interface StringStorageInterface

interface StringStorageInterface {
    
    /**
     * Loads multiple source string objects.
     *
     * @param array $conditions
     *   (optional) Array with conditions that will be used to filter the strings
     *   returned and may include any of the following elements:
     *   - Any simple field value indexed by field name.
     *   - 'translated', TRUE to get only translated strings or FALSE to get only
     *     untranslated strings. If not set it returns both translated and
     *     untranslated strings that fit the other conditions.
     *   Defaults to no conditions which means that it will load all strings.
     * @param array $options
     *   (optional) An associative array of additional options. It may contain
     *   any of the following optional keys:
     *   - 'filters': Array of string filters indexed by field name.
     *   - 'pager limit': Use pager and set this limit value.
     *
     * @return array
     *   Array of \Drupal\locale\StringInterface objects matching the conditions.
     */
    public function getStrings(array $conditions = [], array $options = []);
    
    /**
     * Loads multiple string translation objects.
     *
     * @param array $conditions
     *   (optional) Array with conditions that will be used to filter the strings
     *   returned and may include all of the conditions defined by getStrings().
     * @param array $options
     *   (optional) An associative array of additional options. It may contain
     *   any of the options defined by getStrings().
     *
     * @return \Drupal\locale\StringInterface[]
     *   Array of \Drupal\locale\StringInterface objects matching the conditions.
     *
     * @see \Drupal\locale\StringStorageInterface::getStrings()
     */
    public function getTranslations(array $conditions = [], array $options = []);
    
    /**
     * Loads string location information.
     *
     * @param array $conditions
     *   (optional) Array with conditions to filter the locations that may be any
     *   of the following elements:
     *   - 'sid', The string identifier.
     *   - 'type', The location type.
     *   - 'name', The location name.
     *
     * @return \Drupal\locale\StringInterface[]
     *   Array of \Drupal\locale\StringInterface objects matching the conditions.
     *
     * @see \Drupal\locale\StringStorageInterface::getStrings()
     */
    public function getLocations(array $conditions = []);
    
    /**
     * Loads a string source object, fast query.
     *
     * These 'fast query' methods are the ones in the critical path and their
     * implementation must be optimized for speed, as they may run many times
     * in a single page request.
     *
     * @param array $conditions
     *   (optional) Array with conditions that will be used to filter the strings
     *   returned and may include all of the conditions defined by getStrings().
     *
     * @return \Drupal\locale\SourceString|null
     *   Minimal TranslationString object if found, NULL otherwise.
     */
    public function findString(array $conditions);
    
    /**
     * Loads a string translation object, fast query.
     *
     * This function must only be used when actually translating strings as it
     * will have the effect of updating the string version. For other purposes
     * the getTranslations() method should be used instead.
     *
     * @param array $conditions
     *   (optional) Array with conditions that will be used to filter the strings
     *   returned and may include all of the conditions defined by getStrings().
     *
     * @return \Drupal\locale\TranslationString|null
     *   Minimal TranslationString object if found, NULL otherwise.
     */
    public function findTranslation(array $conditions);
    
    /**
     * Save string object to storage.
     *
     * @param \Drupal\locale\StringInterface $string
     *   The string object.
     *
     * @return $this
     *   The called object.
     *
     * @throws \Drupal\locale\StringStorageException
     *   In case of failures, an exception is thrown.
     */
    public function save($string);
    
    /**
     * Delete string from storage.
     *
     * @param \Drupal\locale\StringInterface $string
     *   The string object.
     *
     * @return $this
     *   The called object.
     *
     * @throws \Drupal\locale\StringStorageException
     *   In case of failures, an exception is thrown.
     */
    public function delete($string);
    
    /**
     * Deletes source strings and translations using conditions.
     *
     * @param array $conditions
     *   Array with simple field conditions for source strings.
     */
    public function deleteStrings($conditions);
    
    /**
     * Deletes translations using conditions.
     *
     * @param array $conditions
     *   Array with simple field conditions for string translations.
     */
    public function deleteTranslations($conditions);
    
    /**
     * Counts source strings.
     *
     * @return int
     *   The number of source strings contained in the storage.
     */
    public function countStrings();
    
    /**
     * Counts translations.
     *
     * @return array
     *   The number of translations for each language indexed by language code.
     */
    public function countTranslations();
    
    /**
     * Creates a source string object bound to this storage but not saved.
     *
     * @param array $values
     *   (optional) Array with initial values. Defaults to empty array.
     *
     * @return \Drupal\locale\SourceString
     *   New source string object.
     */
    public function createString($values = []);
    
    /**
     * Creates a string translation object bound to this storage but not saved.
     *
     * @param array $values
     *   (optional) Array with initial values. Defaults to empty array.
     *
     * @return \Drupal\locale\TranslationString
     *   New string translation object.
     */
    public function createTranslation($values = []);

}