Revert "Hibernate on SQN check"

This reverts commit eedd09a23d.

src/leveled_codec.erl

@@ -136,7 +136,6 @@
 
 -export_type([tag/0,
                 key/0,
-                sqn/0,
                 object_spec/0,
                 segment_hash/0,
                 ledger_status/0,

src/leveled_penciller.erl

@@ -749,14 +749,12 @@ handle_call({fetch, Key, Hash, UseL0Index}, _From, State) ->
     {reply, R, State#state{timings=UpdTimings0, timings_countdown=CountDown}};
 handle_call({check_sqn, Key, Hash, SQN}, _From, State) ->
     {reply,
-        compare_to_sqn(
-            fetch_sqn(
-                Key,
-                Hash,
-                State#state.manifest,
-                State#state.levelzero_cache,
-                State#state.levelzero_index),
-                SQN),
+        compare_to_sqn(plain_fetch_mem(Key,
+                                        Hash,
+                                        State#state.manifest,
+                                        State#state.levelzero_cache,
+                                        State#state.levelzero_index),
+                        SQN),
         State};
 handle_call({fetch_keys, 
                     StartKey, EndKey, 
@@ -1458,18 +1456,14 @@ timed_fetch_mem(Key, Hash, Manifest, L0Cache, L0Index, Timings) ->
     {R, UpdTimings}.
 
 
--spec fetch_sqn(
-    leveled_codec:ledger_key(),
-    leveled_codec:segment_hash(),
-    leveled_pmanifest:manifest(),
-    list(),
-    leveled_pmem:index_array()) ->
-        not_present|leveled_codec:ledger_kv()|leveled_codec:ledger_sqn().
+-spec plain_fetch_mem(tuple(), {integer(), integer()}, 
+                        leveled_pmanifest:manifest(), list(), 
+                        leveled_pmem:index_array()) -> not_present|tuple().
 %% @doc
 %% Fetch the result from the penciller, starting by looking in the memory, 
 %% and if it is not found looking down level by level through the LSM tree.
-fetch_sqn(Key, Hash, Manifest, L0Cache, L0Index) ->
-    R = fetch_mem(Key, Hash, Manifest, L0Cache, L0Index, fun sst_getsqn/4),
+plain_fetch_mem(Key, Hash, Manifest, L0Cache, L0Index) ->
+    R = fetch_mem(Key, Hash, Manifest, L0Cache, L0Index, fun sst_get/4),
     element(1, R).
 
 fetch_mem(Key, Hash, Manifest, L0Cache, L0Index, FetchFun) ->
@@ -1522,8 +1516,8 @@ timed_sst_get(PID, Key, Hash, Level) ->
     T0 = timer:now_diff(os:timestamp(), SW),
     log_slowfetch(T0, R, PID, Level, ?SLOW_FETCH).
 
-sst_getsqn(PID, Key, Hash, _Level) ->
-    leveled_sst:sst_getsqn(PID, Key, Hash).
+sst_get(PID, Key, Hash, Level) ->
+    leveled_sst:sst_get(PID, Key, Hash).
 
 log_slowfetch(T0, R, PID, Level, FetchTolerance) ->
     case {T0, R} of
@@ -1538,26 +1532,29 @@ log_slowfetch(T0, R, PID, Level, FetchTolerance) ->
     end.
 
 
--spec compare_to_sqn(
-    leveled_codec:ledger_kv()|leveled_codec:sqn()|not_present,
-    integer()) -> sqn_check().
+-spec compare_to_sqn(tuple()|not_present, integer()) -> sqn_check().
 %% @doc
 %% Check to see if the SQN in the penciller is after the SQN expected for an 
 %% object (used to allow the journal to check compaction status from a cache
 %% of the ledger - objects with a more recent sequence number can be compacted).
-compare_to_sqn(not_present, _SQN) ->
-    missing;
-compare_to_sqn(ObjSQN, SQN) when is_integer(ObjSQN), ObjSQN > SQN ->
-    replaced;
-compare_to_sqn(ObjSQN, _SQN) when is_integer(ObjSQN) ->
-    % Normally we would expect the SQN to be equal here, but
-    % this also allows for the Journal to have a more advanced
-    % value. We return true here as we wouldn't want to
-    % compact thta more advanced value, but this may cause
-    % confusion in snapshots.
-    current;
 compare_to_sqn(Obj, SQN) ->
-    compare_to_sqn(leveled_codec:strip_to_seqonly(Obj), SQN).
+    case Obj of
+        not_present ->
+            missing;
+        Obj ->
+            SQNToCompare = leveled_codec:strip_to_seqonly(Obj),
+            if
+                SQNToCompare > SQN ->
+                    replaced;
+                true ->
+                    % Normally we would expect the SQN to be equal here, but
+                    % this also allows for the Journal to have a more advanced
+                    % value. We return true here as we wouldn't want to
+                    % compact thta more advanced value, but this may cause
+                    % confusion in snapshots.
+                    current
+            end
+    end.
 
 
 %%%============================================================================

src/leveled_sst.erl

@@ -96,7 +96,6 @@
 -define(TOMB_COUNT, true).
 -define(USE_SET_FOR_SPEED, 64).
 -define(STARTUP_TIMEOUT, 10000).
--define(HIBERNATE_TIMEOUT, 60000).
 
 -include_lib("eunit/include/eunit.hrl").
 
@@ -120,7 +119,6 @@
             sst_open/4,
             sst_get/2,
             sst_get/3,
-            sst_getsqn/3,
             sst_expandpointer/5,
             sst_getmaxsequencenumber/1,
             sst_setfordelete/2,
@@ -436,15 +434,6 @@ sst_get(Pid, LedgerKey) ->
 sst_get(Pid, LedgerKey, Hash) ->
     gen_fsm:sync_send_event(Pid, {get_kv, LedgerKey, Hash}, infinity).
 
--spec sst_getsqn(pid(),
-    leveled_codec:ledger_key(),
-    leveled_codec:segment_hash()) -> leveled_codec:sqn()|not_present.
-%% @doc
-%% Return a SQN for the key or not_present if the key is not in
-%% the store (with the magic hash precalculated).
-sst_getsqn(Pid, LedgerKey, Hash) ->
-    gen_fsm:sync_send_event(Pid, {get_sqn, LedgerKey, Hash}, infinity).
-
 -spec sst_getmaxsequencenumber(pid()) -> integer().
 %% @doc
 %% Get the maximume sequence number for this SST file
@@ -706,11 +695,6 @@ starting({sst_returnslot, FetchedSlot, FetchFun, SlotCount}, State) ->
                 State#state{new_slots = FetchedSlots}}
     end.
 
-reader({get_sqn, LedgerKey, Hash}, _From, State) ->
-    % Get a KV value and potentially take sample timings
-    {Result, UpdState, _UpdTimings} = 
-        fetch(LedgerKey, Hash, State, no_timing),
-    {reply, sqn_only(Result), reader, UpdState, ?HIBERNATE_TIMEOUT};
 reader({get_kv, LedgerKey, Hash}, _From, State) ->
     % Get a KV value and potentially take sample timings
     {Result, UpdState, UpdTimings} = 
@@ -816,11 +800,6 @@ reader({switch_levels, NewLevel}, State) ->
     {next_state, reader, State#state{level = NewLevel}, hibernate}.
 
 
-delete_pending({get_sqn, LedgerKey, Hash}, _From, State) ->
-    % Get a KV value and potentially take sample timings
-    {Result, UpdState, _UpdTimings} = 
-        fetch(LedgerKey, Hash, State, no_timing),
-    {reply, sqn_only(Result), delete_pending, UpdState, ?DELETE_TIMEOUT};
 delete_pending({get_kv, LedgerKey, Hash}, _From, State) ->
     {Result, UpdState, _Ts} = fetch(LedgerKey, Hash, State, no_timing),
     {reply, Result, delete_pending, UpdState, ?DELETE_TIMEOUT};
@@ -1115,12 +1094,6 @@ member_check(Hash, {sets, HashSet}) ->
 member_check(_Miss, _Checker) ->
     false.
 
--spec sqn_only(leveled_codec:ledger_kv()|not_present)
-        -> leveled_codec:sqn()|not_present.
-sqn_only(not_present) ->
-    not_present;
-sqn_only(KV) ->
-    leveled_codec:strip_to_seqonly(KV).
 
 extract_hash({SegHash, _ExtraHash}) when is_integer(SegHash) ->
     tune_hash(SegHash);
@@ -1140,7 +1113,7 @@ fetch_from_cache(CacheHash, Cache) ->
 
 -spec add_to_cache(
     non_neg_integer(),
-    leveled_codec:ledger_kv(),
+    leveled_codec:ledger_kv()
     fetch_cache()) -> fetch_cache().
 add_to_cache(_CacheHash, _KV, no_cache) ->
     no_cache;