Method Open

vfs.go:1020–1106

()

}

func (f *VFSFile) Open() error {
	f.logger.Debug("opening file")

	// Try to get restore plan. For write-enabled VFS, we can create a new database
	// if no LTX files exist yet.
	infos, err := f.waitForRestorePlan()
	if err != nil {
		// If write mode is enabled and no files exist, we can create a new database
		if f.writeEnabled && errors.Is(err, ErrTxNotAvailable) {
			f.logger.Info("no existing database found, creating new database")
			return f.openNewDatabase()
		}
		return err
	}

	pageSize, err := detectPageSizeFromInfos(f.ctx, f.client, infos)
	if err != nil {
		f.logger.Error("cannot detect page size", "error", err)
		return fmt.Errorf("detect page size: %w", err)
	}
	f.pageSize = pageSize

	// Initialize page cache. Convert byte size to number of pages.
	cacheEntries := f.CacheSize / int(pageSize)
	if cacheEntries < 1 {
		cacheEntries = 1
	}
	cache, err := lru.New[uint32, []byte](cacheEntries)
	if err != nil {
		return fmt.Errorf("create page cache: %w", err)
	}
	f.cache = cache

	// Determine the current position based off the latest LTX file.
	var pos ltx.Pos
	if len(infos) > 0 {
		pos = ltx.Pos{TXID: infos[len(infos)-1].MaxTXID}
	}
	f.pos = pos

	// Initialize write support TXID tracking
	if f.writeEnabled {
		f.expectedTXID = pos.TXID
		f.pendingTXID = pos.TXID + 1
		f.logger.Debug("write support enabled", "expectedTXID", f.expectedTXID, "pendingTXID", f.pendingTXID)

		// Initialize write buffer file for durability (discards any existing buffer)
		if err := f.initWriteBuffer(); err != nil {
			return fmt.Errorf("initialize write buffer: %w", err)
		}
	}

	// Build the page index so we can lookup individual pages.
	if err := f.buildIndex(f.ctx, infos); err != nil {
		f.logger.Error("cannot build index", "error", err)
		return fmt.Errorf("cannot build index: %w", err)
	}