On 11/22/06 11:13 PM, [EMAIL PROTECTED] wrote:
> Just found this weird case where load(speculative => 1) in
> 0.756_01 doesn't reuse the database connection, but keeps
> creating new ones:
Hm, I don't recall ever making a "0.756_01" version...
> for (1..100) {
> my $p = My::Product->new(name => "myproduct");
> $p->load(speculative => 1);
> }
>
> If you start this in the debugger and set a breakpoint in DBI::connect,
> you'll see that it gets hit about 100 times.
Yep, and I think you'll also see that without the "speculative" param. Each
RDBO object gets its db (if one is not already set) by calling init_db().
By default, init_db() returns a new Rose::DB object every time it's called.
Here's the code:
sub init_db { Rose::DB->new() }
If you want all of your My::Product objects to share the same Rose::DB
object (or maybe just share the same DBI $dbh among many Rose::DB objects)
you can do that by overriding init_db(), or by using a module that
transparently shares DBI $dbh handles (e.g., Apache::DBI). Here are some
examples:
* Every My::Product object gets the same Rose::DB object:
package My::Product;
...
our $DB;
sub init_db { $DB ||= Rose::DB->new }
* Every My::Product object get its own Rose::DB object, but they all
share a single DBI $dbh.
- Manually:
package My::Product;
...
our $DBH;
sub init_db
{
my $db = Rose::DB->new;
$DBH ||= DBI->connect(...);
$db->dbh($DBH);
return $db;
}
- Automatically:
package My::Product;
...
use Apache::DBI;
sub init_db { Rose::DB->new() }
(In all of the above code, you should think about the eventual destruction
of those global objects.)
There's no one best way to handle database connection sharing. The right
solution for a command-line script is very different from the right solution
for a long-running, persistent environment like a web server.
Finally, remember that no matter what you do in init_db(), you can *always*
manually pass around and share a db object explicitly. For example,
revisiting your code:
my $db = Rose::DB->new;
for (1..100) {
my $p = My::Product->new(name => "myproduct", db => $db);
$p->load(speculative => 1);
}
That should only call DBI::connect() once.
-John
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