@web5/common/dist/esm/multicodec.js

import { varint } from 'multiformats';
/**
 * The `Multicodec` class provides an interface to prepend binary data
 * with a prefix that identifies the data that follows.
 * https://github.com/multiformats/multicodec/blob/master/table.csv
 *
 * Multicodec is a self-describing multiformat, it wraps other formats with
 * a tiny bit of self-description. A multicodec identifier is a
 * varint (variable integer) that indicates the format of the data.
 *
 * The canonical table of multicodecs can be access at the following URL:
 * https://github.com/multiformats/multicodec/blob/master/table.csv
 *
 * Example usage:
 *
 * ```ts
 * Multicodec.registerCodec({ code: 0xed, name: 'ed25519-pub' });
 * const prefixedData = Multicodec.addPrefix({ code: 0xed, data: new Uint8Array(32) });
 * ```
 */
export class Multicodec {
    /**
     * Adds a multicodec prefix to input data.
     *
     * @param options - The options for adding a prefix.
     * @param options.code - The codec code. Either the code or name must be provided.
     * @param options.name - The codec name. Either the code or name must be provided.
     * @param options.data - The data to be prefixed.
     * @returns The data with the added prefix as a Uint8Array.
     */
    static addPrefix(options) {
        var _a;
        let { code, data, name } = options;
        if (!(name ? !code : code)) {
            throw new Error(`Either 'name' or 'code' must be defined, but not both.`);
        }
        // If code was given, confirm it exists, or lookup code by name.
        code = Multicodec.codeToName.has(code) ? code : Multicodec.nameToCode.get(name);
        // Throw error if a registered Codec wasn't found.
        if (code === undefined) {
            throw new Error(`Unsupported multicodec: ${(_a = options.name) !== null && _a !== void 0 ? _a : options.code}`);
        }
        // Create a new array to store the prefix and input data.
        const prefixLength = varint.encodingLength(code);
        const dataWithPrefix = new Uint8Array(prefixLength + data.byteLength);
        dataWithPrefix.set(data, prefixLength);
        // Prepend the prefix.
        varint.encodeTo(code, dataWithPrefix);
        return dataWithPrefix;
    }
    /**
     * Get the Multicodec code from given prefixed data.
     *
     * @param options - The options for getting the codec code.
     * @param options.prefixedData - The data to extract the codec code from.
     * @returns - The Multicodec code as a number.
     */
    static getCodeFromData(options) {
        const { prefixedData } = options;
        const [code, _] = varint.decode(prefixedData);
        return code;
    }
    /**
     * Get the Multicodec code from given Multicodec name.
     *
     * @param options - The options for getting the codec code.
     * @param options.name - The name to lookup.
     * @returns - The Multicodec code as a number.
     */
    static getCodeFromName(options) {
        const { name } = options;
        // Throw error if a registered Codec wasn't found.
        const code = Multicodec.nameToCode.get(name);
        if (code === undefined) {
            throw new Error(`Unsupported multicodec: ${name}`);
        }
        return code;
    }
    /**
     * Get the Multicodec name from given Multicodec code.
     *
     * @param options - The options for getting the codec name.
     * @param options.name - The code to lookup.
     * @returns - The Multicodec name as a string.
     */
    static getNameFromCode(options) {
        const { code } = options;
        // Throw error if a registered Codec wasn't found.
        const name = Multicodec.codeToName.get(code);
        if (name === undefined) {
            throw new Error(`Unsupported multicodec: ${code}`);
        }
        return name;
    }
    /**
     * Registers a new codec in the Multicodec class.
     *
     * @param codec - The codec to be registered.
     */
    static registerCodec(codec) {
        Multicodec.codeToName.set(codec.code, codec.name);
        Multicodec.nameToCode.set(codec.name, codec.code);
    }
    /**
     * Returns the data with the Multicodec prefix removed.
     *
     * @param refixedData - The data to extract the codec code from.
     * @returns {Uint8Array}
     */
    static removePrefix(options) {
        const { prefixedData } = options;
        const [code, codeByteLength] = varint.decode(prefixedData);
        // Throw error if a registered Codec wasn't found.
        const name = Multicodec.codeToName.get(code);
        if (name === undefined) {
            throw new Error(`Unsupported multicodec: ${code}`);
        }
        return { code, data: prefixedData.slice(codeByteLength), name };
    }
}
/**
 * A static field containing a map of codec codes to their corresponding names.
 */
Multicodec.codeToName = new Map();
/**
 * A static field containing a map of codec names to their corresponding codes.
 */
Multicodec.nameToCode = new Map();
// Pre-defined registered codecs:
Multicodec.registerCodec({ code: 0xed, name: 'ed25519-pub' });
Multicodec.registerCodec({ code: 0x1300, name: 'ed25519-priv' });
Multicodec.registerCodec({ code: 0xec, name: 'x25519-pub' });
Multicodec.registerCodec({ code: 0x1302, name: 'x25519-priv' });
Multicodec.registerCodec({ code: 0xe7, name: 'secp256k1-pub' });
Multicodec.registerCodec({ code: 0x1301, name: 'secp256k1-priv' });
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