Enhance certificate verification process

[yhabteab]

This PR reduces the number of database queries performed per certificate chain to a single query and allocates temp file storage per certificate chain (this makes it possible to free all storage files after each iteration, which should prevent the disk from being crowded when there are a large number of certificate chains to verify).

fixes #175

[lippserd]

I'd like to make this a library function, e.g.

/**
 * Yield sets of items from an iterator grouped by a specific criterion gathered from a callback
 *
 * @param Iterator $iterator
 * @param callable $groupBy
 *
 * @return Generator
 */
function yield_groups(Iterator $iterator, callable $groupBy): Generator
{
    if (! $iterator->valid()) {
        return;
    }

    $attribute = $groupBy($iterator->current(), $iterator->key());
    $group = [$iterator->current()];
//    $group = [$iterator->key() => $iterator->current()];

    $iterator->next();
    for (; $iterator->valid(); $iterator->next()) {
        $a = $groupBy($iterator->current(), $iterator->key());
        if ($a !== $attribute) {
            yield $attribute => $group;

            $group = [];
            $attribute = $a;
        }
        
        $group[] = $iterator->current();
//        $group[$iterator->key()] = $iterator->current();
    }

    if (! empty($group)) {
        yield $attribute => $group;
    }
}

What do you think? And @nilmerg what do you think?

[yhabteab]

When the values to be grouped, i.e. $group[] = $iterator->current() could also be specified by a callback, it would work. Such a grouping function would also be used for Sla queries in Icinga DB Web.

[nilmerg]

Sure. Though, why not foreach?

[lippserd]

Sure. Though, why not foreach?

We need special handling for the first item in the iterator. With foreach, we would have this code in every iteration.

Please both have a look at Icinga/ipl-stdlib#46.

[yhabteab]

Blocked by

• Introduce yield_groups() ipl-stdlib#46