--- /dev/null
+<?php
+
+namespace Drupal\comment;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\ContentEntityStorageInterface;
+use Drupal\Core\Entity\FieldableEntityInterface;
+
+/**
+ * Defines an interface for comment entity storage classes.
+ */
+interface CommentStorageInterface extends ContentEntityStorageInterface {
+
+ /**
+ * Gets the maximum encoded thread value for the top level comments.
+ *
+ * @param \Drupal\comment\CommentInterface $comment
+ * A comment entity.
+ *
+ * @return string
+ * The maximum encoded thread value among the top level comments of the
+ * node $comment belongs to.
+ */
+ public function getMaxThread(CommentInterface $comment);
+
+ /**
+ * Gets the maximum encoded thread value for the children of this comment.
+ *
+ * @param \Drupal\comment\CommentInterface $comment
+ * A comment entity.
+ *
+ * @return string
+ * The maximum encoded thread value among all replies of $comment.
+ */
+ public function getMaxThreadPerThread(CommentInterface $comment);
+
+ /**
+ * Calculates the page number for the first new comment.
+ *
+ * @param int $total_comments
+ * The total number of comments that the entity has.
+ * @param int $new_comments
+ * The number of new comments that the entity has.
+ * @param \Drupal\Core\Entity\FieldableEntityInterface $entity
+ * The entity to which the comments belong.
+ * @param string $field_name
+ * The field name on the entity to which comments are attached.
+ *
+ * @return array|null
+ * The page number where first new comment appears. (First page returns 0.)
+ */
+ public function getNewCommentPageNumber($total_comments, $new_comments, FieldableEntityInterface $entity, $field_name);
+
+ /**
+ * Gets the display ordinal or page number for a comment.
+ *
+ * @param \Drupal\comment\CommentInterface $comment
+ * The comment to use as a reference point.
+ * @param int $comment_mode
+ * The comment display mode: CommentManagerInterface::COMMENT_MODE_FLAT or
+ * CommentManagerInterface::COMMENT_MODE_THREADED.
+ * @param int $divisor
+ * Defaults to 1, which returns the display ordinal for a comment. If the
+ * number of comments per page is provided, the returned value will be the
+ * page number. (The return value will be divided by $divisor.)
+ *
+ * @return int
+ * The display ordinal or page number for the comment. It is 0-based, so
+ * will represent the number of items before the given comment/page.
+ */
+ public function getDisplayOrdinal(CommentInterface $comment, $comment_mode, $divisor = 1);
+
+ /**
+ * Gets the comment ids of the passed comment entities' children.
+ *
+ * @param \Drupal\comment\CommentInterface[] $comments
+ * An array of comment entities keyed by their ids.
+ * @return array
+ * The entity ids of the passed comment entities' children as an array.
+ */
+ public function getChildCids(array $comments);
+
+ /**
+ * Retrieves comments for a thread, sorted in an order suitable for display.
+ *
+ * @param \Drupal\Core\Entity\EntityInterface $entity
+ * The entity whose comment(s) needs rendering.
+ * @param string $field_name
+ * The field_name whose comment(s) needs rendering.
+ * @param int $mode
+ * The comment display mode: CommentManagerInterface::COMMENT_MODE_FLAT or
+ * CommentManagerInterface::COMMENT_MODE_THREADED.
+ * @param int $comments_per_page
+ * (optional) The amount of comments to display per page.
+ * Defaults to 0, which means show all comments.
+ * @param int $pager_id
+ * (optional) Pager id to use in case of multiple pagers on the one page.
+ * Defaults to 0; is only used when $comments_per_page is greater than zero.
+ *
+ * @return array
+ * Ordered array of comment objects, keyed by comment id.
+ */
+ public function loadThread(EntityInterface $entity, $field_name, $mode, $comments_per_page = 0, $pager_id = 0);
+
+ /**
+ * Returns the number of unapproved comments.
+ *
+ * @return int
+ * The number of unapproved comments.
+ */
+ public function getUnapprovedCount();
+
+}