key-value-compress/lib/_transform.js

Key-Value interface to deflate, split, concatenate and inflate storage.

"use strict";
/**
 * _transform.ts
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.stringifyKVS = exports.encodeKVS = exports.keyFilterKVS = exports.namespaceKVS = void 0;
/**
 * wrap key-value storage to prepend a prefix string for storage keys
 */
function namespaceKVS(storage, prefix) {
    if (!prefix)
        return storage;
    return keyFilterKVS(storage, key => prefix + key);
}
exports.namespaceKVS = namespaceKVS;
function keyFilterKVS(storage, filter) {
    const out = {};
    out.get = (key) => storage.get(filter(key));
    out.set = (key, value) => storage.set(filter(key), value);
    if (storage.delete)
        out.delete = (key) => storage.delete(filter(key));
    if (storage.has)
        out.has = (key) => storage.has(filter(key));
    return out;
}
exports.keyFilterKVS = keyFilterKVS;
/**
 * transform key-value storage to apply encode() and decode() methods
 */
function encodeKVS(storage, filter) {
    const out = {};
    out.get = async (key) => {
        const value = await storage.get(key);
        if ("undefined" === typeof value)
            return;
        return filter.decode(value);
    };
    out.set = async (key, value) => storage.set(key, filter.encode(value));
    if (storage.delete)
        out.delete = async (key) => storage.delete(key);
    if (storage.has)
        out.has = async (key) => storage.has(key);
    return out;
}
exports.encodeKVS = encodeKVS;
/**
 * transform key-value storage to apply stringify() and parse() methods
 */
function stringifyKVS(storage, filter) {
    return encodeKVS(storage, {
        encode: value => filter.stringify(value),
        decode: value => filter.parse(value),
    });
}
exports.stringifyKVS = stringifyKVS;