On Mon, Apr 6, 2009 at 2:16 PM, Ohad <[email protected]> wrote:
>
> Do you mean doing something like that:
>
> var workerPool = google.gears.factory.create('beta.workerpool');
> workerPool.onmessage = function(a, b, message) {//MY DB function here}
> workerPool.sendMessage(...);?
something like that... you want to execute the DB code in the worker script
// in the 'main' page
var workerPool = google.gears.factory.create('beta.workerpool');
var id =
workerPool.createWorkerFromUrl(urlOfScriptThatContainsMyDBFunction);
workerPool.onmessage = function(messageText, senderId, message) {
if (senderId == id) {
var timeTaken = message;
// do something in the page with this value
}
};
workerPool.sendMessage('doDatabaseFunction', id);
// in the worker script
var workerPool = google.gears.workerPool;
workerPool.onmessage = function(messageText, senderId, message) {
if (message = 'doDatabaseFunction') {
var timeStarted = now();
doDatabaseFunction();
workerPool.sendMessage(senderId, now() - timeStarted);
}
}
function now() {
// implement me :)
}
function doDatabaseFunction() {
// ditto
}
>
> thanks!
>
>
>
> On Apr 7, 12:09 am, Michael Nordman <[email protected]> wrote:
> > Try this same test from within a worker and you should see dramatically
> > better performance on Chrome.
> > In Chrome, Gears is a plugin and executes in a seperate process than a
> page
> > that is using Gears. What you're bumping into are performance penalties
> of
> > doing IPC between the 'renderer' and 'plugin' processes. When you run the
> > same test in a Gears worker, there penalty is not paid.
> >
> > Similary, if you run the same test in Firefox or IE, you should also see
> > dramatically better performance in this test case since Gears runs in
> > process on those browsers.
> >
> > If you arrange to do heavy DB work in a worker (iterate over large result
> > sets), you'll get much better results in Chrome... and overall in all
> > browsers since the UI will not be blocked by this work.
> >
> > On Mon, Apr 6, 2009 at 1:57 PM, Ohad <[email protected]> wrote:
> >
> > > I'm working on a framework that uses Gears as a major component,
> > > it seems like there is a performance issue while using the local Gears
> > > database(SQLite)
> >
> > > I wrote a simple task* that creates a table(with one field), insert
> > > 1000 rows,select all the rows from that table, and iterate the rows
> > > one by one using a resultset, this task takes ~16-19 SECONDS!!!
> > > does it make sense?
> >
> > > I tried the same task* using Java/JDBC over MYSQL(local) and it takes
> > > ~1.5 second...
> >
> > > when I reduce the amount of rows from 1000 to 100, Gears finished the
> > > task in less than 2 second (which is still a lot) , comparing to java
> > > the situation is not that bad( ~500ms).
> >
> > > so it seems like that the performance problem exists when I increase
> > > the number of rows....it seems like an exponential growth..
> > > any thoughts? any ideas?
> >
> > > I'm working with the Chrome browser (Windows vista)
> >
> > > here is the JS code I'm using:
> > > function db(){
> > > var currentTime = new Date().getTime();
> > > var db =
> > > google.gears.factory.create("beta.database");
> > > db.open("gearsDb");
> > > db.execute("delete from data2");
> > > db.execute("create table if not exists data2
> (rowId
> > > int)");
> > > for(i=0;i<100;i++)
> > > db.execute("insert into data2 values
> > > ("+i+")");
> > > var rs = db.execute("select rowId from data2");
> > > while (rs.isValidRow()){
> > > rs.field(0);
> > > rs.next();
> > > }
> > > rs.close();
> > > var currentTime2 = new Date().getTime();
> > > currentTime2 -=currentTime;
> > > document.write(currentTime2 + "<BR/>");
> > > }
>
