%%% ====================================================================
%%% ``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).
-author('bjc@kublai.com').
%% API
-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/5,
delete_node/2]).
-include_lib("stdlib/include/qlc.hrl").
-include("ejabberd.hrl").
-include("pubsub.hrl").
-include("jlib.hrl").
-behaviour(gen_pubsub_nodetree).
-define(DEFAULT_NODETYPE, leaf).
-define(DEFAULT_PARENTS, []).
-define(DEFAULT_CHILDREN, []).
-compile(export_all).
%%====================================================================
%% API
%%====================================================================
init(Host, ServerHost, Opts) ->
nodetree_tree:init(Host, ServerHost, Opts),
mnesia:transaction(fun create_node/5,
[Host, [], "default", service_jid(ServerHost), []]).
terminate(Host, ServerHost) ->
nodetree_tree:terminate(Host, ServerHost).
create_node(Key, NodeID, Type, Owner, Options) ->
OwnerJID = jlib:jid_tolower(jlib:jid_remove_resource(Owner)),
case find_node(Key, NodeID) of
false ->
ID = pubsub_index:new(node),
N = #pubsub_node{nodeid = oid(Key, NodeID),
id = ID,
type = Type,
owners = [OwnerJID],
options = Options},
case set_node(N) of
ok -> {ok, ID};
Other -> Other
end;
_ ->
{error, ?ERR_CONFLICT}
end.
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 ->
%% Update parents whenever the config changes.
mnesia:write(Node#pubsub_node{parents = Parents});
Other ->
Other
end.
delete_node(Key, NodeID) ->
case find_node(Key, NodeID) of
false ->
{error, ?ERR_ITEM_NOT_FOUND};
Node ->
%% Find all of N's children, update their configs to
%% remove N from the collection setting.
lists:foreach(fun (#pubsub_node{options = Opts} = Child) ->
NewOpts = remove_config_parent(NodeID, 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, NodeID)),
%% Remove and return the requested node.
pubsub_index:free(node, Node#pubsub_node.id),
mnesia:delete_object(pubsub_node, Node, write),
[Node]
end.
options() ->
nodetree_tree:options().
get_node(Host, NodeID, _From) ->
get_node(Host, NodeID).
get_node(Host, NodeID) ->
case find_node(Host, NodeID) of
false -> {error, ?ERR_ITEM_NOT_FOUND};
Node -> Node
end.
get_node(NodeId) ->
nodetree_tree:get_node(NodeId).
get_nodes(Key, From) ->
nodetree_tree:get_nodes(Key, From).
get_nodes(Key) ->
nodetree_tree:get_nodes(Key).
get_parentnodes(Host, NodeID, _From) ->
case find_node(Host, NodeID) 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, NodeID, _From) ->
Pred = fun (NID, #pubsub_node{nodeid = {_, NNodeID}}) ->
NID == NNodeID
end,
Tr = fun (#pubsub_node{parents = Parents}) -> Parents end,
traversal_helper(Pred, Tr, Host, [NodeID]).
get_subnodes(Host, NodeID, _From) ->
get_subnodes(Host, NodeID).
get_subnodes(Host, NodeID) ->
case find_node(Host, NodeID) of
false -> {error, ?ERR_ITEM_NOT_FOUND};
_ ->
Q = qlc:q([Node || #pubsub_node{nodeid = {NHost, _},
parents = Parents} = Node <- mnesia:table(pubsub_node),
Host == NHost,
lists:member(NodeID, Parents)]),
qlc:e(Q)
end.
get_subnodes_tree(Host, NodeID, 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, [NodeID],
[{0, [get_node(Host, NodeID, From)]}]).
%%====================================================================
%% Internal functions
%%====================================================================
oid(Key, Name) -> {Key, Name}.
%% Key = jlib:jid() | host()
%% NodeID = string()
find_node(Key, NodeID) ->
case mnesia:read(pubsub_node, oid(Key, NodeID), 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.
traversal_helper(Pred, Tr, Host, NodeIDs) ->
traversal_helper(Pred, Tr, 0, Host, NodeIDs, []).
traversal_helper(_Pred, _Tr, _Depth, _Host, [], Acc) ->
Acc;
traversal_helper(Pred, Tr, Depth, Host, NodeIDs, Acc) ->
Q = qlc:q([Node || #pubsub_node{nodeid = {NHost, _}} = Node <- mnesia:table(pubsub_node),
NodeID <- NodeIDs,
Host == NHost,
Pred(NodeID, Node)]),
Nodes = qlc:e(Q),
IDs = lists:flatmap(Tr, Nodes),
traversal_helper(Pred, Tr, Depth + 1, Host, IDs, [{Depth, Nodes} | Acc]).
remove_config_parent(NodeID, Options) ->
remove_config_parent(NodeID, Options, []).
remove_config_parent(_NodeID, [], Acc) ->
lists:reverse(Acc);
remove_config_parent(NodeID, [{collection, Parents} | T], Acc) ->
remove_config_parent(NodeID, T,
[{collection, lists:delete(NodeID, Parents)} | Acc]);
remove_config_parent(NodeID, [H | T], Acc) ->
remove_config_parent(NodeID, T, [H | Acc]).
validate_parentage(_Key, _Owners, []) ->
true;
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.
%% @spec (Host) -> jid()
%% Host = host()
%% @doc <p>Generate pubsub service JID.</p>
service_jid(Host) ->
case Host of
{U,S,_} -> {jid, U, S, "", U, S, ""};
_ -> {jid, "", Host, "", "", Host, ""}
end.
