Struct Footer 

pub struct Footer {
    pub version: u32,
    pub blocks: Vec<BlockMeta>,
    pub arrays: Vec<ArrayMeta>,
    pub attr_keys: Vec<String>,
    pub attr_values: Vec<AttributeValue>,
    pub overlay_index: u32,
    pub base_file_hint: String,
}

The file footer containing the block table and array table.

Serialized with rkyv for zero-copy access to the archived form.

Fields

version: u32

Format version.

blocks: Vec<BlockMeta>

Block table: metadata for every block in the data region.

arrays: Vec<ArrayMeta>

Array table: metadata for every array stored in the file.

attr_keys: Vec<String>

Global dictionary of attribute key strings.

Array attributes reference keys by index into this vec, so each unique key string is stored exactly once regardless of how many arrays carry that attribute.

attr_values: Vec<AttributeValue>

Global dictionary of attribute values.

Array attributes reference values by index into this vec, so each distinct value is stored exactly once across all arrays. Together with attr_keys this means each ArrayMeta::attributes entry is just 4 bytes (two u16 indices).

overlay_index: u32

Position of this file in the overlay stack.

0 = base file. N > 0 = the Nth sidecar ({stem}.N.arrf). A sidecar footer’s arrays list contains only the delta — arrays and chunks that changed relative to lower layers.

base_file_hint: String

Stem of the base .af file this sidecar belongs to.

Empty for base files. Used to validate that a sidecar was created for the correct base file when opening a layered file.

Implementations

impl Footer

pub fn new() -> Self

Creates a new empty base-file footer.

pub fn new_overlay( overlay_index: u32, base_file_hint: impl Into<String>, ) -> Self

Creates a new empty overlay (sidecar) footer.

pub fn is_overlay(&self) -> bool

Returns true if this footer belongs to a sidecar file.

pub fn serialize(&self) -> Result<Vec<u8>>

Serializes the footer to bytes, appending the trailer.

Layout: [rkyv_bytes][footer_size: u64 LE][MAGIC]

pub fn deserialize(data: &[u8]) -> Result<Self>

Deserializes a footer from bytes that include the trailer.

data must contain at least the trailer and the footer payload.

Trait Implementations

impl Archive for Footer

where u32: Archive, Vec<BlockMeta>: Archive, Vec<ArrayMeta>: Archive, Vec<String>: Archive, Vec<AttributeValue>: Archive, String: Archive,

const COPY_OPTIMIZATION: CopyOptimization<Self>

An optimization flag that allows the bytes of this type to be copied directly to a writer instead of calling serialize.

type Archived = ArchivedFooter

The archived representation of this type.

type Resolver = FooterResolver

The resolver for this type. It must contain all the additional information from serializing needed to make the archived type from the normal type.

fn resolve(&self, resolver: Self::Resolver, out: Place<Self::Archived>)

Creates the archived version of this value at the given position and writes it to the given output.

impl Clone for Footer

fn clone(&self) -> Footer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Footer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Footer

fn default() -> Self

Returns the “default value” for a type.

impl<__D: Fallible + ?Sized> Deserialize<Footer, __D> for Archived<Footer>

where u32: Archive, <u32 as Archive>::Archived: Deserialize<u32, __D>, Vec<BlockMeta>: Archive, <Vec<BlockMeta> as Archive>::Archived: Deserialize<Vec<BlockMeta>, __D>, Vec<ArrayMeta>: Archive, <Vec<ArrayMeta> as Archive>::Archived: Deserialize<Vec<ArrayMeta>, __D>, Vec<String>: Archive, <Vec<String> as Archive>::Archived: Deserialize<Vec<String>, __D>, Vec<AttributeValue>: Archive, <Vec<AttributeValue> as Archive>::Archived: Deserialize<Vec<AttributeValue>, __D>, String: Archive, <String as Archive>::Archived: Deserialize<String, __D>,

fn deserialize( &self, deserializer: &mut __D, ) -> Result<Footer, <__D as Fallible>::Error>

Deserializes using the given deserializer

impl PartialEq for Footer

fn eq(&self, other: &Footer) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<__S: Fallible + ?Sized> Serialize<__S> for Footer

where u32: Serialize<__S>, Vec<BlockMeta>: Serialize<__S>, Vec<ArrayMeta>: Serialize<__S>, Vec<String>: Serialize<__S>, Vec<AttributeValue>: Serialize<__S>, String: Serialize<__S>,

fn serialize( &self, serializer: &mut __S, ) -> Result<<Self as Archive>::Resolver, <__S as Fallible>::Error>

Writes the dependencies for the object and returns a resolver that can create the archived type.

impl StructuralPartialEq for Footer