%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1998-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%%
%%% Purpose : Loads tables from local disc or from remote node
-module(mnesia_loader).
%% Mnesia internal stuff
-export([disc_load_table/2,
net_load_table/4,
send_table/3]).
-export([spawned_receiver/8]). %% Spawned lock taking process
-import(mnesia_lib, [set/2, fatal/2, verbose/2, dbg_out/2]).
-include("mnesia.hrl").
val(Var) ->
case ?catch_val(Var) of
{'EXIT', _} -> mnesia_lib:other_val(Var);
Value -> Value
end.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Load a table from local disc
disc_load_table(Tab, Reason) ->
Storage = val({Tab, storage_type}),
Type = val({Tab, setorbag}),
dbg_out("Getting table ~tp (~p) from disc: ~tp~n",
[Tab, Storage, Reason]),
?eval_debug_fun({?MODULE, do_get_disc_copy},
[{tab, Tab},
{reason, Reason},
{storage, Storage},
{type, Type}]),
do_get_disc_copy2(Tab, Reason, Storage, Type).
do_get_disc_copy2(Tab, _Reason, Storage, _Type) when Storage == unknown ->
verbose("Local table copy of ~tp has recently been deleted, ignored.~n",
[Tab]),
{not_loaded, storage_unknown};
do_get_disc_copy2(Tab, Reason, Storage, Type) when Storage == disc_copies ->
%% NOW we create the actual table
Repair = mnesia_monitor:get_env(auto_repair),
StorageProps = val({Tab, storage_properties}),
EtsOpts = proplists:get_value(ets, StorageProps, []),
Args = [{keypos, 2}, public, named_table, Type | EtsOpts],
case Reason of
{dumper, _} -> %% Resources already allocated
ignore;
_ ->
mnesia_monitor:mktab(Tab, Args),
_Count = mnesia_log:dcd2ets(Tab, Repair),
case mnesia_monitor:get_env(dump_disc_copies_at_startup)
andalso mnesia_dumper:needs_dump_ets(Tab) of
true ->
ok = mnesia_log:ets2dcd(Tab);
_ ->
ignore
end
end,
mnesia_index:init_index(Tab, Storage),
snmpify(Tab, Storage),
set({Tab, load_node}, node()),
set({Tab, load_reason}, Reason),
{loaded, ok};
do_get_disc_copy2(Tab, Reason, Storage, Type) when Storage == ram_copies ->
StorageProps = val({Tab, storage_properties}),
EtsOpts = proplists:get_value(ets, StorageProps, []),
Args = [{keypos, 2}, public, named_table, Type | EtsOpts],
case Reason of
{dumper, _} -> %% Resources allready allocated
ignore;
_ ->
mnesia_monitor:mktab(Tab, Args),
Fname = mnesia_lib:tab2dcd(Tab),
Datname = mnesia_lib:tab2dat(Tab),
Repair = mnesia_monitor:get_env(auto_repair),
case mnesia_monitor:use_dir() of
true ->
case mnesia_lib:exists(Fname) of
true -> mnesia_log:dcd2ets(Tab, Repair);
false ->
case mnesia_lib:exists(Datname) of
true ->
mnesia_lib:dets_to_ets(Tab, Tab, Datname,
Type, Repair, no);
false ->
false
end
end;
false ->
false
end
end,
mnesia_index:init_index(Tab, Storage),
snmpify(Tab, Storage),
set({Tab, load_node}, node()),
set({Tab, load_reason}, Reason),
{loaded, ok};
do_get_disc_copy2(Tab, Reason, Storage, Type) when Storage == disc_only_copies ->
StorageProps = val({Tab, storage_properties}),
DetsOpts = proplists:get_value(dets, StorageProps, []),
Args = [{file, mnesia_lib:tab2dat(Tab)},
{type, mnesia_lib:disk_type(Tab, Type)},
{keypos, 2},
{repair, mnesia_monitor:get_env(auto_repair)}
| DetsOpts],
case Reason of
{dumper, _} ->
mnesia_index:init_index(Tab, Storage),
snmpify(Tab, Storage),
set({Tab, load_node}, node()),
set({Tab, load_reason}, Reason),
{loaded, ok};
_ ->
case mnesia_monitor:open_dets(Tab, Args) of
{ok, _} ->
mnesia_index:init_index(Tab, Storage),
snmpify(Tab, Storage),
set({Tab, load_node}, node()),
set({Tab, load_reason}, Reason),
{loaded, ok};
{error, Error} ->
{not_loaded, {"Failed to create dets table", Error}}
end
end;
do_get_disc_copy2(Tab, Reason, Storage = {ext, Alias, Mod}, _Type) ->
Cs = val({Tab, cstruct}),
case mnesia_monitor:unsafe_create_external(Tab, Alias, Mod, Cs) of
ok ->
ok = ext_load_table(Mod, Alias, Tab, Reason),
mnesia_index:init_index(Tab, Storage),
set({Tab, load_node}, node()),
set({Tab, load_reason}, Reason),
{loaded, ok};
Other ->
{not_loaded, Other}
end.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Load a table from a remote node
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Receiver Sender
%% -------- ------
%% Grab schema lock on table
%% Determine table size
%% Create empty pre-grown table
%% Grab read lock on table
%% Let receiver subscribe on updates done on sender node
%% Disable rehashing of table
%% Release read lock on table
%% Send table to receiver in chunks
%%
%% Grab read lock on table
%% Block dirty updates
%% Update wherabouts
%%
%% Cancel the update subscription
%% Process the subscription events
%% Optionally dump to disc
%% Unblock dirty updates
%% Release read lock on table
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-define(MAX_TRANSFER_SIZE, 7500).
-define(MAX_RAM_FILE_SIZE, 1000000).
-define(MAX_RAM_TRANSFERS, (?MAX_RAM_FILE_SIZE div ?MAX_TRANSFER_SIZE) + 1).
-define(MAX_NOPACKETS, 20).
net_load_table(Tab, {dumper,{add_table_copy, _}}=Reason, Ns, Cs) ->
try_net_load_table(Tab, Reason, Ns, Cs);
net_load_table(Tab, Reason, Ns, _Cs) ->
try_net_load_table(Tab, Reason, Ns, val({Tab, cstruct})).
try_net_load_table(Tab, _Reason, [], _Cs) ->
verbose("Copy failed. No active replicas of ~tp are available.~n", [Tab]),
{not_loaded, none_active};
try_net_load_table(Tab, Reason, Ns, Cs) ->
Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
do_get_network_copy(Tab, Reason, Ns, Storage, Cs).
do_get_network_copy(Tab, _Reason, _Ns, unknown, _Cs) ->
verbose("Local table copy of ~tp has recently been deleted, ignored.~n", [Tab]),
{not_loaded, storage_unknown};
do_get_network_copy(Tab, Reason, Ns, Storage, Cs) ->
[Node | Tail] = Ns,
case lists:member(Node,val({current, db_nodes})) of
true ->
dbg_out("Getting table ~tp (~p) from node ~p: ~tp~n",
[Tab, Storage, Node, Reason]),
?eval_debug_fun({?MODULE, do_get_network_copy},
[{tab, Tab}, {reason, Reason},
{nodes, Ns}, {storage, Storage}]),
case init_receiver(Node, Tab, Storage, Cs, Reason) of
ok ->
set({Tab, load_node}, Node),
set({Tab, load_reason}, Reason),
mnesia_controller:i_have_tab(Tab),
dbg_out("Table ~tp copied from ~p to ~p~n", [Tab, Node, node()]),
{loaded, ok};
Err = {error, _} when element(1, Reason) == dumper ->
{not_loaded,Err};
restart ->
try_net_load_table(Tab, Reason, Tail ++ [Node], Cs);
down ->
try_net_load_table(Tab, Reason, Tail, Cs)
end;
false ->
try_net_load_table(Tab, Reason, Tail, Cs)
end.
snmpify(Tab, Storage) ->
do_snmpify(Tab, val({Tab, snmp}), Storage).
do_snmpify(_Tab, [], _Storage) ->
ignore;
do_snmpify(Tab, Us, Storage) ->
Snmp = mnesia_snmp_hook:create_table(Us, Tab, Storage),
set({Tab, {index, snmp}}, Snmp).
%% Start the recieiver
init_receiver(Node, Tab, Storage, Cs, Reas={dumper,{add_table_copy, Tid}}) ->
rpc:call(Node, mnesia_lib, set, [{?MODULE, active_trans}, Tid]),
case start_remote_sender(Node, Tab, Storage) of
{SenderPid, TabSize, DetsData} ->
start_receiver(Tab,Storage,Cs,SenderPid,TabSize,DetsData,Reas);
Else ->
Else
end;
init_receiver(Node, Tab,Storage,Cs,Reason) ->
%% Grab a schema lock to avoid deadlock between table_loader and schema_commit dumping.
%% Both may grab tables-locks in different order.
Load =
fun() ->
{_,Tid,Ts} = get(mnesia_activity_state),
mnesia_locker:rlock(Tid, Ts#tidstore.store, {schema, Tab}),
%% Check that table still exists
Active = val({Tab, active_replicas}),
%% Check that we havn't loaded it already
case val({Tab,where_to_read}) == node() of
true -> ok;
_ ->
%% And that sender still got a copy
%% (something might have happend while
%% we where waiting for the lock)
true = lists:member(Node, Active),
{SenderPid, TabSize, DetsData} =
start_remote_sender(Node,Tab,Storage),
Init = table_init_fun(SenderPid, Storage),
Args = [self(),Tab,Storage,Cs,SenderPid,
TabSize,DetsData,Init],
Pid = spawn_link(?MODULE, spawned_receiver, Args),
put(mnesia_real_loader, Pid),
wait_on_load_complete(Pid)
end
end,
Res =
case mnesia:transaction(Load, 20) of
{atomic, {error,Result}} when
element(1,Reason) == dumper ->
{error,Result};
{atomic, {error,Result}} ->
fatal("Cannot create table ~tp: ~tp~n",
[[Tab, Storage], Result]);
{atomic, Result} -> Result;
{aborted, nomore} -> restart;
{aborted, _Reas} ->
verbose("Receiver failed on ~tp from ~p:~nReason: ~tp~n",
[Tab,Node,_Reas]),
down %% either this node or sender is dying
end,
unlink(whereis(mnesia_tm)), %% Avoid late unlink from tm
Res.
start_remote_sender(Node,Tab,Storage) ->
mnesia_controller:start_remote_sender(Node, Tab, self(), Storage),
put(mnesia_table_sender_node, {Tab, Node}),
receive
{SenderPid, {first, _} = Msg}
when is_pid(SenderPid), element(1, Storage) == ext ->
{ext, Alias, Mod} = Storage,
{Sz, Data} = Mod:receiver_first_message(SenderPid, Msg, Alias, Tab),
{SenderPid, Sz, Data};
{SenderPid, {first, TabSize}} =_M1 ->
{SenderPid, TabSize, false};
{SenderPid, {first, TabSize, DetsData}} ->
{SenderPid, TabSize, DetsData};
%% Protocol conversion hack
{copier_done, Node} ->
verbose("Sender of table ~tp crashed on node ~p ~n", [Tab, Node]),
down(Tab, Storage)
end.
table_init_fun(SenderPid, Storage) ->
fun(read) ->
Receiver = self(),
SenderPid ! {Receiver, more},
get_data(SenderPid, Receiver, Storage);
(close) ->
ok
end.
%% Add_table_copy get's it's own locks.
start_receiver(Tab,Storage,Cs,SenderPid,TabSize,DetsData,{dumper,{add_table_copy,_}}) ->
Init = table_init_fun(SenderPid, Storage),
case do_init_table(Tab,Storage,Cs,SenderPid,TabSize,DetsData,self(), Init) of
Err = {error, _} ->
SenderPid ! {copier_done, node()},
Err;
Else ->
Else
end.
spawned_receiver(ReplyTo,Tab,Storage,Cs, SenderPid,TabSize,DetsData, Init) ->
process_flag(trap_exit, true),
Done = do_init_table(Tab,Storage,Cs,
SenderPid,TabSize,DetsData,
ReplyTo, Init),
try
ReplyTo ! {self(),Done},
unlink(ReplyTo),
unlink(whereis(mnesia_controller))
catch _:_ -> ok %% avoid error reports when stopping down mnesia
end,
exit(normal).
wait_on_load_complete(Pid) ->
receive
{Pid, Res} ->
Res;
{'EXIT', Pid, Reason} ->
error(Reason);
Else ->
Pid ! Else,
wait_on_load_complete(Pid)
end.
do_init_table(Tab,Storage,Cs,SenderPid,
TabSize,DetsInfo,OrigTabRec,Init) ->
case create_table(Tab, TabSize, Storage, Cs) of
{Storage,Tab} ->
%% Debug info
Node = node(SenderPid),
put(mnesia_table_receiver, {Tab, Node, SenderPid}),
mnesia_tm:block_tab(Tab),
case init_table(Tab,Storage,Init,DetsInfo,SenderPid) of
ok ->
tab_receiver(Node,Tab,Storage,Cs,OrigTabRec);
Reason ->
Msg = "[d]ets:init table failed",
verbose("~ts: ~tp: ~tp~n", [Msg, Tab, Reason]),
down(Tab, Storage)
end;
Error ->
Error
end.
create_table(Tab, TabSize, Storage, Cs) ->
StorageProps = val({Tab, storage_properties}),
if
Storage == disc_only_copies ->
mnesia_lib:lock_table(Tab),
Tmp = mnesia_lib:tab2tmp(Tab),
Size = lists:max([TabSize, 256]),
DetsOpts = lists:keydelete(estimated_no_objects, 1,
proplists:get_value(dets, StorageProps, [])),
Args = [{file, Tmp},
{keypos, 2},
%% {ram_file, true},
{estimated_no_objects, Size},
{repair, mnesia_monitor:get_env(auto_repair)},
{type, mnesia_lib:disk_type(Tab, Cs#cstruct.type)}
| DetsOpts],
file:delete(Tmp),
case mnesia_lib:dets_sync_open(Tab, Args) of
{ok, _} ->
mnesia_lib:unlock_table(Tab),
{Storage, Tab};
Else ->
mnesia_lib:unlock_table(Tab),
Else
end;
(Storage == ram_copies) or (Storage == disc_copies) ->
EtsOpts = proplists:get_value(ets, StorageProps, []),
Args = [{keypos, 2}, public, named_table, Cs#cstruct.type | EtsOpts],
case mnesia_monitor:unsafe_mktab(Tab, Args) of
Tab ->
{Storage, Tab};
Else ->
Else
end;
element(1, Storage) == ext ->
{_, Alias, Mod} = Storage,
case mnesia_monitor:unsafe_create_external(Tab, Alias, Mod, Cs) of
ok ->
{Storage, Tab};
Else ->
Else
end
end.
tab_receiver(Node, Tab, Storage, Cs, OrigTabRec) ->
receive
{SenderPid, {no_more, DatBin}} ->
finish_copy(Storage,Tab,Cs,SenderPid,DatBin,OrigTabRec);
%% Protocol conversion hack
{copier_done, Node} ->
verbose("Sender of table ~tp crashed on node ~p ~n", [Tab, Node]),
down(Tab, Storage);
{'EXIT', Pid, Reason} ->
handle_exit(Pid, Reason),
tab_receiver(Node, Tab, Storage, Cs, OrigTabRec)
end.
make_table_fun(Pid, TabRec, Storage) ->
fun(close) ->
ok;
({read, Msg}) ->
Pid ! {TabRec, Msg},
get_data(Pid, TabRec, Storage);
(read) ->
get_data(Pid, TabRec, Storage)
end.
get_data(Pid, TabRec, Storage) ->
receive
{Pid, {more_z, CompressedRecs}} when is_binary(CompressedRecs) ->
maybe_reply(Pid, {TabRec, more}, Storage),
{zlib_uncompress(CompressedRecs),
make_table_fun(Pid, TabRec, Storage)};
{Pid, {more, Recs}} ->
maybe_reply(Pid, {TabRec, more}, Storage),
{Recs, make_table_fun(Pid, TabRec, Storage)};
{Pid, no_more} ->
end_of_input;
{copier_done, Node} ->
case node(Pid) of
Node ->
{copier_done, Node};
_ ->
get_data(Pid, TabRec, Storage)
end;
{'EXIT', Pid, Reason} ->
handle_exit(Pid, Reason),
get_data(Pid, TabRec, Storage)
end.
maybe_reply(_, _, {ext, _, _}) ->
ignore;
maybe_reply(Pid, Msg, _) ->
Pid ! Msg.
ext_init_table(Alias, Mod, Tab, Fun, State, Sender) ->
ok = ext_load_table(Mod, Alias, Tab, {net_load, node(Sender)}),
ext_init_table(read, Alias, Mod, Tab, Fun, State, Sender).
ext_load_table(Mod, Alias, Tab, Reason) ->
CS = val({Tab, cstruct}),
Mod:load_table(Alias, Tab, Reason, mnesia_schema:cs2list(CS)).
ext_init_table(Action, Alias, Mod, Tab, Fun, State, Sender) ->
case Fun(Action) of
{copier_done, Node} ->
verbose("Receiver of table ~tp crashed on ~p (more)~n", [Tab, Node]),
down(Tab, {ext,Alias,Mod});
{Data, NewFun} ->
case Mod:receive_data(Data, Alias, Tab, Sender, State) of
{more, NewState} ->
ext_init_table({read, more}, Alias, Mod,
Tab, NewFun, NewState, Sender);
{{more,Msg}, NewState} ->
ext_init_table({read, Msg}, Alias, Mod,
Tab, NewFun, NewState, Sender)
end;
end_of_input ->
Mod:receive_done(Alias, Tab, Sender, State),
ok = Fun(close)
end.
init_table(Tab, {ext,Alias,Mod}, Fun, State, Sender) ->
ext_init_table(Alias, Mod, Tab, Fun, State, Sender);
init_table(Tab, disc_only_copies, Fun, DetsInfo,Sender) ->
ErtsVer = erlang:system_info(version),
case DetsInfo of
{ErtsVer, DetsData} ->
try dets:is_compatible_bchunk_format(Tab, DetsData) of
false ->
Sender ! {self(), {old_protocol, Tab}},
dets:init_table(Tab, Fun); %% Old dets version
true ->
dets:init_table(Tab, Fun, [{format, bchunk}])
catch
error:{undef,[{dets,_,_,_}|_]} ->
Sender ! {self(), {old_protocol, Tab}},
dets:init_table(Tab, Fun); %% Old dets version
error:What ->
What
end;
Old when Old /= false ->
Sender ! {self(), {old_protocol, Tab}},
dets:init_table(Tab, Fun); %% Old dets version
_ ->
dets:init_table(Tab, Fun)
end;
init_table(Tab, _, Fun, _DetsInfo,_) ->
try
true = ets:init_table(Tab, Fun),
ok
catch _:Else -> {Else, erlang:get_stacktrace()}
end.
finish_copy(Storage,Tab,Cs,SenderPid,DatBin,OrigTabRec) ->
TabRef = {Storage, Tab},
subscr_receiver(TabRef, Cs#cstruct.record_name),
case handle_last(TabRef, Cs#cstruct.type, DatBin) of
ok ->
mnesia_index:init_index(Tab, Storage),
snmpify(Tab, Storage),
%% OrigTabRec must not be the spawned tab-receiver
%% due to old protocol.
SenderPid ! {OrigTabRec, no_more},
mnesia_tm:unblock_tab(Tab),
ok;
{error, Reason} ->
Msg = "Failed to handle last",
verbose("~ts: ~tp: ~tp~n", [Msg, Tab, Reason]),
down(Tab, Storage)
end.
subscr_receiver(TabRef = {_, Tab}, RecName) ->
receive
{mnesia_table_event, {Op, Val, _Tid}}
when element(1, Val) =:= Tab ->
if
Tab == RecName ->
handle_event(TabRef, Op, Val);
true ->
handle_event(TabRef, Op, setelement(1, Val, RecName))
end,
subscr_receiver(TabRef, RecName);
{mnesia_table_event, {Op, Val, _Tid}} when element(1, Val) =:= schema ->
%% clear_table is faked via two schema events
%% a schema record delete and a write
case Op of
delete -> handle_event(TabRef, clear_table, {Tab, all});
_ -> ok
end,
subscr_receiver(TabRef, RecName);
{'EXIT', Pid, Reason} ->
handle_exit(Pid, Reason),
subscr_receiver(TabRef, RecName)
after 0 ->
ok
end.
handle_event(TabRef, write, Rec) ->
db_put(TabRef, Rec);
handle_event(TabRef, delete, {_Tab, Key}) ->
db_erase(TabRef, Key);
handle_event(TabRef, delete_object, OldRec) ->
db_match_erase(TabRef, OldRec);
handle_event(TabRef, clear_table, {_Tab, _Key}) ->
db_match_erase(TabRef, '_').
handle_last({disc_copies, Tab}, _Type, nobin) ->
Ret = mnesia_log:ets2dcd(Tab),
Fname = mnesia_lib:tab2dat(Tab),
case mnesia_lib:exists(Fname) of
true -> %% Remove old .DAT files.
file:delete(Fname);
false ->
ok
end,
Ret;
handle_last({disc_only_copies, Tab}, Type, nobin) ->
mnesia_lib:dets_sync_close(Tab),
Tmp = mnesia_lib:tab2tmp(Tab),
Dat = mnesia_lib:tab2dat(Tab),
case file:rename(Tmp, Dat) of
ok ->
StorageProps = val({Tab, storage_properties}),
DetsOpts = proplists:get_value(dets, StorageProps, []),
Args = [{file, mnesia_lib:tab2dat(Tab)},
{type, mnesia_lib:disk_type(Tab, Type)},
{keypos, 2},
{repair, mnesia_monitor:get_env(auto_repair)} | DetsOpts],
mnesia_monitor:open_dets(Tab, Args),
ok;
{error, Reason} ->
{error, {"Cannot swap tmp files", Tab, Reason}}
end;
handle_last({ram_copies, _Tab}, _Type, nobin) ->
ok;
handle_last({ram_copies, Tab}, _Type, DatBin) ->
case mnesia_monitor:use_dir() of
true ->
mnesia_lib:lock_table(Tab),
Tmp = mnesia_lib:tab2tmp(Tab),
ok = file:write_file(Tmp, DatBin),
ok = file:rename(Tmp, mnesia_lib:tab2dcd(Tab)),
mnesia_lib:unlock_table(Tab),
ok;
false ->
ok
end;
handle_last(_Storage, _Type, nobin) ->
ok.
down(Tab, Storage) ->
case Storage of
ram_copies ->
?SAFE(?ets_delete_table(Tab));
disc_copies ->
?SAFE(?ets_delete_table(Tab));
disc_only_copies ->
TmpFile = mnesia_lib:tab2tmp(Tab),
mnesia_lib:dets_sync_close(Tab),
file:delete(TmpFile);
{ext, Alias, Mod} ->
catch Mod:close_table(Alias, Tab),
catch Mod:delete_table(Alias, Tab)
end,
mnesia_checkpoint:tm_del_copy(Tab, node()),
mnesia_controller:sync_del_table_copy_whereabouts(Tab, node()),
mnesia_tm:unblock_tab(Tab),
flush_subcrs(),
down.
flush_subcrs() ->
receive
{mnesia_table_event, _} ->
flush_subcrs();
{'EXIT', Pid, Reason} ->
handle_exit(Pid, Reason),
flush_subcrs()
after 0 ->
done
end.
db_erase({ram_copies, Tab}, Key) ->
true = ?ets_delete(Tab, Key);
db_erase({disc_copies, Tab}, Key) ->
true = ?ets_delete(Tab, Key);
db_erase({disc_only_copies, Tab}, Key) ->
ok = dets:delete(Tab, Key);
db_erase({{ext, Alias, Mod}, Tab}, Key) ->
ok = Mod:delete(Alias, Tab, Key).
db_match_erase({ram_copies, Tab} , Pat) ->
true = ?ets_match_delete(Tab, Pat);
db_match_erase({disc_copies, Tab} , Pat) ->
true = ?ets_match_delete(Tab, Pat);
db_match_erase({disc_only_copies, Tab}, Pat) ->
ok = dets:match_delete(Tab, Pat);
db_match_erase({{ext, Alias, Mod}, Tab}, Pat) ->
% "ets style" is to return true
% "dets style" is to return N | { error, Reason }
% or sometimes ok (?)
% be nice and accept both
case Mod:match_delete(Alias, Tab, Pat) of
N when is_integer (N) -> ok;
true -> ok;
ok -> ok
end.
db_put({ram_copies, Tab}, Val) ->
true = ?ets_insert(Tab, Val);
db_put({disc_copies, Tab}, Val) ->
true = ?ets_insert(Tab, Val);
db_put({disc_only_copies, Tab}, Val) ->
ok = dets:insert(Tab, Val);
db_put({{ext, Alias, Mod}, Tab}, Val) ->
ok = Mod:insert(Alias, Tab, Val).
%% This code executes at the remote site where the data is
%% executes in a special copier process.
calc_nokeys(Storage, Tab) ->
%% Calculate #keys per transfer
Key = mnesia_lib:db_first(Storage, Tab),
Recs = mnesia_lib:db_get(Storage, Tab, Key),
BinSize = size(term_to_binary(Recs)),
(?MAX_TRANSFER_SIZE div BinSize) + 1.
send_table(Pid, Tab, RemoteS) ->
case ?catch_val({Tab, storage_type}) of
{'EXIT', _} ->
{error, {no_exists, Tab}};
unknown ->
{error, {no_exists, Tab}};
Storage ->
do_send_table(Pid, Tab, Storage, RemoteS)
end.
do_send_table(Pid, Tab, Storage, RemoteS) ->
{Init, Chunk} =
case Storage of
{ext, Alias, Mod} ->
case Mod:sender_init(Alias, Tab, RemoteS, Pid) of
{standard, I, C} ->
Pid ! {self(), {first, Mod:info(Alias, Tab, size)}},
{I, C};
{_, _} = Res ->
Res
end;
Storage ->
%% Send first
TabSize = mnesia:table_info(Tab, size),
KeysPerTransfer = calc_nokeys(Storage, Tab),
ChunkData = dets:info(Tab, bchunk_format),
UseDetsChunk =
Storage == RemoteS andalso
Storage == disc_only_copies andalso
ChunkData /= undefined,
if
UseDetsChunk == true ->
DetsInfo = erlang:system_info(version),
Pid ! {self(), {first, TabSize, {DetsInfo, ChunkData}}};
true ->
Pid ! {self(), {first, TabSize}}
end,
{_I, _C} =
reader_funcs(UseDetsChunk, Tab, Storage, KeysPerTransfer)
end,
%% Debug info
put(mnesia_table_sender, {Tab, node(Pid), Pid}),
SendIt = fun() ->
NeedLock = need_lock(Tab),
{atomic, ok} = prepare_copy(Pid, Tab, Storage, NeedLock),
send_more(Pid, 1, Chunk, Init(), Tab, Storage),
finish_copy(Pid, Tab, Storage, RemoteS, NeedLock)
end,
try SendIt() of
{_, receiver_died} -> ok;
{atomic, no_more} -> ok
catch
throw:receiver_died ->
cleanup_tab_copier(Pid, Storage, Tab),
ok;
error:Reason -> %% Prepare failed
cleanup_tab_copier(Pid, Storage, Tab),
{error, {tab_copier, Tab, {Reason, erlang:get_stacktrace()}}}
after
unlink(whereis(mnesia_tm))
end.
prepare_copy(Pid, Tab, Storage, NeedLock) ->
Trans =
fun() ->
NeedLock andalso mnesia:lock_table(Tab, load),
mnesia_subscr:subscribe(Pid, {table, Tab}),
update_where_to_write(Tab, node(Pid)),
mnesia_lib:db_fixtable(Storage, Tab, true),
ok
end,
mnesia:transaction(Trans).
need_lock(Tab) ->
case ?catch_val({?MODULE, active_trans}) of
#tid{} = Tid ->
%% move_table_copy grabs it's own table-lock
%% do not deadlock with it
mnesia_lib:unset({?MODULE, active_trans}),
case mnesia_locker:get_held_locks(Tab) of
[{write, Tid}|_] -> false;
_Locks -> true
end;
_ ->
true
end.
update_where_to_write(Tab, Node) ->
case val({Tab, access_mode}) of
read_only ->
ignore;
read_write ->
Current = val({current, db_nodes}),
Ns =
case lists:member(Node, Current) of
true -> Current;
false -> [Node | Current]
end,
update_where_to_write(Ns, Tab, Node)
end.
update_where_to_write([], _, _) ->
ok;
update_where_to_write([H|T], Tab, AddNode) ->
rpc:call(H, mnesia_controller, call,
[{update_where_to_write, [add, Tab, AddNode], self()}]),
update_where_to_write(T, Tab, AddNode).
send_more(Pid, N, Chunk, DataState, Tab, Storage) ->
receive
{NewPid, more} ->
case send_packet(N - 1, NewPid, Chunk, DataState) of
New when is_integer(New) ->
New - 1;
NewData ->
send_more(NewPid, ?MAX_NOPACKETS, Chunk, NewData,
Tab, Storage)
end;
{NewPid, {more, Msg}} when element(1, Storage) == ext ->
{ext, Alias, Mod} = Storage,
{NewChunk, NewState} =
Mod:sender_handle_info(Msg, Alias, Tab, NewPid, DataState),
case send_packet(N - 1, NewPid, NewChunk, NewState) of
New when is_integer(New) ->
New -1;
NewData ->
send_more(NewPid, N, NewChunk, NewData, Tab,
Storage)
end;
{_NewPid, {old_protocol, Tab}} ->
Storage = val({Tab, storage_type}),
{Init, NewChunk} =
reader_funcs(false, Tab, Storage, calc_nokeys(Storage, Tab)),
send_more(Pid, 1, NewChunk, Init(), Tab, Storage);
{copier_done, Node} when Node == node(Pid)->
verbose("Receiver of table ~tp crashed on ~p (more)~n", [Tab, Node]),
throw(receiver_died)
end.
reader_funcs(UseDetsChunk, Tab, Storage, KeysPerTransfer) ->
case UseDetsChunk of
false ->
{fun() -> mnesia_lib:db_init_chunk(Storage, Tab, KeysPerTransfer) end,
fun(Cont) -> mnesia_lib:db_chunk(Storage, Cont) end};
true ->
{fun() -> dets_bchunk(Tab, start) end,
fun(Cont) -> dets_bchunk(Tab, Cont) end}
end.
dets_bchunk(Tab, Chunk) -> %% Arrg
case dets:bchunk(Tab, Chunk) of
{Cont, Data} -> {Data, Cont};
Else -> Else
end.
zlib_compress(Data, Level) ->
BinData = term_to_binary(Data),
Z = zlib:open(),
zlib:deflateInit(Z, Level),
Bs = zlib:deflate(Z, BinData, finish),
zlib:deflateEnd(Z),
zlib:close(Z),
list_to_binary(Bs).
zlib_uncompress(Data) when is_binary(Data) ->
binary_to_term(zlib:uncompress(Data)).
compression_level() ->
NoCompression = 0,
case ?catch_val(send_compressed) of
{'EXIT', _} ->
mnesia_lib:set(send_compressed, NoCompression),
NoCompression;
Val -> Val
end.
send_packet(N, Pid, _Chunk, '$end_of_table') ->
Pid ! {self(), no_more},
N;
send_packet(N, Pid, Chunk, {[], Cont}) ->
send_packet(N, Pid, Chunk, Chunk(Cont));
send_packet(N, Pid, Chunk, {Recs, Cont}) when N < ?MAX_NOPACKETS ->
case compression_level() of
0 ->
Pid ! {self(), {more, Recs}};
Level ->
Pid ! {self(), {more_z, zlib_compress(Recs, Level)}}
end,
send_packet(N+1, Pid, Chunk, Chunk(Cont));
send_packet(_N, _Pid, _Chunk, DataState) ->
DataState.
finish_copy(Pid, Tab, Storage, RemoteS, NeedLock) ->
RecNode = node(Pid),
DatBin = dat2bin(Tab, Storage, RemoteS),
Node = node(Pid),
Trans =
fun() ->
NeedLock andalso mnesia:read_lock_table(Tab),
%% Check that receiver is still alive
receive {copier_done, Node} ->
throw(receiver_died)
after 0 -> ok
end,
A = val({Tab, access_mode}),
mnesia_controller:sync_and_block_table_whereabouts(Tab, RecNode, RemoteS, A),
cleanup_tab_copier(Pid, Storage, Tab),
mnesia_checkpoint:tm_add_copy(Tab, RecNode),
Pid ! {self(), {no_more, DatBin}},
receive
{Pid, no_more} -> % Dont bother about the spurious 'more' message
no_more;
{copier_done, Node} ->
verbose("Tab receiver ~tp crashed (more): ~p~n", [Tab, Node]),
receiver_died
end
end,
mnesia:transaction(Trans).
cleanup_tab_copier(Pid, Storage, Tab) ->
mnesia_lib:db_fixtable(Storage, Tab, false),
mnesia_subscr:unsubscribe(Pid, {table, Tab}).
dat2bin(Tab, ram_copies, ram_copies) ->
mnesia_lib:lock_table(Tab),
Res = file:read_file(mnesia_lib:tab2dcd(Tab)),
mnesia_lib:unlock_table(Tab),
case Res of
{ok, DatBin} -> DatBin;
_ -> nobin
end;
dat2bin(_Tab, _LocalS, _RemoteS) ->
nobin.
handle_exit(Pid, Reason) when node(Pid) == node() ->
error(Reason);
handle_exit(_Pid, _Reason) -> %% Not from our node, this will be handled by
ignore. %% mnesia_down soon.
