Change page cache loading by lookup/no_lookup

By default load the first 4 levels of the ledger into the page cache of lookup is to be supported, but just levels 0 and 1 otherwise.

include/leveled.hrl

@@ -51,7 +51,8 @@
                             :: leveled_sst:press_method(),
                         log_options = leveled_log:get_opts() 
                             :: leveled_log:log_options(),
-                        max_sstslots = 256 :: pos_integer()}).
+                        max_sstslots = 256 :: pos_integer(),
+                        pagecache_level = 1 :: pos_integer()}).
 
 -record(inker_options,
                         {cdb_max_size :: integer() | undefined,

src/leveled_bookie.erl

@@ -127,6 +127,8 @@
 -define(OPEN_LASTMOD_RANGE, {0, infinity}).
 -define(SNAPTIMEOUT_SHORT, 900). % 15 minutes
 -define(SNAPTIMEOUT_LONG, 43200). % 12 hours
+-define(SST_PAGECACHELEVEL_NOLOOKUP, 1).
+-define(SST_PAGECACHELEVEL_LOOKUP, 4).
 -define(OPTION_DEFAULTS,
             [{root_path, undefined},
                 {snapshot_bookie, undefined},
@@ -1177,15 +1179,22 @@ init([Opts]) ->
                     ok
             end,
             
-            {HeadOnly, HeadLookup} = 
+            {HeadOnly, HeadLookup, SSTPageCacheLevel} = 
                 case proplists:get_value(head_only, Opts) of 
                     false ->
-                        {false, true};
+                        {false, true, ?SST_PAGECACHELEVEL_LOOKUP};
                     with_lookup ->
-                        {true, true};
+                        {true, true, ?SST_PAGECACHELEVEL_LOOKUP};
                     no_lookup ->
-                        {true, false}
+                        {true, false, ?SST_PAGECACHELEVEL_NOLOOKUP}
                 end,
+            % Override the default page cache level - we want to load into the
+            % page cache many levels if we intend to support lookups, and only
+            % levels 0 and 1 otherwise
+            SSTOpts = PencillerOpts#penciller_options.sst_options,
+            SSTOpts0 = SSTOpts#sst_options{pagecache_level = SSTPageCacheLevel},
+            PencillerOpts0 =
+                PencillerOpts#penciller_options{sst_options = SSTOpts0},
             
             State0 = #state{cache_size=CacheSize,
                                 is_snapshot=false,
@@ -1193,7 +1202,7 @@ init([Opts]) ->
                                 head_lookup = HeadLookup},
 
             {Inker, Penciller} = 
-                startup(InkerOpts, PencillerOpts, State0),
+                startup(InkerOpts, PencillerOpts0, State0),
 
             NewETS = ets:new(mem, [ordered_set]),
             leveled_log:log("B0001", [Inker, Penciller]),

src/leveled_sst.erl

@@ -486,7 +486,9 @@ init([]) ->
 starting({sst_open, RootPath, Filename, OptsSST, Level}, _From, State) ->
     leveled_log:save(OptsSST#sst_options.log_options),
     {UpdState, Bloom} = 
-        read_file(Filename, State#state{root_path=RootPath}),
+        read_file(Filename,
+                    State#state{root_path=RootPath},
+                    OptsSST#sst_options.pagecache_level >= Level),
     Summary = UpdState#state.summary,
     {reply,
         {ok, {Summary#summary.first_key, Summary#summary.last_key}, Bloom},
@@ -509,7 +511,8 @@ starting({sst_new,
     YBQ = Level =< 2,
     {UpdState, Bloom} = 
         read_file(ActualFilename,
-                    State#state{root_path=RootPath, yield_blockquery=YBQ}),
+                    State#state{root_path=RootPath, yield_blockquery=YBQ},
+                    OptsSST#sst_options.pagecache_level >= Level),
     Summary = UpdState#state.summary,
     leveled_log:log_timer("SST08",
                             [ActualFilename, Level, Summary#summary.max_sqn],
@@ -573,7 +576,8 @@ starting(complete_l0startup, State) ->
                                 % Important to empty this from state rather
                                 % than carry it through to the next stage
                                 new_slots=undefined,
-                                deferred_startup_tuple=undefined}),
+                                deferred_startup_tuple=undefined},
+                    true),
     Summary = UpdState#state.summary,
     Time4 = timer:now_diff(os:timestamp(), SW4),
     
@@ -1215,9 +1219,10 @@ write_file(RootPath, Filename, SummaryBin, SlotsBin,
                 filename:join(RootPath, FinalName)),
     FinalName.
 
-read_file(Filename, State) ->
+read_file(Filename, State, LoadPageCache) ->
     {Handle, FileVersion, SummaryBin} = 
-        open_reader(filename:join(State#state.root_path, Filename)),
+        open_reader(filename:join(State#state.root_path, Filename),
+                    LoadPageCache),
     UpdState0 = imp_fileversion(FileVersion, State),
     {Summary, Bloom, SlotList} = read_table_summary(SummaryBin),
     BlockIndexCache = array:new([{size, Summary#summary.size},
@@ -1269,13 +1274,18 @@ imp_fileversion(VersionInt, State) ->
         end,
     UpdState1.
 
-open_reader(Filename) ->
+open_reader(Filename, LoadPageCache) ->
     {ok, Handle} = file:open(Filename, [binary, raw, read]),
     {ok, Lengths} = file:pread(Handle, 0, 9),
     <<FileVersion:8/integer, 
         SlotsLength:32/integer, 
         SummaryLength:32/integer>> = Lengths,
-    ok = file:advise(Handle, 9, SlotsLength, will_need),
+    case LoadPageCache of
+        true ->
+            file:advise(Handle, 9, SlotsLength, will_need);
+        false ->
+            ok
+    end,
     {ok, SummaryBin} = file:pread(Handle, SlotsLength + 9, SummaryLength),
     {Handle, FileVersion, SummaryBin}.