function qa_recalc_perform_step(&$state)
{
$continue = false;
@(list($operation, $length, $next, $done) = explode("\t", $state));
switch ($operation) {
case 'doreindexcontent':
qa_recalc_transition($state, 'doreindexcontent_pagereindex');
break;
case 'doreindexcontent_pagereindex':
$pages = qa_db_pages_get_for_reindexing($next, 10);
if (count($pages)) {
require_once QA_INCLUDE_DIR . 'app/format.php';
$lastpageid = max(array_keys($pages));
foreach ($pages as $pageid => $page) {
if (!($page['flags'] & QA_PAGE_FLAGS_EXTERNAL)) {
$searchmodules = qa_load_modules_with('search', 'unindex_page');
foreach ($searchmodules as $searchmodule) {
$searchmodule->unindex_page($pageid);
}
$searchmodules = qa_load_modules_with('search', 'index_page');
if (count($searchmodules)) {
$indextext = qa_viewer_text($page['content'], 'html');
foreach ($searchmodules as $searchmodule) {
$searchmodule->index_page($pageid, $page['tags'], $page['heading'], $page['content'], 'html', $indextext);
}
}
}
}
$next = 1 + $lastpageid;
$done += count($pages);
$continue = true;
} else {
qa_recalc_transition($state, 'doreindexcontent_postcount');
}
break;
case 'doreindexcontent_postcount':
qa_db_qcount_update();
qa_db_acount_update();
qa_db_ccount_update();
qa_recalc_transition($state, 'doreindexcontent_postreindex');
break;
case 'doreindexcontent_postreindex':
$posts = qa_db_posts_get_for_reindexing($next, 10);
if (count($posts)) {
require_once QA_INCLUDE_DIR . 'app/format.php';
$lastpostid = max(array_keys($posts));
qa_db_prepare_for_reindexing($next, $lastpostid);
qa_suspend_update_counts();
foreach ($posts as $postid => $post) {
qa_post_unindex($postid);
qa_post_index($postid, $post['type'], $post['questionid'], $post['parentid'], $post['title'], $post['content'], $post['format'], qa_viewer_text($post['content'], $post['format']), $post['tags'], $post['categoryid']);
}
$next = 1 + $lastpostid;
$done += count($posts);
$continue = true;
} else {
qa_db_truncate_indexes($next);
qa_recalc_transition($state, 'doreindexposts_wordcount');
}
break;
case 'doreindexposts_wordcount':
$wordids = qa_db_words_prepare_for_recounting($next, 1000);
if (count($wordids)) {
$lastwordid = max($wordids);
qa_db_words_recount($next, $lastwordid);
$next = 1 + $lastwordid;
$done += count($wordids);
$continue = true;
} else {
qa_db_tagcount_update();
// this is quick so just do it here
qa_recalc_transition($state, 'doreindexposts_complete');
}
break;
case 'dorecountposts':
qa_recalc_transition($state, 'dorecountposts_postcount');
break;
case 'dorecountposts_postcount':
qa_db_qcount_update();
qa_db_acount_update();
qa_db_ccount_update();
qa_db_unaqcount_update();
qa_db_unselqcount_update();
qa_recalc_transition($state, 'dorecountposts_votecount');
break;
case 'dorecountposts_votecount':
$postids = qa_db_posts_get_for_recounting($next, 1000);
if (count($postids)) {
$lastpostid = max($postids);
qa_db_posts_votes_recount($next, $lastpostid);
$next = 1 + $lastpostid;
$done += count($postids);
$continue = true;
} else {
qa_recalc_transition($state, 'dorecountposts_acount');
}
break;
case 'dorecountposts_acount':
$postids = qa_db_posts_get_for_recounting($next, 1000);
if (count($postids)) {
$lastpostid = max($postids);
qa_db_posts_answers_recount($next, $lastpostid);
$next = 1 + $lastpostid;
$done += count($postids);
$continue = true;
} else {
qa_db_unupaqcount_update();
qa_recalc_transition($state, 'dorecountposts_complete');
}
break;
case 'dorecalcpoints':
qa_recalc_transition($state, 'dorecalcpoints_usercount');
break;
case 'dorecalcpoints_usercount':
qa_db_userpointscount_update();
// for progress update - not necessarily accurate
qa_db_uapprovecount_update();
// needs to be somewhere and this is the most appropriate place
qa_recalc_transition($state, 'dorecalcpoints_recalc');
break;
case 'dorecalcpoints_recalc':
$recalccount = 10;
$userids = qa_db_users_get_for_recalc_points($next, $recalccount + 1);
// get one extra so we know where to start from next
$gotcount = count($userids);
$recalccount = min($recalccount, $gotcount);
// can't recalc more than we got
if ($recalccount > 0) {
$lastuserid = $userids[$recalccount - 1];
qa_db_users_recalc_points($next, $lastuserid);
$done += $recalccount;
} else {
$lastuserid = $next;
}
// for truncation
if ($gotcount > $recalccount) {
// more left to do
$next = $userids[$recalccount];
// start next round at first one not recalculated
$continue = true;
} else {
qa_db_truncate_userpoints($lastuserid);
qa_db_userpointscount_update();
// quick so just do it here
qa_recalc_transition($state, 'dorecalcpoints_complete');
}
break;
case 'dorefillevents':
qa_recalc_transition($state, 'dorefillevents_qcount');
break;
case 'dorefillevents_qcount':
qa_db_qcount_update();
qa_recalc_transition($state, 'dorefillevents_refill');
break;
case 'dorefillevents_refill':
$questionids = qa_db_qs_get_for_event_refilling($next, 1);
if (count($questionids)) {
require_once QA_INCLUDE_DIR . 'app/events.php';
require_once QA_INCLUDE_DIR . 'app/updates.php';
require_once QA_INCLUDE_DIR . 'util/sort.php';
$lastquestionid = max($questionids);
foreach ($questionids as $questionid) {
// Retrieve all posts relating to this question
list($question, $childposts, $achildposts) = qa_db_select_with_pending(qa_db_full_post_selectspec(null, $questionid), qa_db_full_child_posts_selectspec(null, $questionid), qa_db_full_a_child_posts_selectspec(null, $questionid));
// Merge all posts while preserving keys as postids
$posts = array($questionid => $question);
foreach ($childposts as $postid => $post) {
$posts[$postid] = $post;
}
foreach ($achildposts as $postid => $post) {
$posts[$postid] = $post;
}
// Creation and editing of each post
foreach ($posts as $postid => $post) {
$followonq = $post['basetype'] == 'Q' && $postid != $questionid;
if ($followonq) {
$updatetype = QA_UPDATE_FOLLOWS;
} elseif ($post['basetype'] == 'C' && @$posts[$post['parentid']]['basetype'] == 'Q') {
$updatetype = QA_UPDATE_C_FOR_Q;
} elseif ($post['basetype'] == 'C' && @$posts[$post['parentid']]['basetype'] == 'A') {
$updatetype = QA_UPDATE_C_FOR_A;
} else {
$updatetype = null;
}
qa_create_event_for_q_user($questionid, $postid, $updatetype, $post['userid'], @$posts[$post['parentid']]['userid'], $post['created']);
if (isset($post['updated']) && !$followonq) {
qa_create_event_for_q_user($questionid, $postid, $post['updatetype'], $post['lastuserid'], $post['userid'], $post['updated']);
}
}
// Tags and categories of question
qa_create_event_for_tags($question['tags'], $questionid, null, $question['userid'], $question['created']);
qa_create_event_for_category($question['categoryid'], $questionid, null, $question['userid'], $question['created']);
// Collect comment threads
$parentidcomments = array();
foreach ($posts as $postid => $post) {
if ($post['basetype'] == 'C') {
$parentidcomments[$post['parentid']][$postid] = $post;
}
}
// For each comment thread, notify all previous comment authors of each comment in the thread (could get slow)
foreach ($parentidcomments as $parentid => $comments) {
$keyuserids = array();
qa_sort_by($comments, 'created');
foreach ($comments as $comment) {
foreach ($keyuserids as $keyuserid => $dummy) {
if ($keyuserid != $comment['userid'] && $keyuserid != @$posts[$parentid]['userid']) {
qa_db_event_create_not_entity($keyuserid, $questionid, $comment['postid'], QA_UPDATE_FOLLOWS, $comment['userid'], $comment['created']);
}
}
if (isset($comment['userid'])) {
$keyuserids[$comment['userid']] = true;
}
}
}
}
$next = 1 + $lastquestionid;
$done += count($questionids);
$continue = true;
} else {
qa_recalc_transition($state, 'dorefillevents_complete');
}
break;
case 'dorecalccategories':
qa_recalc_transition($state, 'dorecalccategories_postcount');
break;
case 'dorecalccategories_postcount':
qa_db_acount_update();
qa_db_ccount_update();
qa_recalc_transition($state, 'dorecalccategories_postupdate');
break;
case 'dorecalccategories_postupdate':
$postids = qa_db_posts_get_for_recategorizing($next, 100);
if (count($postids)) {
$lastpostid = max($postids);
qa_db_posts_recalc_categoryid($next, $lastpostid);
qa_db_posts_calc_category_path($next, $lastpostid);
$next = 1 + $lastpostid;
$done += count($postids);
$continue = true;
} else {
qa_recalc_transition($state, 'dorecalccategories_recount');
}
break;
case 'dorecalccategories_recount':
$categoryids = qa_db_categories_get_for_recalcs($next, 10);
if (count($categoryids)) {
$lastcategoryid = max($categoryids);
foreach ($categoryids as $categoryid) {
qa_db_ifcategory_qcount_update($categoryid);
}
$next = 1 + $lastcategoryid;
$done += count($categoryids);
$continue = true;
} else {
qa_recalc_transition($state, 'dorecalccategories_backpaths');
}
break;
case 'dorecalccategories_backpaths':
$categoryids = qa_db_categories_get_for_recalcs($next, 10);
if (count($categoryids)) {
$lastcategoryid = max($categoryids);
qa_db_categories_recalc_backpaths($next, $lastcategoryid);
$next = 1 + $lastcategoryid;
$done += count($categoryids);
$continue = true;
} else {
qa_recalc_transition($state, 'dorecalccategories_complete');
}
break;
case 'dodeletehidden':
qa_recalc_transition($state, 'dodeletehidden_comments');
break;
case 'dodeletehidden_comments':
$posts = qa_db_posts_get_for_deleting('C', $next, 1);
if (count($posts)) {
require_once QA_INCLUDE_DIR . 'app/posts.php';
$postid = $posts[0];
qa_post_delete($postid);
$next = 1 + $postid;
$done++;
$continue = true;
} else {
qa_recalc_transition($state, 'dodeletehidden_answers');
}
break;
case 'dodeletehidden_answers':
$posts = qa_db_posts_get_for_deleting('A', $next, 1);
if (count($posts)) {
require_once QA_INCLUDE_DIR . 'app/posts.php';
$postid = $posts[0];
qa_post_delete($postid);
$next = 1 + $postid;
$done++;
$continue = true;
} else {
qa_recalc_transition($state, 'dodeletehidden_questions');
}
break;
case 'dodeletehidden_questions':
$posts = qa_db_posts_get_for_deleting('Q', $next, 1);
if (count($posts)) {
require_once QA_INCLUDE_DIR . 'app/posts.php';
$postid = $posts[0];
qa_post_delete($postid);
$next = 1 + $postid;
$done++;
$continue = true;
} else {
qa_recalc_transition($state, 'dodeletehidden_complete');
}
break;
case 'doblobstodisk':
qa_recalc_transition($state, 'doblobstodisk_move');
break;
case 'doblobstodisk_move':
$blob = qa_db_get_next_blob_in_db($next);
if (isset($blob)) {
require_once QA_INCLUDE_DIR . 'app/blobs.php';
require_once QA_INCLUDE_DIR . 'db/blobs.php';
if (qa_write_blob_file($blob['blobid'], $blob['content'], $blob['format'])) {
qa_db_blob_set_content($blob['blobid'], null);
}
$next = 1 + $blob['blobid'];
$done++;
$continue = true;
} else {
qa_recalc_transition($state, 'doblobstodisk_complete');
}
break;
case 'doblobstodb':
qa_recalc_transition($state, 'doblobstodb_move');
break;
case 'doblobstodb_move':
$blob = qa_db_get_next_blob_on_disk($next);
if (isset($blob)) {
require_once QA_INCLUDE_DIR . 'app/blobs.php';
require_once QA_INCLUDE_DIR . 'db/blobs.php';
$content = qa_read_blob_file($blob['blobid'], $blob['format']);
qa_db_blob_set_content($blob['blobid'], $content);
qa_delete_blob_file($blob['blobid'], $blob['format']);
$next = 1 + $blob['blobid'];
$done++;
$continue = true;
} else {
qa_recalc_transition($state, 'doblobstodb_complete');
}
break;
default:
$state = '';
break;
}
if ($continue) {
$state = $operation . "\t" . $length . "\t" . $next . "\t" . $done;
}
return $continue && $done < $length;
}
function qa_comment_delete($oldcomment, $question, $answer, $userid, $handle, $cookieid)
{
if (!$oldcomment['hidden']) {
qa_fatal_error('Tried to delete a non-hidden comment');
}
qa_post_unindex($oldcomment['postid']);
qa_db_post_delete($oldcomment['postid']);
qa_db_points_update_ifuser($oldcomment['userid'], array('cposts'));
qa_db_ccount_update();
qa_report_event('c_delete', $userid, $handle, $cookieid, array('postid' => $oldcomment['postid'], 'parentid' => $oldcomment['parentid'], 'parenttype' => isset($answer) ? $answer['basetype'] : $question['basetype'], 'questionid' => $question['postid']));
}
function qa_comment_delete($oldcomment, $question, $parent, $userid, $handle, $cookieid)
{
if (!isset($parent)) {
$parent = $question;
}
// for backwards compatibility with old answer parameter
if ($oldcomment['type'] != 'C_HIDDEN') {
qa_fatal_error('Tried to delete a non-hidden comment');
}
qa_post_unindex($oldcomment['postid']);
qa_db_post_delete($oldcomment['postid']);
qa_db_points_update_ifuser($oldcomment['userid'], array('cposts'));
qa_db_ccount_update();
qa_report_event('c_delete', $userid, $handle, $cookieid, array('postid' => $oldcomment['postid'], 'parentid' => $oldcomment['parentid'], 'oldcomment' => $oldcomment, 'parenttype' => $parent['basetype'], 'questionid' => $question['postid']));
}
function qa_recalc_perform_step(&$state)
{
$continue = false;
@(list($operation, $length, $next, $done) = explode(',', $state));
switch ($operation) {
case 'doreindexcontent':
qa_recalc_transition($state, 'doreindexcontent_pagereindex');
break;
case 'doreindexcontent_pagereindex':
$pages = qa_db_pages_get_for_reindexing($next, 10);
if (count($pages)) {
require_once QA_INCLUDE_DIR . 'qa-app-format.php';
$lastpageid = max(array_keys($pages));
foreach ($pages as $pageid => $page) {
if (!($page['flags'] & QA_PAGE_FLAGS_EXTERNAL)) {
$searchmodules = qa_load_modules_with('search', 'unindex_page');
foreach ($searchmodules as $searchmodule) {
$searchmodule->unindex_page($pageid);
}
$searchmodules = qa_load_modules_with('search', 'index_page');
if (count($searchmodules)) {
$indextext = qa_viewer_text($page['content'], 'html');
foreach ($searchmodules as $searchmodule) {
$searchmodule->index_page($pageid, $page['tags'], $page['heading'], $page['content'], 'html', $indextext);
}
}
}
}
$next = 1 + $lastpageid;
$done += count($pages);
$continue = true;
} else {
qa_recalc_transition($state, 'doreindexcontent_postcount');
}
break;
case 'doreindexcontent_postcount':
qa_db_qcount_update();
qa_db_acount_update();
qa_db_ccount_update();
qa_recalc_transition($state, 'doreindexcontent_postreindex');
break;
case 'doreindexcontent_postreindex':
$posts = qa_db_posts_get_for_reindexing($next, 10);
if (count($posts)) {
require_once QA_INCLUDE_DIR . 'qa-app-format.php';
$lastpostid = max(array_keys($posts));
qa_db_prepare_for_reindexing($next, $lastpostid);
qa_suspend_update_counts();
foreach ($posts as $postid => $post) {
qa_post_unindex($postid);
qa_post_index($postid, $post['type'], $post['questionid'], $post['parentid'], $post['title'], $post['content'], $post['format'], qa_viewer_text($post['content'], $post['format']), $post['tags'], $post['categoryid']);
}
$next = 1 + $lastpostid;
$done += count($posts);
$continue = true;
} else {
qa_db_truncate_indexes($next);
qa_recalc_transition($state, 'doreindexposts_wordcount');
}
break;
case 'doreindexposts_wordcount':
$wordids = qa_db_words_prepare_for_recounting($next, 1000);
if (count($wordids)) {
$lastwordid = max($wordids);
qa_db_words_recount($next, $lastwordid);
$next = 1 + $lastwordid;
$done += count($wordids);
$continue = true;
} else {
qa_db_tagcount_update();
// this is quick so just do it here
qa_recalc_transition($state, 'doreindexposts_complete');
}
break;
case 'dorecountposts':
qa_recalc_transition($state, 'dorecountposts_postcount');
break;
case 'dorecountposts_postcount':
qa_db_qcount_update();
qa_db_acount_update();
qa_db_ccount_update();
qa_db_unaqcount_update();
qa_db_unselqcount_update();
qa_recalc_transition($state, 'dorecountposts_votecount');
break;
case 'dorecountposts_votecount':
$postids = qa_db_posts_get_for_recounting($next, 1000);
if (count($postids)) {
$lastpostid = max($postids);
qa_db_posts_votes_recount($next, $lastpostid);
$next = 1 + $lastpostid;
$done += count($postids);
$continue = true;
} else {
qa_recalc_transition($state, 'dorecountposts_acount');
}
break;
case 'dorecountposts_acount':
$postids = qa_db_posts_get_for_recounting($next, 1000);
if (count($postids)) {
$lastpostid = max($postids);
qa_db_posts_answers_recount($next, $lastpostid);
$next = 1 + $lastpostid;
$done += count($postids);
$continue = true;
} else {
qa_db_unupaqcount_update();
qa_recalc_transition($state, 'dorecountposts_complete');
}
break;
case 'dorecalcpoints':
qa_recalc_transition($state, 'dorecalcpoints_usercount');
break;
case 'dorecalcpoints_usercount':
qa_db_userpointscount_update();
// for progress update - not necessarily accurate
qa_recalc_transition($state, 'dorecalcpoints_recalc');
break;
case 'dorecalcpoints_recalc':
$userids = qa_db_users_get_for_recalc_points($next, 10);
if (count($userids)) {
$lastuserid = max($userids);
qa_db_users_recalc_points($next, $lastuserid);
$next = 1 + $lastuserid;
$done += count($userids);
$continue = true;
} else {
qa_db_truncate_userpoints($next);
qa_db_userpointscount_update();
// quick so just do it here
qa_recalc_transition($state, 'dorecalcpoints_complete');
}
break;
case 'dorefillevents':
qa_recalc_transition($state, 'dorefillevents_qcount');
break;
case 'dorefillevents_qcount':
qa_db_qcount_update();
qa_recalc_transition($state, 'dorefillevents_refill');
break;
case 'dorefillevents_refill':
$questionids = qa_db_qs_get_for_event_refilling($next, 1);
if (count($questionids)) {
require_once QA_INCLUDE_DIR . 'qa-app-events.php';
require_once QA_INCLUDE_DIR . 'qa-app-updates.php';
require_once QA_INCLUDE_DIR . 'qa-util-sort.php';
$lastquestionid = max($questionids);
foreach ($questionids as $questionid) {
// Retrieve all posts relating to this question
list($question, $childposts, $achildposts) = qa_db_select_with_pending(qa_db_full_post_selectspec(null, $questionid), qa_db_full_child_posts_selectspec(null, $questionid), qa_db_full_a_child_posts_selectspec(null, $questionid));
// Merge all posts while preserving keys as postids
$posts = array($questionid => $question);
foreach ($childposts as $postid => $post) {
$posts[$postid] = $post;
}
foreach ($achildposts as $postid => $post) {
$posts[$postid] = $post;
}
// Creation and editing of each post
foreach ($posts as $postid => $post) {
$followonq = $post['basetype'] == 'Q' && $postid != $questionid;
qa_create_event_for_q_user($questionid, $postid, $followonq ? QA_UPDATE_FOLLOWS : null, $post['userid'], @$posts[$post['parentid']]['userid'], $post['created']);
if (isset($post['updated']) && !$followonq) {
qa_create_event_for_q_user($questionid, $postid, $post['updatetype'], $post['lastuserid'], $post['userid'], $post['updated']);
}
}
// Tags and categories of question
qa_create_event_for_tags($question['tags'], $questionid, null, $question['userid'], $question['created']);
qa_create_event_for_category($question['categoryid'], $questionid, null, $question['userid'], $question['created']);
// Collect comment threads
$parentidcomments = array();
foreach ($posts as $postid => $post) {
if ($post['basetype'] == 'C') {
$parentidcomments[$post['parentid']][$postid] = $post;
}
}
// For each comment thread, notify all previous comment authors of each comment in the thread (could get slow)
foreach ($parentidcomments as $parentid => $comments) {
$keyuserids = array();
qa_sort_by($comments, 'created');
foreach ($comments as $comment) {
foreach ($keyuserids as $keyuserid => $dummy) {
if ($keyuserid != $comment['userid'] && $keyuserid != @$posts[$parentid]['userid']) {
qa_db_event_create_not_entity($keyuserid, $questionid, $comment['postid'], null, $comment['userid'], $comment['created']);
}
}
if (isset($comment['userid'])) {
$keyuserids[$comment['userid']] = true;
}
}
}
}
$next = 1 + $lastquestionid;
$done += count($questionids);
$continue = true;
} else {
qa_recalc_transition($state, 'dorefillevents_complete');
}
break;
case 'dorecalccategories':
qa_recalc_transition($state, 'dorecalccategories_postcount');
break;
case 'dorecalccategories_postcount':
qa_db_acount_update();
qa_db_ccount_update();
qa_recalc_transition($state, 'dorecalccategories_postupdate');
break;
case 'dorecalccategories_postupdate':
$postids = qa_db_posts_get_for_recategorizing($next, 100);
if (count($postids)) {
$lastpostid = max($postids);
qa_db_posts_recalc_categoryid($next, $lastpostid);
qa_db_posts_calc_category_path($next, $lastpostid);
$next = 1 + $lastpostid;
$done += count($postids);
$continue = true;
} else {
qa_recalc_transition($state, 'dorecalccategories_recount');
}
break;
case 'dorecalccategories_recount':
$categoryids = qa_db_categories_get_for_recalcs($next, 10);
if (count($categoryids)) {
$lastcategoryid = max($categoryids);
foreach ($categoryids as $categoryid) {
qa_db_ifcategory_qcount_update($categoryid);
}
$next = 1 + $lastcategoryid;
$done += count($categoryids);
$continue = true;
} else {
qa_recalc_transition($state, 'dorecalccategories_backpaths');
}
break;
case 'dorecalccategories_backpaths':
$categoryids = qa_db_categories_get_for_recalcs($next, 10);
if (count($categoryids)) {
$lastcategoryid = max($categoryids);
qa_db_categories_recalc_backpaths($next, $lastcategoryid);
$next = 1 + $lastcategoryid;
$done += count($categoryids);
$continue = true;
} else {
qa_recalc_transition($state, 'dorecalccategories_complete');
}
break;
case 'dodeletehidden':
qa_recalc_transition($state, 'dodeletehidden_comments');
break;
case 'dodeletehidden_comments':
$posts = qa_db_posts_get_for_deleting('C', $next, 1);
if (count($posts)) {
require_once QA_INCLUDE_DIR . 'qa-app-posts.php';
$postid = $posts[0];
qa_post_delete($postid);
$next = 1 + $postid;
$done++;
$continue = true;
} else {
qa_recalc_transition($state, 'dodeletehidden_answers');
}
break;
case 'dodeletehidden_answers':
$posts = qa_db_posts_get_for_deleting('A', $next, 1);
if (count($posts)) {
require_once QA_INCLUDE_DIR . 'qa-app-posts.php';
$postid = $posts[0];
qa_post_delete($postid);
$next = 1 + $postid;
$done++;
$continue = true;
} else {
qa_recalc_transition($state, 'dodeletehidden_questions');
}
break;
case 'dodeletehidden_questions':
$posts = qa_db_posts_get_for_deleting('Q', $next, 1);
if (count($posts)) {
require_once QA_INCLUDE_DIR . 'qa-app-posts.php';
$postid = $posts[0];
qa_post_delete($postid);
$next = 1 + $postid;
$done++;
$continue = true;
} else {
qa_recalc_transition($state, 'dodeletehidden_complete');
}
break;
default:
$state = '';
break;
}
if ($continue) {
$state = $operation . ',' . $length . ',' . $next . ',' . $done;
}
return $continue && $done < $length;
}