a copy of the License
%% at http://www.mozilla.org/MPL/
%%
%% 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.
%%
%% The Original Code is RabbitMQ.
%%
%% The Initial Developer of the Original Code is VMware, Inc.
%% Copyright (c) 2007-2013 VMware, Inc. All rights reserved.
%%
-module(rabbit_policy).
%% TODO specs
-behaviour(rabbit_runtime_parameter).
-include("rabbit.hrl").
-import(rabbit_misc, [pget/2]).
-export([register/0]).
-export([name/1, get/2, set/1]).
-export([validate/4, validate_clear/3, notify/4, notify_clear/3]).
-export([parse_set/5, set/5, delete/2, lookup/2, list/0, list/1,
list_formatted/1, info_keys/0]).
-rabbit_boot_step({?MODULE,
[{description, "policy parameters"},
{mfa, {rabbit_policy, register, []}},
{requires, rabbit_registry},
{enables, recovery}]}).
register() ->
rabbit_registry:register(runtime_parameter, <<"policy">>, ?MODULE).
name(#amqqueue{policy = Policy}) -> name0(Policy);
name(#exchange{policy = Policy}) -> name0(Policy).
name0(undefined) -> none;
name0(Policy) -> pget(name, Policy).
set(Q = #amqqueue{name = Name}) -> Q#amqqueue{policy = set0(Name)};
set(X = #exchange{name = Name}) -> X#exchange{policy = set0(Name)}.
set0(Name = #resource{virtual_host = VHost}) -> match(Name, list(VHost)).
get(Name, #amqqueue{policy = Policy}) -> get0(Name, Policy);
get(Name, #exchange{policy = Policy}) -> get0(Name, Policy);
%% Caution - SLOW.
get(Name, EntityName = #resource{virtual_host = VHost}) ->
get0(Name, match(EntityName, list(VHost))).
get0(_Name, undefined) -> {error, not_found};
get0(Name, List) -> case pget(definition, List) of
undefined -> {error, not_found};
Policy -> case pget(Name, Policy) of
undefined -> {error, not_found};
Value -> {ok, Value}
end
end.
%%----------------------------------------------------------------------------
parse_set(VHost, Name, Pattern, Definition, undefined) ->
parse_set0(VHost, Name, Pattern, Definition, 0);
parse_set(VHost, Name, Pattern, Definition, Priority) ->
try list_to_integer(Priority) of
Num -> parse_set0(VHost, Name, Pattern, Definition, Num)
catch
error:badarg -> {error, "~p priority must be a number", [Priority]}
end.
parse_set0(VHost, Name, Pattern, Defn, Priority) ->
case rabbit_misc:json_decode(Defn) of
{ok, JSON} ->
set0(VHost, Name,
[{<<"pattern">>, list_to_binary(Pattern)},
{<<"definition">>, rabbit_misc:json_to_term(JSON)},
{<<"priority">>, Priority}]);
error ->
{error_string, "JSON decoding error"}
end.
set(VHost, Name, Pattern, Definition, Priority) ->
PolicyProps = [{<<"pattern">>, Pattern},
{<<"definition">>, Definition},
{<<"priority">>, case Priority of
undefined -> 0;
_ -> Priority
end}],
set0(VHost, Name, PolicyProps).
set0(VHost, Name, Term) ->
rabbit_runtime_parameters:set_any(VHost, <<"policy">>, Name, Term).
delete(VHost, Name) ->
rabbit_runtime_parameters:clear_any(VHost, <<"policy">>, Name).
lookup(VHost, Name) ->
case rabbit_runtime_parameters:lookup(VHost, <<"policy">>, Name) of
not_found -> not_found;
P -> p(P, fun ident/1)
end.
list() ->
list('_').
list(VHost) ->
list0(VHost, fun ident/1).
list_formatted(VHost) ->
order_policies(list0(VHost, fun format/1)).
list0(VHost, DefnFun) ->
[p(P, DefnFun) || P <- rabbit_runtime_parameters:list(VHost, <<"policy">>)].
order_policies(PropList) ->
lists:sort(fun (A, B) -> pget(priority, A) < pget(priority, B) end,
PropList).
p(Parameter, DefnFun) ->
Value = pget(value, Parameter),
[{vhost, pget(vhost, Parameter)},
{name, pget(name, Parameter)},
{pattern, pget(<<"pattern">>, Value)},
{definition, DefnFun(pget(<<"definition">>, Value))},
{priority, pget(<<"priority">>, Value)}].
format(Term) ->
{ok, JSON} = rabbit_misc:json_encode(rabbit_misc:term_to_json(Term)),
list_to_binary(JSON).
ident(X) -> X.
info_keys() -> [vhost, name, pattern, definition, priority].
%%----------------------------------------------------------------------------
validate(_VHost, <<"policy">>, Name, Term) ->
rabbit_parameter_validation:proplist(
Name, policy_validation(), Term).
validate_clear(_VHost, <<"policy">>, _Name) ->
ok.
notify(VHost, <<"policy">>, _Name, _Term) ->
update_policies(VHost).
notify_clear(VHost, <<"policy">>, _Name) ->
update_policies(VHost).
%%----------------------------------------------------------------------------
update_policies(VHost) ->
Policies = list(VHost),
{Xs, Qs} = rabbit_misc:execute_mnesia_transaction(
fun() ->
{[update_exchange(X, Policies) ||
X <- rabbit_exchange:list(VHost)],
[update_queue(Q, Policies) ||
Q <- rabbit_amqqueue:list(VHost)]}
end),
[catch notify(X) || X <- Xs],
[catch notify(Q) || Q <- Qs],
ok.
update_exchange(X = #exchange{name = XName, policy = OldPolicy}, Policies) ->
case match(XName, Policies) of
OldPolicy -> no_change;
NewPolicy -> rabbit_exchange:update(
XName, fun(X1) -> X1#exchange{policy = NewPolicy} end),
{X, X#exchange{policy = NewPolicy}}
end.
update_queue(Q = #amqqueue{name = QName, policy = OldPolicy}, Policies) ->
case match(QName, Policies) of
OldPolicy -> no_change;
NewPolicy -> rabbit_amqqueue:update(
QName, fun(Q1) -> Q1#amqqueue{policy = NewPolicy} end),
{Q, Q#amqqueue{policy = NewPolicy}}
end.
notify(no_change)->
ok;
notify({X1 = #exchange{}, X2 = #exchange{}}) ->
rabbit_exchange:policy_changed(X1, X2);
notify({Q1 = #amqqueue{}, Q2 = #amqqueue{}}) ->
rabbit_amqqueue:policy_changed(Q1, Q2).
match(Name, Policies) ->
case lists:sort(fun sort_pred/2, [P || P <- Policies, matches(Name, P)]) of
[] -> undefined;
[Policy | _Rest] -> Policy
end.
matches(#resource{name = Name}, Policy) ->
match =:= re:run(Name, pget(pattern, Policy), [{capture, none}]).
sort_pred(A, B) -> pget(priority, A) >= pget(priority, B).
%%----------------------------------------------------------------------------
policy_validation() ->
[{<<"priority">>, fun rabbit_parameter_validation:number/2, mandatory},
{<<"pattern">>, fun rabbit_parameter_validation:regex/2, mandatory},
{<<"definition">>, fun validation/2, mandatory}].
validation(_Name, []) ->
{error, "no policy provided", []};
validation(_Name, Terms) when is_list(Terms) ->
{Keys, Modules} = lists:unzip(
rabbit_registry:lookup_all(policy_validator)),
[] = dups(Keys), %% ASSERTION
Validators = lists:zipwith(fun (M, K) -> {M, a2b(K)} end, Modules, Keys),
case is_proplist(Terms) of
true -> {TermKeys, _} = lists:unzip(Terms),
case dups(TermKeys) of
[] -> validation0(Validators, Terms);
Dup -> {error, "~p duplicate keys not allowed", [Dup]}
end;
false -> {error, "definition must be a dictionary: ~p", [Terms]}
end;
validation(_Name, Term) ->
{error, "parse error while reading policy: ~p", [Term]}.
validation0(Validators, Terms) ->
case lists:foldl(
fun (Mod, {ok, TermsLeft}) ->
ModKeys = proplists:get_all_values(Mod, Validators),
case [T || {Key, _} = T <- TermsLeft,
lists:member(Key, ModKeys)] of
[] -> {ok, TermsLeft};
Scope -> {Mod:validate_policy(Scope), TermsLeft -- Scope}
end;
(_, Acc) ->
Acc
end, {ok, Terms}, proplists:get_keys(Validators)) of
{ok, []} ->
ok;
{ok, Unvalidated} ->
{error, "~p are not recognised policy settings", [Unvalidated]};
{Error, _} ->
Error
end.
a2b(A) -> list_to_binary(atom_to_list(A)).
dups(L) -> L -- lists:usort(L).
is_proplist(L) -> length(L) =:= length([I || I = {_, _} <- L]).
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