Pool construction depends on the install request now, so only required
packages get loaded, add some structure for future asynchronously
loading composer repositories
It is known that composer update takes a lot of memory: #5915, #5902,
I am playing with a profiler (@blackfireio) to make a demo in my local
PHP meetup (@phpvigo) and I found out a way to use less memory. These
are my first tests:
* Private project using PHP 5.6:
* Memory: from 1.31GB to 1.07GB
* Wall Time: from 2min 8s to 1min 33s
* symfony-demo using PHP 7.1 in my old mac book:
* Memory: from 667MB to 523MB
* Wall Time: from 5min 29s to 5min 28s
Not use an array inside conflict rules is this improvement main idea:
```php
<?php
//Memory 38MB
gc_collect_cycles();
gc_disable();
class Rule
{
public $literals;
public function __construct(array $literals)
{
$this->literals = $literals;
}
}
$rules = array();
$i = 0;
while ($i<80000){ //
$i++;
$array = array(-$i, $i);
$rule = new Rule($array);
$rules[] = $rule;
}
```
```php
<?php
//Memory 11.1MB
gc_collect_cycles();
gc_disable();
class Rule2Literals
{
public $literal1;
public $literal2;
public function __construct($literal1, $literal2)
{
$this->literal1 = $literal1;
$this->literal2 = $literal2;
}
}
$rules = array();
$i = 0;
while ($i<80000){ //
$i++;
$rule = new ConflictRule(-$i, $i);
$rules[] = $rule;
}
```
More info https://github.com/composer/composer/pull/6168
Since we no longer have suggest/recommend rules and no longer use any update
or feature rules so packages are removed by default, we do not need weak rules
anymore.
Jordi Boggiano
Gabriel Caruso
Nils Adermann
rubenrua
Leszek Prabucki