diff options
Diffstat (limited to 'plugins/jetpack/modules/sitemaps/sitemap-buffer.php')
| -rw-r--r-- | plugins/jetpack/modules/sitemaps/sitemap-buffer.php | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/plugins/jetpack/modules/sitemaps/sitemap-buffer.php b/plugins/jetpack/modules/sitemaps/sitemap-buffer.php new file mode 100644 index 00000000..f1a8d9b1 --- /dev/null +++ b/plugins/jetpack/modules/sitemaps/sitemap-buffer.php @@ -0,0 +1,286 @@ +<?php +/** + * Sitemaps (per the protocol) are essentially lists of XML fragments; + * lists which are subject to size constraints. The Jetpack_Sitemap_Buffer + * class abstracts the details of constructing these lists while + * maintaining the constraints. + * + * @since 4.8.0 + * @package Jetpack + */ + +/** + * A buffer for constructing sitemap xml files. + * + * Models a list of strings such that + * + * 1. the list must have a bounded number of entries, + * 2. the concatenation of the strings must have bounded + * length (including some header and footer strings), and + * 3. each item has a timestamp, and we need to keep track + * of the most recent timestamp of the items in the list. + * + * @since 4.8.0 + */ +class Jetpack_Sitemap_Buffer { + + /** + * Largest number of items the buffer can hold. + * + * @access private + * @since 4.8.0 + * @var int $item_capacity The item capacity. + */ + private $item_capacity; + + /** + * Largest number of bytes the buffer can hold. + * + * @access private + * @since 4.8.0 + * @var int $byte_capacity The byte capacity. + */ + private $byte_capacity; + + /** + * Footer text of the buffer; stored here so it can be appended when the buffer is full. + * + * @access private + * @since 4.8.0 + * @var string $footer_text The footer text. + */ + private $footer_text; + + /** + * The buffer contents. + * + * @access private + * @since 4.8.0 + * @var string The buffer contents. + */ + private $buffer; + + /** + * Flag which detects when the buffer is full. + * + * @access private + * @since 4.8.0 + * @var bool $is_full_flag The flag value. This flag is set to false on construction and only flipped to true if we've tried to add something and failed. + */ + private $is_full_flag; + + /** + * Flag which detects when the buffer is empty. + * + * @access private + * @since 4.8.0 + * @var bool $is_empty_flag The flag value. This flag is set to true on construction and only flipped to false if we've tried to add something and succeeded. + */ + private $is_empty_flag; + + /** + * The most recent timestamp seen by the buffer. + * + * @access private + * @since 4.8.0 + * @var string $timestamp Must be in 'YYYY-MM-DD hh:mm:ss' format. + */ + private $timestamp; + + /** + * Construct a new Jetpack_Sitemap_Buffer. + * + * @since 4.8.0 + * + * @param int $item_limit The maximum size of the buffer in items. + * @param int $byte_limit The maximum size of the buffer in bytes. + * @param string $header The string to prepend to the entire buffer. + * @param string $footer The string to append to the entire buffer. + * @param string $time The initial datetime of the buffer. Must be in 'YYYY-MM-DD hh:mm:ss' format. + */ + public function __construct( + $item_limit, + $byte_limit, + $header = '', + $footer = '', + $time + ) { + $this->item_capacity = max( 1, intval( $item_limit ) ); + + mbstring_binary_safe_encoding(); // So we can safely use strlen(). + $this->byte_capacity = max( 1, intval( $byte_limit ) ) - strlen( $header ) - strlen( $footer ); + reset_mbstring_encoding(); + + $this->footer_text = $footer; + $this->buffer = $header; + $this->is_full_flag = false; + $this->is_empty_flag = true; + $this->timestamp = $time; + return; + } + + /** + * Append an item to the buffer, if there is room for it, + * and set is_empty_flag to false. If there is no room, + * we set is_full_flag to true. If $item is null, + * don't do anything and report success. + * + * @since 4.8.0 + * + * @param string $item The item to be added. + * + * @return bool True if the append succeeded, False if not. + */ + public function try_to_add_item( $item ) { + if ( is_null( $item ) ) { + return true; + } else { + + mbstring_binary_safe_encoding(); // So we can safely use strlen(). + $item_size = strlen( $item ); // Size in bytes. + reset_mbstring_encoding(); + + if ( 0 >= $this->item_capacity || 0 > $this->byte_capacity - $item_size ) { + $this->is_full_flag = true; + return false; + } else { + $this->is_empty_flag = false; + $this->item_capacity -= 1; + $this->byte_capacity -= $item_size; + $this->buffer .= $item; + return true; + } + } + } + + /** + * Retrieve the contents of the buffer. + * + * @since 4.8.0 + * + * @return string The contents of the buffer (with the footer included). + */ + public function contents() { + return $this->buffer . $this->footer_text; + } + + /** + * Detect whether the buffer is full. + * + * @since 4.8.0 + * + * @return bool True if the buffer is full, false otherwise. + */ + public function is_full() { + return $this->is_full_flag; + } + + /** + * Detect whether the buffer is empty. + * + * @since 4.8.0 + * + * @return bool True if the buffer is empty, false otherwise. + */ + public function is_empty() { + return $this->is_empty_flag; + } + + /** + * Update the timestamp of the buffer. + * + * @since 4.8.0 + * + * @param string $new_time A datetime string in 'YYYY-MM-DD hh:mm:ss' format. + */ + public function view_time( $new_time ) { + $this->timestamp = max( $this->timestamp, $new_time ); + return; + } + + /** + * Retrieve the timestamp of the buffer. + * + * @since 4.8.0 + * + * @return string A datetime string in 'YYYY-MM-DD hh:mm:ss' format. + */ + public function last_modified() { + return $this->timestamp; + } + + /** + * Render an associative array as an XML string. This is needed because + * SimpleXMLElement only handles valid XML, but we sometimes want to + * pass around (possibly invalid) fragments. Note that 'null' values make + * a tag self-closing; this is only sometimes correct (depending on the + * version of HTML/XML); see the list of 'void tags'. + * + * Example: + * + * array( + * 'html' => array( |<html xmlns="foo"> + * 'head' => array( | <head> + * 'title' => 'Woo!', | <title>Woo!</title> + * ), | </head> + * 'body' => array( ==> | <body> + * 'h2' => 'Some thing', | <h2>Some thing</h2> + * 'p' => 'it's all up ons', | <p>it's all up ons</p> + * 'br' => null, | <br /> + * ), | </body> + * ), |</html> + * ) + * + * @access public + * @since 3.9.0 + * @since 4.8.0 Rename, add $depth parameter, and change return type. + * + * @param array $array A recursive associative array of tag/child relationships. + * @param string $depth String to prepend to each line. For internal use only. + * + * @return string The rendered XML string. + */ + public static function array_to_xml_string( $array, $depth = '' ) { + $string = ''; + + foreach ( $array as $key => $value ) { + + // Only allow a-z, A-Z, colon, underscore, and hyphen. + $tag = preg_replace( '/[^a-zA-Z:_-]/', '_', $key ); + + if ( is_array( $value ) ) { + $string .= $depth . "<$tag>\n"; + $string .= self::array_to_xml_string( $value, $depth . ' ' ); + $string .= $depth . "</$tag>\n"; + } elseif ( is_null( $value ) ) { + $string .= $depth . "<$tag />\n"; + } else { + $string .= $depth . "<$tag>" . ent2ncr( $value ) . "</$tag>\n"; + } + } + + return $string; + } + + /** + * Render an associative array of XML attribute key/value pairs. + * + * @access public + * @since 4.8.0 + * + * @param array $array Key/value array of attributes. + * + * @return string The rendered attribute string. + */ + public static function array_to_xml_attr_string( $array ) { + $string = ''; + + foreach ( $array as $key => $value ) { + $key = preg_replace( '/[^a-zA-Z:_-]/', '_', $key ); + $string .= ' ' . $key . '="' . esc_attr( $value ) . '"'; + } + + return $string; + } + +} |