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/*
MIT License http://www.opensource.org/licenses/mit-license.php
*/
"use strict";
const cache = new WeakMap();
class ObjectStructure {
constructor() {
this.keys = undefined;
this.children = undefined;
}
getKeys(keys) {
if (this.keys === undefined) this.keys = keys;
return this.keys;
}
key(key) {
if (this.children === undefined) this.children = new Map();
const child = this.children.get(key);
if (child !== undefined) return child;
const newChild = new ObjectStructure();
this.children.set(key, newChild);
return newChild;
}
}
const getCachedKeys = (keys, cacheAssoc) => {
let root = cache.get(cacheAssoc);
if (root === undefined) {
root = new ObjectStructure();
cache.set(cacheAssoc, root);
}
let current = root;
for (const key of keys) {
current = current.key(key);
}
return current.getKeys(keys);
};
class PlainObjectSerializer {
serialize(obj, { write }) {
const keys = Object.keys(obj);
if (keys.length > 128) {
// Objects with so many keys are unlikely to share structure
// with other objects
write(keys);
for (const key of keys) {
write(obj[key]);
}
} else if (keys.length > 1) {
write(getCachedKeys(keys, write));
for (const key of keys) {
write(obj[key]);
}
} else if (keys.length === 1) {
const key = keys[0];
write(key);
write(obj[key]);
} else {
write(null);
}
}
deserialize({ read }) {
const keys = read();
const obj = {};
if (Array.isArray(keys)) {
for (const key of keys) {
obj[key] = read();
}
} else if (keys !== null) {
obj[keys] = read();
}
return obj;
}
}
module.exports = PlainObjectSerializer;