The only type of request job remaining was "install" which is really a
root requirement. The only other kind of input for the solver is now a
set of fixed packages.
Rules have been updated to account for only two kinds of former job
reason: FIXED or ROOT_REQUIRE. The job property has always been
redundant and has been removed, since reasonData suffices.
Problem reasons are always rules, so the unnecessary wrapping in an
array has been removed.
We now only ever generate a single rule per root require or fixed
package, so there is no need for the solver to special handle disabling
"jobs" anymore, the rule can just be disabled as usual.
For consistency special handling of rules for jobs in problems has been
integrated into the rule class like all other rule reasons. As part of
this change the error message for root requirements has been improved a
bit to make it clearer where the package installation request came from.
The word job has also been removed from operations, which are called
operations, not jobs.
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
Jordi Boggiano