jinaga/dist/fact/hash.js

Data management for web and mobile applications.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.computeObjectHash = exports.canonicalPredecessors = exports.verifyHash = exports.canonicalizeFact = exports.computeHash = void 0;
const encoding_1 = require("../util/encoding");
function computeHash(fields, predecessors) {
    return computeObjectHash({
        fields: fields,
        predecessors: canonicalPredecessors(predecessors)
    });
}
exports.computeHash = computeHash;
function canonicalizeFact(fields, predecessors) {
    return canonicalize({
        fields: fields,
        predecessors: canonicalPredecessors(predecessors)
    });
}
exports.canonicalizeFact = canonicalizeFact;
function verifyHash(fact) {
    const computedHash = computeHash(fact.fields, fact.predecessors);
    return fact.hash === computedHash;
}
exports.verifyHash = verifyHash;
function canonicalPredecessors(predecessors) {
    const result = {};
    for (const role in predecessors) {
        const referenceMessages = predecessors[role];
        if (Array.isArray(referenceMessages)) {
            result[role] = sortedPredecessors(referenceMessages);
        }
        else {
            result[role] = referenceMessages;
        }
    }
    return result;
}
exports.canonicalPredecessors = canonicalPredecessors;
function sortedPredecessors(predecessors) {
    return predecessors.slice().sort((a, b) => {
        if (a.hash < b.hash)
            return -1;
        else if (a.hash > b.hash)
            return 1;
        if (a.type < b.type)
            return -1;
        else if (a.type > b.type)
            return 1;
        else
            return 0;
    });
}
function computeObjectHash(obj) {
    if (!obj)
        return '';
    const str = canonicalize(obj);
    return (0, encoding_1.computeStringHash)(str);
}
exports.computeObjectHash = computeObjectHash;
function canonicalize(obj) {
    const pairs = [];
    for (const key in obj) {
        const value = obj[key];
        pairs.push({ key, value });
    }
    pairs.sort((a, b) => {
        if (a.key < b.key)
            return -1;
        else if (a.key > b.key)
            return 1;
        else
            return 0;
    });
    const members = pairs.reduce((text, pair) => {
        if (text.length > 0)
            text += ',';
        text += '"' + pair.key + '":' + serialize(pair.value);
        return text;
    }, '');
    return '{' + members + '}';
}
function serialize(value) {
    if (typeof (value) === 'object') {
        if (value instanceof Date) {
            return 'Date.parse("' + value.toISOString() + '")';
        }
        else if (Array.isArray(value)) {
            const values = value.reduce((text, element) => {
                if (text.length > 0)
                    text += ',';
                text += serialize(element);
                return text;
            }, '');
            return '[' + values + ']';
        }
        else {
            return canonicalize(value);
        }
    }
    else {
        return JSON.stringify(value);
    }
}
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