Keep track of which attachments are referenced by which sync entries.

sync/syncable/directory.cc

 // Copyright 2013 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/syncable/directory.h"
 
 #include <iterator>
 
 #include "base/base64.h"
 #include "base/debug/trace_event.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
+#include "sync/api/attachments/attachment_id.h"
 #include "sync/internal_api/public/base/unique_position.h"
 #include "sync/internal_api/public/util/unrecoverable_error_handler.h"
 #include "sync/syncable/entry.h"
 #include "sync/syncable/entry_kernel.h"
 #include "sync/syncable/in_memory_directory_backing_store.h"
 #include "sync/syncable/on_disk_directory_backing_store.h"
 #include "sync/syncable/scoped_kernel_lock.h"
 #include "sync/syncable/scoped_parent_child_index_updater.h"
 #include "sync/syncable/syncable-inl.h"
 #include "sync/syncable/syncable_base_transaction.h"
@@ skipping 93 matching lines @@
 
   const DirOpenResult result =
       OpenImpl(name, delegate, transaction_observer);
 
   if (OPENED != result)
     Close();
   return result;
 }
 
 void Directory::InitializeIndices(MetahandlesMap* handles_map) {
+  ScopedKernelLock lock(this);
   kernel_->metahandles_map.swap(*handles_map);
   for (MetahandlesMap::const_iterator it = kernel_->metahandles_map.begin();
        it != kernel_->metahandles_map.end(); ++it) {
     EntryKernel* entry = it->second;
     if (ParentChildIndex::ShouldInclude(entry))
       kernel_->parent_child_index.Insert(entry);
     const int64 metahandle = entry->ref(META_HANDLE);
     if (entry->ref(IS_UNSYNCED))
       kernel_->unsynced_metahandles.insert(metahandle);
     if (entry->ref(IS_UNAPPLIED_UPDATE)) {
       const ModelType type = entry->GetServerModelType();
       kernel_->unapplied_update_metahandles[type].insert(metahandle);
     }
     if (!entry->ref(UNIQUE_SERVER_TAG).empty()) {
       DCHECK(kernel_->server_tags_map.find(entry->ref(UNIQUE_SERVER_TAG)) ==
              kernel_->server_tags_map.end())
           << "Unexpected duplicate use of client tag";
       kernel_->server_tags_map[entry->ref(UNIQUE_SERVER_TAG)] = entry;
     }
     if (!entry->ref(UNIQUE_CLIENT_TAG).empty()) {
       DCHECK(kernel_->server_tags_map.find(entry->ref(UNIQUE_SERVER_TAG)) ==
              kernel_->server_tags_map.end())
           << "Unexpected duplicate use of server tag";
       kernel_->client_tags_map[entry->ref(UNIQUE_CLIENT_TAG)] = entry;
     }
     DCHECK(kernel_->ids_map.find(entry->ref(ID).value()) ==
            kernel_->ids_map.end()) << "Unexpected duplicate use of ID";
     kernel_->ids_map[entry->ref(ID).value()] = entry;
     DCHECK(!entry->is_dirty());
+    AddToAttachmentIndex(metahandle, entry->ref(ATTACHMENT_METADATA), lock);
   }
 }
 
 DirOpenResult Directory::OpenImpl(
     const string& name,
     DirectoryChangeDelegate* delegate,
     const WeakHandle<TransactionObserver>&
         transaction_observer) {
   KernelLoadInfo info;
   // Temporary indices before kernel_ initialized in case Load fails. We 0(1)
@@ skipping 190 matching lines @@
     return false;
   }
   if (ParentChildIndex::ShouldInclude(entry)) {
     if (!SyncAssert(kernel_->parent_child_index.Insert(entry),
                     FROM_HERE,
                     error,
                     trans)) {
       return false;
     }
   }
+  AddToAttachmentIndex(
+      entry->ref(META_HANDLE), entry->ref(ATTACHMENT_METADATA), *lock);
 
   // Should NEVER be created with a client tag or server tag.
   if (!SyncAssert(entry->ref(UNIQUE_SERVER_TAG).empty(), FROM_HERE,
                   "Server tag should be empty", trans)) {
     return false;
   }
   if (!SyncAssert(entry->ref(UNIQUE_CLIENT_TAG).empty(), FROM_HERE,
                   "Client tag should be empty", trans))
     return false;
 
@@ skipping 26 matching lines @@
 
   {
     // Update the indices that depend on the PARENT_ID field.
     ScopedParentChildIndexUpdater index_updater(lock, entry,
         &kernel_->parent_child_index);
     entry->put(PARENT_ID, new_parent_id);
   }
   return true;
 }
 
+void Directory::RemoveFromAttachmentIndex(
+    const int64 metahandle,
+    const sync_pb::AttachmentMetadata& attachment_metadata,
+    const ScopedKernelLock& lock) {
+  for (int i = 0; i < attachment_metadata.record_size(); ++i) {
+    AttachmentIdUniqueId unique_id =
+        attachment_metadata.record(i).id().unique_id();
+    IndexByAttachmenId::iterator iter =
+        kernel_->index_by_attachment_id.find(unique_id);
+    if (iter != kernel_->index_by_attachment_id.end()) {
+      iter->second.erase(metahandle);

[pavely, 2014/04/28 23:26:27]

Can entity reference attachment multiple times? Seems like there is noting in
the code to prevent that.

[maniscalco, 2014/04/29 20:53:22]

Good point.  No, a single SyncData (or entry) should not refer to the same
attachment twice.

I've added a DCHECK to SyncData::CreateLocalDataWithAttachments to catch this
case.  Of course, because it's a DCHECK it won't fire in release builds.  A
stronger, but slightly more expensive option would be to skip DCHECKing and
instead just remove the duplicates (std::sort(); std::unique();).  I don't
anticipate more than 10 or 20 attachments for an entry so I would happy to go
with the slightly more expensive option.  WDYT?

+      if (iter->second.empty()) {
+        kernel_->index_by_attachment_id.erase(iter);
+      }
+    }
+  }
+}
+
+void Directory::AddToAttachmentIndex(
+    const int64 metahandle,
+    const sync_pb::AttachmentMetadata& attachment_metadata,
+    const ScopedKernelLock& lock) {
+  for (int i = 0; i < attachment_metadata.record_size(); ++i) {
+    AttachmentIdUniqueId unique_id =
+        attachment_metadata.record(i).id().unique_id();
+    IndexByAttachmenId::iterator iter =
+        kernel_->index_by_attachment_id.find(unique_id);
+    if (iter == kernel_->index_by_attachment_id.end()) {
+      iter = kernel_->index_by_attachment_id.insert(std::make_pair(
+                                                        unique_id,
+                                                        MetahandleSet())).first;
+    }
+    iter->second.insert(metahandle);
+  }
+}
+
+void Directory::UpdateAttachmentIndex(
+    const int64 metahandle,
+    const sync_pb::AttachmentMetadata& old_metadata,
+    const sync_pb::AttachmentMetadata& new_metadata) {
+  ScopedKernelLock lock(this);
+  RemoveFromAttachmentIndex(metahandle, old_metadata, lock);
+  AddToAttachmentIndex(metahandle, new_metadata, lock);
+}
+
 bool Directory::unrecoverable_error_set(const BaseTransaction* trans) const {
   DCHECK(trans != NULL);
   return unrecoverable_error_set_;
 }
 
 void Directory::ClearDirtyMetahandles() {
   kernel_->transaction_mutex.AssertAcquired();
   kernel_->dirty_metahandles.clear();
 }
 
@@ skipping 120 matching lines @@
       if (!entry->ref(UNIQUE_CLIENT_TAG).empty()) {
         num_erased =
             kernel_->client_tags_map.erase(entry->ref(UNIQUE_CLIENT_TAG));
         DCHECK_EQ(1u, num_erased);
       }
       if (!SyncAssert(!kernel_->parent_child_index.Contains(entry),
                       FROM_HERE,
                       "Deleted entry still present",
                       (&trans)))
         return false;
+      RemoveFromAttachmentIndex(
+          entry->ref(META_HANDLE), entry->ref(ATTACHMENT_METADATA), lock);
+
       delete entry;
     }
     if (trans.unrecoverable_error_set())
       return false;
   }
   return true;
 }
 
 void Directory::UnapplyEntry(EntryKernel* entry) {
   int64 handle = entry->ref(META_HANDLE);
@@ skipping 39 matching lines @@
   }
 
   // At this point locally created items that aren't synced will become locally
   // deleted items, and purged on the next snapshot. All other items will match
   // the state they would have had if they were just created via a server
   // update. See MutableEntry::MutableEntry(.., CreateNewUpdateItem, ..).
 }
 
 void Directory::DeleteEntry(bool save_to_journal,
                             EntryKernel* entry,
-                            EntryKernelSet* entries_to_journal) {
+                            EntryKernelSet* entries_to_journal,
+                            const ScopedKernelLock& lock) {
   int64 handle = entry->ref(META_HANDLE);
   ModelType server_type = GetModelTypeFromSpecifics(
       entry->ref(SERVER_SPECIFICS));
 
   kernel_->metahandles_to_purge.insert(handle);
 
   size_t num_erased = 0;
   num_erased = kernel_->metahandles_map.erase(entry->ref(META_HANDLE));
   DCHECK_EQ(1u, num_erased);
   num_erased = kernel_->ids_map.erase(entry->ref(ID).value());
   DCHECK_EQ(1u, num_erased);
   num_erased = kernel_->unsynced_metahandles.erase(handle);
   DCHECK_EQ(entry->ref(IS_UNSYNCED), num_erased > 0);
   num_erased =
       kernel_->unapplied_update_metahandles[server_type].erase(handle);
   DCHECK_EQ(entry->ref(IS_UNAPPLIED_UPDATE), num_erased > 0);
   if (kernel_->parent_child_index.Contains(entry))
     kernel_->parent_child_index.Remove(entry);
 
   if (!entry->ref(UNIQUE_CLIENT_TAG).empty()) {
     num_erased =
         kernel_->client_tags_map.erase(entry->ref(UNIQUE_CLIENT_TAG));
     DCHECK_EQ(1u, num_erased);
   }
   if (!entry->ref(UNIQUE_SERVER_TAG).empty()) {
     num_erased =
         kernel_->server_tags_map.erase(entry->ref(UNIQUE_SERVER_TAG));
     DCHECK_EQ(1u, num_erased);
   }
+  RemoveFromAttachmentIndex(handle, entry->ref(ATTACHMENT_METADATA), lock);
 
   if (save_to_journal) {
     entries_to_journal->insert(entry);
   } else {
     delete entry;
   }
 }
 
 bool Directory::PurgeEntriesWithTypeIn(ModelTypeSet disabled_types,
                                        ModelTypeSet types_to_journal,
@@ skipping 47 matching lines @@
 
         if (types_to_unapply.Has(local_type) ||
             types_to_unapply.Has(server_type)) {
           UnapplyEntry(entry);
         } else {
           bool save_to_journal =
               (types_to_journal.Has(local_type) ||
                types_to_journal.Has(server_type)) &&
               (delete_journal_->IsDeleteJournalEnabled(local_type) ||
                delete_journal_->IsDeleteJournalEnabled(server_type));
-          DeleteEntry(save_to_journal, entry, &entries_to_journal);
+          DeleteEntry(save_to_journal, entry, &entries_to_journal, lock);
         }
       }
 
       delete_journal_->AddJournalBatch(&trans, entries_to_journal);
 
       // Ensure meta tracking for these data types reflects the purged state.
       for (ModelTypeSet::Iterator it = disabled_types.First();
            it.Good(); it.Inc()) {
         kernel_->persisted_info.transaction_version[it.Get()] = 0;
 
@@ skipping 37 matching lines @@
 
     // Note that we do not unset IS_UNSYNCED or IS_UNAPPLIED_UPDATE in order
     // to ensure no in-transit data is lost.
 
     entry->mark_dirty(&kernel_->dirty_metahandles);
   }
 
   return true;
 }
 
+bool Directory::IsAttachmentLinked(const AttachmentId& attachment_id) const {
+  ScopedKernelLock lock(this);
+  IndexByAttachmenId::const_iterator iter =
+      kernel_->index_by_attachment_id.find(
+          attachment_id.GetProto().unique_id());
+  if (iter != kernel_->index_by_attachment_id.end() && !iter->second.empty()) {
+    return true;
+  }
+  return false;
+}
+
 void Directory::HandleSaveChangesFailure(const SaveChangesSnapshot& snapshot) {
   WriteTransaction trans(FROM_HERE, HANDLE_SAVE_FAILURE, this);
   ScopedKernelLock lock(this);
   kernel_->info_status = KERNEL_SHARE_INFO_DIRTY;
 
   // Because we optimistically cleared the dirty bit on the real entries when
   // taking the snapshot, we must restore it on failure.  Not doing this could
   // cause lost data, if no other changes are made to the in-memory entries
   // that would cause the dirty bit to get set again. Setting the bit ensures
   // that SaveChanges will at least try again later.
@@ skipping 581 matching lines @@
 
   for (OrderedChildSet::const_iterator i = children->begin();
        i != children->end(); ++i) {
     DCHECK_EQ(parent_id, (*i)->ref(PARENT_ID));
     result->push_back((*i)->ref(META_HANDLE));
   }
 }
 
 }  // namespace syncable
 }  // namespace syncer