%%% ====================================================================
%%% ``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 via the world wide web 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.
%%%
%%%
%%% @author Brian Cully <bjc@kublai.com>
%%% @version {@vsn}, {@date} {@time}
%%% @end
%%% ====================================================================
-module(nodetree_dag).
-behaviour(gen_pubsub_nodetree).
-author('bjc@kublai.com').
-include_lib("stdlib/include/qlc.hrl").
-include("pubsub.hrl").
-include("jlib.hrl").
-export([init/3, terminate/2, options/0, set_node/1,
get_node/3, get_node/2, get_node/1, get_nodes/2,
get_nodes/1, get_parentnodes/3, get_parentnodes_tree/3,
get_subnodes/3, get_subnodes_tree/3, create_node/6,
delete_node/2]).
-define(DEFAULT_NODETYPE, leaf).
-define(DEFAULT_PARENTS, []).
-define(DEFAULT_CHILDREN, []).
init(Host, ServerHost, Opts) ->
nodetree_tree:init(Host, ServerHost, Opts).
terminate(Host, ServerHost) ->
nodetree_tree:terminate(Host, ServerHost).
set_node(#pubsub_node{nodeid = {Key, _}, owners = Owners, options = Options} = Node) ->
Parents = find_opt(collection, ?DEFAULT_PARENTS, Options),
case validate_parentage(Key, Owners, Parents) of
true -> mnesia:write(Node#pubsub_node{parents = Parents});
Other -> Other
end.
create_node(Key, Node, Type, Owner, Options, Parents) ->
OwnerJID = jlib:jid_tolower(jlib:jid_remove_resource(Owner)),
case find_node(Key, Node) of
false ->
Nidx = pubsub_index:new(node),
N = #pubsub_node{nodeid = oid(Key, Node), id = Nidx,
type = Type, parents = Parents, owners = [OwnerJID],
options = Options},
case set_node(N) of
ok -> {ok, Nidx};
Other -> Other
end;
_ ->
{error, ?ERR_CONFLICT}
end.
delete_node(Key, Node) ->
case find_node(Key, Node) of
false ->
{error, ?ERR_ITEM_NOT_FOUND};
Record ->
lists:foreach(fun (#pubsub_node{options = Opts} = Child) ->
NewOpts = remove_config_parent(Node, Opts),
Parents = find_opt(collection, ?DEFAULT_PARENTS, NewOpts),
ok = mnesia:write(pubsub_node,
Child#pubsub_node{parents = Parents,
options = NewOpts},
write)
end,
get_subnodes(Key, Node)),
pubsub_index:free(node, Record#pubsub_node.id),
mnesia:delete_object(pubsub_node, Record, write),
[Record]
end.
options() ->
nodetree_tree:options().
get_node(Host, Node, _From) ->
get_node(Host, Node).
get_node(Host, Node) ->
case find_node(Host, Node) of
false -> {error, ?ERR_ITEM_NOT_FOUND};
Record -> Record
end.
get_node(Node) ->
nodetree_tree:get_node(Node).
get_nodes(Key, From) ->
nodetree_tree:get_nodes(Key, From).
get_nodes(Key) ->
nodetree_tree:get_nodes(Key).
get_parentnodes(Host, Node, _From) ->
case find_node(Host, Node) of
false ->
{error, ?ERR_ITEM_NOT_FOUND};
#pubsub_node{parents = Parents} ->
Q = qlc:q([N
|| #pubsub_node{nodeid = {NHost, NNode}} = N
<- mnesia:table(pubsub_node),
Parent <- Parents, Host == NHost, Parent == NNode]),
qlc:e(Q)
end.
get_parentnodes_tree(Host, Node, _From) ->
Pred = fun (NID, #pubsub_node{nodeid = {_, NNode}}) ->
NID == NNode
end,
Tr = fun (#pubsub_node{parents = Parents}) -> Parents
end,
traversal_helper(Pred, Tr, Host, [Node]).
get_subnodes(Host, Node, _From) ->
get_subnodes(Host, Node).
get_subnodes(Host, <<>>) ->
get_subnodes_helper(Host, <<>>);
get_subnodes(Host, Node) ->
case find_node(Host, Node) of
false -> {error, ?ERR_ITEM_NOT_FOUND};
_ -> get_subnodes_helper(Host, Node)
end.
get_subnodes_helper(Host, Node) ->
Q = qlc:q([N
|| #pubsub_node{nodeid = {NHost, _},
parents = Parents} =
N
<- mnesia:table(pubsub_node),
Host == NHost, lists:member(Node, Parents)]),
qlc:e(Q).
get_subnodes_tree(Host, Node, From) ->
Pred = fun (NID, #pubsub_node{parents = Parents}) ->
lists:member(NID, Parents)
end,
Tr = fun (#pubsub_node{nodeid = {_, N}}) -> [N] end,
traversal_helper(Pred, Tr, 1, Host, [Node],
[{0, [get_node(Host, Node, From)]}]).
%%====================================================================
%% Internal functions
%%====================================================================
oid(Key, Name) -> {Key, Name}.
%% Key = jlib:jid() | host()
%% Node = string()
-spec(find_node/2 ::
(
Key :: mod_pubsub:hostPubsub(),
Node :: mod_pubsub:nodeId())
-> mod_pubsub:pubsubNode() | false
).
find_node(Key, Node) ->
case mnesia:read(pubsub_node, oid(Key, Node), read) of
[] -> false;
[Node] -> Node
end.
%% Key = jlib:jid() | host()
%% Default = term()
%% Options = [{Key = atom(), Value = term()}]
find_opt(Key, Default, Options) ->
case lists:keysearch(Key, 1, Options) of
{value, {Key, Val}} -> Val;
_ -> Default
end.
-spec(traversal_helper/4 ::
(
Pred :: fun(),
Tr :: fun(),
Host :: mod_pubsub:hostPubsub(),
Nodes :: [mod_pubsub:nodeId(),...])
-> [{Depth::non_neg_integer(), Nodes::[mod_pubsub:pubsubNode(),...]}]
).
traversal_helper(Pred, Tr, Host, Nodes) ->
traversal_helper(Pred, Tr, 0, Host, Nodes, []).
traversal_helper(_Pred, _Tr, _Depth, _Host, [], Acc) ->
Acc;
traversal_helper(Pred, Tr, Depth, Host, Nodes, Acc) ->
Q = qlc:q([N
|| #pubsub_node{nodeid = {NHost, _}} = N
<- mnesia:table(pubsub_node),
Node <- Nodes, Host == NHost, Pred(Node, N)]),
Nodes = qlc:e(Q),
IDs = lists:flatmap(Tr, Nodes),
traversal_helper(Pred, Tr, Depth + 1, Host, IDs, [{Depth, Nodes} | Acc]).
remove_config_parent(Node, Options) ->
remove_config_parent(Node, Options, []).
remove_config_parent(_Node, [], Acc) ->
lists:reverse(Acc);
remove_config_parent(Node, [{collection, Parents} | T], Acc) ->
remove_config_parent(Node, T, [{collection, lists:delete(Node, Parents)} | Acc]);
remove_config_parent(Node, [H | T], Acc) ->
remove_config_parent(Node, T, [H | Acc]).
-spec(validate_parentage/3 ::
(
Key :: mod_pubsub:hostPubsub(),
Owners :: [ljid(),...],
Parent_Nodes :: [mod_pubsub:nodeId()])
-> true
%%%
| {error, xmlel()}
).
validate_parentage(_Key, _Owners, []) ->
true;
validate_parentage(Key, Owners, [[] | T]) ->
validate_parentage(Key, Owners, T);
validate_parentage(Key, Owners, [<<>> | T]) ->
validate_parentage(Key, Owners, T);
validate_parentage(Key, Owners, [ParentID | T]) ->
case find_node(Key, ParentID) of
false ->
{error, ?ERR_ITEM_NOT_FOUND};
#pubsub_node{owners = POwners, options = POptions} ->
NodeType = find_opt(node_type, ?DEFAULT_NODETYPE, POptions),
MutualOwners = [O || O <- Owners, PO <- POwners, O == PO],
case {MutualOwners, NodeType} of
{[], _} -> {error, ?ERR_FORBIDDEN};
{_, collection} -> validate_parentage(Key, Owners, T);
{_, _} -> {error, ?ERR_NOT_ALLOWED}
end
end.
