logger.js

// ~ 120k log op/s
(function() {
  var originalArrayValueOf = Array.prototype.valueOf;
  var logs = {};
  var index = 1;
  function hasher(str) {
    var target = Array.from(str);
    target.length > 16 && (target = target.slice(0, 16)); // perf: avoid alloc
    return target
      .reduce(function(acc, i) {
        return 0 | ((acc << 5) - acc) + i.charCodeAt(0); }, 0);
  }
  Array.prototype.valueOf = function() {
    if (this.length > 0 && typeof this[0] === 'string') {
      var bucket = hasher(this[0]);
      switch (bucket) {
        case 57093687: // :show
          console.info('$' + index,
            window['$' + index++] = Array.prototype.concat.apply([], this
              .slice(1)
              .map(function(x) { return (logs[hasher(x)] || []).map(JSON.parse); }))
          );
          break;
        case -904836167: // :unload
          Array.prototype.valueOf = originalArrayValueOf;
          break;
        case 56763003: // :help
          [ "Valid commands are",
            "  :show, bucket [, bucket2..]",
            "  :unload"
          ].map(function(s) { console.info(s); });
          break;
        default:
          logs[bucket] === undefined && (logs[bucket] = []);
          logs[bucket].push(JSON.stringify(this.slice(1)));
          break;
      }
    }
    return this;
  }
})();

• config = { max_logs per bucket, log expiry ... }
• get/set configs
• clear a bucket or clear all logs
• return all logs