Make tictac more efficient by making level1 a map (martinsumner#441)

* Make tictac more efficient by making level1 a map

Pre-change (1M keys, tree size large):

Generating Keys took 2513 milliseconds
Memory footprint [{total,356732576},{processes,334051328},{processes_used,334044488},{system,22681248},{atom,540873},{atom_used,524383},{binary,1015120},{code,9692859},{ets,721496}]
Generating new tree took 1 milliseconds
Loading tree took 27967 milliseconds
Memory footprint [{total,36733040},{processes,8875472},{processes_used,8875048},{system,27857568},{atom,540873},{atom_used,524449},{binary,6236480},{code,9692859},{ets,721496}]
Exporting tree took 434 milliseconds
Importing tree took 100 milliseconds
Memory footprint [{total,155941512},{processes,123734808},{processes_used,123734384},{system,32206704},{atom,540873},{atom_used,524449},{binary,10401144},{code,9692859},{ets,721496}]
Garbage collect
Memory footprint [{total,39660504},{processes,8257520},{processes_used,8256968},{system,31402984},{atom,540873},{atom_used,524449},{binary,9781760},{code,9692859},{ets,721496}]

Post change:

Generating Keys took 2416 milliseconds
Memory footprint [{total,284678120},{processes,258349528},{processes_used,257758568},{system,26328592},{atom,893161},{atom_used,878150},{binary,1013880},{code,11770188},{ets,774224}]
Generating new tree took 0 milliseconds
Loading tree took 2072 milliseconds
Memory footprint [{total,49957448},{processes,17244856},{processes_used,16653896},{system,32712592},{atom,893161},{atom_used,878216},{binary,7397496},{code,11770188},{ets,774224}]
Exporting tree took 448 milliseconds
Importing tree took 108 milliseconds
Memory footprint [{total,46504880},{processes,11197344},{processes_used,10606384},{system,35307536},{atom,893161},{atom_used,878216},{binary,9992112},{code,11770188},{ets,774224}]
Garbage collect
Memory footprint [{total,47394048},{processes,12223608},{processes_used,11632520},{system,35170440},{atom,893161},{atom_used,878216},{binary,9855008},{code,11770188},{ets,774224}]

* Tidy-up

* Add type

* Remove ++ requiring copy of Acc

Rely on mechanism producing a sorted result, not sorting

* Update src/leveled_tictac.erl

Co-authored-by: Thomas Arts <[email protected]>

* Update following review

---------

Co-authored-by: Thomas Arts <[email protected]>

src/leveled_penciller.erl

@@ -159,7 +159,7 @@
 
 -behaviour(gen_server).
 
--include("include/leveled.hrl").
+-include("leveled.hrl").
 
 -export([
         init/1,
@@ -207,23 +207,17 @@
 -export([clean_testdir/1]).
 -endif.
 
--define(MAX_WORK_WAIT, 300).
 -define(MANIFEST_FP, "ledger_manifest").
 -define(FILES_FP, "ledger_files").
--define(CURRENT_FILEX, "crr").
--define(PENDING_FILEX, "pnd").
 -define(SST_FILEX, ".sst").
 -define(ARCHIVE_FILEX, ".bak").
 -define(SUPER_MAX_TABLE_SIZE, 40000).
--define(PROMPT_WAIT_ONL0, 5).
 -define(WORKQUEUE_BACKLOG_TOLERANCE, 4).
 -define(COIN_SIDECOUNT, 4).
 -define(SLOW_FETCH, 500000). % Log a very slow fetch - longer than 500ms
 -define(FOLD_SCANWIDTH, 32).
 -define(ITERATOR_SCANWIDTH, 4).
 -define(ITERATOR_MINSCANWIDTH, 1).
--define(TIMING_SAMPLECOUNTDOWN, 10000).
--define(TIMING_SAMPLESIZE, 100).
 -define(SHUTDOWN_LOOPS, 10).
 -define(SHUTDOWN_PAUSE, 10000).
     % How long to wait for snapshots to be released on shutdown