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PageCodec

quiver_embed

Trait PageCodec 

Source 
pub trait PageCodec: Send + Sync {
    // Required methods
    fn block_size(&self) -> usize;
    fn seal(
        &self,
        page_id: u64,
        plaintext: &[u8; 16384],
        out: &mut [u8],
    ) -> Result<(), CoreError>;
    fn open(
        &self,
        page_id: u64,
        block: &[u8],
        out: &mut [u8; 16384],
    ) -> Result<(), CoreError>;
    fn clone_box(&self) -> Box<dyn PageCodec>;

    // Provided methods
    fn seal_record(&self, plaintext: &[u8]) -> Result<Vec<u8>, CoreError> { ... }
    fn open_record(&self, sealed: &[u8]) -> Result<Vec<u8>, CoreError> { ... }
}
Expand description

Transforms Quiver’s durable bytes — fixed-size pages and variable-length records — to and from their on-disk representation.

The plaintext codec (PlainCodec) is the identity transform; integrity then comes from the page’s inner CRC (and, for records, the WAL frame CRC). The encryption-at-rest codec (added with quiver-crypto) seals each page with an AEAD into a [nonce][ciphertext][tag] block of PageCodec::block_size bytes, deriving a unique nonce per page so reuse is impossible by construction; the inner CRC still protects the plaintext.

The WAL is record-framed rather than paged, so the AEAD codec must also seal each WAL record via PageCodec::seal_record; otherwise an encrypted-at-rest store would still leak its log in plaintext. The default record methods are the identity transform, so PlainCodec needs no change and a non-encrypting codec writes records verbatim.

Required Methods§

Source

fn block_size(&self) -> usize

On-disk size, in bytes, of one sealed page.

Source

fn seal( &self, page_id: u64, plaintext: &[u8; 16384], out: &mut [u8], ) -> Result<(), CoreError>

Seal a plaintext page into its on-disk block. out must be exactly PageCodec::block_size bytes. page_id lets an AEAD codec bind the page to its position (nonce derivation).

Source

fn open( &self, page_id: u64, block: &[u8], out: &mut [u8; 16384], ) -> Result<(), CoreError>

Open an on-disk block back into a plaintext page. block must be exactly PageCodec::block_size bytes.

Source

fn clone_box(&self) -> Box<dyn PageCodec>

Clone this codec into a new boxed instance. A codec holds only key material (or nothing), so a clone shares the same keys — this lets a component that needs its own handle, such as a disk-resident index sealing its own files, reuse the store’s codec (ADR-0019).

Provided Methods§

Source

fn seal_record(&self, plaintext: &[u8]) -> Result<Vec<u8>, CoreError>

Seal a variable-length record — a WAL frame payload — into a self-describing on-disk blob. The default is the identity transform used by PlainCodec; an AEAD codec overrides it to return [nonce][ciphertext+tag], so no plaintext record ever reaches the disk.

Source

fn open_record(&self, sealed: &[u8]) -> Result<Vec<u8>, CoreError>

Open a record produced by PageCodec::seal_record. The default is the identity transform; an AEAD codec authenticates and decrypts, returning an error on a wrong key or any tampering.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§