%%%---------------------------------------------------------------------- %%% File : node_flat.erl %%% Author : Christophe Romain %%% Purpose : Standard PubSub node plugin %%% Created : 1 Dec 2007 by Christophe Romain %%% %%% %%% ejabberd, Copyright (C) 2002-2018 ProcessOne %%% %%% This program is free software; you can redistribute it and/or %%% modify it under the terms of the GNU General Public License as %%% published by the Free Software Foundation; either version 2 of the %%% License, or (at your option) any later version. %%% %%% This program is distributed in the hope that it will be useful, %%% but WITHOUT ANY WARRANTY; without even the implied warranty of %%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU %%% General Public License for more details. %%% %%% You should have received a copy of the GNU General Public License along %%% with this program; if not, write to the Free Software Foundation, Inc., %%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. %%% %%%---------------------------------------------------------------------- %%% @doc The module {@module} is the default PubSub plugin. %%%

It is used as a default for all unknown PubSub node type. It can serve %%% as a developer basis and reference to build its own custom pubsub node %%% types.

%%%

PubSub plugin nodes are using the {@link gen_node} behaviour.

-module(node_flat). -behaviour(gen_pubsub_node). -author('christophe.romain@process-one.net'). -include("pubsub.hrl"). -include("xmpp.hrl"). -export([init/3, terminate/2, options/0, features/0, create_node_permission/6, create_node/2, delete_node/1, purge_node/2, subscribe_node/8, unsubscribe_node/4, publish_item/7, delete_item/4, remove_extra_items/3, get_entity_affiliations/2, get_node_affiliations/1, get_affiliation/2, set_affiliation/3, get_entity_subscriptions/2, get_node_subscriptions/1, get_subscriptions/2, set_subscriptions/4, get_pending_nodes/2, get_states/1, get_state/2, set_state/1, get_items/7, get_items/3, get_item/7, get_last_items/3, get_item/2, set_item/1, get_item_name/3, node_to_path/1, path_to_node/1, can_fetch_item/2, is_subscribed/1, transform/1]). init(_Host, _ServerHost, _Opts) -> %pubsub_subscription:init(Host, ServerHost, Opts), ejabberd_mnesia:create(?MODULE, pubsub_state, [{disc_copies, [node()]}, {index, [nodeidx]}, {type, ordered_set}, {attributes, record_info(fields, pubsub_state)}]), ejabberd_mnesia:create(?MODULE, pubsub_item, [{disc_only_copies, [node()]}, {index, [nodeidx]}, {attributes, record_info(fields, pubsub_item)}]), ejabberd_mnesia:create(?MODULE, pubsub_orphan, [{disc_copies, [node()]}, {attributes, record_info(fields, pubsub_orphan)}]), ItemsFields = record_info(fields, pubsub_item), case mnesia:table_info(pubsub_item, attributes) of ItemsFields -> ok; _ -> mnesia:transform_table(pubsub_item, ignore, ItemsFields) end, ok. terminate(_Host, _ServerHost) -> ok. options() -> [{deliver_payloads, true}, {notify_config, false}, {notify_delete, false}, {notify_retract, true}, {purge_offline, false}, {persist_items, true}, {max_items, ?MAXITEMS}, {subscribe, true}, {access_model, open}, {roster_groups_allowed, []}, {publish_model, publishers}, {notification_type, headline}, {max_payload_size, ?MAX_PAYLOAD_SIZE}, {send_last_published_item, on_sub_and_presence}, {deliver_notifications, true}, {presence_based_delivery, false}, {itemreply, none}]. features() -> [<<"create-nodes">>, <<"auto-create">>, <<"access-authorize">>, <<"delete-nodes">>, <<"delete-items">>, <<"get-pending">>, <<"instant-nodes">>, <<"manage-subscriptions">>, <<"modify-affiliations">>, <<"outcast-affiliation">>, <<"persistent-items">>, <<"multi-items">>, <<"publish">>, <<"publish-only-affiliation">>, <<"publish-options">>, <<"purge-nodes">>, <<"retract-items">>, <<"retrieve-affiliations">>, <<"retrieve-items">>, <<"retrieve-subscriptions">>, <<"subscribe">>, %%<<"subscription-options">>, <<"subscription-notifications">>]. %% @doc Checks if the current user has the permission to create the requested node %%

In flat node, any unused node name is allowed. The access parameter is also %% checked. This parameter depends on the value of the %% access_createnode ACL value in ejabberd config file.

create_node_permission(Host, ServerHost, _Node, _ParentNode, Owner, Access) -> LOwner = jid:tolower(Owner), Allowed = case LOwner of {<<"">>, Host, <<"">>} -> true; % pubsub service always allowed _ -> acl:match_rule(ServerHost, Access, LOwner) =:= allow end, {result, Allowed}. create_node(Nidx, Owner) -> OwnerKey = jid:tolower(jid:remove_resource(Owner)), set_state(#pubsub_state{stateid = {OwnerKey, Nidx}, nodeidx = Nidx, affiliation = owner}), {result, {default, broadcast}}. delete_node(Nodes) -> Tr = fun (#pubsub_state{stateid = {J, _}, subscriptions = Ss}) -> lists:map(fun (S) -> {J, S} end, Ss) end, Reply = lists:map(fun (#pubsub_node{id = Nidx} = PubsubNode) -> {result, States} = get_states(Nidx), lists:foreach(fun (State) -> del_items(Nidx, State#pubsub_state.items), del_state(State#pubsub_state{items = []}) end, States), del_orphan_items(Nidx), {PubsubNode, lists:flatmap(Tr, States)} end, Nodes), {result, {default, broadcast, Reply}}. %% @doc

Accepts or rejects subcription requests on a PubSub node.

%%

The mechanism works as follow: %%

%%

The selected behaviour depends on the return parameter: %%

%%

%%

In the default plugin module, the record is unchanged.

subscribe_node(Nidx, Sender, Subscriber, AccessModel, SendLast, PresenceSubscription, RosterGroup, _Options) -> SubKey = jid:tolower(Subscriber), GenKey = jid:remove_resource(SubKey), Authorized = jid:tolower(jid:remove_resource(Sender)) == GenKey, GenState = get_state(Nidx, GenKey), SubState = case SubKey of GenKey -> GenState; _ -> get_state(Nidx, SubKey) end, Affiliation = GenState#pubsub_state.affiliation, Subscriptions = SubState#pubsub_state.subscriptions, Whitelisted = lists:member(Affiliation, [member, publisher, owner]), PendingSubscription = lists:any(fun ({pending, _}) -> true; (_) -> false end, Subscriptions), Owner = Affiliation == owner, if not Authorized -> {error, mod_pubsub:extended_error((xmpp:err_bad_request()), mod_pubsub:err_invalid_jid())}; (Affiliation == outcast) or (Affiliation == publish_only) -> {error, xmpp:err_forbidden()}; PendingSubscription -> {error, mod_pubsub:extended_error((xmpp:err_not_authorized()), mod_pubsub:err_pending_subscription())}; (AccessModel == presence) and (not PresenceSubscription) and (not Owner) -> {error, mod_pubsub:extended_error((xmpp:err_not_authorized()), mod_pubsub:err_presence_subscription_required())}; (AccessModel == roster) and (not RosterGroup) and (not Owner) -> {error, mod_pubsub:extended_error((xmpp:err_not_authorized()), mod_pubsub:err_not_in_roster_group())}; (AccessModel == whitelist) and (not Whitelisted) and (not Owner) -> {error, mod_pubsub:extended_error((xmpp:err_not_allowed()), mod_pubsub:err_closed_node())}; %%MustPay -> %% % Payment is required for a subscription %% {error, ?ERR_PAYMENT_REQUIRED}; %%ForbiddenAnonymous -> %% % Requesting entity is anonymous %% {error, xmpp:err_forbidden()}; true -> %%SubId = pubsub_subscription:add_subscription(Subscriber, Nidx, Options), {NewSub, SubId} = case Subscriptions of [{subscribed, Id}|_] -> {subscribed, Id}; [] -> Id = pubsub_subscription:make_subid(), Sub = case AccessModel of authorize -> pending; _ -> subscribed end, set_state(SubState#pubsub_state{subscriptions = [{Sub, Id} | Subscriptions]}), {Sub, Id} end, case {NewSub, SendLast} of {subscribed, never} -> {result, {default, subscribed, SubId}}; {subscribed, _} -> {result, {default, subscribed, SubId, send_last}}; {_, _} -> {result, {default, pending, SubId}} end end. %% @doc

Unsubscribe the Subscriber from the Node.

unsubscribe_node(Nidx, Sender, Subscriber, SubId) -> SubKey = jid:tolower(Subscriber), GenKey = jid:remove_resource(SubKey), Authorized = jid:tolower(jid:remove_resource(Sender)) == GenKey, GenState = get_state(Nidx, GenKey), SubState = case SubKey of GenKey -> GenState; _ -> get_state(Nidx, SubKey) end, Subscriptions = lists:filter(fun ({_Sub, _SubId}) -> true; (_SubId) -> false end, SubState#pubsub_state.subscriptions), SubIdExists = case SubId of <<>> -> false; Binary when is_binary(Binary) -> true; _ -> false end, if %% Requesting entity is prohibited from unsubscribing entity not Authorized -> {error, xmpp:err_forbidden()}; %% Entity did not specify SubId %%SubId == "", ?? -> %% {error, mod_pubsub:extended_error(xmpp:err_bad_request(), "subid-required")}; %% Invalid subscription identifier %%InvalidSubId -> %% {error, mod_pubsub:extended_error(?ERR_NOT_ACCEPTABLE, "invalid-subid")}; %% Requesting entity is not a subscriber Subscriptions == [] -> {error, mod_pubsub:extended_error(xmpp:err_unexpected_request(), mod_pubsub:err_not_subscribed())}; %% Subid supplied, so use that. SubIdExists -> Sub = first_in_list(fun ({_, S}) when S == SubId -> true; (_) -> false end, SubState#pubsub_state.subscriptions), case Sub of {value, S} -> delete_subscriptions(SubState, [S]), {result, default}; false -> {error, mod_pubsub:extended_error(xmpp:err_unexpected_request(), mod_pubsub:err_not_subscribed())} end; %% Asking to remove all subscriptions to the given node SubId == all -> delete_subscriptions(SubState, Subscriptions), {result, default}; %% No subid supplied, but there's only one matching subscription length(Subscriptions) == 1 -> delete_subscriptions(SubState, Subscriptions), {result, default}; %% No subid and more than one possible subscription match. true -> {error, mod_pubsub:extended_error((xmpp:err_bad_request()), mod_pubsub:err_subid_required())} end. delete_subscriptions(SubState, Subscriptions) -> NewSubs = lists:foldl(fun ({Subscription, SubId}, Acc) -> %%pubsub_subscription:delete_subscription(SubKey, Nidx, SubId), Acc -- [{Subscription, SubId}] end, SubState#pubsub_state.subscriptions, Subscriptions), case {SubState#pubsub_state.affiliation, NewSubs} of {none, []} -> del_state(SubState); _ -> set_state(SubState#pubsub_state{subscriptions = NewSubs}) end. %% @doc

Publishes the item passed as parameter.

%%

The mechanism works as follow: %%

%%

The selected behaviour depends on the return parameter: %%

%%

%%

In the default plugin module, the record is unchanged.

publish_item(Nidx, Publisher, PublishModel, MaxItems, ItemId, Payload, _PubOpts) -> SubKey = jid:tolower(Publisher), GenKey = jid:remove_resource(SubKey), GenState = get_state(Nidx, GenKey), SubState = case SubKey of GenKey -> GenState; _ -> get_state(Nidx, SubKey) end, Affiliation = GenState#pubsub_state.affiliation, Subscribed = case PublishModel of subscribers -> is_subscribed(GenState#pubsub_state.subscriptions) orelse is_subscribed(SubState#pubsub_state.subscriptions); _ -> undefined end, if not ((PublishModel == open) or (PublishModel == publishers) and ((Affiliation == owner) or (Affiliation == publisher) or (Affiliation == publish_only)) or (Subscribed == true)) -> {error, xmpp:err_forbidden()}; true -> if MaxItems > 0 -> Now = p1_time_compat:timestamp(), case get_item(Nidx, ItemId) of {result, #pubsub_item{creation = {_, GenKey}} = OldItem} -> set_item(OldItem#pubsub_item{ modification = {Now, SubKey}, payload = Payload}), {result, {default, broadcast, []}}; {result, _} -> {error, xmpp:err_forbidden()}; _ -> Items = [ItemId | GenState#pubsub_state.items], {result, {NI, OI}} = remove_extra_items(Nidx, MaxItems, Items), set_state(GenState#pubsub_state{items = NI}), set_item(#pubsub_item{ itemid = {ItemId, Nidx}, nodeidx = Nidx, creation = {Now, GenKey}, modification = {Now, SubKey}, payload = Payload}), {result, {default, broadcast, OI}} end; true -> {result, {default, broadcast, []}} end end. %% @doc

This function is used to remove extra items, most notably when the %% maximum number of items has been reached.

%%

This function is used internally by the core PubSub module, as no %% permission check is performed.

%%

In the default plugin module, the oldest items are removed, but other %% rules can be used.

%%

If another PubSub plugin wants to delegate the item removal (and if the %% plugin is using the default pubsub storage), it can implements this function like this: %% ```remove_extra_items(Nidx, MaxItems, ItemIds) -> %% node_default:remove_extra_items(Nidx, MaxItems, ItemIds).'''

remove_extra_items(_Nidx, unlimited, ItemIds) -> {result, {ItemIds, []}}; remove_extra_items(Nidx, MaxItems, ItemIds) -> NewItems = lists:sublist(ItemIds, MaxItems), OldItems = lists:nthtail(length(NewItems), ItemIds), del_items(Nidx, OldItems), {result, {NewItems, OldItems}}. %% @doc

Triggers item deletion.

%%

Default plugin: The user performing the deletion must be the node owner %% or a publisher, or PublishModel being open.

delete_item(Nidx, Publisher, PublishModel, ItemId) -> SubKey = jid:tolower(Publisher), GenKey = jid:remove_resource(SubKey), GenState = get_state(Nidx, GenKey), #pubsub_state{affiliation = Affiliation, items = Items} = GenState, Allowed = Affiliation == publisher orelse Affiliation == owner orelse (PublishModel == open andalso case get_item(Nidx, ItemId) of {result, #pubsub_item{creation = {_, GenKey}}} -> true; _ -> false end), if not Allowed -> {error, xmpp:err_forbidden()}; true -> case lists:member(ItemId, Items) of true -> del_item(Nidx, ItemId), set_state(GenState#pubsub_state{items = lists:delete(ItemId, Items)}), {result, {default, broadcast}}; false -> case Affiliation of owner -> {result, States} = get_states(Nidx), Records = States ++ mnesia:read({pubsub_orphan, Nidx}), lists:foldl(fun (#pubsub_state{items = RI} = S, Res) -> case lists:member(ItemId, RI) of true -> NI = lists:delete(ItemId, RI), del_item(Nidx, ItemId), mnesia:write(S#pubsub_state{items = NI}), {result, {default, broadcast}}; false -> Res end; (#pubsub_orphan{items = RI} = S, Res) -> case lists:member(ItemId, RI) of true -> NI = lists:delete(ItemId, RI), del_item(Nidx, ItemId), mnesia:write(S#pubsub_orphan{items = NI}), {result, {default, broadcast}}; false -> Res end end, {error, xmpp:err_item_not_found()}, Records); _ -> {error, xmpp:err_forbidden()} end end end. purge_node(Nidx, Owner) -> SubKey = jid:tolower(Owner), GenKey = jid:remove_resource(SubKey), GenState = get_state(Nidx, GenKey), case GenState of #pubsub_state{affiliation = owner} -> {result, States} = get_states(Nidx), lists:foreach(fun (#pubsub_state{items = []}) -> ok; (#pubsub_state{items = Items} = S) -> del_items(Nidx, Items), set_state(S#pubsub_state{items = []}) end, States), del_orphan_items(Nidx), {result, {default, broadcast}}; _ -> {error, xmpp:err_forbidden()} end. %% @doc

Return the current affiliations for the given user

%%

The default module reads affiliations in the main Mnesia %% pubsub_state table. If a plugin stores its data in the same %% table, it should return an empty list, as the affiliation will be read by %% the default PubSub module. Otherwise, it should return its own affiliation, %% that will be added to the affiliation stored in the main %% pubsub_state table.

get_entity_affiliations(Host, Owner) -> SubKey = jid:tolower(Owner), GenKey = jid:remove_resource(SubKey), States = mnesia:match_object(#pubsub_state{stateid = {GenKey, '_'}, _ = '_'}), NodeTree = mod_pubsub:tree(Host), Reply = lists:foldl(fun (#pubsub_state{stateid = {_, N}, affiliation = A}, Acc) -> case NodeTree:get_node(N) of #pubsub_node{nodeid = {Host, _}} = Node -> [{Node, A} | Acc]; _ -> Acc end end, [], States), {result, Reply}. get_node_affiliations(Nidx) -> {result, States} = get_states(Nidx), Tr = fun (#pubsub_state{stateid = {J, _}, affiliation = A}) -> {J, A} end, {result, lists:map(Tr, States)}. get_affiliation(Nidx, Owner) -> SubKey = jid:tolower(Owner), GenKey = jid:remove_resource(SubKey), #pubsub_state{affiliation = Affiliation} = get_state(Nidx, GenKey), {result, Affiliation}. set_affiliation(Nidx, Owner, Affiliation) -> SubKey = jid:tolower(Owner), GenKey = jid:remove_resource(SubKey), GenState = get_state(Nidx, GenKey), case {Affiliation, GenState#pubsub_state.subscriptions} of {none, []} -> del_state(GenState); _ -> set_state(GenState#pubsub_state{affiliation = Affiliation}) end. %% @doc

Return the current subscriptions for the given user

%%

The default module reads subscriptions in the main Mnesia %% pubsub_state table. If a plugin stores its data in the same %% table, it should return an empty list, as the affiliation will be read by %% the default PubSub module. Otherwise, it should return its own affiliation, %% that will be added to the affiliation stored in the main %% pubsub_state table.

get_entity_subscriptions(Host, Owner) -> {U, D, _} = SubKey = jid:tolower(Owner), GenKey = jid:remove_resource(SubKey), States = case SubKey of GenKey -> mnesia:match_object(#pubsub_state{stateid = {{U, D, '_'}, '_'}, _ = '_'}); _ -> mnesia:match_object(#pubsub_state{stateid = {GenKey, '_'}, _ = '_'}) ++ mnesia:match_object(#pubsub_state{stateid = {SubKey, '_'}, _ = '_'}) end, NodeTree = mod_pubsub:tree(Host), Reply = lists:foldl(fun (#pubsub_state{stateid = {J, N}, subscriptions = Ss}, Acc) -> case NodeTree:get_node(N) of #pubsub_node{nodeid = {Host, _}} = Node -> lists:foldl(fun ({Sub, SubId}, Acc2) -> [{Node, Sub, SubId, J} | Acc2] end, Acc, Ss); _ -> Acc end end, [], States), {result, Reply}. get_node_subscriptions(Nidx) -> {result, States} = get_states(Nidx), Tr = fun (#pubsub_state{stateid = {J, _}, subscriptions = Subscriptions}) -> lists:foldl(fun ({S, SubId}, Acc) -> [{J, S, SubId} | Acc] end, [], Subscriptions) end, {result, lists:flatmap(Tr, States)}. get_subscriptions(Nidx, Owner) -> SubKey = jid:tolower(Owner), SubState = get_state(Nidx, SubKey), {result, SubState#pubsub_state.subscriptions}. set_subscriptions(Nidx, Owner, Subscription, SubId) -> SubKey = jid:tolower(Owner), SubState = get_state(Nidx, SubKey), case {SubId, SubState#pubsub_state.subscriptions} of {_, []} -> case Subscription of none -> {error, mod_pubsub:extended_error((xmpp:err_bad_request()), mod_pubsub:err_not_subscribed())}; _ -> new_subscription(Nidx, Owner, Subscription, SubState) end; {<<>>, [{_, SID}]} -> case Subscription of none -> unsub_with_subid(SubState, SID); _ -> replace_subscription({Subscription, SID}, SubState) end; {<<>>, [_ | _]} -> {error, mod_pubsub:extended_error((xmpp:err_bad_request()), mod_pubsub:err_subid_required())}; _ -> case Subscription of none -> unsub_with_subid(SubState, SubId); _ -> replace_subscription({Subscription, SubId}, SubState) end end. replace_subscription(NewSub, SubState) -> NewSubs = replace_subscription(NewSub, SubState#pubsub_state.subscriptions, []), set_state(SubState#pubsub_state{subscriptions = NewSubs}). replace_subscription(_, [], Acc) -> Acc; replace_subscription({Sub, SubId}, [{_, SubId} | T], Acc) -> replace_subscription({Sub, SubId}, T, [{Sub, SubId} | Acc]). new_subscription(_Nidx, _Owner, Sub, SubState) -> %%SubId = pubsub_subscription:add_subscription(Owner, Nidx, []), SubId = pubsub_subscription:make_subid(), Subs = SubState#pubsub_state.subscriptions, set_state(SubState#pubsub_state{subscriptions = [{Sub, SubId} | Subs]}), {Sub, SubId}. unsub_with_subid(SubState, SubId) -> %%pubsub_subscription:delete_subscription(SubState#pubsub_state.stateid, Nidx, SubId), NewSubs = [{S, Sid} || {S, Sid} <- SubState#pubsub_state.subscriptions, SubId =/= Sid], case {NewSubs, SubState#pubsub_state.affiliation} of {[], none} -> del_state(SubState); _ -> set_state(SubState#pubsub_state{subscriptions = NewSubs}) end. %% @doc

Returns a list of Owner's nodes on Host with pending %% subscriptions.

get_pending_nodes(Host, Owner) -> GenKey = jid:remove_resource(jid:tolower(Owner)), States = mnesia:match_object(#pubsub_state{stateid = {GenKey, '_'}, affiliation = owner, _ = '_'}), NodeIdxs = [Nidx || #pubsub_state{stateid = {_, Nidx}} <- States], NodeTree = mod_pubsub:tree(Host), Reply = mnesia:foldl(fun (#pubsub_state{stateid = {_, Nidx}} = S, Acc) -> case lists:member(Nidx, NodeIdxs) of true -> case get_nodes_helper(NodeTree, S) of {value, Node} -> [Node | Acc]; false -> Acc end; false -> Acc end end, [], pubsub_state), {result, Reply}. get_nodes_helper(NodeTree, #pubsub_state{stateid = {_, N}, subscriptions = Subs}) -> HasPending = fun ({pending, _}) -> true; (pending) -> true; (_) -> false end, case lists:any(HasPending, Subs) of true -> case NodeTree:get_node(N) of #pubsub_node{nodeid = {_, Node}} -> {value, Node}; _ -> false end; false -> false end. %% @doc Returns the list of stored states for a given node. %%

For the default PubSub module, states are stored in Mnesia database.

%%

We can consider that the pubsub_state table have been created by the main %% mod_pubsub module.

%%

PubSub plugins can store the states where they wants (for example in a %% relational database).

%%

If a PubSub plugin wants to delegate the states storage to the default node, %% they can implement this function like this: %% ```get_states(Nidx) -> %% node_default:get_states(Nidx).'''

get_states(Nidx) -> States = case catch mnesia:index_read(pubsub_state, Nidx, #pubsub_state.nodeidx) of List when is_list(List) -> List; _ -> [] end, {result, States}. %% @doc

Returns a state (one state list), given its reference.

get_state(Nidx, Key) -> StateId = {Key, Nidx}, case catch mnesia:read({pubsub_state, StateId}) of [State] when is_record(State, pubsub_state) -> State; _ -> #pubsub_state{stateid = StateId, nodeidx = Nidx} end. %% @doc

Write a state into database.

set_state(State) when is_record(State, pubsub_state) -> mnesia:write(State). %set_state(_) -> {error, ?ERR_INTERNAL_SERVER_ERROR}. %% @doc

Delete a state from database.

del_state(#pubsub_state{stateid = {Key, Nidx}, items = Items}) -> case Items of [] -> ok; _ -> Orphan = #pubsub_orphan{nodeid = Nidx, items = case mnesia:read({pubsub_orphan, Nidx}) of [#pubsub_orphan{items = ItemIds}] -> lists:usort(ItemIds++Items); _ -> Items end}, mnesia:write(Orphan) end, mnesia:delete({pubsub_state, {Key, Nidx}}). %% @doc Returns the list of stored items for a given node. %%

For the default PubSub module, items are stored in Mnesia database.

%%

We can consider that the pubsub_item table have been created by the main %% mod_pubsub module.

%%

PubSub plugins can store the items where they wants (for example in a %% relational database), or they can even decide not to persist any items.

get_items(Nidx, _From, undefined) -> RItems = lists:keysort(#pubsub_item.creation, mnesia:index_read(pubsub_item, Nidx, #pubsub_item.nodeidx)), {result, {RItems, undefined}}; get_items(Nidx, _From, #rsm_set{max = Max, index = IncIndex, 'after' = After, before = Before}) -> case lists:keysort(#pubsub_item.creation, mnesia:index_read(pubsub_item, Nidx, #pubsub_item.nodeidx)) of [] -> {result, {[], #rsm_set{count = 0}}}; RItems -> Count = length(RItems), Limit = case Max of undefined -> ?MAXITEMS; _ -> Max end, {Offset, ItemsPage} = case {IncIndex, Before, After} of {I, undefined, undefined} -> SubList = lists:nthtail(I, RItems), {I, lists:sublist(SubList, Limit)}; {_, <<>>, undefined} -> %% 2.5 Requesting the Last Page in a Result Set SubList = lists:reverse(RItems), {0, lists:sublist(SubList, Limit)}; {_, Stamp, undefined} -> BeforeNow = encode_stamp(Stamp), SubList = lists:dropwhile( fun(#pubsub_item{creation = {Now, _}}) -> Now >= BeforeNow end, lists:reverse(RItems)), {0, lists:sublist(SubList, Limit)}; {_, undefined, Stamp} -> AfterNow = encode_stamp(Stamp), SubList = lists:dropwhile( fun(#pubsub_item{creation = {Now, _}}) -> Now =< AfterNow end, RItems), {0, lists:sublist(SubList, Limit)} end, Rsm = rsm_page(Count, IncIndex, Offset, ItemsPage), {result, {ItemsPage, Rsm}} end. get_items(Nidx, JID, AccessModel, PresenceSubscription, RosterGroup, _SubId, RSM) -> SubKey = jid:tolower(JID), GenKey = jid:remove_resource(SubKey), GenState = get_state(Nidx, GenKey), SubState = get_state(Nidx, SubKey), Affiliation = GenState#pubsub_state.affiliation, BareSubscriptions = GenState#pubsub_state.subscriptions, FullSubscriptions = SubState#pubsub_state.subscriptions, Whitelisted = can_fetch_item(Affiliation, BareSubscriptions) orelse can_fetch_item(Affiliation, FullSubscriptions), if %%SubId == "", ?? -> %% Entity has multiple subscriptions to the node but does not specify a subscription ID %{error, mod_pubsub:extended_error(xmpp:err_bad_request(), "subid-required")}; %%InvalidSubId -> %% Entity is subscribed but specifies an invalid subscription ID %{error, mod_pubsub:extended_error(?ERR_NOT_ACCEPTABLE, "invalid-subid")}; (Affiliation == outcast) or (Affiliation == publish_only) -> {error, xmpp:err_forbidden()}; (AccessModel == presence) and not PresenceSubscription -> {error, mod_pubsub:extended_error((xmpp:err_not_authorized()), mod_pubsub:err_presence_subscription_required())}; (AccessModel == roster) and not RosterGroup -> {error, mod_pubsub:extended_error((xmpp:err_not_authorized()), mod_pubsub:err_not_in_roster_group())}; (AccessModel == whitelist) and not Whitelisted -> {error, mod_pubsub:extended_error((xmpp:err_not_allowed()), mod_pubsub:err_closed_node())}; (AccessModel == authorize) and not Whitelisted -> {error, xmpp:err_forbidden()}; %%MustPay -> %% % Payment is required for a subscription %% {error, ?ERR_PAYMENT_REQUIRED}; true -> get_items(Nidx, JID, RSM) end. get_last_items(Nidx, _From, Count) when Count > 0 -> Items = mnesia:index_read(pubsub_item, Nidx, #pubsub_item.nodeidx), LastItems = lists:reverse(lists:keysort(#pubsub_item.modification, Items)), {result, lists:sublist(LastItems, Count)}; get_last_items(_Nidx, _From, _Count) -> {result, []}. %% @doc

Returns an item (one item list), given its reference.

get_item(Nidx, ItemId) -> case mnesia:read({pubsub_item, {ItemId, Nidx}}) of [Item] when is_record(Item, pubsub_item) -> {result, Item}; _ -> {error, xmpp:err_item_not_found()} end. get_item(Nidx, ItemId, JID, AccessModel, PresenceSubscription, RosterGroup, _SubId) -> SubKey = jid:tolower(JID), GenKey = jid:remove_resource(SubKey), GenState = get_state(Nidx, GenKey), Affiliation = GenState#pubsub_state.affiliation, Subscriptions = GenState#pubsub_state.subscriptions, Whitelisted = can_fetch_item(Affiliation, Subscriptions), if %%SubId == "", ?? -> %% Entity has multiple subscriptions to the node but does not specify a subscription ID %{error, mod_pubsub:extended_error(xmpp:err_bad_request(), "subid-required")}; %%InvalidSubId -> %% Entity is subscribed but specifies an invalid subscription ID %{error, mod_pubsub:extended_error(?ERR_NOT_ACCEPTABLE, "invalid-subid")}; (Affiliation == outcast) or (Affiliation == publish_only) -> {error, xmpp:err_forbidden()}; (AccessModel == presence) and not PresenceSubscription -> {error, mod_pubsub:extended_error((xmpp:err_not_authorized()), mod_pubsub:err_presence_subscription_required())}; (AccessModel == roster) and not RosterGroup -> {error, mod_pubsub:extended_error((xmpp:err_not_authorized()), mod_pubsub:err_not_in_roster_group())}; (AccessModel == whitelist) and not Whitelisted -> {error, mod_pubsub:extended_error((xmpp:err_not_allowed()), mod_pubsub:err_closed_node())}; (AccessModel == authorize) and not Whitelisted -> {error, xmpp:err_forbidden()}; %%MustPay -> %% % Payment is required for a subscription %% {error, ?ERR_PAYMENT_REQUIRED}; true -> get_item(Nidx, ItemId) end. %% @doc

Write an item into database.

set_item(Item) when is_record(Item, pubsub_item) -> mnesia:write(Item). %set_item(_) -> {error, ?ERR_INTERNAL_SERVER_ERROR}. %% @doc

Delete an item from database.

del_item(Nidx, ItemId) -> mnesia:delete({pubsub_item, {ItemId, Nidx}}). del_items(Nidx, ItemIds) -> lists:foreach(fun (ItemId) -> del_item(Nidx, ItemId) end, ItemIds). del_orphan_items(Nidx) -> case mnesia:read({pubsub_orphan, Nidx}) of [#pubsub_orphan{items = ItemIds}] -> del_items(Nidx, ItemIds), mnesia:delete({pubsub_orphan, Nidx}); _ -> ok end. get_item_name(_Host, _Node, Id) -> Id. %% @doc

Return the path of the node. In flat it's just node id.

node_to_path(Node) -> [(Node)]. path_to_node(Path) -> case Path of % default slot [Node] -> iolist_to_binary(Node); % handle old possible entries, used when migrating database content to new format [Node | _] when is_binary(Node) -> iolist_to_binary(str:join([<<"">> | Path], <<"/">>)); % default case (used by PEP for example) _ -> iolist_to_binary(Path) end. can_fetch_item(owner, _) -> true; can_fetch_item(member, _) -> true; can_fetch_item(publisher, _) -> true; can_fetch_item(publish_only, _) -> false; can_fetch_item(outcast, _) -> false; can_fetch_item(none, Subscriptions) -> is_subscribed(Subscriptions). %can_fetch_item(_Affiliation, _Subscription) -> false. is_subscribed(Subscriptions) -> lists:any(fun ({subscribed, _SubId}) -> true; (_) -> false end, Subscriptions). first_in_list(_Pred, []) -> false; first_in_list(Pred, [H | T]) -> case Pred(H) of true -> {value, H}; _ -> first_in_list(Pred, T) end. rsm_page(Count, _, _, []) -> #rsm_set{count = Count}; rsm_page(Count, Index, Offset, Items) -> FirstItem = hd(Items), LastItem = lists:last(Items), First = decode_stamp(element(1, FirstItem#pubsub_item.creation)), Last = decode_stamp(element(1, LastItem#pubsub_item.creation)), #rsm_set{count = Count, index = Index, first = #rsm_first{index = Offset, data = First}, last = Last}. encode_stamp(Stamp) -> case catch xmpp_util:decode_timestamp(Stamp) of {MS,S,US} -> {MS,S,US}; _ -> Stamp end. decode_stamp(Stamp) -> case catch xmpp_util:encode_timestamp(Stamp) of TimeStamp when is_binary(TimeStamp) -> TimeStamp; _ -> Stamp end. transform({pubsub_state, {Id, Nidx}, Is, A, Ss}) -> {pubsub_state, {Id, Nidx}, Nidx, Is, A, Ss}; transform({pubsub_item, {Id, Nidx}, C, M, P}) -> {pubsub_item, {Id, Nidx}, Nidx, C, M, P}; transform(Rec) -> Rec.