Function httpQuery

lib/index-browser.js:8281–8394

(db, fun, opts)

  }

  async function httpQuery(db, fun, opts) {
    // List of parameters to add to the PUT request
    let params = [];
    let body;
    let method = 'GET';
    let ok;

    // If opts.reduce exists and is defined, then add it to the list
    // of parameters.
    // If reduce=false then the results are that of only the map function
    // not the final result of map and reduce.
    addHttpParam('reduce', opts, params);
    addHttpParam('include_docs', opts, params);
    addHttpParam('attachments', opts, params);
    addHttpParam('limit', opts, params);
    addHttpParam('descending', opts, params);
    addHttpParam('group', opts, params);
    addHttpParam('group_level', opts, params);
    addHttpParam('skip', opts, params);
    addHttpParam('stale', opts, params);
    addHttpParam('conflicts', opts, params);
    addHttpParam('startkey', opts, params, true);
    addHttpParam('start_key', opts, params, true);
    addHttpParam('endkey', opts, params, true);
    addHttpParam('end_key', opts, params, true);
    addHttpParam('inclusive_end', opts, params);
    addHttpParam('key', opts, params, true);
    addHttpParam('update_seq', opts, params);

    // Format the list of parameters into a valid URI query string
    params = params.join('&');
    params = params === '' ? '' : '?' + params;

    // If keys are supplied, issue a POST to circumvent GET query string limits
    // see http://wiki.apache.org/couchdb/HTTP_view_API#Querying_Options
    if (typeof opts.keys !== 'undefined') {
      const MAX_URL_LENGTH = 2000;
      // according to http://stackoverflow.com/a/417184/680742,
      // the de facto URL length limit is 2000 characters

      const keysAsString = `keys=${encodeURIComponent(JSON.stringify(opts.keys))}`;
      if (keysAsString.length + params.length + 1 <= MAX_URL_LENGTH) {
        // If the keys are short enough, do a GET. we do this to work around
        // Safari not understanding 304s on POSTs (see pouchdb/pouchdb#1239)
        params += (params[0] === '?' ? '&' : '?') + keysAsString;
      } else {
        method = 'POST';
        if (typeof fun === 'string') {
          body = {keys: opts.keys};
        } else { // fun is {map : mapfun}, so append to this
          fun.keys = opts.keys;
        }
      }
    }

    // We are referencing a query defined in the design doc
    if (typeof fun === 'string') {
      const parts = parseViewName(fun);