Annotation.php
Public
Actions

Authored By

	• bzimport
	Nov 21 2014, 6:56 PM

Size

8 KB

Referenced Files

None

Subscribers

None

Annotation.php
View Options

	<?php

	/**
	* Defines Annotation object to implement annotate/blame functionality
	*
	* An Annotation is an array of ExtendedStrings. Both Annotation and
	* ExtendedStrings must act like regular strings, but their sets of
	* functionality vary. An ExtendedString must be able to be chopped up without
	* damaging information. An Annotation must be able to have segments of text
	* deleted, added or modified while keeping track of all the ExtendedStrings,
	* chopping up them if necessary. RevisionInfo is a parameter object that
	* contains the interesting information that regular strings don't have.
	*/

	/**
	* A regular string that has RevisionInfo. Automatically normalizes newlines.
	*/
	class ExtendedString
	{
	var $string;
	var $revision_info;

	function ExtendedString($string, $revision_info) {
	$this->string = str_replace( "\r\n", "\n", $string );
	$this->revision_info = $revision_info;
	}
	function newFromArray($array, $revision_info) {
	if (!is_array($array)) return null;
	return new ExtendedString(implode($array, ''), $revision_info);
	}

	function strlen() {
	return strlen($this->string);
	}
	function substr($start, $length = null) {
	if ($length === null) {
	$string = substr($this->string, $start);
	} else {
	$string = substr($this->string, $start, $length);
	}
	return new ExtendedString($string, $this->revision_info);
	}
	function append($string) {
	$this->string .= $string;
	}
	function splitAt($position) {
	return array(
	new ExtendedString( substr( $this->string, 0, $position ),
	$this->revision_info ),
	new ExtendedString( substr( $this->string, $position ),
	$this->revision_info )
	);
	}
	}
	/**
	* This string is used to show that something was deleted here
	*/
	class PhantomString extends ExtendedString
	{
	var $phantom = true;
	function PhantomString($revision_info) {
	$this->ExtendedString('', $revision_info);
	}
	function strlen() {return 0;}
	function substr() {return new PhantomString($this->revision_info);}
	function append() {}
	function splitAt() {return array();}
	}

	/**
	* Indicates something was deleted here in the specified revision.
	*/
	class DeletionMark
	{
	var $revision_info;
	}

	/**
	* Specifies extra authorship information, such as the user and the ID of it
	*/
	class RevisionInfo
	{
	var $id;
	var $user;
	var $user_text;
	var $timestamp;
	var $minor_edit;
	function RevisionInfo($id, $user, $user_text, $timestamp, $minor_edit) {
	$this->id = $id;
	$this->user = $user;
	$this->user_text = $user_text;
	$this->timestamp = $timestamp;
	$this->minor_edit = $minor_edit;
	}
	}
	class UnknownRevisionInfo
	{
	var $unknown = true;
	function UnknownRevisionInfo() {}
	}

	/**
	* Represents a string, but keeps track of RevisionInfo. Has diffs applied to
	* it.
	*/
	class Annotation
	{
	var $strings;
	var $ac = 0;
	var $sc = 0;

	function Annotation($strings = array(), $positions = array(0, 0)) {
	$this->strings = $strings; //expects an array of ExtendedString objects
	list($this->ac, $this->sc) = $positions;
	}

	function copy($distance, $extended_string = null) {
	//scroll ahead specified distance
	//loop iterates each time we advance one element in the array
	for(
	// i represents the string, as we scroll ahead, we chop off bits of
	// the string until nothing is left
	$i = $distance;
	// every iteration, we check that there is stil is string left, and
	// do a sanity check, making sure that our entry exists
	$i > 0 && isset($this->strings[$this->ac]);
	// an iteration represents scrolling forward in the array, resetting
	// the string counter
	$this->ac++, $this->sc = 0
	) {
	$length = $this->strings[$this->ac]->strlen() - $this->sc;
	if ($length > $i) {
	// we have to break it up, since the distance can't get
	// all the way across
	$new_strings = $this->strings[$this->ac]->splitAt($i);
	array_splice($this->strings, $this->ac, 1, $new_strings);
	}
	$i -= $length;
	}

	//fix extra possible addition to extended_string
	if ($extended_string !== null &&
	$distance != $extended_string->strlen()) {
	$extra = $extended_string->substr($distance);
	$extra = $extra->string;
	$this->strings[$this->ac - 1]->append($extra);
	}
	}
	function add($extended_string) {
	//scroll past all phantom strings before inserting
	while (isset($this->strings[$this->ac]->phantom)) $this->ac++;
	array_splice(
	$this->strings,
	$this->ac++,
	0,
	array($extended_string)
	);
	}
	function delete($distance, $revision_info) {
	// loop is similar to structure as copy, it just has different meat
	for (
	$i = $distance;
	$i > 0 && isset($this->strings[$this->ac]);
	//ac does not get reset because we just shifted the array
	$this->sc = 0
	) {
	// sc expected to be 0, too lazy to write defense code
	$length = $this->strings[$this->ac]->strlen();
	if ($i < $length) {
	$array = array();
	if ($revision_info !== false) {
	$array[] = new PhantomString($revision_info);
	}
	$array[] = $this->strings[$this->ac]->substr($i);
	array_splice($this->strings, $this->ac, 1, $array);
	} else {
	array_splice($this->strings, $this->ac, 1);
	}
	$i -= $length;
	}
	if ($i == 0 && $revision_info !== false) {
	//ahh, it finished perfectly, so no phantom was added
	$this->add(new PhantomString($revision_info));
	}
	}
	function change($distance, $extended_string) {
	$this->delete($distance, false);
	$this->add($extended_string);
	}
	function newFromRevisions($strings) {
	require_once('DifferenceEngine.php');
	$annotation = new Annotation();
	$num_diffs = count($strings) - 1;
	for($i = 0; $i < $num_diffs; $i++) {
	$annotation->reset();
	if ($i == 0) {
	//this is the first iteration, load up annotation
	$annotation->strings[] = $strings[$i];
	}
	//get the diff
	$ota =explode("\n",str_replace("\r\n","\n",$strings[$i]->string));
	$nta =explode("\n",str_replace("\r\n","\n",$strings[$i+1]->string));
	$diff = new WordLevelDiff($ota, $nta);
	$edits = $diff->edits;
	$info = $strings[$i+1]->revision_info;
	foreach ($edits as $edit) {
	$orig = ExtendedString::newFromArray($edit->orig, $info);
	$closing = ExtendedString::newFromArray($edit->closing, $info);
	switch ($edit->type) {
	case 'copy':
	$annotation->copy($orig->strlen(), $closing);
	break;
	case 'add':
	$annotation->add($closing);
	break;
	case 'delete':
	$annotation->delete($orig->strlen());
	break;
	case 'change':
	$annotation->change($orig->strlen(), $closing);
	break;
	default:
	exit;
	}
	}
	}
	$annotation->reset();
	return $annotation;
	}

	function reset() {$this->ac = $this->sc = 0;}
	function clump() {}
	}

	?>

File Metadata

Mime Type: text/x-php
Storage Engine: blob
Storage Format: Raw Data
Storage Handle: 1206
Default Alt Text: Annotation.php (8 KB)

Annotation.phpPublicActions

Annotation.phpView Options

File Metadata

Event Timeline

Annotation.php
Public
Actions

Annotation.php
View Options