@directus/api/dist/utils/get-default-index-name.js

Directus is a real-time API and App dashboard for managing SQL database content

import { getSimpleHash } from '@directus/utils';
/**
 * Generate an index name for a given collection + fields combination.
 *
 * Based on the default index name generation of knex, with the caveat that it limits the index to options.maxLength
 * which defaults to 60 characters.
 *
 * @see
 * https://github.com/knex/knex/blob/fff6eb15d7088d4198650a2c6e673dedaf3b8f36/lib/schema/tablecompiler.js#L282-L297
 */
export function getDefaultIndexName(type, collection, fields, options) {
    const maxLength = options?.maxLength ?? 60;
    if (!Array.isArray(fields))
        fields = fields ? [fields] : [];
    const table = collection.replace(/\.|-/g, '_');
    const indexName = (table + '_' + fields.join('_') + '_' + type).toLowerCase();
    if (indexName.length <= maxLength)
        return indexName;
    const suffix = `__${getSimpleHash(indexName)}_${type}`;
    const prefix = indexName.substring(0, maxLength - suffix.length);
    return `${prefix}${suffix}`;
}