Struct Resource 

pub struct Resource { /* private fields */ }

A handle to a bundled resource’s bytes with efficient random read-only access.

The bytes stay valid for the lifetime of the Resource: it owns a guard (an mmap, a native GBytes/QResource/AAsset handle, or an owned buffer) that keeps the backing store alive. Resource is neither Send nor Sync — like the rest of the day runtime it is used on the main/UI thread.

Implementations

impl Resource

pub unsafe fn from_raw( ptr: *const u8, len: usize, guard: Box<dyn Any>, ) -> Resource

Build a Resource from a raw byte view plus the guard that owns it. Backends call this from their opener after obtaining a zero-copy pointer from the native resource API.

Safety

ptr must point to len valid, immutable bytes that remain valid for as long as guard is alive, and guard must own (and keep alive) that backing store.

pub fn from_vec(bytes: Vec<u8>) -> Resource

Build a Resource from owned bytes — the copy fallback for backends that cannot expose a stable pointer into their store (or when a native API only offers a read-into-buffer call).

pub fn len(&self) -> usize

Total byte length of the resource.

pub fn is_empty(&self) -> bool

Whether the resource is empty.

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

A zero-copy view of the full contents. Backed directly by the native store (no allocation, no copy). Wrap in std::io::Cursor for Read/Seek-style access.

pub fn read_at(&self, offset: usize, buf: &mut [u8]) -> usize

Random-access read: copy up to buf.len() bytes starting at offset into buf, returning the number of bytes copied (0 if offset >= len). A direct memcpy from the backing store, no allocation — the efficient primitive for seeking around a large embedded blob.

pub fn to_vec(&self) -> Vec<u8>

Copy the full contents into a freshly allocated Vec.