too big an array?

php3ch0

I am writing a forum script and I want to use an array to store the users last visit to show what topics are new.

it would be in the format

$array[ topic id] -> [last visit]

from here I would check the date of the most recent post agains the users last forum visit array for that topic.

Would this array bcome too large and slow things down considerably.

Is there a better way to do this?

Thanks

DAn

bpat1434

The array would become rather large, and what if you had like 800 members on with a total of 5000 posts each? That's a whole lot of memory that's being eaten....

The way most forums do it (as I understand) is just a simple check:
-- You login in
----> In the database, a field ("LastLogin") is updated with current timestamp
-- You post, reply, edit, or click links on the forum
----> In the database, the field is updated with current timestamp
-- You log out
----> In the database, the field is updated with the current timestamp

Now, to get whether the post(s) is (are) newer, you just take the timestamp (which can be stored in their Session so you don't have to do a select query every time) of their last action, and compare it to the timestamp of the post. If the post timestamp is less, it's not new. If it's more, it's newer.

Understand?

Now, you can split this up, and have "LastLogin" and "LastAction", and only modify the LastLogin field when they login/logout, and update the LastAction field when they do anything else. That's an alternative, and gives you slightly more freedom to say "Welcome, your last login was XXX date at YYY time, you last did something here on UUU date at ZZZ time".

php3ch0

IS there any way to update this immediately when the user visits a specific topic.

so above would show all new topics since the last user visit. When the user visits a particular topic and goes back to the indes it would still show as new!

I would like it so when the user goes back to the index page it will show as read.

Thanks in advance

bpat1434

Well, there are inherent flaws in the system. Ones which you can't really work around. THat being the back button being pressed. If the user visits a topic (one which is marked as "new"), and then hits the back button, he didn't actually take any "action" on the topic, just viewed it. So when he goes back, the time-stamps will be no different. Plus it's a partially cached page.

You can write it to update it when the user views a topic. It's totally possible, but running that many calls can become problomatic, and may even (under very high loads) slow your site down or crash it.

The way to implement that would be to have the database update each time a topic is viewed (similar to updating the topic row with number of views), you'd execute a query to update the user row with the last view/action.