basket.js 笔记

basket.js

//每次set的时候，检查localStorage是否溢出，做LRU处理
var addLocalStorage = function( key, storeObj ) {
  try {
     localStorage.setItem( storagePrefix + key, JSON.stringify( storeObj ) );
     return true;
   } catch( e ) {
     if ( e.name.toUpperCase().indexOf('QUOTA') >= 0 ) {
      var item;
       var tempScripts = [];

      for ( item in localStorage ) {
         if ( item.indexOf( storagePrefix ) === 0 ) {
          tempScripts.push( JSON.parse( localStorage[ item ] ) );
        }
      }

      if ( tempScripts.length ) {
         tempScripts.sort(function( a, b ) {
           return a.stamp - b.stamp;
         });

         basket.remove( tempScripts[ 0 ].key );

        return addLocalStorage( key, storeObj );
      } else {
        // no files to remove. Larger than available quota
        return;
      }

    } else {
       // some other error
       return;
    }
  }
};
  
//请求超时则中断
setTimeout( function () {
  if( xhr.readyState < 4 ) {
    xhr.abort();
  }
}, basket.timeout );