Function sublevel

lib/index.js:4178–4298

(nut, prefix, createStream, options)

var NOT_FOUND_ERROR = new NotFoundError();

var sublevel = function (nut, prefix, createStream, options) {
  var emitter = new EventEmitter();
  emitter.sublevels = {};
  emitter.options = options;

  emitter.version = version$1;

  emitter.methods = {};
  prefix = prefix || [];

  function mergeOpts(opts) {
    var o = {};
    var k;
    if (options) {
      for (k in options) {
        if (typeof options[k] !== 'undefined') {
          o[k] = options[k];
        }
      }
    }
    if (opts) {
      for (k in opts) {
        if (typeof opts[k] !== 'undefined') {
          o[k] = opts[k];
        }
      }
    }
    return o;
  }

  emitter.put = function (key, value, opts, cb) {
    if ('function' === typeof opts) {
      cb = opts;
      opts = {};
    }

    nut.apply([{
      key, value,
      prefix: prefix.slice(), type: 'put'
    }], mergeOpts(opts), function (err) {
      /* istanbul ignore next */
      if (err) {
        return cb(err);
      }
      emitter.emit('put', key, value);
      cb(null);
    });
  };

  emitter.prefix = function () {
    return prefix.slice();
  };

  emitter.batch = function (ops, opts, cb) {
    if ('function' === typeof opts) {
      cb = opts;
      opts = {};
    }