glam/src/weak-cache.js

inline css for your jsx

// @flow

const nullRule = {};
let inputCaches =
  typeof WeakMap !== 'undefined'
    ? [nullRule, new WeakMap(), new WeakMap(), new WeakMap()]
    : [nullRule];

let warnedWeakMapError = false;
function multiIndexCache(fn) {
  return function(args) {
    if (inputCaches[args.length]) {
      let coi = inputCaches[args.length];
      let ctr = 0;
      while (ctr < args.length - 1) {
        if (!coi.has(args[ctr])) {
          coi.set(args[ctr], new WeakMap());
        }
        coi = coi.get(args[ctr]);
        ctr++;
      }
      if (coi.has(args[args.length - 1])) {
        let ret = coi.get(args[ctr]);

        if (registered[ret.toString().substring(4)]) {
          // make sure it hasn't been flushed
          return ret;
        }
      }
    }
    let value = fn(args);
    if (inputCaches[args.length]) {
      let ctr = 0,
        coi = inputCaches[args.length];
      while (ctr < args.length - 1) {
        coi = coi.get(args[ctr]);
        ctr++;
      }
      try {
        coi.set(args[ctr], value);
      } catch (err) {
        if (process.env.NODE_ENV !== 'production' && !warnedWeakMapError) {
          warnedWeakMapError = true;
          console.warn('failed setting the WeakMap cache for args:', ...args); // eslint-disable-line no-console
          console.warn(
            'this should NOT happen, please file a bug on the github repo.',
          ); // eslint-disable-line no-console
        }
      }
    }
    return value;
  };
}