Struct ReadOptions 

#[non_exhaustive]
pub struct ReadOptions {
    pub max_bytes: Option<usize>,
    pub max_nodes: Option<usize>,
    pub max_edges: Option<usize>,
    pub max_nested_graphs: Option<usize>,
    pub version_policy: VersionPolicy,
}

Allocation and collection policy for decoding an untrusted .nir file with read_with.

Defaults are permissive: every field is None, so read stays unbounded aside from the existing hard cap of 1024 NIRGraph groups (root plus nested). That cap is a stack/alias safety bound, not a substitute for a caller-chosen collection budget.

max_bytes is a decoded-allocation budget, not an on-disk file-size limit and not a bound on the returned graph’s exact resident size. Charging is monotonic and conservative: temporary allocations stay charged after they are released. The exact rules are:

• numeric datasets: element count times decoded width;
• u64 datasets: both the temporary Vec<u64> and converted Vec<i64>;
• i64 extent lists converted to Vec<usize> (e.g. Input.shape): both the source Vec<i64> and the destination Vec<usize>;
• fixed strings: fixed-capacity HDF5 buffers, resulting String headers, and the worst-case copied payload;
• variable-length strings: descriptor buffers, payload bytes reported by H5Dvlen_get_buf_size, resulting String headers, and copied payload. Scalar VLEN strings use the containing file size as a payload bound because H5Dvlen_get_buf_size can abort on scalar VLEN;
• scalar metadata: its decoded width;
• missing v_reset and w_in: the synthesized tensor payload.

max_nodes, max_edges, and max_nested_graphs are global count budgets for the whole file: nested subgraphs add to the same totals rather than resetting per group. Counts are charged from HDF5 metadata (H5Gget_info link counts, edges shape, one charge per NIRGraph group) before the corresponding Vec / map is materialized. Hard-link aliases are rejected before they can charge a second time.

All arithmetic is checked; overflow is treated as over budget. Node and link names, collection bookkeeping, allocator overhead, and libhdf5’s own caches are not charged against max_bytes.

Untrusted inputs

Conservative starting points when the file is not from a trusted producer — tighten further for your threat model:

use nir_rs::io::ReadOptions;

let opts = ReadOptions::default()
    .with_max_bytes(Some(64 * 1024 * 1024))
    .with_max_nodes(Some(10_000))
    .with_max_edges(Some(50_000))
    .with_max_nested_graphs(Some(64));

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

max_bytes: Option<usize>

Maximum total bytes charged by decoded allocations, or None for no allocation budget.

max_nodes: Option<usize>

Maximum total nodes across root and nested graphs, or None for no node-count budget.

max_edges: Option<usize>

Maximum total edges across root and nested graphs, or None for no edge-count budget.

max_nested_graphs: Option<usize>

Maximum total NIRGraph groups decoded from the file (root included), or None to use only the hard cap of 1024 groups.

version_policy: VersionPolicy

How to treat the root /version dataset. Defaults to VersionPolicy::Permissive, which is the Python nir.read behaviour and keeps read byte-for-byte compatible with earlier crate versions.

Implementations

impl ReadOptions

pub fn with_max_bytes(self, max_bytes: Option<usize>) -> Self

Set the decoded-allocation budget in bytes; None makes it unbounded.

pub fn with_max_nodes(self, max_nodes: Option<usize>) -> Self

Set the global node-count budget; None makes it unbounded.

pub fn with_max_edges(self, max_edges: Option<usize>) -> Self

Set the global edge-count budget; None makes it unbounded.

pub fn with_max_nested_graphs(self, max_nested_graphs: Option<usize>) -> Self

Set the global nested-graph budget; None keeps only the hard cap of 1024 groups.

pub fn with_version_policy(self, version_policy: VersionPolicy) -> Self

Set the /version compatibility policy.

use nir_rs::io::{ReadOptions, VersionPolicy};

// Permissive tooling (default): accept missing or arbitrary versions.
let tool = ReadOptions::default();
assert_eq!(tool.version_policy, VersionPolicy::Permissive);

// Fail-closed importer: paper 0.x fixtures and 1.x writers.
let importer = ReadOptions::default()
    .with_version_policy(VersionPolicy::compatible_major([0, 1]));

Trait Implementations

impl Clone for ReadOptions

fn clone(&self) -> ReadOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ReadOptions

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

Formats the value using the given formatter.

impl Default for ReadOptions

fn default() -> ReadOptions

Returns the “default value” for a type.

impl Eq for ReadOptions

impl PartialEq for ReadOptions

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ReadOptions