gdata: Move GDataWapiFeedParser to a set of new files

chrome/browser/chromeos/gdata/gdata_wapi_feed_processor.cc

+// 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 "base/metrics/histogram.h"
+#include "chrome/browser/chromeos/gdata/gdata_files.h"
+#include "chrome/browser/chromeos/gdata/gdata_wapi_feed_processor.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace gdata {
+
+namespace {
+
+// Recursively extracts the paths set of all sub-directories of |entry|.
+void GetChildDirectoryPaths(GDataEntry* entry,
+                            std::set<FilePath>* changed_dirs) {
+  GDataDirectory* dir = entry->AsGDataDirectory();
+  if (!dir)
+    return;
+
+  for (GDataDirectoryCollection::const_iterator it =
+       dir->child_directories().begin();
+       it != dir->child_directories().end(); ++it) {
+    GDataDirectory* child_dir = it->second;
+    changed_dirs->insert(child_dir->GetFilePath());
+    GetChildDirectoryPaths(child_dir, changed_dirs);
+  }
+}
+
+}  // namespace
+
+FeedToFileResourceMapUmaStats::FeedToFileResourceMapUmaStats()
+    : num_regular_files(0),
+      num_hosted_documents(0) {
+}
+
+FeedToFileResourceMapUmaStats::~FeedToFileResourceMapUmaStats() {
+}
+
+GDataWapiFeedProcessor::GDataWapiFeedProcessor(
+    GDataDirectoryService* directory_service)
+  : directory_service_(directory_service) {
+}
+
+GDataWapiFeedProcessor::~GDataWapiFeedProcessor() {
+}
+
+GDataFileError GDataWapiFeedProcessor::ApplyFeeds(
+    const std::vector<DocumentFeed*>& feed_list,
+    int start_changestamp,
+    int root_feed_changestamp,
+    std::set<FilePath>* changed_dirs) {
+  bool is_delta_feed = start_changestamp != 0;
+
+  directory_service_->set_origin(FROM_SERVER);
+
+  int delta_feed_changestamp = 0;
+  FeedToFileResourceMapUmaStats uma_stats;
+  FileResourceIdMap file_map;
+  GDataFileError error = FeedToFileResourceMap(feed_list,
+                                               &file_map,
+                                               &delta_feed_changestamp,
+                                               &uma_stats);
+  if (error != GDATA_FILE_OK)
+    return error;
+
+  ApplyFeedFromFileUrlMap(
+      is_delta_feed,
+      is_delta_feed ? delta_feed_changestamp : root_feed_changestamp,
+      &file_map,
+      changed_dirs);
+
+  // Shouldn't record histograms when processing delta feeds.
+  if (!is_delta_feed)
+    UpdateFileCountUmaHistograms(uma_stats);
+
+  return GDATA_FILE_OK;
+}
+
+void GDataWapiFeedProcessor::UpdateFileCountUmaHistograms(
+    const FeedToFileResourceMapUmaStats& uma_stats) const {
+  const int num_total_files =
+      uma_stats.num_hosted_documents + uma_stats.num_regular_files;
+  UMA_HISTOGRAM_COUNTS("GData.NumberOfRegularFiles",
+                       uma_stats.num_regular_files);
+  UMA_HISTOGRAM_COUNTS("GData.NumberOfHostedDocuments",
+                       uma_stats.num_hosted_documents);
+  UMA_HISTOGRAM_COUNTS("GData.NumberOfTotalFiles", num_total_files);
+  const std::vector<int> all_entry_kinds = DocumentEntry::GetAllEntryKinds();
+  for (FeedToFileResourceMapUmaStats::EntryKindToCountMap::const_iterator iter =
+           uma_stats.num_files_with_entry_kind.begin();
+       iter != uma_stats.num_files_with_entry_kind.end();
+       ++iter) {
+    const DocumentEntry::EntryKind kind = iter->first;
+    const int count = iter->second;
+    for (int i = 0; i < count; ++i) {
+      UMA_HISTOGRAM_CUSTOM_ENUMERATION(
+          "GData.EntryKind", kind, all_entry_kinds);
+    }
+  }
+}
+
+void GDataWapiFeedProcessor::ApplyFeedFromFileUrlMap(
+    bool is_delta_feed,
+    int feed_changestamp,
+    FileResourceIdMap* file_map,
+  std::set<FilePath>* changed_dirs) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(changed_dirs);
+
+  if (!is_delta_feed) {  // Full update.
+    directory_service_->root()->RemoveChildren();
+    changed_dirs->insert(directory_service_->root()->GetFilePath());
+  }
+  directory_service_->set_largest_changestamp(feed_changestamp);
+
+  scoped_ptr<GDataDirectoryService> orphaned_dir_service(
+      new GDataDirectoryService);
+  // Go through all entries generated by the feed and apply them to the local
+  // snapshot of the file system.
+  for (FileResourceIdMap::iterator it = file_map->begin();
+       it != file_map->end();) {
+    // Ensure that the entry is deleted, unless the ownership is explicitly
+    // transferred by entry.release().
+    scoped_ptr<GDataEntry> entry(it->second);
+    DCHECK_EQ(it->first, entry->resource_id());
+    // Erase the entry so the deleted entry won't be referenced.
+    file_map->erase(it++);
+
+    GDataEntry* old_entry =
+        directory_service_->GetEntryByResourceId(entry->resource_id());
+    GDataDirectory* dest_dir = NULL;
+    if (entry->is_deleted()) {  // Deleted file/directory.
+      DVLOG(1) << "Removing file " << entry->base_name();
+      if (!old_entry)
+        continue;
+
+      dest_dir = old_entry->parent();
+      if (!dest_dir) {
+        NOTREACHED();
+        continue;
+      }
+      RemoveEntryFromDirectoryAndCollectChangedDirectories(
+          dest_dir, old_entry, changed_dirs);
+    } else if (old_entry) {  // Change or move of existing entry.
+      // Please note that entry rename is just a special case of change here
+      // since name is just one of the properties that can change.
+      DVLOG(1) << "Changed file " << entry->base_name();
+      dest_dir = old_entry->parent();
+      if (!dest_dir) {
+        NOTREACHED();
+        continue;
+      }
+      // Move children files over if we are dealing with directories.
+      if (old_entry->AsGDataDirectory() && entry->AsGDataDirectory()) {
+        entry->AsGDataDirectory()->TakeOverEntries(
+            old_entry->AsGDataDirectory());
+      }
+      // Remove the old instance of this entry.
+      RemoveEntryFromDirectoryAndCollectChangedDirectories(
+          dest_dir, old_entry, changed_dirs);
+      // Did we actually move the new file to another directory?
+      if (dest_dir->resource_id() != entry->parent_resource_id()) {
+        changed_dirs->insert(dest_dir->GetFilePath());
+        dest_dir = FindDirectoryForNewEntry(entry.get(),
+                                            *file_map,
+                                            orphaned_dir_service.get());
+      }
+      DCHECK(dest_dir);
+      AddEntryToDirectoryAndCollectChangedDirectories(
+          entry.release(),
+          dest_dir,
+          orphaned_dir_service.get(),
+          changed_dirs);
+    } else {  // Adding a new file.
+      dest_dir = FindDirectoryForNewEntry(entry.get(),
+                                          *file_map,
+                                          orphaned_dir_service.get());
+      DCHECK(dest_dir);
+      AddEntryToDirectoryAndCollectChangedDirectories(
+          entry.release(),
+          dest_dir,
+          orphaned_dir_service.get(),
+          changed_dirs);
+    }
+
+    // Record changed directory if this was a delta feed and the parent
+    // directory is already properly rooted within its parent.
+    if (dest_dir && (dest_dir->parent() ||
+        dest_dir == directory_service_->root()) &&
+        dest_dir != orphaned_dir_service->root() && is_delta_feed) {
+      changed_dirs->insert(dest_dir->GetFilePath());
+    }
+  }
+  // All entry must be erased from the map.
+  DCHECK(file_map->empty());
+}
+
+// static
+void GDataWapiFeedProcessor::AddEntryToDirectoryAndCollectChangedDirectories(
+    GDataEntry* entry,
+    GDataDirectory* directory,
+    GDataDirectoryService* orphaned_dir_service,
+    std::set<FilePath>* changed_dirs) {
+  directory->AddEntry(entry);
+  if (entry->AsGDataDirectory() && directory != orphaned_dir_service->root())
+    changed_dirs->insert(entry->GetFilePath());
+}
+
+// static
+void GDataWapiFeedProcessor::
+RemoveEntryFromDirectoryAndCollectChangedDirectories(
+    GDataDirectory* directory,
+    GDataEntry* entry,
+    std::set<FilePath>* changed_dirs) {
+  // Get the list of all sub-directory paths, so we can notify their listeners
+  // that they are smoked.
+  GetChildDirectoryPaths(entry, changed_dirs);
+  directory->RemoveEntry(entry);
+}
+
+GDataDirectory* GDataWapiFeedProcessor::FindDirectoryForNewEntry(
+    GDataEntry* new_entry,
+    const FileResourceIdMap& file_map,
+    GDataDirectoryService* orphaned_dir_service) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  GDataDirectory* dir = NULL;
+  // Added file.
+  const std::string& parent_id = new_entry->parent_resource_id();
+  if (parent_id.empty()) {
+    dir = directory_service_->root();
+    DVLOG(1) << "Root parent for " << new_entry->base_name();
+  } else {
+    GDataEntry* entry = directory_service_->GetEntryByResourceId(parent_id);
+    dir = entry ? entry->AsGDataDirectory() : NULL;
+    if (!dir) {
+      // The parent directory was also added with this set of feeds.
+      FileResourceIdMap::const_iterator find_iter =
+          file_map.find(parent_id);
+      dir = (find_iter != file_map.end() &&
+             find_iter->second) ?
+                find_iter->second->AsGDataDirectory() : NULL;
+      if (dir) {
+        DVLOG(1) << "Found parent for " << new_entry->base_name()
+                 << " in file_map " << parent_id;
+      } else {
+        DVLOG(1) << "Adding orphan " << new_entry->GetFilePath().value();
+        dir = orphaned_dir_service->root();
+      }
+    }
+  }
+  return dir;
+}
+
+GDataFileError GDataWapiFeedProcessor::FeedToFileResourceMap(
+    const std::vector<DocumentFeed*>& feed_list,
+    FileResourceIdMap* file_map,
+    int* feed_changestamp,
+    FeedToFileResourceMapUmaStats* uma_stats) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(uma_stats);
+
+  GDataFileError error = GDATA_FILE_OK;
+  uma_stats->num_regular_files = 0;
+  uma_stats->num_hosted_documents = 0;
+  uma_stats->num_files_with_entry_kind.clear();
+  for (size_t i = 0; i < feed_list.size(); ++i) {
+    const DocumentFeed* feed = feed_list[i];
+
+    // Get upload url from the root feed. Links for all other collections will
+    // be handled in GDatadirectory::FromDocumentEntry();
+    if (i == 0) {
+      const Link* root_feed_upload_link =
+          feed->GetLinkByType(Link::RESUMABLE_CREATE_MEDIA);
+      if (root_feed_upload_link)
+        directory_service_->root()->set_upload_url(
+            root_feed_upload_link->href());
+      *feed_changestamp = feed->largest_changestamp();
+      DCHECK_GE(*feed_changestamp, 0);
+    }
+
+    for (ScopedVector<DocumentEntry>::const_iterator iter =
+             feed->entries().begin();
+         iter != feed->entries().end(); ++iter) {
+      DocumentEntry* doc = *iter;
+      GDataEntry* entry = GDataEntry::FromDocumentEntry(
+          NULL, doc, directory_service_);
+      // Some document entries don't map into files (i.e. sites).
+      if (!entry)
+        continue;
+      // Count the number of files.
+      GDataFile* as_file = entry->AsGDataFile();
+      if (as_file) {
+        if (as_file->is_hosted_document())
+          ++uma_stats->num_hosted_documents;
+        else
+          ++uma_stats->num_regular_files;
+        ++uma_stats->num_files_with_entry_kind[as_file->kind()];
+      }
+
+      FileResourceIdMap::iterator map_entry =
+          file_map->find(entry->resource_id());
+
+      // An entry with the same self link may already exist, so we need to
+      // release the existing GDataEntry instance before overwriting the
+      // entry with another GDataEntry instance.
+      if (map_entry != file_map->end()) {
+        LOG(WARNING) << "Found duplicate file "
+                     << map_entry->second->base_name();
+
+        delete map_entry->second;
+        file_map->erase(map_entry);
+      }
+      file_map->insert(
+          std::pair<std::string, GDataEntry*>(entry->resource_id(), entry));
+    }
+  }
+
+  if (error != GDATA_FILE_OK) {
+    // If the code above fails to parse a feed, any GDataEntry instance
+    // added to |file_by_url| is not managed by a GDataDirectory instance,
+    // so we need to explicitly release them here.
+    STLDeleteValues(file_map);
+  }
+
+  return error;
+}
+
+}  // namespace gdata