@chainsafe/ssz
Version:
Simple Serialize
91 lines • 4.27 kB
JavaScript
import { BranchNodeStruct } from "../branchNodeStruct.js";
import { isCompositeType } from "../type/composite.js";
import { TreeView } from "./abstract.js";
/**
* Intented usage:
*
* - Get initial BeaconState from disk.
* - Before applying next block, switch to mutable
* - Get some field, create a view in mutable mode
* - Do modifications of the state in the state transition function
* - When done, commit and apply new root node once to og BeaconState
* - However, keep all the caches and transfer them to the new BeaconState
*
* Questions:
* - Can the child views created in mutable mode switch to not mutable? If so, it seems that it needs to recursively
* iterate the entire data structure and views
*
*/
class ContainerTreeView extends TreeView {
type;
tree;
constructor(type, tree) {
super();
this.type = type;
this.tree = tree;
}
get node() {
return this.tree.rootNode;
}
}
export function getContainerTreeViewClass(type) {
class CustomContainerTreeView extends ContainerTreeView {
}
// Dynamically define prototype methods
for (let index = 0; index < type.fieldsEntries.length; index++) {
const { fieldName, fieldType } = type.fieldsEntries[index];
// If the field type is basic, the value to get and set will be the actual 'struct' value (i.e. a JS number).
// The view must use the tree_getFromNode() and tree_setToNode() methods to persist the struct data to the node,
// and use the cached views array to store the new node.
if (fieldType.isBasic) {
Object.defineProperty(CustomContainerTreeView.prototype, fieldName, {
configurable: false,
enumerable: true,
// TODO: Review the memory cost of this closures
get: function () {
return this.tree.rootNode.value[fieldName];
},
set: function (value) {
const node = this.tree.rootNode;
const newNodeValue = this.type.clone(node.value);
// TODO: Should this check for valid field name? Benchmark the cost
newNodeValue[fieldName] = value;
// biome-ignore lint/complexity/useLiteralKeys: The key `valueToNode` is private field
this.tree.rootNode = new BranchNodeStruct(node["valueToNode"], newNodeValue);
},
});
}
// If the field type is composite, the value to get and set will be another TreeView. The parent TreeView must
// cache the view itself to retain the caches of the child view. To set a value the view must return a node to
// set it to the parent tree in the field gindex.
else if (isCompositeType(fieldType)) {
Object.defineProperty(CustomContainerTreeView.prototype, fieldName, {
configurable: false,
enumerable: true,
// Returns TreeView of fieldName
get: function () {
const { value } = this.tree.rootNode;
return fieldType.toView(value[fieldName]);
},
// Expects TreeView of fieldName
set: function (view) {
const node = this.tree.rootNode;
const newNodeValue = this.type.clone(node.value);
// TODO: Should this check for valid field name? Benchmark the cost
newNodeValue[fieldName] = fieldType.toValueFromView(view);
// biome-ignore lint/complexity/useLiteralKeys: The key `valueToNode` is private field
this.tree.rootNode = new BranchNodeStruct(node["valueToNode"], newNodeValue);
},
});
}
// Should never happen
else {
/* istanbul ignore next - unreachable code */
throw Error(`Unknown fieldType ${fieldType.typeName} for fieldName ${String(fieldName)}`);
}
}
// Change class name
Object.defineProperty(CustomContainerTreeView, "name", { value: type.typeName, writable: false });
return CustomContainerTreeView;
}
//# sourceMappingURL=containerNodeStruct.js.map