Пример #1
0
void BufferManager::pageIn(int index, int pageNum) {
	// Read page data from disk into buffer
	char buffer[4096] = {};
	int blockOffset = getBlockOffset(pageNum);
	fm->read(dbName, blockOffset, 8, buffer);

	// Create page
	pages[index] = Page(buffer);

	// Set page status
	pageNums[index] = pageNum;
	dirtied[index] = 0;
	pinned[index] = 0;
}
Пример #2
0
void LogManager::forceLSNRecord(int index) {
	for (int pageNum = 0; pageNum < 4; pageNum++) {
		char page[4096] = {};
		fm->read(logName, pageNum * 8, 8, page);

		for (int i = 0; i < 73; i++) {
			char bytes[56] = {};
			int start = i * 56;

			for (int j = 0; j < 56; j++) { bytes[j] = page[start + j]; }
			LogRecord rec = LogRecord(bytes);

			if (rec.LSN == 0) {
				char* recordBytes = (char*) &log[index];
				for (int k = 0; k < 56; k++) { page[start + k] = recordBytes[k]; }
				fm->write(logName, pageNum * 8, 8, page);
				return;
			}
		}
	}
}
Пример #3
0
void LogManager::start(char* inLogName) {
	logName = inLogName;
	char page[4096] = {};

	for (int pageNum = 0; pageNum < 4; pageNum++) {
		fm->read(logName, pageNum * 8, 8, page);

		for (int i = 0; i < 73; i++) {
			char bytes[56] = {};
			int start = i * 56;

			for (int j = 0; j < 56; j++) { bytes[j] = page[start + j]; }
			LogRecord rec = LogRecord(bytes);

			if (rec.LSN == 0) { return; }
			else if (rec.LSN != 0) {
				log[tail] = rec;
				tail++;
			}
		}
	}
}