Crate javm_cap 

JAR v3 capability system.

Defines the four v3 cap kinds (Instance, Image, Data, CNode), their content-bearing representations, a two-tier cache for identity-keyed mutable state + content-addressed blobs, and the primitives (BMT, hash) used by upstream layers.

Cap and its inner storage use the default Global allocator (= std heap on host, talc on guest via #[global_allocator]). The cache layer’s outer storage (HashMap / Box parameters) may still be parameterised on a custom allocator for shared-memory layouts.

Cap itself is the wire form: it derives rkyv::Archive/Serialize/Deserialize so callers move caps across the host/guest boundary by writing rkyv::to_bytes(&cap)? (errors on unsettled Ref targets) and rkyv::access::<rkyv::Archived<Cap>, _>(bytes)? for zero-copy decode. See cache::CapHasRefError for the encode-time error.

See ~/jar/website/content/spec/implementation/architecture.md for the crate’s role in the overall layering.

Re-exports

pub use cache::CacheDirectory;

pub use cache::CacheError;

pub use cache::CapHasRefError;

pub use cache::CapHashOrRef;

pub use cache::CapRef;

pub use cache::ResidentCap;

pub use cap::cnode::CNodeCap;

pub use cap::data::DataCap;

pub use cap::data::GROUP_SIZE;

pub use cap::data::PAGE_SIZE;

pub use cap::data::PageResolution;

pub use cap::data::PageSlab;

pub use cap::image::EndpointDef;

pub use cap::image::ImageCap;

pub use cap::image::ImageConvertError;

pub use cap::image::ImageSlotEntry;

pub use cap::image::MemoryMapping;

pub use cap::image::image_cap;

pub use cap::instance::InstanceCap;

pub use cap::page::PageBytes;

pub use cap::page::PageRef;

pub use cap::page::PageSlot;

pub use cap::Cap;

pub use cap::CapHash;

pub use cap::MAX_SOURCE_DEPTH;

pub use cap::NUM_REGS;

pub use error::CapError;

pub use error::OpError;

pub use hash::Blake2b256;

pub use hash::Hash;

pub use hash::Hasher;

pub use image::ArenaPageRef;

pub use image::CodeRef;

pub use image::DataDesc;

pub use image::DataDescError;

pub use image::Image;

pub use image::ImageBuilder;

pub use image::InitialDataCap;

pub use image::PinnedCap;

pub use image::chain_extend;

pub use image::chain_genesis;

pub use image::image_content_hash;

pub use kernel_image::ALL_KERNEL_IMAGES;

pub use kernel_image::KernelImage;

pub use kernel_image::kernel_image_hash;

pub use kernel_image::recognize_kernel_image;

pub use slot::Key;

pub use slot::MAX_KEY_LEN;

pub use slot::SlotPath;

pub use slot::key_from_regs;

pub use slot::key_to_regs;

pub use yield_cap::gas_handle;

pub use yield_cap::gas_meter_key;

pub use yield_cap::is_kernel_yield_key;

pub use yield_cap::merge_yield_receivers;

pub use yield_cap::quota_handle;

pub use yield_cap::quota_key;

pub use yield_cap::yield_receiver;

pub use yield_cap::yield_receiver_keys;

pub use yield_cap::yield_sender;

pub use yield_cap::yield_sender_key;

Modules

abi

Well-known cnode slot keys the v3 chain ABI exposes at genesis. Shared between jar-kernel (which populates the slots at chain init) and consumers like the JAVM transpiler (which emit chain Images referencing them).

cache

CacheDirectory<S> — two-tier cap store.

cap

Cap — cap enum + shared constants.

error

Errors for cap operations.

hash

Hash trait and default Blake2b-256 implementation.

image

Image: the smallest unit of program specification.

kernel_image

Kernel-assisted Image registry.

layout

PVM2 guest virtual-address-space layout (ABI constants).

slot

Byte-string keys and slot addressing.

yield_cap

YieldSender / YieldReceiver kernel-assisted cap helpers + the reserved kernel:* yield-key namespace.

Enums

MissingOr

Either a fully materialized value or a precomputed hash placeholder.