moeralib/lib/crypto/fingerprint.js

Library to interact with Moera decentralized social network

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.FingerprintWriter = void 0;
class FingerprintWriter {
    constructor() {
        this.data = [];
    }
    appendNull() {
        this.data.push(0xff);
    }
    appendString(str) {
        if (str == null) {
            this.appendNull();
            return;
        }
        const buf = Buffer.from(str);
        this.appendNumber(buf.length);
        this.data.push(...buf.values());
    }
    appendBoolean(b) {
        this.data.push(b ? 1 : 0);
    }
    appendNumber(l) {
        let len;
        if (l < 0xfc) {
            len = 1;
        }
        else if (l <= 0xffff) {
            this.data.push(0xfc);
            len = 2;
        }
        else if (l <= 0xffffffff) {
            this.data.push(0xfd);
            len = 4;
        }
        else {
            this.data.push(0xfe);
            len = 8;
        }
        for (let i = 0; i < len; i++) {
            this.data.push(l & 0xff);
            l = l >> 8;
        }
    }
    appendBytes(b) {
        this.appendNumber(b.length);
        this.data.push(...b.values());
    }
    appendFingerprint(fingerprint, schema) {
        for (const field of schema) {
            this.append(fingerprint[field[0]], field[1]);
        }
    }
    appendList(list, type) {
        const writer = new FingerprintWriter();
        list.forEach(value => writer.append(value, type));
        this.appendBytes(writer.toBytes());
    }
    append(value, type) {
        if (value == null) {
            this.appendNull();
        }
        else if (Array.isArray(type)) {
            this.appendFingerprint(value, type);
        }
        else if (type.endsWith("[]")) {
            this.appendList(value, type.substring(0, type.length - 2));
        }
        else if (type === "string") {
            this.appendString(value);
        }
        else if (type === "boolean") {
            this.appendBoolean(value);
        }
        else if (type === "number") {
            this.appendNumber(value);
        }
        else if (type === "bytes") {
            this.appendBytes(value);
        }
    }
    toBytes() {
        return Buffer.from(this.data);
    }
}
exports.FingerprintWriter = FingerprintWriter;