components/sync_driver/generic_change_processor.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/sync_driver/generic_change_processor.h"
   6
   7 #include "base/location.h"
   8 #include "base/strings/string_number_conversions.h"
   9 #include "base/strings/utf_string_conversions.h"
  10 #include "components/sync_driver/sync_api_component_factory.h"
  11 #include "sync/api/sync_change.h"
  12 #include "sync/api/sync_error.h"
  13 #include "sync/api/syncable_service.h"
  14 #include "sync/internal_api/public/base_node.h"
  15 #include "sync/internal_api/public/change_record.h"
  16 #include "sync/internal_api/public/read_node.h"
  17 #include "sync/internal_api/public/read_transaction.h"
  18 #include "sync/internal_api/public/util/unrecoverable_error_handler.h"
  19 #include "sync/internal_api/public/write_node.h"
  20 #include "sync/internal_api/public/write_transaction.h"
  21 #include "sync/syncable/entry.h"  // TODO(tim): Bug 123674.
  22
  23 namespace sync_driver {
  24
  25 namespace {
  26
  27 const int kContextSizeLimit = 1024;  // Datatype context size limit.
  28
  29 void SetNodeSpecifics(const sync_pb::EntitySpecifics& entity_specifics,
  30                       syncer::WriteNode* write_node) {
  31   if (syncer::GetModelTypeFromSpecifics(entity_specifics) ==
  32           syncer::PASSWORDS) {
  33     write_node->SetPasswordSpecifics(
  34         entity_specifics.password().client_only_encrypted_data());
  35   } else {
  36     write_node->SetEntitySpecifics(entity_specifics);
  37   }
  38 }
  39
  40 // Helper function to convert AttachmentId to AttachmentMetadataRecord.
  41 sync_pb::AttachmentMetadataRecord AttachmentIdToRecord(
  42     const syncer::AttachmentId& attachment_id) {
  43   sync_pb::AttachmentMetadataRecord record;
  44   *record.mutable_id() = attachment_id.GetProto();
  45   return record;
  46 }
  47
  48 // Replace |write_nodes|'s attachment ids with |attachment_ids|.
  49 void SetAttachmentMetadata(const syncer::AttachmentIdList& attachment_ids,
  50                            syncer::WriteNode* write_node) {
  51   DCHECK(write_node);
  52   sync_pb::AttachmentMetadata attachment_metadata;
  53   std::transform(
  54       attachment_ids.begin(),
  55       attachment_ids.end(),
  56       RepeatedFieldBackInserter(attachment_metadata.mutable_record()),
  57       AttachmentIdToRecord);
  58   write_node->SetAttachmentMetadata(attachment_metadata);
  59 }
  60
  61 syncer::SyncData BuildRemoteSyncData(
  62     int64 sync_id,
  63     const syncer::BaseNode& read_node,
  64     const syncer::AttachmentServiceProxy& attachment_service_proxy) {
  65   const syncer::AttachmentIdList& attachment_ids = read_node.GetAttachmentIds();
  66   // Use the specifics of non-password datatypes directly (encryption has
  67   // already been handled).
  68   if (read_node.GetModelType() != syncer::PASSWORDS) {
  69     return syncer::SyncData::CreateRemoteData(sync_id,
  70                                               read_node.GetEntitySpecifics(),
  71                                               read_node.GetModificationTime(),
  72                                               attachment_ids,
  73                                               attachment_service_proxy);
  74   }
  75
  76   // Passwords must be accessed differently, to account for their encryption,
  77   // and stored into a temporary EntitySpecifics.
  78   sync_pb::EntitySpecifics password_holder;
  79   password_holder.mutable_password()->mutable_client_only_encrypted_data()->
  80       CopyFrom(read_node.GetPasswordSpecifics());
  81   return syncer::SyncData::CreateRemoteData(sync_id,
  82                                             password_holder,
  83                                             read_node.GetModificationTime(),
  84                                             attachment_ids,
  85                                             attachment_service_proxy);
  86 }
  87
  88 }  // namespace
  89
  90 GenericChangeProcessor::GenericChangeProcessor(
  91     syncer::ModelType type,
  92     DataTypeErrorHandler* error_handler,
  93     const base::WeakPtr<syncer::SyncableService>& local_service,
  94     const base::WeakPtr<syncer::SyncMergeResult>& merge_result,
  95     syncer::UserShare* user_share,
  96     SyncApiComponentFactory* sync_factory,
  97     const scoped_refptr<syncer::AttachmentStore>& attachment_store)
  98     : ChangeProcessor(error_handler),
  99       type_(type),
 100       local_service_(local_service),
 101       merge_result_(merge_result),
 102       share_handle_(user_share),
 103       weak_ptr_factory_(this) {
 104   DCHECK(CalledOnValidThread());
 105   DCHECK_NE(type_, syncer::UNSPECIFIED);
 106   if (attachment_store.get()) {
 107     attachment_service_ = sync_factory->CreateAttachmentService(
 108         attachment_store, *user_share, this);
 109     attachment_service_weak_ptr_factory_.reset(
 110         new base::WeakPtrFactory<syncer::AttachmentService>(
 111             attachment_service_.get()));
 112     attachment_service_proxy_.reset(new syncer::AttachmentServiceProxy(
 113         base::MessageLoopProxy::current(),
 114         attachment_service_weak_ptr_factory_->GetWeakPtr()));
 115     UploadAllAttachmentsNotOnServer();
 116   } else {
 117     attachment_service_proxy_.reset(new syncer::AttachmentServiceProxy(
 118         base::MessageLoopProxy::current(),
 119         base::WeakPtr<syncer::AttachmentService>()));
 120   }
 121 }
 122
 123 GenericChangeProcessor::~GenericChangeProcessor() {
 124   DCHECK(CalledOnValidThread());
 125 }
 126
 127 void GenericChangeProcessor::ApplyChangesFromSyncModel(
 128     const syncer::BaseTransaction* trans,
 129     int64 model_version,
 130     const syncer::ImmutableChangeRecordList& changes) {
 131   DCHECK(CalledOnValidThread());
 132   DCHECK(syncer_changes_.empty());
 133   for (syncer::ChangeRecordList::const_iterator it =
 134            changes.Get().begin(); it != changes.Get().end(); ++it) {
 135     if (it->action == syncer::ChangeRecord::ACTION_DELETE) {
 136       scoped_ptr<sync_pb::EntitySpecifics> specifics;
 137       if (it->specifics.has_password()) {
 138         DCHECK(it->extra.get());
 139         specifics.reset(new sync_pb::EntitySpecifics(it->specifics));
 140         specifics->mutable_password()->mutable_client_only_encrypted_data()->
 141             CopyFrom(it->extra->unencrypted());
 142       }
 143       const syncer::AttachmentIdList empty_list_of_attachment_ids;
 144       syncer_changes_.push_back(
 145           syncer::SyncChange(FROM_HERE,
 146                              syncer::SyncChange::ACTION_DELETE,
 147                              syncer::SyncData::CreateRemoteData(
 148                                  it->id,
 149                                  specifics ? *specifics : it->specifics,
 150                                  base::Time(),
 151                                  empty_list_of_attachment_ids,
 152                                  *attachment_service_proxy_)));
 153     } else {
 154       syncer::SyncChange::SyncChangeType action =
 155           (it->action == syncer::ChangeRecord::ACTION_ADD) ?
 156           syncer::SyncChange::ACTION_ADD : syncer::SyncChange::ACTION_UPDATE;
 157       // Need to load specifics from node.
 158       syncer::ReadNode read_node(trans);
 159       if (read_node.InitByIdLookup(it->id) != syncer::BaseNode::INIT_OK) {
 160         syncer::SyncError error(
 161             FROM_HERE,
 162             syncer::SyncError::DATATYPE_ERROR,
 163             "Failed to look up data for received change with id " +
 164                 base::Int64ToString(it->id),
 165             syncer::GetModelTypeFromSpecifics(it->specifics));
 166         error_handler()->OnSingleDataTypeUnrecoverableError(error);
 167         return;
 168       }
 169       syncer_changes_.push_back(syncer::SyncChange(
 170           FROM_HERE,
 171           action,
 172           BuildRemoteSyncData(it->id, read_node, *attachment_service_proxy_)));
 173     }
 174   }
 175 }
 176
 177 void GenericChangeProcessor::CommitChangesFromSyncModel() {
 178   DCHECK(CalledOnValidThread());
 179   if (syncer_changes_.empty())
 180     return;
 181   if (!local_service_.get()) {
 182     syncer::ModelType type = syncer_changes_[0].sync_data().GetDataType();
 183     syncer::SyncError error(FROM_HERE,
 184                             syncer::SyncError::DATATYPE_ERROR,
 185                             "Local service destroyed.",
 186                             type);
 187     error_handler()->OnSingleDataTypeUnrecoverableError(error);
 188     return;
 189   }
 190   syncer::SyncError error = local_service_->ProcessSyncChanges(FROM_HERE,
 191                                                        syncer_changes_);
 192   syncer_changes_.clear();
 193   if (error.IsSet())
 194     error_handler()->OnSingleDataTypeUnrecoverableError(error);
 195 }
 196
 197 syncer::SyncDataList GenericChangeProcessor::GetAllSyncData(
 198     syncer::ModelType type) const {
 199   DCHECK_EQ(type_, type);
 200   // This is slow / memory intensive.  Should be used sparingly by datatypes.
 201   syncer::SyncDataList data;
 202   GetAllSyncDataReturnError(&data);
 203   return data;
 204 }
 205
 206 syncer::SyncError GenericChangeProcessor::UpdateDataTypeContext(
 207     syncer::ModelType type,
 208     syncer::SyncChangeProcessor::ContextRefreshStatus refresh_status,
 209     const std::string& context) {
 210   DCHECK(syncer::ProtocolTypes().Has(type));
 211   DCHECK_EQ(type_, type);
 212
 213   if (context.size() > static_cast<size_t>(kContextSizeLimit)) {
 214     return syncer::SyncError(FROM_HERE,
 215                              syncer::SyncError::DATATYPE_ERROR,
 216                              "Context size limit exceeded.",
 217                              type);
 218   }
 219
 220   syncer::WriteTransaction trans(FROM_HERE, share_handle());
 221   trans.SetDataTypeContext(type, refresh_status, context);
 222
 223   // TODO(zea): plumb a pointer to the PSS or SyncManagerImpl here so we can
 224   // trigger a datatype nudge if |refresh_status == REFRESH_NEEDED|.
 225
 226   return syncer::SyncError();
 227 }
 228
 229 void GenericChangeProcessor::OnAttachmentUploaded(
 230     const syncer::AttachmentId& attachment_id) {
 231   syncer::WriteTransaction trans(FROM_HERE, share_handle());
 232   trans.UpdateEntriesMarkAttachmentAsOnServer(attachment_id);
 233 }
 234
 235 syncer::SyncError GenericChangeProcessor::GetAllSyncDataReturnError(
 236     syncer::SyncDataList* current_sync_data) const {
 237   DCHECK(CalledOnValidThread());
 238   std::string type_name = syncer::ModelTypeToString(type_);
 239   syncer::ReadTransaction trans(FROM_HERE, share_handle());
 240   syncer::ReadNode root(&trans);
 241   if (root.InitTypeRoot(type_) != syncer::BaseNode::INIT_OK) {
 242     syncer::SyncError error(FROM_HERE,
 243                             syncer::SyncError::DATATYPE_ERROR,
 244                             "Server did not create the top-level " + type_name +
 245                                 " node. We might be running against an out-of-"
 246                                 "date server.",
 247                             type_);
 248     return error;
 249   }
 250
 251   // TODO(akalin): We'll have to do a tree traversal for bookmarks.
 252   DCHECK_NE(type_, syncer::BOOKMARKS);
 253
 254   std::vector<int64> child_ids;
 255   root.GetChildIds(&child_ids);
 256
 257   for (std::vector<int64>::iterator it = child_ids.begin();
 258        it != child_ids.end(); ++it) {
 259     syncer::ReadNode sync_child_node(&trans);
 260     if (sync_child_node.InitByIdLookup(*it) !=
 261             syncer::BaseNode::INIT_OK) {
 262       syncer::SyncError error(
 263           FROM_HERE,
 264           syncer::SyncError::DATATYPE_ERROR,
 265           "Failed to fetch child node for type " + type_name + ".",
 266           type_);
 267       return error;
 268     }
 269     current_sync_data->push_back(BuildRemoteSyncData(
 270         sync_child_node.GetId(), sync_child_node, *attachment_service_proxy_));
 271   }
 272   return syncer::SyncError();
 273 }
 274
 275 bool GenericChangeProcessor::GetDataTypeContext(std::string* context) const {
 276   syncer::ReadTransaction trans(FROM_HERE, share_handle());
 277   sync_pb::DataTypeContext context_proto;
 278   trans.GetDataTypeContext(type_, &context_proto);
 279   if (!context_proto.has_context())
 280     return false;
 281
 282   DCHECK_EQ(type_,
 283             syncer::GetModelTypeFromSpecificsFieldNumber(
 284                 context_proto.data_type_id()));
 285   *context = context_proto.context();
 286   return true;
 287 }
 288
 289 int GenericChangeProcessor::GetSyncCount() {
 290   syncer::ReadTransaction trans(FROM_HERE, share_handle());
 291   syncer::ReadNode root(&trans);
 292   if (root.InitTypeRoot(type_) != syncer::BaseNode::INIT_OK)
 293     return 0;
 294
 295   // Subtract one to account for type's root node.
 296   return root.GetTotalNodeCount() - 1;
 297 }
 298
 299 namespace {
 300
 301 // WARNING: this code is sensitive to compiler optimizations. Be careful
 302 // modifying any code around an OnSingleDataTypeUnrecoverableError call, else
 303 // the compiler attempts to merge it with other calls, losing useful information
 304 // in breakpad uploads.
 305 syncer::SyncError LogLookupFailure(
 306     syncer::BaseNode::InitByLookupResult lookup_result,
 307     const tracked_objects::Location& from_here,
 308     const std::string& error_prefix,
 309     syncer::ModelType type,
 310     DataTypeErrorHandler* error_handler) {
 311   switch (lookup_result) {
 312     case syncer::BaseNode::INIT_FAILED_ENTRY_NOT_GOOD: {
 313       syncer::SyncError error;
 314       error.Reset(from_here,
 315                   error_prefix +
 316                       "could not find entry matching the lookup criteria.",
 317                   type);
 318       error_handler->OnSingleDataTypeUnrecoverableError(error);
 319       LOG(ERROR) << "Delete: Bad entry.";
 320       return error;
 321     }
 322     case syncer::BaseNode::INIT_FAILED_ENTRY_IS_DEL: {
 323       syncer::SyncError error;
 324       error.Reset(from_here, error_prefix + "entry is already deleted.", type);
 325       error_handler->OnSingleDataTypeUnrecoverableError(error);
 326       LOG(ERROR) << "Delete: Deleted entry.";
 327       return error;
 328     }
 329     case syncer::BaseNode::INIT_FAILED_DECRYPT_IF_NECESSARY: {
 330       syncer::SyncError error;
 331       error.Reset(from_here, error_prefix + "unable to decrypt", type);
 332       error_handler->OnSingleDataTypeUnrecoverableError(error);
 333       LOG(ERROR) << "Delete: Undecryptable entry.";
 334       return error;
 335     }
 336     case syncer::BaseNode::INIT_FAILED_PRECONDITION: {
 337       syncer::SyncError error;
 338       error.Reset(from_here,
 339                   error_prefix + "a precondition was not met for calling init.",
 340                   type);
 341       error_handler->OnSingleDataTypeUnrecoverableError(error);
 342       LOG(ERROR) << "Delete: Failed precondition.";
 343       return error;
 344     }
 345     default: {
 346       syncer::SyncError error;
 347       // Should have listed all the possible error cases above.
 348       error.Reset(from_here, error_prefix + "unknown error", type);
 349       error_handler->OnSingleDataTypeUnrecoverableError(error);
 350       LOG(ERROR) << "Delete: Unknown error.";
 351       return error;
 352     }
 353   }
 354 }
 355
 356 syncer::SyncError AttemptDelete(const syncer::SyncChange& change,
 357                                 syncer::ModelType type,
 358                                 const std::string& type_str,
 359                                 syncer::WriteNode* node,
 360                                 DataTypeErrorHandler* error_handler) {
 361   DCHECK_EQ(change.change_type(), syncer::SyncChange::ACTION_DELETE);
 362   if (change.sync_data().IsLocal()) {
 363     const std::string& tag = syncer::SyncDataLocal(change.sync_data()).GetTag();
 364     if (tag.empty()) {
 365       syncer::SyncError error(
 366           FROM_HERE,
 367           syncer::SyncError::DATATYPE_ERROR,
 368           "Failed to delete " + type_str + " node. Local data, empty tag. " +
 369               change.location().ToString(),
 370           type);
 371       error_handler->OnSingleDataTypeUnrecoverableError(error);
 372       NOTREACHED();
 373       return error;
 374     }
 375
 376     syncer::BaseNode::InitByLookupResult result =
 377         node->InitByClientTagLookup(change.sync_data().GetDataType(), tag);
 378     if (result != syncer::BaseNode::INIT_OK) {
 379       return LogLookupFailure(
 380           result, FROM_HERE,
 381           "Failed to delete " + type_str + " node. Local data. " +
 382               change.location().ToString(),
 383           type, error_handler);
 384     }
 385   } else {
 386     syncer::BaseNode::InitByLookupResult result = node->InitByIdLookup(
 387         syncer::SyncDataRemote(change.sync_data()).GetId());
 388     if (result != syncer::BaseNode::INIT_OK) {
 389       return LogLookupFailure(
 390           result, FROM_HERE,
 391           "Failed to delete " + type_str + " node. Non-local data. " +
 392               change.location().ToString(),
 393           type, error_handler);
 394     }
 395   }
 396   if (IsActOnceDataType(type))
 397     node->Drop();
 398   else
 399     node->Tombstone();
 400   return syncer::SyncError();
 401 }
 402
 403 }  // namespace
 404
 405 syncer::SyncError GenericChangeProcessor::ProcessSyncChanges(
 406     const tracked_objects::Location& from_here,
 407     const syncer::SyncChangeList& list_of_changes) {
 408   DCHECK(CalledOnValidThread());
 409
 410   // Keep track of brand new attachments so we can persist them on this device
 411   // and upload them to the server.
 412   syncer::AttachmentIdSet new_attachments;
 413
 414   syncer::WriteTransaction trans(from_here, share_handle());
 415
 416   for (syncer::SyncChangeList::const_iterator iter = list_of_changes.begin();
 417        iter != list_of_changes.end();
 418        ++iter) {
 419     const syncer::SyncChange& change = *iter;
 420     DCHECK_EQ(change.sync_data().GetDataType(), type_);
 421     std::string type_str = syncer::ModelTypeToString(type_);
 422     syncer::WriteNode sync_node(&trans);
 423     if (change.change_type() == syncer::SyncChange::ACTION_DELETE) {
 424       syncer::SyncError error =
 425           AttemptDelete(change, type_, type_str, &sync_node, error_handler());
 426       if (error.IsSet()) {
 427         NOTREACHED();
 428         return error;
 429       }
 430       if (merge_result_.get()) {
 431         merge_result_->set_num_items_deleted(
 432             merge_result_->num_items_deleted() + 1);
 433       }
 434     } else if (change.change_type() == syncer::SyncChange::ACTION_ADD) {
 435       syncer::SyncError error = HandleActionAdd(
 436           change, type_str, trans, &sync_node, &new_attachments);
 437       if (error.IsSet()) {
 438         return error;
 439       }
 440     } else if (change.change_type() == syncer::SyncChange::ACTION_UPDATE) {
 441       syncer::SyncError error = HandleActionUpdate(
 442           change, type_str, trans, &sync_node, &new_attachments);
 443       if (error.IsSet()) {
 444         return error;
 445       }
 446     } else {
 447       syncer::SyncError error(
 448           FROM_HERE,
 449           syncer::SyncError::DATATYPE_ERROR,
 450           "Received unset SyncChange in the change processor, " +
 451               change.location().ToString(),
 452           type_);
 453       error_handler()->OnSingleDataTypeUnrecoverableError(error);
 454       NOTREACHED();
 455       LOG(ERROR) << "Unset sync change.";
 456       return error;
 457     }
 458   }
 459
 460   if (!new_attachments.empty()) {
 461     // If datatype uses attachments it should have supplied attachment store
 462     // which would initialize attachment_service_. Fail if it isn't so.
 463     if (!attachment_service_.get()) {
 464       syncer::SyncError error(
 465           FROM_HERE,
 466           syncer::SyncError::DATATYPE_ERROR,
 467           "Datatype performs attachment operation without initializing "
 468           "attachment store",
 469           type_);
 470       error_handler()->OnSingleDataTypeUnrecoverableError(error);
 471       NOTREACHED();
 472       return error;
 473     }
 474     attachment_service_->UploadAttachments(new_attachments);
 475   }
 476
 477   return syncer::SyncError();
 478 }
 479
 480 // WARNING: this code is sensitive to compiler optimizations. Be careful
 481 // modifying any code around an OnSingleDataTypeUnrecoverableError call, else
 482 // the compiler attempts to merge it with other calls, losing useful information
 483 // in breakpad uploads.
 484 syncer::SyncError GenericChangeProcessor::HandleActionAdd(
 485     const syncer::SyncChange& change,
 486     const std::string& type_str,
 487     const syncer::WriteTransaction& trans,
 488     syncer::WriteNode* sync_node,
 489     syncer::AttachmentIdSet* new_attachments) {
 490   // TODO(sync): Handle other types of creation (custom parents, folders,
 491   // etc.).
 492   syncer::ReadNode root_node(&trans);
 493   const syncer::SyncDataLocal sync_data_local(change.sync_data());
 494   if (root_node.InitTypeRoot(sync_data_local.GetDataType()) !=
 495       syncer::BaseNode::INIT_OK) {
 496     syncer::SyncError error(FROM_HERE,
 497                             syncer::SyncError::DATATYPE_ERROR,
 498                             "Failed to look up root node for type " + type_str,
 499                             type_);
 500     error_handler()->OnSingleDataTypeUnrecoverableError(error);
 501     NOTREACHED();
 502     LOG(ERROR) << "Create: no root node.";
 503     return error;
 504   }
 505   syncer::WriteNode::InitUniqueByCreationResult result =
 506       sync_node->InitUniqueByCreation(
 507           sync_data_local.GetDataType(), root_node, sync_data_local.GetTag());
 508   if (result != syncer::WriteNode::INIT_SUCCESS) {
 509     std::string error_prefix = "Failed to create " + type_str + " node: " +
 510                                change.location().ToString() + ", ";
 511     switch (result) {
 512       case syncer::WriteNode::INIT_FAILED_EMPTY_TAG: {
 513         syncer::SyncError error;
 514         error.Reset(FROM_HERE, error_prefix + "empty tag", type_);
 515         error_handler()->OnSingleDataTypeUnrecoverableError(error);
 516         LOG(ERROR) << "Create: Empty tag.";
 517         return error;
 518       }
 519       case syncer::WriteNode::INIT_FAILED_ENTRY_ALREADY_EXISTS: {
 520         syncer::SyncError error;
 521         error.Reset(FROM_HERE, error_prefix + "entry already exists", type_);
 522         error_handler()->OnSingleDataTypeUnrecoverableError(error);
 523         LOG(ERROR) << "Create: Entry exists.";
 524         return error;
 525       }
 526       case syncer::WriteNode::INIT_FAILED_COULD_NOT_CREATE_ENTRY: {
 527         syncer::SyncError error;
 528         error.Reset(FROM_HERE, error_prefix + "failed to create entry", type_);
 529         error_handler()->OnSingleDataTypeUnrecoverableError(error);
 530         LOG(ERROR) << "Create: Could not create entry.";
 531         return error;
 532       }
 533       case syncer::WriteNode::INIT_FAILED_SET_PREDECESSOR: {
 534         syncer::SyncError error;
 535         error.Reset(
 536             FROM_HERE, error_prefix + "failed to set predecessor", type_);
 537         error_handler()->OnSingleDataTypeUnrecoverableError(error);
 538         LOG(ERROR) << "Create: Bad predecessor.";
 539         return error;
 540       }
 541       default: {
 542         syncer::SyncError error;
 543         error.Reset(FROM_HERE, error_prefix + "unknown error", type_);
 544         error_handler()->OnSingleDataTypeUnrecoverableError(error);
 545         LOG(ERROR) << "Create: Unknown error.";
 546         return error;
 547       }
 548     }
 549   }
 550   sync_node->SetTitle(change.sync_data().GetTitle());
 551   SetNodeSpecifics(sync_data_local.GetSpecifics(), sync_node);
 552
 553   syncer::AttachmentIdList attachment_ids = sync_data_local.GetAttachmentIds();
 554   SetAttachmentMetadata(attachment_ids, sync_node);
 555
 556   // Return any newly added attachments.
 557   new_attachments->insert(attachment_ids.begin(), attachment_ids.end());
 558   if (merge_result_.get()) {
 559     merge_result_->set_num_items_added(merge_result_->num_items_added() + 1);
 560   }
 561   return syncer::SyncError();
 562 }
 563 // WARNING: this code is sensitive to compiler optimizations. Be careful
 564 // modifying any code around an OnSingleDataTypeUnrecoverableError call, else
 565 // the compiler attempts to merge it with other calls, losing useful information
 566 // in breakpad uploads.
 567 syncer::SyncError GenericChangeProcessor::HandleActionUpdate(
 568     const syncer::SyncChange& change,
 569     const std::string& type_str,
 570     const syncer::WriteTransaction& trans,
 571     syncer::WriteNode* sync_node,
 572     syncer::AttachmentIdSet* new_attachments) {
 573   // TODO(zea): consider having this logic for all possible changes?
 574
 575   const syncer::SyncDataLocal sync_data_local(change.sync_data());
 576   syncer::BaseNode::InitByLookupResult result =
 577       sync_node->InitByClientTagLookup(sync_data_local.GetDataType(),
 578                                        sync_data_local.GetTag());
 579   if (result != syncer::BaseNode::INIT_OK) {
 580     std::string error_prefix = "Failed to load " + type_str + " node. " +
 581                                change.location().ToString() + ", ";
 582     if (result == syncer::BaseNode::INIT_FAILED_PRECONDITION) {
 583       syncer::SyncError error;
 584       error.Reset(FROM_HERE, error_prefix + "empty tag", type_);
 585       error_handler()->OnSingleDataTypeUnrecoverableError(error);
 586       LOG(ERROR) << "Update: Empty tag.";
 587       return error;
 588     } else if (result == syncer::BaseNode::INIT_FAILED_ENTRY_NOT_GOOD) {
 589       syncer::SyncError error;
 590       error.Reset(FROM_HERE, error_prefix + "bad entry", type_);
 591       error_handler()->OnSingleDataTypeUnrecoverableError(error);
 592       LOG(ERROR) << "Update: bad entry.";
 593       return error;
 594     } else if (result == syncer::BaseNode::INIT_FAILED_ENTRY_IS_DEL) {
 595       syncer::SyncError error;
 596       error.Reset(FROM_HERE, error_prefix + "deleted entry", type_);
 597       error_handler()->OnSingleDataTypeUnrecoverableError(error);
 598       LOG(ERROR) << "Update: deleted entry.";
 599       return error;
 600     } else {
 601       syncer::Cryptographer* crypto = trans.GetCryptographer();
 602       syncer::ModelTypeSet encrypted_types(trans.GetEncryptedTypes());
 603       const sync_pb::EntitySpecifics& specifics =
 604           sync_node->GetEntry()->GetSpecifics();
 605       CHECK(specifics.has_encrypted());
 606       const bool can_decrypt = crypto->CanDecrypt(specifics.encrypted());
 607       const bool agreement = encrypted_types.Has(type_);
 608       if (!agreement && !can_decrypt) {
 609         syncer::SyncError error;
 610         error.Reset(FROM_HERE,
 611                     "Failed to load encrypted entry, missing key and "
 612                     "nigori mismatch for " +
 613                         type_str + ".",
 614                     type_);
 615         error_handler()->OnSingleDataTypeUnrecoverableError(error);
 616         LOG(ERROR) << "Update: encr case 1.";
 617         return error;
 618       } else if (agreement && can_decrypt) {
 619         syncer::SyncError error;
 620         error.Reset(FROM_HERE,
 621                     "Failed to load encrypted entry, we have the key "
 622                     "and the nigori matches (?!) for " +
 623                         type_str + ".",
 624                     type_);
 625         error_handler()->OnSingleDataTypeUnrecoverableError(error);
 626         LOG(ERROR) << "Update: encr case 2.";
 627         return error;
 628       } else if (agreement) {
 629         syncer::SyncError error;
 630         error.Reset(FROM_HERE,
 631                     "Failed to load encrypted entry, missing key and "
 632                     "the nigori matches for " +
 633                         type_str + ".",
 634                     type_);
 635         error_handler()->OnSingleDataTypeUnrecoverableError(error);
 636         LOG(ERROR) << "Update: encr case 3.";
 637         return error;
 638       } else {
 639         syncer::SyncError error;
 640         error.Reset(FROM_HERE,
 641                     "Failed to load encrypted entry, we have the key"
 642                     "(?!) and nigori mismatch for " +
 643                         type_str + ".",
 644                     type_);
 645         error_handler()->OnSingleDataTypeUnrecoverableError(error);
 646         LOG(ERROR) << "Update: encr case 4.";
 647         return error;
 648       }
 649     }
 650   }
 651
 652   sync_node->SetTitle(change.sync_data().GetTitle());
 653   SetNodeSpecifics(sync_data_local.GetSpecifics(), sync_node);
 654   syncer::AttachmentIdList attachment_ids = sync_data_local.GetAttachmentIds();
 655   SetAttachmentMetadata(attachment_ids, sync_node);
 656
 657   // Return any newly added attachments.
 658   new_attachments->insert(attachment_ids.begin(), attachment_ids.end());
 659
 660   if (merge_result_.get()) {
 661     merge_result_->set_num_items_modified(merge_result_->num_items_modified() +
 662                                           1);
 663   }
 664   // TODO(sync): Support updating other parts of the sync node (title,
 665   // successor, parent, etc.).
 666   return syncer::SyncError();
 667 }
 668
 669 bool GenericChangeProcessor::SyncModelHasUserCreatedNodes(bool* has_nodes) {
 670   DCHECK(CalledOnValidThread());
 671   DCHECK(has_nodes);
 672   std::string type_name = syncer::ModelTypeToString(type_);
 673   std::string err_str = "Server did not create the top-level " + type_name +
 674       " node. We might be running against an out-of-date server.";
 675   *has_nodes = false;
 676   syncer::ReadTransaction trans(FROM_HERE, share_handle());
 677   syncer::ReadNode type_root_node(&trans);
 678   if (type_root_node.InitTypeRoot(type_) != syncer::BaseNode::INIT_OK) {
 679     LOG(ERROR) << err_str;
 680     return false;
 681   }
 682
 683   // The sync model has user created nodes if the type's root node has any
 684   // children.
 685   *has_nodes = type_root_node.HasChildren();
 686   return true;
 687 }
 688
 689 bool GenericChangeProcessor::CryptoReadyIfNecessary() {
 690   DCHECK(CalledOnValidThread());
 691   // We only access the cryptographer while holding a transaction.
 692   syncer::ReadTransaction trans(FROM_HERE, share_handle());
 693   const syncer::ModelTypeSet encrypted_types = trans.GetEncryptedTypes();
 694   return !encrypted_types.Has(type_) || trans.GetCryptographer()->is_ready();
 695 }
 696
 697 void GenericChangeProcessor::StartImpl() {
 698 }
 699
 700 syncer::UserShare* GenericChangeProcessor::share_handle() const {
 701   DCHECK(CalledOnValidThread());
 702   return share_handle_;
 703 }
 704
 705 void GenericChangeProcessor::UploadAllAttachmentsNotOnServer() {
 706   DCHECK(CalledOnValidThread());
 707   DCHECK(attachment_service_.get());
 708   syncer::AttachmentIdSet id_set;
 709   {
 710     syncer::ReadTransaction trans(FROM_HERE, share_handle());
 711     trans.GetAttachmentIdsToUpload(type_, &id_set);
 712   }
 713   if (!id_set.empty()) {
 714     attachment_service_->UploadAttachments(id_set);
 715   }
 716 }
 717
 718 }  // namespace sync_driver