@metamask/ocap-kernel/dist/store/methods/reachable.mjs

OCap kernel core components

import { getBaseMethods } from "./base.mjs";
import { getObjectMethods } from "./object.mjs";
import { getRefCountMethods } from "./refcount.mjs";
import { parseRef } from "../utils/parse-ref.mjs";
import { parseReachableAndVatSlot, buildReachableAndVatSlot } from "../utils/reachable.mjs";
/**
 * Get the reachable methods that provide functionality for managing reachable flags.
 *
 * @param ctx - The store context.
 * @returns The reachable methods.
 */
// eslint-disable-next-line @typescript-eslint/explicit-function-return-type
export function getReachableMethods(ctx) {
    const { getSlotKey } = getBaseMethods(ctx.kv);
    const { getObjectRefCount, setObjectRefCount } = getObjectMethods(ctx);
    const { kernelRefExists } = getRefCountMethods(ctx);
    /**
     * Check if a kernel object is reachable.
     *
     * @param endpointId - The endpoint for which the reachable flag is being checked.
     * @param kref - The kref.
     * @returns True if the kernel object is reachable, false otherwise.
     */
    function getReachableFlag(endpointId, kref) {
        const key = getSlotKey(endpointId, kref);
        const data = ctx.kv.getRequired(key);
        const { isReachable } = parseReachableAndVatSlot(data);
        return isReachable;
    }
    /**
     * Get the reachable and vat slot for a given vat and kernel slot.
     *
     * @param endpointId - The vat ID.
     * @param kref - The kernel slot.
     * @returns The reachable and vat slot.
     */
    function getReachableAndVatSlot(endpointId, kref) {
        const key = getSlotKey(endpointId, kref);
        const data = ctx.kv.getRequired(key);
        return parseReachableAndVatSlot(data);
    }
    /**
     * Clear the reachable flag for a given endpoint and kref.
     *
     * @param endpointId - The endpoint for which the reachable flag is being cleared.
     * @param kref - The kref.
     */
    function clearReachableFlag(endpointId, kref) {
        const key = getSlotKey(endpointId, kref);
        const { isReachable, vatSlot } = getReachableAndVatSlot(endpointId, kref);
        ctx.kv.set(key, buildReachableAndVatSlot(false, vatSlot));
        const { direction, isPromise } = parseRef(vatSlot);
        // decrement 'reachable' part of refcount, but only for object imports
        if (isReachable &&
            !isPromise &&
            direction === 'import' &&
            kernelRefExists(kref)) {
            const counts = getObjectRefCount(kref);
            counts.reachable -= 1;
            setObjectRefCount(kref, counts);
            if (counts.reachable === 0) {
                ctx.maybeFreeKrefs.add(kref);
            }
        }
    }
    return {
        getReachableFlag,
        getReachableAndVatSlot,
        clearReachableFlag,
    };
}
//# sourceMappingURL=reachable.mjs.map