Struct MmapBundle 

pub struct MmapBundle {
    pub header: FileHeader,
    pub manifest: Manifest,
    /* private fields */
}

A memory-mapped ahu bundle for zero-copy serving at scale.

Uses MAP_PRIVATE (copy-on-write). The backing inode must remain immutable: publish replacements with atomic rename, never truncate an open bundle. The OS demand-pages only the regions actually accessed — a 45 GB bundle uses ~200 MB RSS under typical access patterns.

The index is searched via binary search directly in the mapped region. Response bytes are returned as slices into the mapping — no allocation.

Fields

header: FileHeader

manifest: Manifest

Implementations

impl MmapBundle

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

Open a bundle file with MAP_PRIVATE (copy-on-write).

Safety

Uses unsafe for the mmap syscall. Publishers must replace files atomically; MAP_PRIVATE does not protect against truncation. Size is validated against header offsets before any section is accessed.

pub fn lookup(&self, entry_key: &[u8; 32]) -> Option<&[u8]>

Look up an entry by its entry key (SHA-256 of DER CertID). Returns the default (discriminator=0) entry.

pub fn lookup_preferred( &self, entry_key: &[u8; 32], preferences: &[u16], ) -> Option<&[u8]>

Look up the best-matching entry given preferred discriminators.

pub fn manifest_bytes(&self) -> &[u8]

Get the raw manifest bytes (slice into mmap).

pub fn seal_bytes(&self) -> &[u8]

Get the raw seal bytes (slice into mmap).

pub fn entry_count(&self) -> usize

Number of index records.