Struct PageManager 

pub struct PageManager { /* private fields */ }

Manages page allocation and deallocation for a database file.

Implementations

impl PageManager

pub fn new( db_path: PathBuf, page_size: usize, existing_pages: u64, fsm: Arc<FreeSpaceManager>, ) -> Self

Create a new page manager.

existing_pages is the number of pages already present in the file (determined from file metadata on open).

pub fn page_size(&self) -> usize

Page size in bytes.

pub fn total_pages(&self) -> u64

Total number of pages managed (allocated + free).

pub fn allocate_page(&self) -> u64

Allocate a new page index.

Tries the FSM first for a free page; if none available, extends the file (incrementing next_page).

pub fn free_page(&self, page_idx: u64)

Free a previously allocated page.

The page is added back to the FSM for future reuse.

pub fn free_pages(&self, start_page_idx: u64, num_pages: u64)

Free a range of pages.

pub fn fsm(&self) -> &Arc<FreeSpaceManager>

Access the underlying free space manager.

pub fn page_offset(&self, page_idx: u64) -> u64

Get the byte offset for a page index.

pub fn extend_file(&self, num_pages: u64) -> Result<u64>

Extend the database file by num_pages pages.

This writes zero-filled pages to the end of the file. Returns the starting page index of the newly extended region.