Struct FormatTable 

pub struct FormatTable { /* private fields */ }

A plane’s accepted (fourcc, modifier) pairs, sorted and de-duplicated.

Implementations

impl FormatTable

pub const fn new() -> Self

An empty table, accepting nothing.

pub fn from_blob(data: &[u8]) -> Self

Parse a raw IN_FORMATS blob payload.

Malformed input yields an empty (or partial) table rather than an error: a plane whose blob does not parse is simply a plane nothing is eligible for, and the caller’s fallback (“formats[] implies LINEAR only”) is the same either way. This matches the C++, which returns a default- constructed table on every guard.

Robustness

The blob’s arrays may begin at offsets that are not naturally aligned. In C++ that made indexing a typed pointer into the blob undefined behavior, and it faulted on strict-alignment targets — the C++ fix was to memcpy each element out. Here every field is read byte-wise from a slice with a bounds-checked accessor, so alignment cannot arise as a concern at all. Counts are validated against the remaining length before use, in division form, so no count * size product can overflow.

use drmkit_fmt::FormatTable;
// Too short to hold a header: empty table, no panic.
assert!(FormatTable::from_blob(&[0u8; 4]).all().is_empty());
assert!(FormatTable::from_blob(&[]).all().is_empty());

pub fn from_pairs<I>(pairs: I) -> Self

where I: IntoIterator<Item = (u32, Modifier)>,

Build a table from already-decoded pairs — for a caller that harvested IN_FORMATS by other means and wants the queryable table without re-reading the blob.

Duplicates are removed; input order does not matter.

use drmkit_fmt::{FormatTable, Modifier, fourcc};
let table = FormatTable::from_pairs([
    (fourcc::XRGB8888, Modifier::LINEAR),
    (fourcc::XRGB8888, Modifier::LINEAR), // duplicate
    (fourcc::NV12, Modifier::LINEAR),
]);
assert_eq!(table.all().len(), 2);

pub fn supports(&self, fourcc: u32, modifier: Modifier) -> bool

Whether the plane advertises this exact (fourcc, modifier) pair.

This is exact-match only. Family-aware eligibility — which is what the allocator wants — is crate::layer_fits_plane.

pub fn modifiers_for(&self, fourcc: u32) -> impl Iterator<Item = Modifier> + '_

Every modifier advertised for fourcc, ascending.

pub fn all(&self) -> &[FormatMod]

Every advertised pair, sorted by (fourcc, modifier).

pub fn is_empty(&self) -> bool

Whether the table advertises nothing.

pub fn len(&self) -> usize

Number of advertised pairs.

Trait Implementations

impl Clone for FormatTable

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FormatTable

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

Formats the value using the given formatter.

impl Default for FormatTable

fn default() -> Self

Returns the “default value” for a type.

impl Eq for FormatTable

impl PartialEq for FormatTable

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FormatTable