You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@couchdb.apache.org by ja...@apache.org on 2020/04/16 05:09:39 UTC
[couchdb] 01/02: Refactor expiring cache FDB interface
This is an automated email from the ASF dual-hosted git repository.
jaydoane pushed a commit to branch prototype/fdb-layer
in repository https://gitbox.apache.org/repos/asf/couchdb.git
commit 0eb1a73af424aa6403c420f8f6ebb3fe4d760f62
Author: Jay Doane <ja...@apache.org>
AuthorDate: Wed Apr 15 22:01:13 2020 -0700
Refactor expiring cache FDB interface
- Rename `clear_expired_range` to `clear_range_to`
- Move `EXPIRING_CACHE` layer prefix into fabric2.hrl
- Move primary key setting to just after key & value calculations
- Factor out `get_val/2` to lookup a key from FDB and unpack the value
- Factor out `prefixes/2`
- Factor out `fold_range/5`
---
.../src/couch_expiring_cache_fdb.erl | 60 +++++++++++++---------
.../src/couch_expiring_cache_server.erl | 2 +-
src/fabric/include/fabric2.hrl | 1 +
3 files changed, 38 insertions(+), 25 deletions(-)
diff --git a/src/couch_expiring_cache/src/couch_expiring_cache_fdb.erl b/src/couch_expiring_cache/src/couch_expiring_cache_fdb.erl
index fa8508e..dc33766 100644
--- a/src/couch_expiring_cache/src/couch_expiring_cache_fdb.erl
+++ b/src/couch_expiring_cache/src/couch_expiring_cache_fdb.erl
@@ -16,15 +16,15 @@
insert/6,
lookup/3,
clear_all/1,
- clear_expired_range/3
+ clear_range_to/3
]).
--define(EXPIRING_CACHE, 53). % coordinate with fabric2.hrl
-define(PK, 1).
-define(EXP, 2).
+-include_lib("fabric/include/fabric2.hrl").
-include_lib("couch_expiring_cache/include/couch_expiring_cache.hrl").
@@ -41,9 +41,9 @@ insert(#{jtx := true} = JTx, Name, Key, Val, StaleTS, ExpiresTS) ->
#{tx := Tx, layer_prefix := LayerPrefix} = couch_jobs_fdb:get_jtx(JTx),
PK = primary_key(Name, Key, LayerPrefix),
PV = erlfdb_tuple:pack({Val, StaleTS, ExpiresTS}),
+ ok = erlfdb:set(Tx, PK, PV),
XK = expiry_key(ExpiresTS, Name, Key, LayerPrefix),
XV = erlfdb_tuple:pack({}),
- ok = erlfdb:set(Tx, PK, PV),
ok = erlfdb:set(Tx, XK, XV).
@@ -52,11 +52,10 @@ insert(#{jtx := true} = JTx, Name, Key, Val, StaleTS, ExpiresTS) ->
lookup(#{jtx := true} = JTx, Name, Key) ->
#{tx := Tx, layer_prefix := LayerPrefix} = couch_jobs_fdb:get_jtx(JTx),
PK = primary_key(Name, Key, LayerPrefix),
- case erlfdb:wait(erlfdb:get(Tx, PK)) of
+ case get_val(Tx, PK) of
not_found ->
not_found;
- Bin when is_binary(Bin) ->
- {Val, StaleTS, ExpiresTS} = erlfdb_tuple:unpack(Bin),
+ {Val, StaleTS, ExpiresTS} ->
Now = erlang:system_time(?TIME_UNIT),
if
Now < StaleTS -> {fresh, Val};
@@ -76,32 +75,30 @@ clear_all(Name) ->
end).
--spec clear_expired_range(Name :: binary(), EndTS :: ?TIME_UNIT,
+-spec clear_range_to(Name :: binary(), EndTS :: ?TIME_UNIT,
Limit :: non_neg_integer()) ->
OldestTS :: ?TIME_UNIT.
-clear_expired_range(Name, EndTS, Limit) when Limit > 0 ->
- fabric2_fdb:transactional(fun(Tx) ->
- LayerPrefix = fabric2_fdb:get_dir(Tx),
- ExpiresPrefix = erlfdb_tuple:pack(
- {?EXPIRING_CACHE, Name, ?EXP}, LayerPrefix),
- fabric2_fdb:fold_range({tx, Tx}, ExpiresPrefix, fun({K, _V}, Acc) ->
- Unpacked = erlfdb_tuple:unpack(K, ExpiresPrefix),
- couch_log:debug("~p clearing ~p", [?MODULE, Unpacked]),
- {ExpiresTS, Key} = Unpacked,
- clear_expired(Tx, ExpiresTS, Name, Key, LayerPrefix),
+clear_range_to(Name, EndTS, Limit) when Limit > 0 ->
+ fold_range(Name, EndTS, Limit,
+ fun(Tx, PK, XK, _Key, ExpiresTS, Acc) ->
+ ok = erlfdb:clear(Tx, PK),
+ ok = erlfdb:clear(Tx, XK),
oldest_ts(ExpiresTS, Acc)
- end, 0, [{end_key, EndTS}, {limit, Limit}])
- end).
+ end, 0).
%% Private
-clear_expired(Tx, ExpiresTS, Name, Key, Prefix) ->
- PK = primary_key(Name, Key, Prefix),
- XK = expiry_key(ExpiresTS, Name, Key, Prefix),
- ok = erlfdb:clear(Tx, PK),
- ok = erlfdb:clear(Tx, XK).
+fold_range(Name, EndTS, Limit, Fun, Acc0) when Limit > 0 ->
+ fabric2_fdb:transactional(fun(Tx) ->
+ {LayerPrefix, ExpiresPrefix} = prefixes(Tx, Name),
+ fabric2_fdb:fold_range({tx, Tx}, ExpiresPrefix, fun({XK, _XV}, Acc) ->
+ {ExpiresTS, Key} = erlfdb_tuple:unpack(XK, ExpiresPrefix),
+ PK = primary_key(Name, Key, LayerPrefix),
+ Fun(Tx, PK, XK, Key, ExpiresTS, Acc)
+ end, Acc0, [{end_key, EndTS}, {limit, Limit}])
+ end).
oldest_ts(TS, 0) -> TS; % handle initial Acc = 0 case
@@ -114,3 +111,18 @@ primary_key(Name, Key, Prefix) ->
expiry_key(ExpiresTS, Name, Key, Prefix) ->
erlfdb_tuple:pack({?EXPIRING_CACHE, Name, ?EXP, ExpiresTS, Key}, Prefix).
+
+
+prefixes(Tx, Name) ->
+ Layer = fabric2_fdb:get_dir(Tx),
+ Expires = erlfdb_tuple:pack({?EXPIRING_CACHE, Name, ?EXP}, Layer),
+ {Layer, Expires}.
+
+
+get_val(Tx, PK) ->
+ case erlfdb:wait(erlfdb:get(Tx, PK)) of
+ not_found ->
+ not_found;
+ Bin when is_binary(Bin) ->
+ erlfdb_tuple:unpack(Bin)
+ end.
diff --git a/src/couch_expiring_cache/src/couch_expiring_cache_server.erl b/src/couch_expiring_cache/src/couch_expiring_cache_server.erl
index 99d3864..eb74e6e 100644
--- a/src/couch_expiring_cache/src/couch_expiring_cache_server.erl
+++ b/src/couch_expiring_cache/src/couch_expiring_cache_server.erl
@@ -82,7 +82,7 @@ handle_info(remove_expired, St) ->
NowTS = erlang:system_time(?TIME_UNIT),
OldestTS = max(OldestTS0,
- couch_expiring_cache_fdb:clear_expired_range(Name, NowTS, BatchSize)),
+ couch_expiring_cache_fdb:clear_range_to(Name, NowTS, BatchSize)),
Elapsed = erlang:system_time(?TIME_UNIT) - NowTS,
{noreply, St#{
diff --git a/src/fabric/include/fabric2.hrl b/src/fabric/include/fabric2.hrl
index 2e588f8..bf3e2aa 100644
--- a/src/fabric/include/fabric2.hrl
+++ b/src/fabric/include/fabric2.hrl
@@ -24,6 +24,7 @@
-define(DB_HCA, 2).
-define(DELETED_DBS, 3).
-define(DBS, 15).
+-define(EXPIRING_CACHE, 53).
-define(TX_IDS, 255).
% Database Level: (LayerPrefix, ?DBS, DbPrefix, X, ...)