SyncFS: Convert WAPI ResourceID to DriveAPI FileID

chrome/browser/sync_file_system/drive/metadata_db_migration_util.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 "chrome/browser/sync_file_system/drive/metadata_db_migration_util.h"
+
+#include "base/files/file_path.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/string_util.h"
+#include "googleurl/src/gurl.h"
+#include "third_party/leveldatabase/src/include/leveldb/write_batch.h"
+
+namespace sync_file_system {
+namespace drive {
+
+namespace {
+
+const char kWapiFileIdPrefix[] = "file:";
+const char kWapiFolderIdPrefix[] = "folder:";
+
+std::string RemovePrefix(const std::string& str, const std::string& prefix) {
+  if (StartsWithASCII(str, prefix, true))
+    return std::string(str.begin() + prefix.size(), str.end());
+  return str;
+}
+
+}  // namespace
+
+std::string AddWapiFilePrefix(const std::string& resource_id) {
+  if (resource_id.empty() ||
+      StartsWithASCII(resource_id, kWapiFileIdPrefix, true) ||
+      StartsWithASCII(resource_id, kWapiFolderIdPrefix, true))
+    return resource_id;
+  return kWapiFileIdPrefix + resource_id;
+}
+
+std::string AddWapiFolderPrefix(const std::string& resource_id) {
+  if (resource_id.empty() ||
+      StartsWithASCII(resource_id, kWapiFileIdPrefix, true) ||
+      StartsWithASCII(resource_id, kWapiFolderIdPrefix, true))
+    return resource_id;
+  return kWapiFolderIdPrefix + resource_id;
+}
+
+std::string AddWapiIdPrefix(const std::string& resource_id,
+                            DriveMetadata_ResourceType type) {
+  switch (type) {
+    case DriveMetadata_ResourceType_RESOURCE_TYPE_FILE:
+      return AddWapiFilePrefix(resource_id);
+    case DriveMetadata_ResourceType_RESOURCE_TYPE_FOLDER:
+      return AddWapiFolderPrefix(resource_id);
+    default:

[tzik, 2013/05/29 04:30:24]

Could you drop "default:" and move this case out of the switch?
That will detect enum value adding on the compile time.

[nhiroki, 2013/05/29 06:31:03]

Done.

+      NOTREACHED();
+      return resource_id;
+  }
+}
+
+std::string RemoveWapiIdPrefix(const std::string& resource_id) {
+  if (StartsWithASCII(resource_id, kWapiFileIdPrefix, true))
+    return RemovePrefix(resource_id, kWapiFileIdPrefix);
+  if (StartsWithASCII(resource_id, kWapiFolderIdPrefix, true))
+    return RemovePrefix(resource_id, kWapiFolderIdPrefix);
+  return resource_id;
+}
+
+SyncStatusCode MigrateDatabaseFromV1ToV2(leveldb::DB* db) {
+  // Strips prefix of WAPI resource ID.
+  // (i.e. "file:xxxx" => "xxxx", "folder:yyyy" => "yyyy")
+  //
+  // Version 2 database format (changed keys/fields are marked with '*'):
+  //   key: "VERSION"
+  // * value: 2
+  //
+  //   key: "CHANGE_STAMP"
+  //   value: <Largest Changestamp>
+  //
+  //   key: "SYNC_ROOT_DIR"
+  // * value: <Resource ID of the sync root directory> (striped)
+  //
+  //   key: "METADATA: " + <Origin and URL>
+  // * value: <Serialized DriveMetadata> (striped)
+  //
+  //   key: "ISYNC_ORIGIN: " + <URL string of a incremental sync origin>
+  // * value: <Resource ID of the drive directory for the origin> (striped)
+  //
+  //   key: "DISABLED_ORIGIN: " + <URL string of a disabled origin>
+  // * value: <Resource ID of the drive directory for the origin> (striped)
+
+  const char kDatabaseVersionKey[] = "VERSION";
+  const char kSyncRootDirectoryKey[] = "SYNC_ROOT_DIR";
+  const char kDriveMetadataKeyPrefix[] = "METADATA: ";
+  const char kDriveIncrementalSyncOriginKeyPrefix[] = "ISYNC_ORIGIN: ";
+  const char kDriveDisabledOriginKeyPrefix[] = "DISABLED_ORIGIN: ";
+
+  leveldb::WriteBatch write_batch;
+  write_batch.Put(kDatabaseVersionKey, "2");
+
+  // Strip resource id for the sync root directory.
+  std::string sync_root_resource_id;
+  leveldb::Status status = db->Get(
+      leveldb::ReadOptions(), kSyncRootDirectoryKey, &sync_root_resource_id);
+  write_batch.Put(kSyncRootDirectoryKey,
+                  RemoveWapiIdPrefix(sync_root_resource_id));

[kinuko, 2013/05/29 04:44:36]

I wonder if writing this in a single for could be simpler / makes sense as we
seem to be rewriting most key-value pairs:

for (itr->SeekToFirst(); itr->Valid(); itr->Next()) {
  std::string key = ...;
  if (StartsWithASCII(key, kSyncRootDirectory...)) {
    ...
    continue;
  }
  if (StartsWithASCII(key, kDriveMetadata...)) {
    ...
    continue;
  }
  if (StartsWithASCII(key, kDriveIncremental...)) {
    ...
    continue;
  }
  ...
}

[nhiroki, 2013/05/29 06:31:03]

Done.

+
+  // Strip resource ids in the drive metadata.
+  scoped_ptr<leveldb::Iterator> itr(db->NewIterator(leveldb::ReadOptions()));
+  for (itr->Seek(kDriveMetadataKeyPrefix); itr->Valid(); itr->Next()) {
+    std::string key = itr->key().ToString();
+    if (!StartsWithASCII(key, kDriveMetadataKeyPrefix, true))
+      break;
+
+    DriveMetadata metadata;
+    bool success = metadata.ParseFromString(itr->value().ToString());
+    DCHECK(success);
+
+    metadata.set_resource_id(RemoveWapiIdPrefix(metadata.resource_id()));
+    std::string metadata_string;
+    metadata.SerializeToString(&metadata_string);
+
+    write_batch.Put(key, metadata_string);
+  }
+
+  // Strip resource ids of the incremental sync origins.
+  for (itr->Seek(kDriveIncrementalSyncOriginKeyPrefix);
+       itr->Valid(); itr->Next()) {
+    std::string key = itr->key().ToString();
+    if (!StartsWithASCII(key, kDriveIncrementalSyncOriginKeyPrefix, true))
+      break;
+    write_batch.Put(key, RemoveWapiIdPrefix(itr->value().ToString()));
+  }
+
+  // Strip resource ids of the disabled sync origins.
+  for (itr->Seek(kDriveDisabledOriginKeyPrefix); itr->Valid(); itr->Next()) {
+    std::string key = itr->key().ToString();
+    if (!StartsWithASCII(key, kDriveDisabledOriginKeyPrefix, true))
+      break;
+    write_batch.Put(key, RemoveWapiIdPrefix(itr->value().ToString()));
+  }
+
+  return LevelDBStatusToSyncStatusCode(
+      db->Write(leveldb::WriteOptions(), &write_batch));
+}
+
+}  // namespace drive
+}  // namespace sync_file_system