File

source: bluebase/pf/file.py

---

class PfFileHeader(page: PfPage, *, offset: int, limit: int)

Bases: PfPageView, LayoutMixin

file header를 관리하는 view 클래스입니다.

Layout

Offset	Size	Name	Format
0	4	page_count	'<i'
4	4	first_free_pid	'<i'

PID: ClassVar[PfPageId] = 0

file header의 page id를 나타내는 상수.

NO_FREE_PAGE: ClassVar[PfPageId] = -1

free page가 없을 경우 사용하는 상수.

size: ClassVar[int] = 8

The total size of the layout, automatically calculated from fields.

class PfFile(fid: PfFileId, cache: PfPageCache)

Bases: object

Variables:

• fid (PfFileId)

• cache (PfPageCache)

• stream (BinaryIO)

static get_header(page: PfPage) → PfFileHeader

static fetch_header(file: PfFile) → tuple[PfPage, PfFileHeader]

classmethod new(fid: PfFileId, cache: PfPageCache) → Self

classmethod open(fid: PfFileId, cache: PfPageCache) → Self

property page_count: intread-write

property first_free_pid: PfPageId | Noneread-write

validate_pid(pid: PfPageId) → None

Raises:

PfInvalidPageIdError –

assignmentget_page(pid: PfPageId) → PfPage

Raises:

• PfInvalidPageIdError –

• PfFreePageAccessError –

assignmentfind_next_page(pid: PfPageId) → PfPage | None

Raises:

• PfInvalidPageIdError –

• PfFreePageAccessError –

assignmentallocate_page() → PfPage

assignmentdispose_page(page: PfPage) → None

Raises:

• PfFileHeaderDisposeError –

• PfPinnedPageDisposeError –

• PfFreePageDisposeError –

assignmentpersist() → None

assignmentflush() → None