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Posted to commits@couchdb.apache.org by va...@apache.org on 2019/10/17 21:43:42 UTC
[couchdb] branch check-metadata-first created (now b35a9f6)
This is an automated email from the ASF dual-hosted git repository.
vatamane pushed a change to branch check-metadata-first
in repository https://gitbox.apache.org/repos/asf/couchdb.git.
at b35a9f6 WIP
This branch includes the following new commits:
new b35a9f6 WIP
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[couchdb] 01/01: WIP
Posted by va...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
vatamane pushed a commit to branch check-metadata-first
in repository https://gitbox.apache.org/repos/asf/couchdb.git
commit b35a9f633dcb9498e2c5ca465b1b07588882aa2b
Author: Nick Vatamaniuc <va...@apache.org>
AuthorDate: Thu Oct 17 17:43:10 2019 -0400
WIP
---
src/fabric/include/fabric2.hrl | 2 +
src/fabric/src/fabric2_fdb.erl | 101 +++++++++++++++++++++---------
src/fabric/test/fabric2_db_misc_tests.erl | 25 +++++++-
3 files changed, 98 insertions(+), 30 deletions(-)
diff --git a/src/fabric/include/fabric2.hrl b/src/fabric/include/fabric2.hrl
index 3e22498..fe11e6b 100644
--- a/src/fabric/include/fabric2.hrl
+++ b/src/fabric/include/fabric2.hrl
@@ -59,8 +59,10 @@
-define(PDICT_DB_KEY, '$fabric_db_handle').
-define(PDICT_LAYER_CACHE, '$fabric_layer_id').
-define(PDICT_CHECKED_DB_IS_CURRENT, '$fabric_checked_db_is_current').
+-define(PDICT_CHECKED_MD_IS_CURRENT, '$fabric_checked_md_is_current').
-define(PDICT_TX_ID_KEY, '$fabric_tx_id').
-define(PDICT_TX_RES_KEY, '$fabric_tx_result').
+-define(PDICT_ON_COMMIT_FUN, '$fabric_on_commit_fun').
-define(COMMIT_UNKNOWN_RESULT, 1021).
diff --git a/src/fabric/src/fabric2_fdb.erl b/src/fabric/src/fabric2_fdb.erl
index 0f55d91..2bd01ad 100644
--- a/src/fabric/src/fabric2_fdb.erl
+++ b/src/fabric/src/fabric2_fdb.erl
@@ -864,6 +864,28 @@ bump_metadata_version(Tx) ->
erlfdb:set_versionstamped_value(Tx, ?METADATA_VERSION_KEY, <<0:112>>).
+check_metadata_version(#{} = Db) ->
+ #{
+ tx := Tx,
+ md_version := Version
+ } = Db,
+
+ AlreadyChecked = get(?PDICT_CHECKED_MD_IS_CURRENT),
+ if AlreadyChecked == true -> current; true ->
+ Snapshot = erlfdb:snapshot(Tx),
+ case erlfdb:wait(erlfdb:get(Snapshot, ?METADATA_VERSION_KEY)) of
+ Version ->
+ put(?PDICT_CHECKED_MD_IS_CURRENT, true),
+ current;
+ NewVersion ->
+ on_commit(Tx, fun() ->
+ fabric2_server:store(Db#{md_version := NewVersion})
+ end),
+ stale
+ end
+ end.
+
+
bump_db_version(#{} = Db) ->
#{
tx := Tx,
@@ -872,7 +894,29 @@ bump_db_version(#{} = Db) ->
DbVersionKey = erlfdb_tuple:pack({?DB_VERSION}, DbPrefix),
DbVersion = fabric2_util:uuid(),
- ok = erlfdb:set(Tx, DbVersionKey, DbVersion).
+ ok = erlfdb:set(Tx, DbVersionKey, DbVersion),
+ ok = bump_metadata_version(Tx).
+
+
+check_db_version(#{} = Db, CheckDbVersion) ->
+ #{
+ tx := Tx,
+ db_prefix := DbPrefix,
+ db_version := DbVersion
+ } = Db,
+
+ AlreadyChecked = get(?PDICT_CHECKED_DB_IS_CURRENT),
+ if not CheckDbVersion orelse AlreadyChecked == true -> Db; true ->
+ DbVersionKey = erlfdb_tuple:pack({?DB_VERSION}, DbPrefix),
+ case erlfdb:wait(erlfdb:get(Tx, DbVersionKey)) of
+ DbVersion ->
+ put(?PDICT_CHECKED_DB_IS_CURRENT, true),
+ Db;
+ _NewDBVersion ->
+ fabric2_server:remove(maps:get(name, Db)),
+ throw({?MODULE, reopen})
+ end
+ end.
write_doc_body(#{} = Db0, #doc{} = Doc) ->
@@ -1171,34 +1215,9 @@ ensure_current(Db) ->
ensure_current(#{} = Db, CheckDbVersion) ->
require_transaction(Db),
-
- #{
- tx := Tx,
- md_version := MetaDataVersion
- } = Db,
-
- case erlfdb:wait(erlfdb:get(Tx, ?METADATA_VERSION_KEY)) of
- MetaDataVersion -> Db;
- _NewVersion -> throw({?MODULE, reopen})
- end,
-
- AlreadyChecked = get(?PDICT_CHECKED_DB_IS_CURRENT),
- if not CheckDbVersion orelse AlreadyChecked == true -> Db; true ->
- #{
- db_prefix := DbPrefix,
- db_version := DbVersion
- } = Db,
-
- DbVersionKey = erlfdb_tuple:pack({?DB_VERSION}, DbPrefix),
-
- case erlfdb:wait(erlfdb:get(Tx, DbVersionKey)) of
- DbVersion ->
- put(?PDICT_CHECKED_DB_IS_CURRENT, true),
- Db;
- _NewDBVersion ->
- fabric2_server:remove(maps:get(name, Db)),
- throw({?MODULE, reopen})
- end
+ case check_metadata_version(Db) of
+ current -> Db;
+ stale -> check_db_version(Db, CheckDbVersion)
end.
@@ -1222,12 +1241,14 @@ execute_transaction(Tx, Fun, LayerPrefix) ->
erlfdb:set(Tx, get_transaction_id(Tx, LayerPrefix), <<>>),
put(?PDICT_TX_RES_KEY, Result)
end,
+ ok = run_on_commit_fun(Tx),
Result.
clear_transaction() ->
fabric2_txids:remove(get(?PDICT_TX_ID_KEY)),
erase(?PDICT_CHECKED_DB_IS_CURRENT),
+ erase(?PDICT_CHECKED_MD_IS_CURRENT),
erase(?PDICT_TX_ID_KEY),
erase(?PDICT_TX_RES_KEY).
@@ -1259,3 +1280,25 @@ new_versionstamp(Tx) ->
TxId = erlfdb:get_next_tx_id(Tx),
{versionstamp, 16#FFFFFFFFFFFFFFFF, 16#FFFF, TxId}.
+
+on_commit(Tx, Fun) when is_function(Fun, 0) ->
+ % Here we rely on Tx objects matching. However they contain a nif resource
+ % object. Before Erlang 20.0 those would have been represented as empty
+ % binaries and would have compared equal to each other. See
+ % http://erlang.org/doc/man/erl_nif.html for more info. We assume we run on
+ % Erlang 20+ here and don't worry about that anymore.
+ case get({?PDICT_ON_COMMIT_FUN, Tx}) of
+ undefined -> put({?PDICT_ON_COMMIT_FUN, Tx}, Fun);
+ _ -> error({?MODULE, on_commit_function_already_set})
+ end.
+
+
+run_on_commit_fun(Tx) ->
+ case get({?PDICT_ON_COMMIT_FUN, Tx}) of
+ undefined ->
+ ok;
+ Fun when is_function(Fun, 0) ->
+ Fun(),
+ erase({?PDICT_ON_COMMIT_FUN, Tx}),
+ ok
+ end.
diff --git a/src/fabric/test/fabric2_db_misc_tests.erl b/src/fabric/test/fabric2_db_misc_tests.erl
index 8e64056..dc28f92 100644
--- a/src/fabric/test/fabric2_db_misc_tests.erl
+++ b/src/fabric/test/fabric2_db_misc_tests.erl
@@ -16,6 +16,7 @@
-include_lib("couch/include/couch_db.hrl").
-include_lib("couch/include/couch_eunit.hrl").
-include_lib("eunit/include/eunit.hrl").
+-include("fabric2.hrl").
-define(TDEF(A), {atom_to_list(A), fun A/1}).
@@ -34,7 +35,8 @@ misc_test_() ->
fun set_revs_limit/1,
fun set_security/1,
fun is_system_db/1,
- fun ensure_full_commit/1
+ fun ensure_full_commit/1,
+ fun metadata_bump/1
]}
}
}.
@@ -111,3 +113,24 @@ is_system_db({DbName, Db, _}) ->
ensure_full_commit({_, Db, _}) ->
?assertEqual({ok, 0}, fabric2_db:ensure_full_commit(Db)),
?assertEqual({ok, 0}, fabric2_db:ensure_full_commit(Db, 5)).
+
+
+metadata_bump({DbName, _, _}) ->
+ % Call open again here to make sure we have a version in the cache
+ % as we'll be checking if that version gets its metadata bumped
+ {ok, Db} = fabric2_db:open(DbName, [{user_ctx, ?ADMIN_USER}]),
+
+ % Emulate a remote client bumping the metadataversion
+ {ok, Fdb} = application:get_env(fabric, db),
+ erlfdb:transactional(Fdb, fun(Tx) ->
+ erlfdb:set_versionstamped_value(Tx, ?METADATA_VERSION_KEY, <<0:112>>)
+ end),
+ NewMDVersion = erlfdb:transactional(Fdb, fun(Tx) ->
+ erlfdb:wait(erlfdb:get(Tx, ?METADATA_VERSION_KEY))
+ end),
+
+ % Perform a random operation which calls ensure_current
+ {ok, _} = fabric2_db:get_db_info(Db),
+
+ % Check that db handle in the cache got the new metadata version
+ ?assertMatch(#{md_version := NewMDVersion}, fabric2_server:fetch(DbName)).