Merge change 5162 into donut (8068d16d) · Commits · e / os / platform_frameworks_native

libs/utils/BackupHelpers.cpp

+89 −13

Original line number	Diff line number	Diff line
		@@ -41,7 +41,43 @@ namespace android {
		#define MAGIC0 0x70616e53 // Snap
		#define MAGIC1 0x656c6946 // File

		#if 1 // TEST_BACKUP_HELPERS
		/*
		* File entity data format (v1):
		*
		* - 4-byte version number of the metadata, little endian (0x00000001 for v1)
		* - 12 bytes of metadata
		* - the file data itself
		*
		* i.e. a 16-byte metadata header followed by the raw file data. If the
		* restore code does not recognize the metadata version, it can still
		* interpret the file data itself correctly.
		*
		* file_metadata_v1:
		*
		* - 4 byte version number === 0x00000001 (little endian)
		* - 4-byte access mode (little-endian)
		* - undefined (8 bytes)
		*/

		struct file_metadata_v1 {
		int version;
		int mode;
		int undefined_1;
		int undefined_2;
		};

		const static int CURRENT_METADATA_VERSION = 1;

		// auto-free buffer management object
		class StAutoFree {
		public:
		StAutoFree(void* buffer) { mBuf = buffer; }
		~StAutoFree() { free(mBuf); }
		private:
		void* mBuf;
		};

		#if 0 // TEST_BACKUP_HELPERS
		#define LOGP(f, x...) printf(f "\n", x)
		#else
		#define LOGP(x...) LOGD(x)
		@@ -181,29 +217,48 @@ write_delete_file(BackupDataWriter* dataStream, const String8& key)
		}

		static int
		write_update_file(BackupDataWriter* dataStream, int fd, const String8& key,
		write_update_file(BackupDataWriter* dataStream, int fd, int mode, const String8& key,
		char const* realFilename)
		{
		LOGP("write_update_file %s (%s)\n", realFilename, key.string());
		LOGP("write_update_file %s (%s) : mode 0%o\n", realFilename, key.string(), mode);

		const int bufsize = 4*1024;
		int err;
		int amt;
		int fileSize;
		int bytesLeft;
		file_metadata_v1 metadata;

		char* buf = (char*)malloc(bufsize);
		StAutoFree _autoFree(buf);

		int crc = crc32(0L, Z_NULL, 0);


		bytesLeft = fileSize = lseek(fd, 0, SEEK_END);
		fileSize = lseek(fd, 0, SEEK_END);
		lseek(fd, 0, SEEK_SET);

		if (sizeof(metadata) != 16) {
		LOGE("ERROR: metadata block is the wrong size!");
		}

		bytesLeft = fileSize + sizeof(metadata);
		err = dataStream->WriteEntityHeader(key, bytesLeft);
		if (err != 0) {
		return err;
		}

		// store the file metadata first
		metadata.version = tolel(CURRENT_METADATA_VERSION);
		metadata.mode = tolel(mode);
		metadata.undefined_1 = metadata.undefined_2 = 0;
		err = dataStream->WriteEntityData(&metadata, sizeof(metadata));
		if (err != 0) {
		return err;
		}
		bytesLeft -= sizeof(metadata); // bytesLeft should == fileSize now

		// now store the file content
		while ((amt = read(fd, buf, bufsize)) != 0 && bytesLeft > 0) {
		bytesLeft -= amt;
		if (bytesLeft < 0) {
		@@ -232,8 +287,6 @@ write_update_file(BackupDataWriter* dataStream, int fd, const String8& key,
		" You aren't doing proper locking!", realFilename, fileSize, fileSize-bytesLeft);
		}

		free(buf);

		return NO_ERROR;
		}

		@@ -241,11 +294,19 @@ static int
		write_update_file(BackupDataWriter* dataStream, const String8& key, char const* realFilename)
		{
		int err;
		struct stat st;

		err = stat(realFilename, &st);
		if (err < 0) {
		return errno;
		}

		int fd = open(realFilename, O_RDONLY);
		if (fd == -1) {
		return errno;
		}
		err = write_update_file(dataStream, fd, key, realFilename);

		err = write_update_file(dataStream, fd, st.st_mode, key, realFilename);
		close(fd);
		return err;
		}
		@@ -257,6 +318,8 @@ compute_crc32(int fd)
		int amt;

		char* buf = (char*)malloc(bufsize);
		StAutoFree _autoFree(buf);

		int crc = crc32(0L, Z_NULL, 0);

		lseek(fd, 0, SEEK_SET);
		@@ -265,8 +328,6 @@ compute_crc32(int fd)
		crc = crc32(crc, (Bytef*)buf, amt);
		}

		free(buf);

		return crc;
		}

		@@ -356,7 +417,7 @@ back_up_files(int oldSnapshotFD, BackupDataWriter* dataStream, int newSnapshotFD
		g.s.modTime_sec, g.s.modTime_nsec, g.s.mode, g.s.size, g.s.crc32);
		if (f.modTime_sec != g.s.modTime_sec \|\| f.modTime_nsec != g.s.modTime_nsec
		\|\| f.mode != g.s.mode \|\| f.size != g.s.size \|\| f.crc32 != g.s.crc32) {
		write_update_file(dataStream, fd, p, g.file.string());
		write_update_file(dataStream, fd, g.s.mode, p, g.file.string());
		}

		close(fd);
		@@ -416,8 +477,22 @@ RestoreHelperBase::WriteFile(const String8& filename, BackupDataReader* in)
		return err;
		}

		// TODO: World readable/writable for now.
		mode = 0666;
		// Get the metadata block off the head of the file entity and use that to
		// set up the output file
		file_metadata_v1 metadata;
		amt = in->ReadEntityData(&metadata, sizeof(metadata));
		if (amt != sizeof(metadata)) {
		LOGW("Could not read metadata for %s -- %ld / %s", filename.string(),
		(long)amt, strerror(errno));
		return EIO;
		}
		metadata.version = fromlel(metadata.version);
		metadata.mode = fromlel(metadata.mode);
		if (metadata.version > CURRENT_METADATA_VERSION) {
		LOGW("Restoring file with unsupported metadata version %d (currently %d)",
		metadata.version, CURRENT_METADATA_VERSION);
		}
		mode = metadata.mode;

		// Write the file and compute the crc
		crc = crc32(0L, Z_NULL, 0);
		@@ -512,6 +587,7 @@ compare_file(const char* path, const unsigned char* data, int len)
		fprintf(stderr, "malloc(%d) failed\n", len);
		return ENOMEM;
		}
		StAutoFree _autoFree(contents);

		bool sizesMatch = true;
		amt = lseek(fd, 0, SEEK_END);
		@@ -843,6 +919,7 @@ test_read_header_and_entity(BackupDataReader& reader, const char* str)
		int err;
		int bufSize = strlen(str)+1;
		char* buf = (char*)malloc(bufSize);
		StAutoFree _autoFree(buf);
		String8 string;
		int cookie = 0x11111111;
		size_t actualSize;
		@@ -904,7 +981,6 @@ finished:
		if (err != NO_ERROR) {
		fprintf(stderr, "test_read_header_and_entity failed with %s\n", strerror(err));
		}
		free(buf);
		return err;
		}