javascript - Inserting large quantities in IndexedDB's objectstore blocks UI

Question

I want to save some ~35000 objects in my IndexedDB's objectstore. I am using below code to insert.

AddListings = function (x2j_list_new, callback) {   
    var transaction = db.transaction(["listings"], IDBTransaction.READ_WRITE);
    var count = 0;
    transaction.oncomplete = function (event) {
        if (callback) {
            console.log('x2jShowListing Added ' + count + '/' + x2j_list_new.length);
                callback([count, x2j_list_new.length]);
            }
    };
    transaction.onerror = function (e) {
       console.log("myError: ", e);  
       if (callback) {
          callback(false);
       }
    };
    var store = transaction.objectStore("listings");

    $.each(x2j_list_new, function (index0, item0) {
        var request = store.put(item0);
        request.onsuccess = function (event) {
            count++;
            // event.target.result  
            };
        });
    });        
};

The above code works fine, but looping and inserting over ~35000 objects makes the UI unresponsive for ~200 seconds. I thought maybe i can use WebWorkers, but IndexedDB is not available inside WebWorkers. I tried to find a way to bulk insert, couldn't find one. Any ideas of how to insert large quantities of objects without blocking the UI?

Answer 1

You're on the right track, but you're asking the browser to store 35,000 objects before it's had a chance to finish storing one. Here's code which asynchronously waits for one request to finish before starting the next (but using the same transaction):

    openRequest = window.indexedDB.open("MyDatabase", 1);
    openRequest.onerror = function(event) {
        console.error(event);
    };
    openRequest.onsuccess = function (event) {
        var db = openRequest.result;
        db.onerror = function(event) {
            // Generic error handler for all errors targeted at this database's requests
            console.error(event.target);
            window.alert("Database error: " + event.target.wePutrrorMessage || event.target.error.name || event.target.error || event.target.errorCode);
        };
        var transaction = db.transaction('item', "readwrite");
        var itemStore = transaction.objectStore("item");
        putNext();

        function putNext() {
            if (i<items.length) {
                itemStore.put(items[i]).onsuccess = putNext;
                ++i;
            } else {   // complete
                console.log('populate complete');
                callback();
            }
        }           
    };