Struct Reader 

pub struct Reader { /* private fields */ }

Reader for loading burnpack containers.

Implementations

impl Reader

pub fn from_bytes(bytes: Bytes) -> Result<Self, Error>

Load a pack from an in-memory Bytes buffer.

Loading is lazy: only the header and metadata are parsed here. The buffer is kept as-is (no copy, no share) and is only turned into zero-copy Bytes::view windows when you consume the reader with into_tensors. For large models, prefer from_file, which keeps tensor data file-backed and lazy.

pub fn from_file<P: AsRef<Path>>(path: P) -> Result<Self, Error>

Load a pack from a file.

Only the header and metadata are read up front; the whole file is wrapped in a single lazy Bytes::from_file source, and each tensor’s data is a Bytes::view window into it, read from disk only when accessed. This integrates with the Burn ecosystem’s file allocation (pinned-memory staging) for fast file-to-GPU transfers.

If path has no extension and does not exist as given, the canonical crate::EXTENSION (.bpk) is appended.

pub fn into_tensors(self) -> Result<Vec<Tensor>, Error>

Consume the reader, returning all tensors in sorted (alphabetical) name order.

Each tensor’s bytes are a zero-copy Bytes::view window into the source — no per-tensor copy. For an in-memory source the buffer is shared once here (a cheap Arc move, never a data copy) to make those views available; for a file source the windows are file-backed and read lazily on access. Consuming self lets us hand the source’s ownership to the views directly, so loading never reads or copies tensor data eagerly.

pub fn metadata(&self) -> &BTreeMap<String, String>

The user-supplied key/value metadata stored alongside the tensors.

For per-tensor info (dtype/shape/param id), use into_tensors — for a file-backed reader that does not read any tensor data until a tensor’s bytes are accessed.

pub fn scalars(&self) -> &BTreeMap<String, Scalar>

The typed scalars stored alongside the tensors.

Empty for files written before scalar support.

pub fn tensor_names(&self) -> Vec<&str>

The names of all tensors in the pack, in sorted (alphabetical) order.

pub fn tensor_data(&self, name: &str) -> Result<Vec<u8>, Error>

Read a single tensor’s raw little-endian bytes by name (always copies).

Returns Error::TensorNotFound if no tensor with that name exists.