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Fix bug in backpointer handling, derp!

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This commit is contained in:
Scott Lystig Fritchie 2014-09-19 18:03:24 +09:00
parent 004a18d948
commit 970eb263db
1 changed files with 6 additions and 5 deletions
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11
prototype/tango-prototype/src/tango_dt.erl
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@ -75,7 +75,7 @@ checkpoint(Pid) ->
init([PageSize, SequencerPid, Proj, CallbackMod, StreamNum]) ->
LastLPN = find_last_lpn(SequencerPid),
{BackPs, Pages} = fetch_unread_pages(Proj, LastLPN, 0, StreamNum),
{BackPs, Pages} = fetch_unread_pages(Proj, LastLPN, 0, [], StreamNum),
I_State = play_log_pages(Pages, CallbackMod:fresh(), CallbackMod, false),
{ok, #state{page_size=PageSize,
seq=SequencerPid,
@ -153,17 +153,18 @@ fetch_unread_pages(LastLPN, State) ->
fetch_unread_pages2(LastLPN, State).
fetch_unread_pages2(LastLPN,
#state{proj=Proj, stream_num=StreamNum,
#state{proj=Proj, stream_num=StreamNum, back_ps=OldBackPs,
last_read_lpn=StopAtLPN} = State) ->
{BackPs, Pages} = fetch_unread_pages(Proj, LastLPN, StopAtLPN, StreamNum),
{BackPs, Pages} = fetch_unread_pages(Proj, LastLPN, StopAtLPN,
OldBackPs, StreamNum),
{Pages, State#state{last_read_lpn=LastLPN, back_ps=BackPs}}.
fetch_unread_pages(Proj, LastLPN, StopAtLPN, StreamNum) ->
fetch_unread_pages(Proj, LastLPN, StopAtLPN, OldBackPs, StreamNum) ->
LPNandPages = tango:scan_backward(Proj, StreamNum, LastLPN,
StopAtLPN, true),
{LPNs, Pages} = lists:unzip(LPNandPages),
BackPs = lists:foldl(fun(P, BPs) -> tango:add_back_pointer(BPs, P) end,
[], LPNs),
OldBackPs, LPNs),
{BackPs, Pages}.
play_log_pages(Pages, SideEffectsP,