/* * Copyright (C) 2009 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef _UTILS_BACKUP_HELPERS_H #define _UTILS_BACKUP_HELPERS_H #include #include namespace android { int back_up_files(int oldSnapshotFD, int oldDataStream, int newSnapshotFD, char const* fileBase, char const* const* files, int fileCount); // the sizes of all of these match. typedef struct { int type; // == APP_MAGIC_V1 int packageLen; // length of the name of the package that follows, not including the null. int cookie; } app_header_v1; typedef struct { int type; // ENTITY_MAGIC_V1 int keyLen; // length of the key name, not including the null terminator int dataSize; // size of the data, not including the padding } entity_header_v1; typedef struct { int type; // FOOTER_MAGIC_V1 int entityCount; // the number of entities that were written int cookie; } app_footer_v1; /** * Writes the data. * * If an error occurs, it poisons this object and all write calls will fail * with the error that occurred. */ class BackupDataWriter { public: BackupDataWriter(int fd); // does not close fd ~BackupDataWriter(); status_t WriteAppHeader(const String8& packageName, int cookie); status_t WriteEntityHeader(const String8& key, size_t dataSize); status_t WriteEntityData(const void* data, size_t size); status_t WriteAppFooter(int cookie); private: explicit BackupDataWriter(); status_t write_padding_for(int n); int m_fd; status_t m_status; ssize_t m_pos; int m_entityCount; }; /** * Reads the data. * * If an error occurs, it poisons this object and all write calls will fail * with the error that occurred. */ class BackupDataReader { public: BackupDataReader(int fd); // does not close fd ~BackupDataReader(); status_t Status(); status_t ReadNextHeader(); status_t ReadAppHeader(String8* packageName, int* cookie); bool HasEntities(); status_t ReadEntityHeader(String8* key, size_t* dataSize); status_t ReadEntityData(void* data, size_t size); status_t ReadAppFooter(int* cookie); private: explicit BackupDataReader(); status_t skip_padding(); int m_fd; status_t m_status; ssize_t m_pos; int m_entityCount; union { int type; app_header_v1 app; entity_header_v1 entity; app_footer_v1 footer; } m_header; }; #define TEST_BACKUP_HELPERS 0 #if TEST_BACKUP_HELPERS int backup_helper_test_empty(); int backup_helper_test_four(); int backup_helper_test_files(); int backup_helper_test_data_writer(); int backup_helper_test_data_reader(); #endif } // namespace android #endif // _UTILS_BACKUP_HELPERS_H