1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "sync/engine/process_updates_command.h"
#include <vector>
#include "base/basictypes.h"
#include "base/location.h"
#include "sync/engine/syncer.h"
#include "sync/engine/syncer_proto_util.h"
#include "sync/engine/syncer_util.h"
#include "sync/sessions/sync_session.h"
#include "sync/syncable/directory.h"
#include "sync/syncable/mutable_entry.h"
#include "sync/syncable/syncable_proto_util.h"
#include "sync/syncable/syncable_util.h"
#include "sync/syncable/write_transaction.h"
#include "sync/util/cryptographer.h"
using std::vector;
namespace syncer {
using sessions::SyncSession;
using sessions::StatusController;
using sessions::UpdateProgress;
ProcessUpdatesCommand::ProcessUpdatesCommand() {}
ProcessUpdatesCommand::~ProcessUpdatesCommand() {}
std::set<ModelSafeGroup> ProcessUpdatesCommand::GetGroupsToChange(
const sessions::SyncSession& session) const {
return session.GetEnabledGroupsWithVerifiedUpdates();
}
SyncerError ProcessUpdatesCommand::ModelChangingExecuteImpl(
SyncSession* session) {
syncable::Directory* dir = session->context()->directory();
const sessions::UpdateProgress* progress =
session->status_controller().update_progress();
if (!progress)
return SYNCER_OK; // Nothing to do.
syncable::WriteTransaction trans(FROM_HERE, syncable::SYNCER, dir);
vector<sessions::VerifiedUpdate>::const_iterator it;
for (it = progress->VerifiedUpdatesBegin();
it != progress->VerifiedUpdatesEnd();
++it) {
const sync_pb::SyncEntity& update = it->second;
if (it->first != VERIFY_SUCCESS && it->first != VERIFY_UNDELETE)
continue;
switch (ProcessUpdate(update,
dir->GetCryptographer(&trans),
&trans)) {
case SUCCESS_PROCESSED:
case SUCCESS_STORED:
break;
default:
NOTREACHED();
break;
}
}
StatusController* status = session->mutable_status_controller();
status->mutable_update_progress()->ClearVerifiedUpdates();
return SYNCER_OK;
}
namespace {
// Returns true if the entry is still ok to process.
bool ReverifyEntry(syncable::WriteTransaction* trans,
const sync_pb::SyncEntity& entry,
syncable::MutableEntry* same_id) {
const bool deleted = entry.has_deleted() && entry.deleted();
const bool is_directory = IsFolder(entry);
const ModelType model_type = GetModelType(entry);
return VERIFY_SUCCESS == VerifyUpdateConsistency(trans,
entry,
same_id,
deleted,
is_directory,
model_type);
}
} // namespace
// Process a single update. Will avoid touching global state.
ServerUpdateProcessingResult ProcessUpdatesCommand::ProcessUpdate(
const sync_pb::SyncEntity& update,
const Cryptographer* cryptographer,
syncable::WriteTransaction* const trans) {
const syncable::Id& server_id = SyncableIdFromProto(update.id_string());
const std::string name = SyncerProtoUtil::NameFromSyncEntity(update);
// Look to see if there's a local item that should recieve this update,
// maybe due to a duplicate client tag or a lost commit response.
syncable::Id local_id = FindLocalIdToUpdate(trans, update);
// FindLocalEntryToUpdate has veto power.
if (local_id.IsNull()) {
return SUCCESS_PROCESSED; // The entry has become irrelevant.
}
CreateNewEntry(trans, local_id);
// We take a two step approach. First we store the entries data in the
// server fields of a local entry and then move the data to the local fields
syncable::MutableEntry target_entry(trans, syncable::GET_BY_ID, local_id);
// We need to run the Verify checks again; the world could have changed
// since VerifyUpdatesCommand.
if (!ReverifyEntry(trans, update, &target_entry)) {
return SUCCESS_PROCESSED; // The entry has become irrelevant.
}
// If we're repurposing an existing local entry with a new server ID,
// change the ID now, after we're sure that the update can succeed.
if (local_id != server_id) {
DCHECK(!update.deleted());
ChangeEntryIDAndUpdateChildren(trans, &target_entry, server_id);
// When IDs change, versions become irrelevant. Forcing BASE_VERSION
// to zero would ensure that this update gets applied, but would indicate
// creation or undeletion if it were committed that way. Instead, prefer
// forcing BASE_VERSION to entry.version() while also forcing
// IS_UNAPPLIED_UPDATE to true. If the item is UNSYNCED, it's committable
// from the new state; it may commit before the conflict resolver gets
// a crack at it.
if (target_entry.Get(syncable::IS_UNSYNCED) ||
target_entry.Get(syncable::BASE_VERSION) > 0) {
// If either of these conditions are met, then we can expect valid client
// fields for this entry. When BASE_VERSION is positive, consistency is
// enforced on the client fields at update-application time. Otherwise,
// we leave the BASE_VERSION field alone; it'll get updated the first time
// we successfully apply this update.
target_entry.Put(syncable::BASE_VERSION, update.version());
}
// Force application of this update, no matter what.
target_entry.Put(syncable::IS_UNAPPLIED_UPDATE, true);
}
// If this is a newly received undecryptable update, and the only thing that
// has changed are the specifics, store the original decryptable specifics,
// (on which any current or future local changes are based) before we
// overwrite SERVER_SPECIFICS.
// MTIME, CTIME, and NON_UNIQUE_NAME are not enforced.
if (!update.deleted() && !target_entry.Get(syncable::SERVER_IS_DEL) &&
(SyncableIdFromProto(update.parent_id_string()) ==
target_entry.Get(syncable::SERVER_PARENT_ID)) &&
(update.position_in_parent() ==
target_entry.Get(syncable::SERVER_POSITION_IN_PARENT)) &&
update.has_specifics() && update.specifics().has_encrypted() &&
!cryptographer->CanDecrypt(update.specifics().encrypted())) {
sync_pb::EntitySpecifics prev_specifics =
target_entry.Get(syncable::SERVER_SPECIFICS);
// We only store the old specifics if they were decryptable and applied and
// there is no BASE_SERVER_SPECIFICS already. Else do nothing.
if (!target_entry.Get(syncable::IS_UNAPPLIED_UPDATE) &&
!IsRealDataType(GetModelTypeFromSpecifics(
target_entry.Get(syncable::BASE_SERVER_SPECIFICS))) &&
(!prev_specifics.has_encrypted() ||
cryptographer->CanDecrypt(prev_specifics.encrypted()))) {
DVLOG(2) << "Storing previous server specifcs: "
<< prev_specifics.SerializeAsString();
target_entry.Put(syncable::BASE_SERVER_SPECIFICS, prev_specifics);
}
} else if (IsRealDataType(GetModelTypeFromSpecifics(
target_entry.Get(syncable::BASE_SERVER_SPECIFICS)))) {
// We have a BASE_SERVER_SPECIFICS, but a subsequent non-specifics-only
// change arrived. As a result, we can't use the specifics alone to detect
// changes, so we clear BASE_SERVER_SPECIFICS.
target_entry.Put(syncable::BASE_SERVER_SPECIFICS,
sync_pb::EntitySpecifics());
}
UpdateServerFieldsFromUpdate(&target_entry, update, name);
return SUCCESS_PROCESSED;
}
} // namespace syncer
|
