Keep cache size within limit

class-wpml-element-translation.php

	public function shutdown_action() {
		$keys = $this->get_data_keys();
		$data = [];

		foreach ( $keys as $key ) {
			$this->data[ $key ] = isset( $this->data[ $key ] ) ? $this->data[ $key ] : [];
			$data[ $key ]       = array_replace( $this->data[ $key ], $this->{$key} );
		}

		wp_cache_set( $this->get_cache_key(), $this->maybe_reduce_cache_size( $data ) );

		$this->onShutDown();
	}

	/**
	 * @param array $data
	 *
	 * @return string
	 */
	private function maybe_reduce_cache_size( $data ) {
		$json = wp_json_encode( $data );
		$size = strlen( $json );

		while ( $size > self::MAX_CACHE_SIZE ) {
			$count        = count( $data['element_data'] );
			$keep_count   = intval( $count / ( $size / self::MAX_CACHE_SIZE ) );
			$remove_count = $count - $keep_count;

			foreach ( $data['element_data'] as $key => &$element_datum ) {
				if ( 0 === $remove_count ) {
					break;
				}

				// Remove 'element_data' and relevant items on FIFO principle.
				unset( $data['translations'][ $key ] );
				unset( $data['trid_groups'][ $element_datum['trid'] ] );
				unset( $data['translation_ids_element'][ $element_datum['translation_id'] ] );
				unset( $data['element_data'][ $key ] );
				$remove_count --;
			}

			$json     = wp_json_encode( $data );
			$new_size = strlen( $json );
			if ( $new_size === $size ) {
				break; // Prevent infinite loop if remove_count was estimated improperly.
			}
			$size = $new_size;
		}

		return $json;
	}