Struct PageStore 

pub struct PageStore { /* private fields */ }

Page store: maps logical page IDs to on-disk locations, with optional at-rest encryption via EncryptionContext.

On-disk layout

When encryption is disabled (passthrough mode), each page occupies exactly page_size bytes at offset page_id * page_size.

When encryption is enabled, each page occupies page_size + 40 bytes (the “encrypted stride”):

┌────────────────────────┬───────────────────────────────────┐
│  nonce (24 bytes)      │  ciphertext + auth tag            │
│                        │  (page_size + 16 bytes)           │
└────────────────────────┴───────────────────────────────────┘
total: page_size + 40 bytes per page slot

The encryption stride ensures that a file opened without a key cannot be accidentally decoded as raw pages (sizes won’t align).

Implementations

impl PageStore

pub fn open(path: &Path) -> Result<Self>

Open (or create) a page store at path with the given page_size and no encryption.

Use PageStore::open_encrypted to enable at-rest encryption.

pub fn open_with_page_size(path: &Path, page_size: usize) -> Result<Self>

Open (or create) a page store with the given page size and no encryption.

pub fn open_encrypted( path: &Path, page_size: usize, key: [u8; 32], ) -> Result<Self>

Open (or create) an encrypted page store.

key — 32-byte master encryption key (XChaCha20-Poly1305).

If the file already exists and was written with a different key, the first read_page call will return Error::EncryptionAuthFailed.

pub fn read_page(&self, id: PageId, buf: &mut [u8]) -> Result<()>

Read page id into buf.

buf must be exactly page_size bytes.

Errors

• Error::InvalidArgument — buf.len() != page_size.
• Error::EncryptionAuthFailed — AEAD tag rejected (wrong key or corrupted page).
• Error::Io — underlying I/O failure.

pub fn write_page(&self, id: PageId, buf: &[u8]) -> Result<()>

Write buf as page id.

buf must be exactly page_size bytes.

Errors

• Error::InvalidArgument — buf.len() != page_size.
• Error::Io — underlying I/O failure.

pub fn fsync(&self) -> Result<()>

Flush and fsync the backing file to durable storage.