Struct ArrayStore 

pub struct ArrayStore {
    pub entities: EntityTable,
    /* private fields */
}

Storage for PostScript array element data.

Fields

entities: EntityTable

Implementations

impl ArrayStore

pub fn new() -> Self

pub fn allocated_objects(&self) -> usize

Number of object slots handed out so far.

The backing arena only ever grows — nothing is reclaimed without a restore — so this doubles as the store’s high-water mark. Useful for asserting that a code path which evaluates PostScript repeatedly isn’t allocating a fresh array per evaluation.

pub fn data_len(&self) -> usize

Release every object slot and entity from the given marks onward.

Used by restore to reclaim the objects a save level created. See crate::entity_table::EntityTable::truncate for the safety argument and the EntityId-reuse caveat. Number of PsObject slots currently held.

Used for VM accounting; see crate::context::Context::vm_bytes.

pub fn data_capacity(&self) -> usize

Slots currently reserved, which is what the allocator actually holds.

VM accounting has to use this rather than the length. The backing Vec grows geometrically, so a store holding just under the ceiling by length asks the allocator for roughly twice that on its next growth — which is how { 1000000 string pop } loop still aborted with a 16 GB request after a length-based check had passed at 8 GB.

pub fn truncate_to(&mut self, data_len: usize, entity_len: usize)

pub fn allocate(&mut self, len: usize) -> EntityId

Allocate len null-filled slots, returning an EntityId.

pub fn allocate_from(&mut self, items: &[PsObject]) -> EntityId

Allocate and copy items into the store.

pub fn allocate_from_with( &mut self, items: &[PsObject], save_level: u16, global: bool, created_after_save: u32, ) -> EntityId

Allocate and copy items with a specific save level and global flag.

pub fn allocate_with( &mut self, len: usize, save_level: u16, global: bool, created_after_save: u32, ) -> EntityId

Allocate with a specific save level and global flag.

pub fn iter_entities(&self) -> impl Iterator<Item = (EntityId, &[PsObject])>

Iterate every allocated array in this store as (EntityId, elements).

Used by the VM audit (see crate::vm_audit) to sweep global VM for PLRM 3.7.2 violations. Sweeping the entity table rather than following references catches arrays written through ArrayStore::get_mut, which hands out &mut [PsObject] and so bypasses any per-store checkpoint.

pub fn get(&self, entity: EntityId, start: u32, len: u32) -> &[PsObject]

Get a slice of array elements via entity table indirection.

pub fn get_mut( &mut self, entity: EntityId, start: u32, len: u32, ) -> &mut [PsObject]

Get a mutable slice of array elements via entity table indirection.

pub fn get_element(&self, entity: EntityId, index: u32) -> PsObject

Get a single element.

pub fn set_element(&mut self, entity: EntityId, index: u32, obj: PsObject)

Set a single element.

pub fn cow_copy(&mut self, entity: EntityId) -> EntityId

Copy entity data to a new region (for COW). Returns the new EntityId pointing at the backup. The original entity’s offset is updated to point at the fresh copy.

pub fn swap_offsets(&mut self, a: EntityId, b: EntityId)

Swap offsets between two entities (used by restore).

Trait Implementations

impl Default for ArrayStore

fn default() -> Self

Returns the “default value” for a type.