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Merged
mworrell merged 2 commits into from
Apr 7, 2025
Merged

Fix an issue with removing a non existant key from the cache #11

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b988eb2
Fix an issue with removing a non existant key from the cache
mworrell Apr 7, 2025
8087eb6
Add test
mworrell Apr 7, 2025
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79 changes: 44 additions & 35 deletions src/filezcache_entry_manager.erl
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Original file line number Diff line number Diff line change
Expand Up @@ -539,22 +539,27 @@ scan_files(Dir, [F|Fs]) ->

%% @doc Delete an entry by key.
delete_key(Key, #state{ lru = LRU } = State) ->
{_, LRU1} = filezcache_lru:take(Key, LRU),
Delta = case ets:lookup(?FILE_ENTRY_TAB, Key) of
LRU2 = case filezcache_lru:take(Key, LRU) of
{_, LRU1} -> LRU1;
error -> LRU
end,
case ets:lookup(?FILE_ENTRY_TAB, Key) of
[] ->
0;
State#state{
lru = LRU2
};
[ #filezcache_entry{ filename = Filename, size = Size } ] ->
ok = delete_file(Key, Filename),
case Size of
Delta = case Size of
undefined -> 0;
_ -> Size
end
end,
State#state{
bytes = State#state.bytes - Delta,
lru = LRU1,
delete_count = State#state.delete_count + 1
}.
end,
State#state{
lru = LRU2,
bytes = State#state.bytes - Delta,
delete_count = State#state.delete_count + 1
}
end.

%% @doc Delete an entry and its associated cache file.
delete_file(Key, Filename) ->
Expand Down Expand Up @@ -599,32 +604,36 @@ do_gc(#state{ bytes = Bytes, lru = LRU } = State, N) ->
end.

drop_oldest_key(#state{ lru = LRU } = State) ->
{Key, _Value, LRU1} = filezcache_lru:pop(LRU),
case filezcache_store:lookup(Key) of
{ok, _Pid} ->
LRU2 = filezcache_lru:push(Key, State#state.tick, LRU1),
State#state{ lru = LRU2 };
{error, enoent} ->
case is_referred(Key, State) of
true ->
case filezcache_lru:pop(LRU) of
error ->
State;
{Key, _Value, LRU1} ->
case filezcache_store:lookup(Key) of
{ok, _Pid} ->
LRU2 = filezcache_lru:push(Key, State#state.tick, LRU1),
State#state{ lru = LRU2 };
false ->
Delta = case ets:lookup(?FILE_ENTRY_TAB, Key) of
[] ->
0;
[ #filezcache_entry{ filename = Filename, size = Size } ] ->
ok = delete_file(Key, Filename),
case Size of
undefined -> 0;
_ -> Size
end
end,
State#state{
bytes = State#state.bytes - Delta,
lru = LRU1,
evict_count = State#state.evict_count + 1
}
{error, enoent} ->
case is_referred(Key, State) of
true ->
LRU2 = filezcache_lru:push(Key, State#state.tick, LRU1),
State#state{ lru = LRU2 };
false ->
Delta = case ets:lookup(?FILE_ENTRY_TAB, Key) of
[] ->
0;
[ #filezcache_entry{ filename = Filename, size = Size } ] ->
ok = delete_file(Key, Filename),
case Size of
undefined -> 0;
_ -> Size
end
end,
State#state{
bytes = State#state.bytes - Delta,
lru = LRU1,
evict_count = State#state.evict_count + 1
}
end
end
end.

Expand Down
41 changes: 24 additions & 17 deletions src/filezcache_lru.erl
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Original file line number Diff line number Diff line change
Expand Up @@ -79,7 +79,7 @@ push(Key, Value, LRU) ->
%% @doc Pop element from head.
%%
%% Complexity: O(log(N))
-spec pop(lru()) -> {key(), value(), lru()}.
-spec pop(lru()) -> {key(), value(), lru()} | error.
pop(LRU) ->
pop_oldest(LRU).

Expand Down Expand Up @@ -175,28 +175,35 @@ update_key(Key, Value, LRU) ->
last = NewIndex
}.

-spec pop_oldest(lru()) -> {key(), value(), lru()}.
-spec pop_oldest(lru()) -> {key(), value(), lru()} | error.
pop_oldest(LRU) ->
#lru{current_size = CurrentSize, usage = Usage, lookup_cache = LookupCache, last = Last } = LRU,
{_, OldestKey, NewUsage} = gb_trees:take_smallest(Usage),
{{_, OldestValue}, NewLookupCache} = maps:take(OldestKey, LookupCache),
NewLast =
case CurrentSize of
1 -> 0;
_ -> Last
end,
NewLRU = LRU#lru{current_size = CurrentSize - 1,
lookup_cache = NewLookupCache,
usage = NewUsage,
last = NewLast
},
{OldestKey, OldestValue, NewLRU}.
case gb_trees:is_empty(Usage) of
true ->
error;
false ->
{_, OldestKey, NewUsage} = gb_trees:take_smallest(Usage),
{{_, OldestValue}, NewLookupCache} = maps:take(OldestKey, LookupCache),
NewLast =
case CurrentSize of
1 -> 0;
_ -> Last
end,
NewLRU = LRU#lru{current_size = CurrentSize - 1,
lookup_cache = NewLookupCache,
usage = NewUsage,
last = NewLast
},
{OldestKey, OldestValue, NewLRU}
end.

-spec apply_limits(lru()) -> lru().
apply_limits(#lru{max_size = unlimited} = LRU) ->
LRU;
apply_limits(#lru{current_size = CS, max_size = MaxSize} = LRU) when CS =< MaxSize ->
LRU;
apply_limits(LRU) ->
{_, _, NewLRU} = pop_oldest(LRU),
apply_limits(NewLRU).
case pop_oldest(LRU) of
error -> LRU;
{_, _, NewLRU} -> apply_limits(NewLRU)
end.
5 changes: 5 additions & 0 deletions test/filezcache_SUITE.erl
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Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,7 @@ end_per_testcase(_TestCase, _Config) ->

all() ->
[
remove_unknown_key_test,
cache_binary_test,
cache_delete_test,
cache_tmpfile_test,
Expand All @@ -37,6 +38,10 @@ all() ->
%% TEST CASES
%%--------------------------------------------------------------------

remove_unknown_key_test(_Config) ->
ok = filezcache:delete(unknown_key),
ok.

cache_binary_test(_Config) ->
#{
insert_count := 0,
Expand Down