--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/class-wp-token-map.php Fri Sep 05 18:40:08 2025 +0200
@@ -0,0 +1,818 @@
+<?php
+
+/**
+ * Class for efficiently looking up and mapping string keys to string values, with limits.
+ *
+ * @package WordPress
+ * @since 6.6.0
+ */
+
+/**
+ * WP_Token_Map class.
+ *
+ * Use this class in specific circumstances with a static set of lookup keys which map to
+ * a static set of transformed values. For example, this class is used to map HTML named
+ * character references to their equivalent UTF-8 values.
+ *
+ * This class works differently than code calling `in_array()` and other methods. It
+ * internalizes lookup logic and provides helper interfaces to optimize lookup and
+ * transformation. It provides a method for precomputing the lookup tables and storing
+ * them as PHP source code.
+ *
+ * All tokens and substitutions must be shorter than 256 bytes.
+ *
+ * Example:
+ *
+ * $smilies = WP_Token_Map::from_array( array(
+ * '8O' => 'π―',
+ * ':(' => 'π',
+ * ':)' => 'π',
+ * ':?' => 'π',
+ * ) );
+ *
+ * true === $smilies->contains( ':)' );
+ * false === $smilies->contains( 'simile' );
+ *
+ * 'π' === $smilies->read_token( 'Not sure :?.', 9, $length_of_smily_syntax );
+ * 2 === $length_of_smily_syntax;
+ *
+ * ## Precomputing the Token Map.
+ *
+ * Creating the class involves some work sorting and organizing the tokens and their
+ * replacement values. In order to skip this, it's possible for the class to export
+ * its state and be used as actual PHP source code.
+ *
+ * Example:
+ *
+ * // Export with four spaces as the indent, only for the sake of this docblock.
+ * // The default indent is a tab character.
+ * $indent = ' ';
+ * echo $smilies->precomputed_php_source_table( $indent );
+ *
+ * // Output, to be pasted into a PHP source file:
+ * WP_Token_Map::from_precomputed_table(
+ * array(
+ * "storage_version" => "6.6.0",
+ * "key_length" => 2,
+ * "groups" => "",
+ * "long_words" => array(),
+ * "small_words" => "8O\x00:)\x00:(\x00:?\x00",
+ * "small_mappings" => array( "π―", "π", "π", "π" )
+ * )
+ * );
+ *
+ * ## Large vs. small words.
+ *
+ * This class uses a short prefix called the "key" to optimize lookup of its tokens.
+ * This means that some tokens may be shorter than or equal in length to that key.
+ * Those words that are longer than the key are called "large" while those shorter
+ * than or equal to the key length are called "small."
+ *
+ * This separation of large and small words is incidental to the way this class
+ * optimizes lookup, and should be considered an internal implementation detail
+ * of the class. It may still be important to be aware of it, however.
+ *
+ * ## Determining Key Length.
+ *
+ * The choice of the size of the key length should be based on the data being stored in
+ * the token map. It should divide the data as evenly as possible, but should not create
+ * so many groups that a large fraction of the groups only contain a single token.
+ *
+ * For the HTML5 named character references, a key length of 2 was found to provide a
+ * sufficient spread and should be a good default for relatively large sets of tokens.
+ *
+ * However, for some data sets this might be too long. For example, a list of smilies
+ * may be too small for a key length of 2. Perhaps 1 would be more appropriate. It's
+ * best to experiment and determine empirically which values are appropriate.
+ *
+ * ## Generate Pre-Computed Source Code.
+ *
+ * Since the `WP_Token_Map` is designed for relatively static lookups, it can be
+ * advantageous to precompute the values and instantiate a table that has already
+ * sorted and grouped the tokens and built the lookup strings.
+ *
+ * This can be done with `WP_Token_Map::precomputed_php_source_table()`.
+ *
+ * Note that if there is a leading character that all tokens need, such as `&` for
+ * HTML named character references, it can be beneficial to exclude this from the
+ * token map. Instead, find occurrences of the leading character and then use the
+ * token map to see if the following characters complete the token.
+ *
+ * Example:
+ *
+ * $map = WP_Token_Map::from_array( array( 'simple_smile:' => 'π', 'sob:' => 'π', 'soba:' => 'π' ) );
+ * echo $map->precomputed_php_source_table();
+ * // Output
+ * WP_Token_Map::from_precomputed_table(
+ * array(
+ * "storage_version" => "6.6.0",
+ * "key_length" => 2,
+ * "groups" => "si\x00so\x00",
+ * "long_words" => array(
+ * // simple_smile:[π].
+ * "\x0bmple_smile:\x04π",
+ * // soba:[π] sob:[π].
+ * "\x03ba:\x04π\x02b:\x04π",
+ * ),
+ * "short_words" => "",
+ * "short_mappings" => array()
+ * }
+ * );
+ *
+ * This precomputed value can be stored directly in source code and will skip the
+ * startup cost of generating the lookup strings. See `$html5_named_character_entities`.
+ *
+ * Note that any updates to the precomputed format should update the storage version
+ * constant. It would also be best to provide an update function to take older known
+ * versions and upgrade them in place when loading into `from_precomputed_table()`.
+ *
+ * ## Future Direction.
+ *
+ * It may be viable to dynamically increase the length limits such that there's no need to impose them.
+ * The limit appears because of the packing structure, which indicates how many bytes each segment of
+ * text in the lookup tables spans. If, however, care were taken to track the longest word length, then
+ * the packing structure could change its representation to allow for that. Each additional byte storing
+ * length, however, increases the memory overhead and lookup runtime.
+ *
+ * An alternative approach could be to borrow the UTF-8 variable-length encoding and store lengths of less
+ * than 127 as a single byte with the high bit unset, storing longer lengths as the combination of
+ * continuation bytes.
+ *
+ * Since it has not been shown during the development of this class that longer strings are required, this
+ * update is deferred until such a need is clear.
+ *
+ * @since 6.6.0
+ */
+class WP_Token_Map {
+ /**
+ * Denotes the version of the code which produces pre-computed source tables.
+ *
+ * This version will be used not only to verify pre-computed data, but also
+ * to upgrade pre-computed data from older versions. Choosing a name that
+ * corresponds to the WordPress release will help people identify where an
+ * old copy of data came from.
+ */
+ const STORAGE_VERSION = '6.6.0-trunk';
+
+ /**
+ * Maximum length for each key and each transformed value in the table (in bytes).
+ *
+ * @since 6.6.0
+ */
+ const MAX_LENGTH = 256;
+
+ /**
+ * How many bytes of each key are used to form a group key for lookup.
+ * This also determines whether a word is considered short or long.
+ *
+ * @since 6.6.0
+ *
+ * @var int
+ */
+ private $key_length = 2;
+
+ /**
+ * Stores an optimized form of the word set, where words are grouped
+ * by a prefix of the `$key_length` and then collapsed into a string.
+ *
+ * In each group, the keys and lookups form a packed data structure.
+ * The keys in the string are stripped of their "group key," which is
+ * the prefix of length `$this->key_length` shared by all of the items
+ * in the group. Each word in the string is prefixed by a single byte
+ * whose raw unsigned integer value represents how many bytes follow.
+ *
+ * ββββββββββββββββββ¬ββββββββββββββββ¬ββββββββββββββββββ¬βββββββββ
+ * β Length of rest β Rest of key β Length of value β Value β
+ * β of key (bytes) β β (bytes) β β
+ * ββββββββββββββββββΌββββββββββββββββΌββββββββββββββββββΌβββββββββ€
+ * β 0x08 β nterDot; β 0x02 β Β· β
+ * ββββββββββββββββββ΄ββββββββββββββββ΄ββββββββββββββββββ΄βββββββββ
+ *
+ * In this example, the key `CenterDot;` has a group key `Ce`, leaving
+ * eight bytes for the rest of the key, `nterDot;`, and two bytes for
+ * the transformed value `Β·` (or U+B7 or "\xC2\xB7").
+ *
+ * Example:
+ *
+ * // Stores array( 'CenterDot;' => 'Β·', 'Cedilla;' => 'ΒΈ' ).
+ * $groups = "Ce\x00";
+ * $large_words = array( "\x08nterDot;\x02Β·\x06dilla;\x02ΒΈ" )
+ *
+ * The prefixes appear in the `$groups` string, each followed by a null
+ * byte. This makes for quick lookup of where in the group string the key
+ * is found, and then a simple division converts that offset into the index
+ * in the `$large_words` array where the group string is to be found.
+ *
+ * This lookup data structure is designed to optimize cache locality and
+ * minimize indirect memory reads when matching strings in the set.
+ *
+ * @since 6.6.0
+ *
+ * @var array
+ */
+ private $large_words = array();
+
+ /**
+ * Stores the group keys for sequential string lookup.
+ *
+ * The offset into this string where the group key appears corresponds with the index
+ * into the group array where the rest of the group string appears. This is an optimization
+ * to improve cache locality while searching and minimize indirect memory accesses.
+ *
+ * @since 6.6.0
+ *
+ * @var string
+ */
+ private $groups = '';
+
+ /**
+ * Stores an optimized row of small words, where every entry is
+ * `$this->key_size + 1` bytes long and zero-extended.
+ *
+ * This packing allows for direct lookup of a short word followed
+ * by the null byte, if extended to `$this->key_size + 1`.
+ *
+ * Example:
+ *
+ * // Stores array( 'GT', 'LT', 'gt', 'lt' ).
+ * "GT\x00LT\x00gt\x00lt\x00"
+ *
+ * @since 6.6.0
+ *
+ * @var string
+ */
+ private $small_words = '';
+
+ /**
+ * Replacements for the small words, in the same order they appear.
+ *
+ * With the position of a small word it's possible to index the translation
+ * directly, as its position in the `$small_words` string corresponds to
+ * the index of the replacement in the `$small_mapping` array.
+ *
+ * Example:
+ *
+ * array( '>', '<', '>', '<' )
+ *
+ * @since 6.6.0
+ *
+ * @var string[]
+ */
+ private $small_mappings = array();
+
+ /**
+ * Create a token map using an associative array of key/value pairs as the input.
+ *
+ * Example:
+ *
+ * $smilies = WP_Token_Map::from_array( array(
+ * '8O' => 'π―',
+ * ':(' => 'π',
+ * ':)' => 'π',
+ * ':?' => 'π',
+ * ) );
+ *
+ * @since 6.6.0
+ *
+ * @param array $mappings The keys transform into the values, both are strings.
+ * @param int $key_length Determines the group key length. Leave at the default value
+ * of 2 unless there's an empirical reason to change it.
+ *
+ * @return WP_Token_Map|null Token map, unless unable to create it.
+ */
+ public static function from_array( $mappings, $key_length = 2 ) {
+ $map = new WP_Token_Map();
+ $map->key_length = $key_length;
+
+ // Start by grouping words.
+
+ $groups = array();
+ $shorts = array();
+ foreach ( $mappings as $word => $mapping ) {
+ if (
+ self::MAX_LENGTH <= strlen( $word ) ||
+ self::MAX_LENGTH <= strlen( $mapping )
+ ) {
+ _doing_it_wrong(
+ __METHOD__,
+ sprintf(
+ /* translators: 1: maximum byte length (a count) */
+ __( 'Token Map tokens and substitutions must all be shorter than %1$d bytes.' ),
+ self::MAX_LENGTH
+ ),
+ '6.6.0'
+ );
+ return null;
+ }
+
+ $length = strlen( $word );
+
+ if ( $key_length >= $length ) {
+ $shorts[] = $word;
+ } else {
+ $group = substr( $word, 0, $key_length );
+
+ if ( ! isset( $groups[ $group ] ) ) {
+ $groups[ $group ] = array();
+ }
+
+ $groups[ $group ][] = array( substr( $word, $key_length ), $mapping );
+ }
+ }
+
+ /*
+ * Sort the words to ensure that no smaller substring of a match masks the full match.
+ * For example, `Cap` should not match before `CapitalDifferentialD`.
+ */
+ usort( $shorts, 'WP_Token_Map::longest_first_then_alphabetical' );
+ foreach ( $groups as $group_key => $group ) {
+ usort(
+ $groups[ $group_key ],
+ static function ( $a, $b ) {
+ return self::longest_first_then_alphabetical( $a[0], $b[0] );
+ }
+ );
+ }
+
+ // Finally construct the optimized lookups.
+
+ foreach ( $shorts as $word ) {
+ $map->small_words .= str_pad( $word, $key_length + 1, "\x00", STR_PAD_RIGHT );
+ $map->small_mappings[] = $mappings[ $word ];
+ }
+
+ $group_keys = array_keys( $groups );
+ sort( $group_keys );
+
+ foreach ( $group_keys as $group ) {
+ $map->groups .= "{$group}\x00";
+
+ $group_string = '';
+
+ foreach ( $groups[ $group ] as $group_word ) {
+ list( $word, $mapping ) = $group_word;
+
+ $word_length = pack( 'C', strlen( $word ) );
+ $mapping_length = pack( 'C', strlen( $mapping ) );
+ $group_string .= "{$word_length}{$word}{$mapping_length}{$mapping}";
+ }
+
+ $map->large_words[] = $group_string;
+ }
+
+ return $map;
+ }
+
+ /**
+ * Creates a token map from a pre-computed table.
+ * This skips the initialization cost of generating the table.
+ *
+ * This function should only be used to load data created with
+ * WP_Token_Map::precomputed_php_source_tag().
+ *
+ * @since 6.6.0
+ *
+ * @param array $state {
+ * Stores pre-computed state for directly loading into a Token Map.
+ *
+ * @type string $storage_version Which version of the code produced this state.
+ * @type int $key_length Group key length.
+ * @type string $groups Group lookup index.
+ * @type array $large_words Large word groups and packed strings.
+ * @type string $small_words Small words packed string.
+ * @type array $small_mappings Small word mappings.
+ * }
+ *
+ * @return WP_Token_Map Map with precomputed data loaded.
+ */
+ public static function from_precomputed_table( $state ) {
+ $has_necessary_state = isset(
+ $state['storage_version'],
+ $state['key_length'],
+ $state['groups'],
+ $state['large_words'],
+ $state['small_words'],
+ $state['small_mappings']
+ );
+
+ if ( ! $has_necessary_state ) {
+ _doing_it_wrong(
+ __METHOD__,
+ __( 'Missing required inputs to pre-computed WP_Token_Map.' ),
+ '6.6.0'
+ );
+ return null;
+ }
+
+ if ( self::STORAGE_VERSION !== $state['storage_version'] ) {
+ _doing_it_wrong(
+ __METHOD__,
+ /* translators: 1: version string, 2: version string. */
+ sprintf( __( 'Loaded version \'%1$s\' incompatible with expected version \'%2$s\'.' ), $state['storage_version'], self::STORAGE_VERSION ),
+ '6.6.0'
+ );
+ return null;
+ }
+
+ $map = new WP_Token_Map();
+
+ $map->key_length = $state['key_length'];
+ $map->groups = $state['groups'];
+ $map->large_words = $state['large_words'];
+ $map->small_words = $state['small_words'];
+ $map->small_mappings = $state['small_mappings'];
+
+ return $map;
+ }
+
+ /**
+ * Indicates if a given word is a lookup key in the map.
+ *
+ * Example:
+ *
+ * true === $smilies->contains( ':)' );
+ * false === $smilies->contains( 'simile' );
+ *
+ * @since 6.6.0
+ *
+ * @param string $word Determine if this word is a lookup key in the map.
+ * @param string $case_sensitivity Optional. Pass 'ascii-case-insensitive' to ignore ASCII case when matching. Default 'case-sensitive'.
+ * @return bool Whether there's an entry for the given word in the map.
+ */
+ public function contains( $word, $case_sensitivity = 'case-sensitive' ) {
+ $ignore_case = 'ascii-case-insensitive' === $case_sensitivity;
+
+ if ( $this->key_length >= strlen( $word ) ) {
+ if ( 0 === strlen( $this->small_words ) ) {
+ return false;
+ }
+
+ $term = str_pad( $word, $this->key_length + 1, "\x00", STR_PAD_RIGHT );
+ $word_at = $ignore_case ? stripos( $this->small_words, $term ) : strpos( $this->small_words, $term );
+ if ( false === $word_at ) {
+ return false;
+ }
+
+ return true;
+ }
+
+ $group_key = substr( $word, 0, $this->key_length );
+ $group_at = $ignore_case ? stripos( $this->groups, $group_key ) : strpos( $this->groups, $group_key );
+ if ( false === $group_at ) {
+ return false;
+ }
+ $group = $this->large_words[ $group_at / ( $this->key_length + 1 ) ];
+ $group_length = strlen( $group );
+ $slug = substr( $word, $this->key_length );
+ $length = strlen( $slug );
+ $at = 0;
+
+ while ( $at < $group_length ) {
+ $token_length = unpack( 'C', $group[ $at++ ] )[1];
+ $token_at = $at;
+ $at += $token_length;
+ $mapping_length = unpack( 'C', $group[ $at++ ] )[1];
+ $mapping_at = $at;
+
+ if ( $token_length === $length && 0 === substr_compare( $group, $slug, $token_at, $token_length, $ignore_case ) ) {
+ return true;
+ }
+
+ $at = $mapping_at + $mapping_length;
+ }
+
+ return false;
+ }
+
+ /**
+ * If the text starting at a given offset is a lookup key in the map,
+ * return the corresponding transformation from the map, else `false`.
+ *
+ * This function returns the translated string, but accepts an optional
+ * parameter `$matched_token_byte_length`, which communicates how many
+ * bytes long the lookup key was, if it found one. This can be used to
+ * advance a cursor in calling code if a lookup key was found.
+ *
+ * Example:
+ *
+ * false === $smilies->read_token( 'Not sure :?.', 0, $token_byte_length );
+ * 'π' === $smilies->read_token( 'Not sure :?.', 9, $token_byte_length );
+ * 2 === $token_byte_length;
+ *
+ * Example:
+ *
+ * while ( $at < strlen( $input ) ) {
+ * $next_at = strpos( $input, ':', $at );
+ * if ( false === $next_at ) {
+ * break;
+ * }
+ *
+ * $smily = $smilies->read_token( $input, $next_at, $token_byte_length );
+ * if ( false === $next_at ) {
+ * ++$at;
+ * continue;
+ * }
+ *
+ * $prefix = substr( $input, $at, $next_at - $at );
+ * $at += $token_byte_length;
+ * $output .= "{$prefix}{$smily}";
+ * }
+ *
+ * @since 6.6.0
+ *
+ * @param string $text String in which to search for a lookup key.
+ * @param int $offset Optional. How many bytes into the string where the lookup key ought to start. Default 0.
+ * @param ?int &$matched_token_byte_length Optional. Holds byte-length of found token matched, otherwise not set. Default null.
+ * @param string $case_sensitivity Optional. Pass 'ascii-case-insensitive' to ignore ASCII case when matching. Default 'case-sensitive'.
+ * @return string|null Mapped value of lookup key if found, otherwise `null`.
+ */
+ public function read_token( $text, $offset = 0, &$matched_token_byte_length = null, $case_sensitivity = 'case-sensitive' ) {
+ $ignore_case = 'ascii-case-insensitive' === $case_sensitivity;
+ $text_length = strlen( $text );
+
+ // Search for a long word first, if the text is long enough, and if that fails, a short one.
+ if ( $text_length > $this->key_length ) {
+ $group_key = substr( $text, $offset, $this->key_length );
+
+ $group_at = $ignore_case ? stripos( $this->groups, $group_key ) : strpos( $this->groups, $group_key );
+ if ( false === $group_at ) {
+ // Perhaps a short word then.
+ return strlen( $this->small_words ) > 0
+ ? $this->read_small_token( $text, $offset, $matched_token_byte_length, $case_sensitivity )
+ : null;
+ }
+
+ $group = $this->large_words[ $group_at / ( $this->key_length + 1 ) ];
+ $group_length = strlen( $group );
+ $at = 0;
+ while ( $at < $group_length ) {
+ $token_length = unpack( 'C', $group[ $at++ ] )[1];
+ $token = substr( $group, $at, $token_length );
+ $at += $token_length;
+ $mapping_length = unpack( 'C', $group[ $at++ ] )[1];
+ $mapping_at = $at;
+
+ if ( 0 === substr_compare( $text, $token, $offset + $this->key_length, $token_length, $ignore_case ) ) {
+ $matched_token_byte_length = $this->key_length + $token_length;
+ return substr( $group, $mapping_at, $mapping_length );
+ }
+
+ $at = $mapping_at + $mapping_length;
+ }
+ }
+
+ // Perhaps a short word then.
+ return strlen( $this->small_words ) > 0
+ ? $this->read_small_token( $text, $offset, $matched_token_byte_length, $case_sensitivity )
+ : null;
+ }
+
+ /**
+ * Finds a match for a short word at the index.
+ *
+ * @since 6.6.0.
+ *
+ * @param string $text String in which to search for a lookup key.
+ * @param int $offset Optional. How many bytes into the string where the lookup key ought to start. Default 0.
+ * @param ?int &$matched_token_byte_length Optional. Holds byte-length of found lookup key if matched, otherwise not set. Default null.
+ * @param string $case_sensitivity Optional. Pass 'ascii-case-insensitive' to ignore ASCII case when matching. Default 'case-sensitive'.
+ * @return string|null Mapped value of lookup key if found, otherwise `null`.
+ */
+ private function read_small_token( $text, $offset, &$matched_token_byte_length, $case_sensitivity = 'case-sensitive' ) {
+ $ignore_case = 'ascii-case-insensitive' === $case_sensitivity;
+ $small_length = strlen( $this->small_words );
+ $search_text = substr( $text, $offset, $this->key_length );
+ if ( $ignore_case ) {
+ $search_text = strtoupper( $search_text );
+ }
+ $starting_char = $search_text[0];
+
+ $at = 0;
+ while ( $at < $small_length ) {
+ if (
+ $starting_char !== $this->small_words[ $at ] &&
+ ( ! $ignore_case || strtoupper( $this->small_words[ $at ] ) !== $starting_char )
+ ) {
+ $at += $this->key_length + 1;
+ continue;
+ }
+
+ for ( $adjust = 1; $adjust < $this->key_length; $adjust++ ) {
+ if ( "\x00" === $this->small_words[ $at + $adjust ] ) {
+ $matched_token_byte_length = $adjust;
+ return $this->small_mappings[ $at / ( $this->key_length + 1 ) ];
+ }
+
+ if (
+ $search_text[ $adjust ] !== $this->small_words[ $at + $adjust ] &&
+ ( ! $ignore_case || strtoupper( $this->small_words[ $at + $adjust ] !== $search_text[ $adjust ] ) )
+ ) {
+ $at += $this->key_length + 1;
+ continue 2;
+ }
+ }
+
+ $matched_token_byte_length = $adjust;
+ return $this->small_mappings[ $at / ( $this->key_length + 1 ) ];
+ }
+
+ return null;
+ }
+
+ /**
+ * Exports the token map into an associate array of key/value pairs.
+ *
+ * Example:
+ *
+ * $smilies->to_array() === array(
+ * '8O' => 'π―',
+ * ':(' => 'π',
+ * ':)' => 'π',
+ * ':?' => 'π',
+ * );
+ *
+ * @return array The lookup key/substitution values as an associate array.
+ */
+ public function to_array() {
+ $tokens = array();
+
+ $at = 0;
+ $small_mapping = 0;
+ $small_length = strlen( $this->small_words );
+ while ( $at < $small_length ) {
+ $key = rtrim( substr( $this->small_words, $at, $this->key_length + 1 ), "\x00" );
+ $value = $this->small_mappings[ $small_mapping++ ];
+ $tokens[ $key ] = $value;
+
+ $at += $this->key_length + 1;
+ }
+
+ foreach ( $this->large_words as $index => $group ) {
+ $prefix = substr( $this->groups, $index * ( $this->key_length + 1 ), 2 );
+ $group_length = strlen( $group );
+ $at = 0;
+ while ( $at < $group_length ) {
+ $length = unpack( 'C', $group[ $at++ ] )[1];
+ $key = $prefix . substr( $group, $at, $length );
+
+ $at += $length;
+ $length = unpack( 'C', $group[ $at++ ] )[1];
+ $value = substr( $group, $at, $length );
+
+ $tokens[ $key ] = $value;
+ $at += $length;
+ }
+ }
+
+ return $tokens;
+ }
+
+ /**
+ * Export the token map for quick loading in PHP source code.
+ *
+ * This function has a specific purpose, to make loading of static token maps fast.
+ * It's used to ensure that the HTML character reference lookups add a minimal cost
+ * to initializing the PHP process.
+ *
+ * Example:
+ *
+ * echo $smilies->precomputed_php_source_table();
+ *
+ * // Output.
+ * WP_Token_Map::from_precomputed_table(
+ * array(
+ * "storage_version" => "6.6.0",
+ * "key_length" => 2,
+ * "groups" => "",
+ * "long_words" => array(),
+ * "small_words" => "8O\x00:)\x00:(\x00:?\x00",
+ * "small_mappings" => array( "π―", "π", "π", "π" )
+ * )
+ * );
+ *
+ * @since 6.6.0
+ *
+ * @param string $indent Optional. Use this string for indentation, or rely on the default horizontal tab character. Default "\t".
+ * @return string Value which can be pasted into a PHP source file for quick loading of table.
+ */
+ public function precomputed_php_source_table( $indent = "\t" ) {
+ $i1 = $indent;
+ $i2 = $i1 . $indent;
+ $i3 = $i2 . $indent;
+
+ $class_version = self::STORAGE_VERSION;
+
+ $output = self::class . "::from_precomputed_table(\n";
+ $output .= "{$i1}array(\n";
+ $output .= "{$i2}\"storage_version\" => \"{$class_version}\",\n";
+ $output .= "{$i2}\"key_length\" => {$this->key_length},\n";
+
+ $group_line = str_replace( "\x00", "\\x00", $this->groups );
+ $output .= "{$i2}\"groups\" => \"{$group_line}\",\n";
+
+ $output .= "{$i2}\"large_words\" => array(\n";
+
+ $prefixes = explode( "\x00", $this->groups );
+ foreach ( $prefixes as $index => $prefix ) {
+ if ( '' === $prefix ) {
+ break;
+ }
+ $group = $this->large_words[ $index ];
+ $group_length = strlen( $group );
+ $comment_line = "{$i3}//";
+ $data_line = "{$i3}\"";
+ $at = 0;
+ while ( $at < $group_length ) {
+ $token_length = unpack( 'C', $group[ $at++ ] )[1];
+ $token = substr( $group, $at, $token_length );
+ $at += $token_length;
+ $mapping_length = unpack( 'C', $group[ $at++ ] )[1];
+ $mapping = substr( $group, $at, $mapping_length );
+ $at += $mapping_length;
+
+ $token_digits = str_pad( dechex( $token_length ), 2, '0', STR_PAD_LEFT );
+ $mapping_digits = str_pad( dechex( $mapping_length ), 2, '0', STR_PAD_LEFT );
+
+ $mapping = preg_replace_callback(
+ "~[\\x00-\\x1f\\x22\\x5c]~",
+ static function ( $match_result ) {
+ switch ( $match_result[0] ) {
+ case '"':
+ return '\\"';
+
+ case '\\':
+ return '\\\\';
+
+ default:
+ $hex = dechex( ord( $match_result[0] ) );
+ return "\\x{$hex}";
+ }
+ },
+ $mapping
+ );
+
+ $comment_line .= " {$prefix}{$token}[{$mapping}]";
+ $data_line .= "\\x{$token_digits}{$token}\\x{$mapping_digits}{$mapping}";
+ }
+ $comment_line .= ".\n";
+ $data_line .= "\",\n";
+
+ $output .= $comment_line;
+ $output .= $data_line;
+ }
+
+ $output .= "{$i2}),\n";
+
+ $small_words = array();
+ $small_length = strlen( $this->small_words );
+ $at = 0;
+ while ( $at < $small_length ) {
+ $small_words[] = substr( $this->small_words, $at, $this->key_length + 1 );
+ $at += $this->key_length + 1;
+ }
+
+ $small_text = str_replace( "\x00", '\x00', implode( '', $small_words ) );
+ $output .= "{$i2}\"small_words\" => \"{$small_text}\",\n";
+
+ $output .= "{$i2}\"small_mappings\" => array(\n";
+ foreach ( $this->small_mappings as $mapping ) {
+ $output .= "{$i3}\"{$mapping}\",\n";
+ }
+ $output .= "{$i2})\n";
+ $output .= "{$i1})\n";
+ $output .= ')';
+
+ return $output;
+ }
+
+ /**
+ * Compares two strings, returning the longest, or whichever
+ * is first alphabetically if they are the same length.
+ *
+ * This is an important sort when building the token map because
+ * it should not form a match on a substring of a longer potential
+ * match. For example, it should not detect `Cap` when matching
+ * against the string `CapitalDifferentialD`.
+ *
+ * @since 6.6.0
+ *
+ * @param string $a First string to compare.
+ * @param string $b Second string to compare.
+ * @return int -1 or lower if `$a` is less than `$b`; 1 or greater if `$a` is greater than `$b`, and 0 if they are equal.
+ */
+ private static function longest_first_then_alphabetical( $a, $b ) {
+ if ( $a === $b ) {
+ return 0;
+ }
+
+ $length_a = strlen( $a );
+ $length_b = strlen( $b );
+
+ // Longer strings are less-than for comparison's sake.
+ if ( $length_a !== $length_b ) {
+ return $length_b - $length_a;
+ }
+
+ return strcmp( $a, $b );
+ }
+}