Files
gerrit/proto/cache.proto
Dave Borowitz bab45861b7 Optionally persist ChangeNotesCache
Loading ChangeNotes into the ChangeNotesCache should generally be pretty
fast when the underlying git repository storage is fast, but there are
some situations where that is not the case:

* The repo hasn't been GC'ed in a while, so may contain a lot of loose
  objects.
* On googlesource.com using the JGit DFS backend, when GC has happened
  recently and the DFS block cache is cold.

These problems are particularly noticeable on a cold server start.

As an optional optimization, allow persisting the ChangeNotesCache. For
installations where cache loading latency hasn't proven to be a problem,
it may not be worth the disk space, but we think it will make a
difference for googlesource.com.

Writing the necessary protos was a bit of work, but actually the
marginal cost of tweaking fields should be relatively low, and any
change should cause a small test to fail, so we should be able to detect
any changes as they arise. I explicitly chose to reuse existing
serialization mechanisms where possible (ProtobufCodecs, JSON), to limit
the size of this change. This is just cache data, so it's not like it
has to be particularly pretty or long-lasting.

This change is not intended to indicate we are giving up on optimizing
loading ChangeNotes from storage, but is more of a bandaid for fixing
performance problems in production today.

Change-Id: I1ffe15fe56b6822b7f9af55635b063793e66d6fd
2018-05-18 11:17:49 -04:00

187 lines
5.4 KiB
Protocol Buffer

// Copyright (C) 2018 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
syntax = "proto3";
package gerrit.cache;
option java_package = "com.google.gerrit.server.cache.proto";
// Serialized form of com.google.gerrit.server.change.CHangeKindCacheImpl.Key.
// Next ID: 4
message ChangeKindKeyProto {
bytes prior = 1;
bytes next = 2;
string strategy_name = 3;
}
// Serialized form of
// com.google.gerrit.server.change.MergeabilityCacheImpl.EntryKey.
// Next ID: 5
message MergeabilityKeyProto {
bytes commit = 1;
bytes into = 2;
string submit_type = 3;
string merge_strategy = 4;
}
// Serialized form of com.google.gerrit.extensions.auth.oauth.OAuthToken.
// Next ID: 6
message OAuthTokenProto {
string token = 1;
string secret = 2;
string raw = 3;
int64 expires_at = 4;
string provider_id = 5;
}
// Serialized form of com.google.gerrit.server.notedb.ChangeNotesCache.Key.
// Next ID: 4
message ChangeNotesKeyProto {
string project = 1;
int32 change_id = 2;
bytes id = 3;
}
// Serialized from of com.google.gerrit.server.notedb.ChangeNotesState.
//
// Note on embedded protos: this is just for storing in a cache, so some formats
// were chosen ease of coding the initial implementation. In particular, where
// there already exists another serialization mechanism in Gerrit for
// serializing a particular field, we use that rather than defining a new proto
// type. This includes ReviewDb types that can be serialized to proto using
// ProtobufCodec as well as NoteDb and indexed types that are serialized using
// JSON. We can always revisit this decision later, particularly when we
// eliminate the ReviewDb types; it just requires bumping the cache version.
//
// Note on nullability: there are a lot of nullable fields in ChangeNotesState
// and its dependencies. It's likely we could make some of them non-nullable,
// but each one of those would be a potentially significant amount of cleanup,
// and there's no guarantee we'd be able to eliminate all of them. (For a less
// complex class, it's likely the cleanup would be more feasible.)
//
// Instead, we just take the tedious yet simple approach of having a "has_foo"
// field for each nullable field "foo", indicating whether or not foo is null.
//
// Next ID: 19
message ChangeNotesStateProto {
// Effectively required, even though the corresponding ChangeNotesState field
// is optional, since the field is only absent when NoteDb is disabled, in
// which case attempting to use the ChangeNotesCache is programmer error.
bytes meta_id = 1;
int32 change_id = 2;
// Next ID: 24
message ChangeColumnsProto {
string change_key = 1;
int64 created_on = 2;
int64 last_updated_on = 3;
int32 owner = 4;
string branch = 5;
int32 current_patch_set_id = 6;
bool has_current_patch_set_id = 7;
string subject = 8;
string topic = 9;
bool has_topic = 10;
string original_subject = 11;
bool has_original_subject = 12;
string submission_id = 13;
bool has_submission_id = 14;
int32 assignee = 15;
bool has_assignee = 16;
string status = 17;
bool has_status = 18;
bool is_private = 19;
bool work_in_progress = 20;
bool review_started = 21;
int32 revert_of = 22;
bool has_revert_of = 23;
}
// Effectively required, even though the corresponding ChangeNotesState field
// is optional, since the field is only absent when NoteDb is disabled, in
// which case attempting to use the ChangeNotesCache is programmer error.
ChangeColumnsProto columns = 3;
repeated int32 past_assignee = 4;
repeated string hashtag = 5;
// Raw PatchSet proto as produced by ProtobufCodec.
repeated bytes patch_set = 6;
// Raw PatchSetApproval proto as produced by ProtobufCodec.
repeated bytes approval = 7;
// Next ID: 4
message ReviewerSetEntryProto {
string state = 1;
int32 account_id = 2;
int64 timestamp = 3;
}
repeated ReviewerSetEntryProto reviewer = 8;
// Next ID: 4
message ReviewerByEmailSetEntryProto {
string state = 1;
string address = 2;
int64 timestamp = 3;
}
repeated ReviewerByEmailSetEntryProto reviewer_by_email = 9;
repeated ReviewerSetEntryProto pending_reviewer = 10;
repeated ReviewerByEmailSetEntryProto pending_reviewer_by_email = 11;
repeated int32 past_reviewer = 12;
// Next ID: 5
message ReviewerStatusUpdateProto {
int64 date = 1;
int32 updated_by = 2;
int32 reviewer = 3;
string state = 4;
}
repeated ReviewerStatusUpdateProto reviewer_update = 13;
// JSON produced from
// com.google.gerrit.server.index.change.ChangeField.StoredSubmitRecord.
repeated string submit_record = 14;
// Raw ChangeMessage proto as produced by ProtobufCodec.
repeated bytes change_message = 15;
// JSON produced from com.google.gerrit.reviewdb.client.Comment.
repeated string published_comment = 16;
int64 read_only_until = 17;
bool has_read_only_until = 18;
}