More efficient Wordpress-query parsing? (get_posts($query))

What is the most efficient way (time-wise) to count number of posts returned from a query and parse the posts returned?

PART 1:

I currently have this code:

/* $query = {
'numberposts' = '15',
'queryvar1' = '…',
'queryvar2' = '…';
}
*/
$lastposts = get_posts($query); // This uses the original query, and will only return 15 results

$print['returnedcount'] = count($lastposts); // Uses some resources (+ acceptable time)

$query['numberposts'] = "-1"; // Get total results from query 
$print['totalposts'] = count(get_posts($query)); // Uses lots of resources (+ lots of time)

I have no use for the other data this second get_posts($query)-provides me with, how can I speed that up? I only need to count the total number of posts returned by the query (except the numberposts-value.

PART 2:

The $lastposts-object will be used later to get post data (ID, date, title, comment count, thumbnail and author ID).

These datas are inputed into the $print-array like this:

foreach ($lastposts as $post){
    // ID
    $print['id'][] = (string)$post->ID;
    // Date
    $print['date'][] = (string)$post->post_date;
    // Title
    $print['title'][] = (string)$post->post_title;
    // Comment count
    $print['comments'][] = (string)$post->comment_count;
    // Images
    $image = wp_get_attachment_image_src(get_post_thumbnail_id($post->ID), 'medium');
    $print['image'][] = (string)$image[开发者_运维知识库0];
    $imageRetina = wp_get_attachment_image_src(get_post_thumbnail_id($post->ID), 'large');
    $print['imageretina'][] = (string)$imageRetina[0];
    // Author
    $print['author'][] = (string)$post->post_author;
}

Is there a more time-efficient way to do this? I have noticed that the image-actions do take quite some time.

Thanks alot!

For part one you could create a new WP_Query object rather than using get_posts. This should be more efficient than the code in your question, but the difference is likely to be negligible.

$query = new WP_Query();
$query->query(array(
    'posts_per_page' => 15
));

$print['returnedcount'] = $query->post_count;
$print['totalposts'] = $query->found_posts;

Could you populate an array with what you need the first time the query is run - that would make running get_posts() unnecessary.

So, in your template files you have

while( have_posts() ): the_post();
    // do your normal output here e.g. the_content(); etc.

    $print['title'][] = get_the_title();
    // any more data you want to collect.

endwhile;

You could move the whole data collection bit to functions.php. Are you using caching too? That might help. (e.g. http://wordpress.org/extend/plugins/hyper-cache/)