Struct FormatMeta 

pub struct FormatMeta {
    pub id: FormatId,
    pub kind: FormatKind,
    pub extensions: &'static [&'static str],
    pub magics: &'static [MagicRule],
    pub priority: i16,
    pub confirm: Option<ConfirmFn>,
    pub magic_optional: bool,
}

Registration metadata for one format.

Fields

id: FormatId

kind: FormatKind

extensions: &'static [&'static str]

Extensions without the leading dot, lowercase. e.g. ["gz", "tgz"].

magics: &'static [MagicRule]

priority: i16

Breaks ties when several formats share a magic. Higher wins.

The ZIP family is why this exists: jar, apk, docx, epub, odt and zip all begin PK\x03\x04, so longest-magic-wins cannot separate them. Rank the base format above its derivatives, and a bare stream resolves to the base while a derivative is reached by extension.

confirm: Option<ConfirmFn>

The format’s confirmation of its own magic hits — see ConfirmFn.

None from Self::codec and Self::container: a format that registers no function is treated as confirming every hit, so adding the hook changes nothing for a format until it opts in with Self::with_confirm.

magic_optional: bool

The format’s writers can emit a stream its magic does not match, so a missing magic is not by itself a refusal: a v7 tar has no ustar at 257, and an empty tar is zero blocks. Set by Self::with_magic_optional; tar is the one format that needs it.

Without it, crate::registry::Registry::confirm refuses any prefix the format’s own magic does not match before its ConfirmFn runs, because that function judges only “a prefix its magic already matched” — a .pak file named for arc but beginning 05 00 read as arc’s method 0, an empty archive, and passed.

Implementations

impl FormatMeta

pub const fn codec( id: FormatId, extensions: &'static [&'static str], magics: &'static [MagicRule], ) -> Self

pub const fn container( id: FormatId, extensions: &'static [&'static str], magics: &'static [MagicRule], ) -> Self

pub const fn with_priority(self, priority: i16) -> Self

pub const fn with_confirm(self, f: ConfirmFn) -> Self

Registers f as this format’s confirmation — see ConfirmFn.

pub const fn with_magic_optional(self) -> Self

Marks the format as one whose writers may omit its magic — see Self::magic_optional.

Trait Implementations

impl Clone for FormatMeta

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FormatMeta

impl Debug for FormatMeta

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

Formats the value using the given formatter.