mergedOutput());
}
function MergeSimulEdits($pagename,&$page,&$new) {
global $Now, $EnablePost, $MessagesFmt, $WorkDir;
if (@!$_POST['basetime'] || !PageExists($pagename)
|| $page['time'] >= $Now
|| $_POST['basetime']>=$page['time']
|| $page['text'] == $new['text']) return;
$EnablePost = 0;
$old = array();
RestorePage($pagename,$page,$old,"diff:{$_POST['basetime']}");
$text = Merge($new['text'],$old['text'],$page['text']);
if ($text > '') { $new['text'] = $text; $ec = '$[EditConflict]'; }
else $ec = '$[EditWarning]';
XLSDV('en', array(
'EditConflict' => "The page you are
editing has been modified since you started editing it.
The modifications have been merged into the text below,
you may want to verify the results of the merge before
pressing save. Conflicts the system couldn't resolve are
bracketed by <<<<<<< and
>>>>>>>.",
'EditWarning' => "The page you are editing has been modified
since you started editing it. If you continue, your
changes will overwrite any changes that others have made."));
$MessagesFmt[] = "$ec
($[View changes])
\n";
}
/**
* General API for generating and formatting diffs - the differences between
* two sequences of strings.
*
* The original PHP version of this code was written by Geoffrey T. Dairiki
* , and is used/adapted with his permission.
*
* $Horde: framework/Text_Diff/Diff.php,v 1.11.2.12 2009/01/06 15:23:41 jan Exp $
*
* Copyright 2004 Geoffrey T. Dairiki
* Copyright 2004-2009 The Horde Project (http://www.horde.org/)
*
* See the enclosed file COPYING for license information (LGPL). If you did
* not receive this file, see http://opensource.org/licenses/lgpl-license.php.
*
* @package Text_Diff
* @author Geoffrey T. Dairiki
*/
class Text_Diff {
/**
* Array of changes.
*
* @var array
*/
var $_edits;
/**
* Computes diffs between sequences of strings.
*
* @param string $engine Name of the diffing engine to use. 'auto'
* will automatically select the best.
* @param array $params Parameters to pass to the diffing engine.
* Normally an array of two arrays, each
* containing the lines from a file.
*/
function __construct($engine, $params)
{
// Backward compatibility workaround.
if (!is_string($engine)) {
$params = array($engine, $params);
$engine = 'auto';
}
$engine = 'native';
$class = 'Text_Diff_Engine_native';
$diff_engine = new $class();
$this->_edits = call_user_func_array(array($diff_engine, 'diff'), $params);
}
/**
* Returns the array of differences.
*/
function getDiff()
{
return $this->_edits;
}
/**
* returns the number of new (added) lines in a given diff.
*
* @since Text_Diff 1.1.0
* @since Horde 3.2
*
* @return integer The number of new lines
*/
function countAddedLines()
{
$count = 0;
foreach ($this->_edits as $edit) {
if (is_a($edit, 'Text_Diff_Op_add') ||
is_a($edit, 'Text_Diff_Op_change')) {
$count += $edit->nfinal();
}
}
return $count;
}
/**
* Returns the number of deleted (removed) lines in a given diff.
*
* @since Text_Diff 1.1.0
* @since Horde 3.2
*
* @return integer The number of deleted lines
*/
function countDeletedLines()
{
$count = 0;
foreach ($this->_edits as $edit) {
if (is_a($edit, 'Text_Diff_Op_delete') ||
is_a($edit, 'Text_Diff_Op_change')) {
$count += $edit->norig();
}
}
return $count;
}
/**
* Computes a reversed diff.
*
* Example:
*
* $diff = new Text_Diff($lines1, $lines2);
* $rev = $diff->reverse();
*
*
* @return Text_Diff A Diff object representing the inverse of the
* original diff. Note that we purposely don't return a
* reference here, since this essentially is a clone()
* method.
*/
function reverse()
{
if (version_compare(zend_version(), '2', '>')) {
$rev = clone($this);
} else {
$rev = $this;
}
$rev->_edits = array();
foreach ($this->_edits as $edit) {
$rev->_edits[] = $edit->reverse();
}
return $rev;
}
/**
* Checks for an empty diff.
*
* @return boolean True if two sequences were identical.
*/
function isEmpty()
{
foreach ($this->_edits as $edit) {
if (!is_a($edit, 'Text_Diff_Op_copy')) {
return false;
}
}
return true;
}
/**
* Computes the length of the Longest Common Subsequence (LCS).
*
* This is mostly for diagnostic purposes.
*
* @return integer The length of the LCS.
*/
function lcs()
{
$lcs = 0;
foreach ($this->_edits as $edit) {
if (is_a($edit, 'Text_Diff_Op_copy')) {
$lcs += count($edit->orig);
}
}
return $lcs;
}
/**
* Gets the original set of lines.
*
* This reconstructs the $from_lines parameter passed to the constructor.
*
* @return array The original sequence of strings.
*/
function getOriginal()
{
$lines = array();
foreach ($this->_edits as $edit) {
if ($edit->orig) {
array_splice($lines, count($lines), 0, $edit->orig);
}
}
return $lines;
}
/**
* Gets the final set of lines.
*
* This reconstructs the $to_lines parameter passed to the constructor.
*
* @return array The sequence of strings.
*/
function getFinal()
{
$lines = array();
foreach ($this->_edits as $edit) {
if ($edit->final) {
array_splice($lines, count($lines), 0, $edit->final);
}
}
return $lines;
}
/**
* Removes trailing newlines from a line of text. This is meant to be used
* with array_walk().
*
* @param string $line The line to trim.
* @param integer $key The index of the line in the array. Not used.
*/
static function trimNewlines(&$line, $key)
{
$line = str_replace(array("\n", "\r"), '', $line);
}
/**
* Determines the location of the system temporary directory.
*
* @static
*
* @access protected
*
* @return string A directory name which can be used for temp files.
* Returns false if one could not be found.
*/
function _getTempDir()
{
$tmp_locations = array('/tmp', '/var/tmp', 'c:\WUTemp', 'c:\temp',
'c:\windows\temp', 'c:\winnt\temp');
/* Try PHP's upload_tmp_dir directive. */
$tmp = ini_get('upload_tmp_dir');
/* Otherwise, try to determine the TMPDIR environment variable. */
if (!strlen($tmp)) {
$tmp = getenv('TMPDIR');
}
/* If we still cannot determine a value, then cycle through a list of
* preset possibilities. */
while (!strlen($tmp) && count($tmp_locations)) {
$tmp_check = array_shift($tmp_locations);
if (@is_dir($tmp_check)) {
$tmp = $tmp_check;
}
}
/* If it is still empty, we have failed, so return false; otherwise
* return the directory determined. */
return strlen($tmp) ? $tmp : false;
}
/**
* Checks a diff for validity.
*
* This is here only for debugging purposes.
*/
function _check($from_lines, $to_lines)
{
if (serialize($from_lines) != serialize($this->getOriginal())) {
trigger_error("Reconstructed original doesn't match", E_USER_ERROR);
}
if (serialize($to_lines) != serialize($this->getFinal())) {
trigger_error("Reconstructed final doesn't match", E_USER_ERROR);
}
$rev = $this->reverse();
if (serialize($to_lines) != serialize($rev->getOriginal())) {
trigger_error("Reversed original doesn't match", E_USER_ERROR);
}
if (serialize($from_lines) != serialize($rev->getFinal())) {
trigger_error("Reversed final doesn't match", E_USER_ERROR);
}
$prevtype = null;
foreach ($this->_edits as $edit) {
if ($prevtype == get_class($edit)) {
trigger_error("Edit sequence is non-optimal", E_USER_ERROR);
}
$prevtype = get_class($edit);
}
return true;
}
}
/**
* @package Text_Diff
* @author Geoffrey T. Dairiki
*/
class Text_MappedDiff extends Text_Diff {
/**
* Computes a diff between sequences of strings.
*
* This can be used to compute things like case-insensitve diffs, or diffs
* which ignore changes in white-space.
*
* @param array $from_lines An array of strings.
* @param array $to_lines An array of strings.
* @param array $mapped_from_lines This array should have the same size
* number of elements as $from_lines. The
* elements in $mapped_from_lines and
* $mapped_to_lines are what is actually
* compared when computing the diff.
* @param array $mapped_to_lines This array should have the same number
* of elements as $to_lines.
*/
function __construct($from_lines, $to_lines,
$mapped_from_lines, $mapped_to_lines)
{
assert(count($from_lines) == count($mapped_from_lines));
assert(count($to_lines) == count($mapped_to_lines));
parent::__construct($mapped_from_lines, $mapped_to_lines);
$xi = $yi = 0;
for ($i = 0; $i < count($this->_edits); $i++) {
$orig = &$this->_edits[$i]->orig;
if (is_array($orig)) {
$orig = array_slice($from_lines, $xi, count($orig));
$xi += count($orig);
}
$final = &$this->_edits[$i]->final;
if (is_array($final)) {
$final = array_slice($to_lines, $yi, count($final));
$yi += count($final);
}
}
}
}
/**
* @package Text_Diff
* @author Geoffrey T. Dairiki
*
* @access private
*/
class Text_Diff_Op {
var $orig;
var $final;
function &reverse()
{
trigger_error('Abstract method', E_USER_ERROR);
}
function norig()
{
return $this->orig ? count($this->orig) : 0;
}
function nfinal()
{
return $this->final ? count($this->final) : 0;
}
}
/**
* @package Text_Diff
* @author Geoffrey T. Dairiki
*
* @access private
*/
class Text_Diff_Op_copy extends Text_Diff_Op {
function __construct($orig, $final = false)
{
if (!is_array($final)) {
$final = $orig;
}
$this->orig = $orig;
$this->final = $final;
}
function &reverse()
{
$reverse = new Text_Diff_Op_copy($this->final, $this->orig);
return $reverse;
}
}
/**
* @package Text_Diff
* @author Geoffrey T. Dairiki
*
* @access private
*/
class Text_Diff_Op_delete extends Text_Diff_Op {
function __construct($lines)
{
$this->orig = $lines;
$this->final = false;
}
function &reverse()
{
$reverse = new Text_Diff_Op_add($this->orig);
return $reverse;
}
}
/**
* @package Text_Diff
* @author Geoffrey T. Dairiki
*
* @access private
*/
class Text_Diff_Op_add extends Text_Diff_Op {
function __construct($lines)
{
$this->final = $lines;
$this->orig = false;
}
function &reverse()
{
$reverse = new Text_Diff_Op_delete($this->final);
return $reverse;
}
}
/**
* @package Text_Diff
* @author Geoffrey T. Dairiki
*
* @access private
*/
class Text_Diff_Op_change extends Text_Diff_Op {
function __construct($orig, $final)
{
$this->orig = $orig;
$this->final = $final;
}
function &reverse()
{
$reverse = new Text_Diff_Op_change($this->final, $this->orig);
return $reverse;
}
}
/**
* A class for computing three way diffs.
*
* $Horde: framework/Text_Diff/Diff3.php,v 1.2.10.7 2009/01/06 15:23:41 jan Exp $
*
* Copyright 2007-2009 The Horde Project (http://www.horde.org/)
*
* See the enclosed file COPYING for license information (LGPL). If you did
* not receive this file, see http://opensource.org/licenses/lgpl-license.php.
*
* @package Text_Diff
* @since 0.3.0
*/
/**
* A class for computing three way diffs.
*
* @package Text_Diff
* @author Geoffrey T. Dairiki
*/
class Text_Diff3 extends Text_Diff {
/**
* Conflict counter.
*
* @var integer
*/
var $_conflictingBlocks = 0;
/**
* Computes diff between 3 sequences of strings.
*
* @param array $orig The original lines to use.
* @param array $final1 The first version to compare to.
* @param array $final2 The second version to compare to.
*/
function __construct($orig, $final1, $final2)
{
$engine = new Text_Diff_Engine_native();
$this->_edits = $this->_diff3($engine->diff($orig, $final1),
$engine->diff($orig, $final2));
}
/**
*/
function mergedOutput($label1 = false, $label2 = false)
{
$lines = array();
foreach ($this->_edits as $edit) {
if ($edit->isConflict()) {
/* FIXME: this should probably be moved somewhere else. */
$lines = array_merge($lines,
array('<<<<<<<' . ($label1 ? ' ' . $label1 : '')),
$edit->final1,
array("======="),
$edit->final2,
array('>>>>>>>' . ($label2 ? ' ' . $label2 : '')));
$this->_conflictingBlocks++;
} else {
$lines = array_merge($lines, $edit->merged());
}
}
return $lines;
}
/**
* @access private
*/
function _diff3($edits1, $edits2)
{
$edits = array();
$bb = new Text_Diff3_BlockBuilder();
$e1 = current($edits1);
$e2 = current($edits2);
while ($e1 || $e2) {
if ($e1 && $e2 && is_a($e1, 'Text_Diff_Op_copy') && is_a($e2, 'Text_Diff_Op_copy')) {
/* We have copy blocks from both diffs. This is the (only)
* time we want to emit a diff3 copy block. Flush current
* diff3 diff block, if any. */
if ($edit = $bb->finish()) {
$edits[] = $edit;
}
$ncopy = min($e1->norig(), $e2->norig());
assert($ncopy > 0);
$edits[] = new Text_Diff3_Op_copy(array_slice($e1->orig, 0, $ncopy));
if ($e1->norig() > $ncopy) {
array_splice($e1->orig, 0, $ncopy);
array_splice($e1->final, 0, $ncopy);
} else {
$e1 = next($edits1);
}
if ($e2->norig() > $ncopy) {
array_splice($e2->orig, 0, $ncopy);
array_splice($e2->final, 0, $ncopy);
} else {
$e2 = next($edits2);
}
} else {
if ($e1 && $e2) {
if ($e1->orig && $e2->orig) {
$norig = min($e1->norig(), $e2->norig());
$orig = array_splice($e1->orig, 0, $norig);
array_splice($e2->orig, 0, $norig);
$bb->input($orig);
}
if (is_a($e1, 'Text_Diff_Op_copy')) {
$bb->out1(array_splice($e1->final, 0, $norig));
}
if (is_a($e2, 'Text_Diff_Op_copy')) {
$bb->out2(array_splice($e2->final, 0, $norig));
}
}
if ($e1 && ! $e1->orig) {
$bb->out1($e1->final);
$e1 = next($edits1);
}
if ($e2 && ! $e2->orig) {
$bb->out2($e2->final);
$e2 = next($edits2);
}
}
}
if ($edit = $bb->finish()) {
$edits[] = $edit;
}
return $edits;
}
}
/**
* @package Text_Diff
* @author Geoffrey T. Dairiki
*
* @access private
*/
class Text_Diff3_Op {
function __construct($orig = false, $final1 = false, $final2 = false)
{
$this->orig = $orig ? $orig : array();
$this->final1 = $final1 ? $final1 : array();
$this->final2 = $final2 ? $final2 : array();
}
function merged()
{
if (!isset($this->_merged)) {
if ($this->final1 === $this->final2) {
$this->_merged = &$this->final1;
} elseif ($this->final1 === $this->orig) {
$this->_merged = &$this->final2;
} elseif ($this->final2 === $this->orig) {
$this->_merged = &$this->final1;
} else {
$this->_merged = false;
}
}
return $this->_merged;
}
function isConflict()
{
return $this->merged() === false;
}
}
/**
* @package Text_Diff
* @author Geoffrey T. Dairiki
*
* @access private
*/
class Text_Diff3_Op_copy extends Text_Diff3_Op {
function __construct($lines = false)
{
$this->orig = $lines ? $lines : array();
$this->final1 = &$this->orig;
$this->final2 = &$this->orig;
}
function merged()
{
return $this->orig;
}
function isConflict()
{
return false;
}
}
/**
* @package Text_Diff
* @author Geoffrey T. Dairiki
*
* @access private
*/
class Text_Diff3_BlockBuilder {
function __construct()
{
$this->_init();
}
function input($lines)
{
if ($lines) {
$this->_append($this->orig, $lines);
}
}
function out1($lines)
{
if ($lines) {
$this->_append($this->final1, $lines);
}
}
function out2($lines)
{
if ($lines) {
$this->_append($this->final2, $lines);
}
}
function isEmpty()
{
return !$this->orig && !$this->final1 && !$this->final2;
}
function finish()
{
if ($this->isEmpty()) {
return false;
} else {
$edit = new Text_Diff3_Op($this->orig, $this->final1, $this->final2);
$this->_init();
return $edit;
}
}
function _init()
{
$this->orig = $this->final1 = $this->final2 = array();
}
function _append(&$array, $lines)
{
array_splice($array, sizeof($array), 0, $lines);
}
}
/**
* Class used internally by Text_Diff to actually compute the diffs.
*
* This class is implemented using native PHP code.
*
* The algorithm used here is mostly lifted from the perl module
* Algorithm::Diff (version 1.06) by Ned Konz, which is available at:
* http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip
*
* More ideas are taken from: http://www.ics.uci.edu/~eppstein/161/960229.html
*
* Some ideas (and a bit of code) are taken from analyze.c, of GNU
* diffutils-2.7, which can be found at:
* ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz
*
* Some ideas (subdivision by NCHUNKS > 2, and some optimizations) are from
* Geoffrey T. Dairiki . The original PHP version of this
* code was written by him, and is used/adapted with his permission.
*
* $Horde: framework/Text_Diff/Diff/Engine/native.php,v 1.7.2.5 2009/01/06 15:23:41 jan Exp $
*
* Copyright 2004-2009 The Horde Project (http://www.horde.org/)
*
* See the enclosed file COPYING for license information (LGPL). If you did
* not receive this file, see http://opensource.org/licenses/lgpl-license.php.
*
* @author Geoffrey T. Dairiki
* @package Text_Diff
*/
class Text_Diff_Engine_native {
function diff($from_lines, $to_lines)
{
array_walk($from_lines, array('Text_Diff', 'trimNewlines'));
array_walk($to_lines, array('Text_Diff', 'trimNewlines'));
$n_from = count($from_lines);
$n_to = count($to_lines);
$this->xchanged = $this->ychanged = array();
$this->xv = $this->yv = array();
$this->xind = $this->yind = array();
unset($this->seq);
unset($this->in_seq);
unset($this->lcs);
// Skip leading common lines.
for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) {
if ($from_lines[$skip] !== $to_lines[$skip]) {
break;
}
$this->xchanged[$skip] = $this->ychanged[$skip] = false;
}
// Skip trailing common lines.
$xi = $n_from; $yi = $n_to;
for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) {
if ($from_lines[$xi] !== $to_lines[$yi]) {
break;
}
$this->xchanged[$xi] = $this->ychanged[$yi] = false;
}
// Ignore lines which do not exist in both files.
for ($xi = $skip; $xi < $n_from - $endskip; $xi++) {
$xhash[$from_lines[$xi]] = 1;
}
for ($yi = $skip; $yi < $n_to - $endskip; $yi++) {
$line = $to_lines[$yi];
if (($this->ychanged[$yi] = empty($xhash[$line]))) {
continue;
}
$yhash[$line] = 1;
$this->yv[] = $line;
$this->yind[] = $yi;
}
for ($xi = $skip; $xi < $n_from - $endskip; $xi++) {
$line = $from_lines[$xi];
if (($this->xchanged[$xi] = empty($yhash[$line]))) {
continue;
}
$this->xv[] = $line;
$this->xind[] = $xi;
}
// Find the LCS.
$this->_compareseq(0, count($this->xv), 0, count($this->yv));
// Merge edits when possible.
$this->_shiftBoundaries($from_lines, $this->xchanged, $this->ychanged);
$this->_shiftBoundaries($to_lines, $this->ychanged, $this->xchanged);
// Compute the edit operations.
$edits = array();
$xi = $yi = 0;
while ($xi < $n_from || $yi < $n_to) {
assert($yi < $n_to || $this->xchanged[$xi]);
assert($xi < $n_from || $this->ychanged[$yi]);
// Skip matching "snake".
$copy = array();
while ($xi < $n_from && $yi < $n_to
&& !$this->xchanged[$xi] && !$this->ychanged[$yi]) {
$copy[] = $from_lines[$xi++];
++$yi;
}
if ($copy) {
$edits[] = new Text_Diff_Op_copy($copy);
}
// Find deletes & adds.
$delete = array();
while ($xi < $n_from && $this->xchanged[$xi]) {
$delete[] = $from_lines[$xi++];
}
$add = array();
while ($yi < $n_to && $this->ychanged[$yi]) {
$add[] = $to_lines[$yi++];
}
if ($delete && $add) {
$edits[] = new Text_Diff_Op_change($delete, $add);
} elseif ($delete) {
$edits[] = new Text_Diff_Op_delete($delete);
} elseif ($add) {
$edits[] = new Text_Diff_Op_add($add);
}
}
return $edits;
}
/**
* Divides the Largest Common Subsequence (LCS) of the sequences (XOFF,
* XLIM) and (YOFF, YLIM) into NCHUNKS approximately equally sized
* segments.
*
* Returns (LCS, PTS). LCS is the length of the LCS. PTS is an array of
* NCHUNKS+1 (X, Y) indexes giving the diving points between sub
* sequences. The first sub-sequence is contained in (X0, X1), (Y0, Y1),
* the second in (X1, X2), (Y1, Y2) and so on. Note that (X0, Y0) ==
* (XOFF, YOFF) and (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM).
*
* This function assumes that the first lines of the specified portions of
* the two files do not match, and likewise that the last lines do not
* match. The caller must trim matching lines from the beginning and end
* of the portions it is going to specify.
*/
function _diag ($xoff, $xlim, $yoff, $ylim, $nchunks)
{
$flip = false;
if ($xlim - $xoff > $ylim - $yoff) {
/* Things seems faster (I'm not sure I understand why) when the
* shortest sequence is in X. */
$flip = true;
list ($xoff, $xlim, $yoff, $ylim)
= array($yoff, $ylim, $xoff, $xlim);
}
if ($flip) {
for ($i = $ylim - 1; $i >= $yoff; $i--) {
$ymatches[$this->xv[$i]][] = $i;
}
} else {
for ($i = $ylim - 1; $i >= $yoff; $i--) {
$ymatches[$this->yv[$i]][] = $i;
}
}
$this->lcs = 0;
$this->seq[0]= $yoff - 1;
$this->in_seq = array();
$ymids[0] = array();
$numer = $xlim - $xoff + $nchunks - 1;
$x = $xoff;
for ($chunk = 0; $chunk < $nchunks; $chunk++) {
if ($chunk > 0) {
for ($i = 0; $i <= $this->lcs; $i++) {
$ymids[$i][$chunk - 1] = $this->seq[$i];
}
}
$x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $chunk) / $nchunks);
for (; $x < $x1; $x++) {
$line = $flip ? $this->yv[$x] : $this->xv[$x];
if (empty($ymatches[$line])) {
continue;
}
$matches = $ymatches[$line];
reset($matches);
while (list(, $y) = each($matches)) {
if (empty($this->in_seq[$y])) {
$k = $this->_lcsPos($y);
assert($k > 0);
$ymids[$k] = $ymids[$k - 1];
break;
}
}
while (list(, $y) = each($matches)) {
if ($y > $this->seq[$k - 1]) {
assert($y <= $this->seq[$k]);
/* Optimization: this is a common case: next match is
* just replacing previous match. */
$this->in_seq[$this->seq[$k]] = false;
$this->seq[$k] = $y;
$this->in_seq[$y] = 1;
} elseif (empty($this->in_seq[$y])) {
$k = $this->_lcsPos($y);
assert($k > 0);
$ymids[$k] = $ymids[$k - 1];
}
}
}
}
$seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff);
$ymid = $ymids[$this->lcs];
for ($n = 0; $n < $nchunks - 1; $n++) {
$x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks);
$y1 = $ymid[$n] + 1;
$seps[] = $flip ? array($y1, $x1) : array($x1, $y1);
}
$seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim);
return array($this->lcs, $seps);
}
function _lcsPos($ypos)
{
$end = $this->lcs;
if ($end == 0 || $ypos > $this->seq[$end]) {
$this->seq[++$this->lcs] = $ypos;
$this->in_seq[$ypos] = 1;
return $this->lcs;
}
$beg = 1;
while ($beg < $end) {
$mid = (int)(($beg + $end) / 2);
if ($ypos > $this->seq[$mid]) {
$beg = $mid + 1;
} else {
$end = $mid;
}
}
assert($ypos != $this->seq[$end]);
$this->in_seq[$this->seq[$end]] = false;
$this->seq[$end] = $ypos;
$this->in_seq[$ypos] = 1;
return $end;
}
/**
* Finds LCS of two sequences.
*
* The results are recorded in the vectors $this->{x,y}changed[], by
* storing a 1 in the element for each line that is an insertion or
* deletion (ie. is not in the LCS).
*
* The subsequence of file 0 is (XOFF, XLIM) and likewise for file 1.
*
* Note that XLIM, YLIM are exclusive bounds. All line numbers are
* origin-0 and discarded lines are not counted.
*/
function _compareseq ($xoff, $xlim, $yoff, $ylim)
{
/* Slide down the bottom initial diagonal. */
while ($xoff < $xlim && $yoff < $ylim
&& $this->xv[$xoff] == $this->yv[$yoff]) {
++$xoff;
++$yoff;
}
/* Slide up the top initial diagonal. */
while ($xlim > $xoff && $ylim > $yoff
&& $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) {
--$xlim;
--$ylim;
}
if ($xoff == $xlim || $yoff == $ylim) {
$lcs = 0;
} else {
/* This is ad hoc but seems to work well. $nchunks =
* sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); $nchunks =
* max(2,min(8,(int)$nchunks)); */
$nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1;
list($lcs, $seps)
= $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks);
}
if ($lcs == 0) {
/* X and Y sequences have no common subsequence: mark all
* changed. */
while ($yoff < $ylim) {
$this->ychanged[$this->yind[$yoff++]] = 1;
}
while ($xoff < $xlim) {
$this->xchanged[$this->xind[$xoff++]] = 1;
}
} else {
/* Use the partitions to split this problem into subproblems. */
reset($seps);
$pt1 = $seps[0];
while ($pt2 = next($seps)) {
$this->_compareseq ($pt1[0], $pt2[0], $pt1[1], $pt2[1]);
$pt1 = $pt2;
}
}
}
/**
* Adjusts inserts/deletes of identical lines to join changes as much as
* possible.
*
* We do something when a run of changed lines include a line at one end
* and has an excluded, identical line at the other. We are free to
* choose which identical line is included. `compareseq' usually chooses
* the one at the beginning, but usually it is cleaner to consider the
* following identical line to be the "change".
*
* This is extracted verbatim from analyze.c (GNU diffutils-2.7).
*/
function _shiftBoundaries($lines, &$changed, $other_changed)
{
$i = 0;
$j = 0;
assert('count($lines) == count($changed)');
$len = count($lines);
$other_len = count($other_changed);
while (1) {
/* Scan forward to find the beginning of another run of
* changes. Also keep track of the corresponding point in the
* other file.
*
* Throughout this code, $i and $j are adjusted together so that
* the first $i elements of $changed and the first $j elements of
* $other_changed both contain the same number of zeros (unchanged
* lines).
*
* Furthermore, $j is always kept so that $j == $other_len or
* $other_changed[$j] == false. */
while ($j < $other_len && $other_changed[$j]) {
$j++;
}
while ($i < $len && ! $changed[$i]) {
assert('$j < $other_len && ! $other_changed[$j]');
$i++; $j++;
while ($j < $other_len && $other_changed[$j]) {
$j++;
}
}
if ($i == $len) {
break;
}
$start = $i;
/* Find the end of this run of changes. */
while (++$i < $len && $changed[$i]) {
continue;
}
do {
/* Record the length of this run of changes, so that we can
* later determine whether the run has grown. */
$runlength = $i - $start;
/* Move the changed region back, so long as the previous
* unchanged line matches the last changed one. This merges
* with previous changed regions. */
while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) {
$changed[--$start] = 1;
$changed[--$i] = false;
while ($start > 0 && $changed[$start - 1]) {
$start--;
}
assert('$j > 0');
while ($other_changed[--$j]) {
continue;
}
assert('$j >= 0 && !$other_changed[$j]');
}
/* Set CORRESPONDING to the end of the changed run, at the
* last point where it corresponds to a changed run in the
* other file. CORRESPONDING == LEN means no such point has
* been found. */
$corresponding = $j < $other_len ? $i : $len;
/* Move the changed region forward, so long as the first
* changed line matches the following unchanged one. This
* merges with following changed regions. Do this second, so
* that if there are no merges, the changed region is moved
* forward as far as possible. */
while ($i < $len && $lines[$start] == $lines[$i]) {
$changed[$start++] = false;
$changed[$i++] = 1;
while ($i < $len && $changed[$i]) {
$i++;
}
assert('$j < $other_len && ! $other_changed[$j]');
$j++;
if ($j < $other_len && $other_changed[$j]) {
$corresponding = $i;
while ($j < $other_len && $other_changed[$j]) {
$j++;
}
}
}
} while ($runlength != $i - $start);
/* If possible, move the fully-merged run of changes back to a
* corresponding run in the other file. */
while ($corresponding < $i) {
$changed[--$start] = 1;
$changed[--$i] = 0;
assert('$j > 0');
while ($other_changed[--$j]) {
continue;
}
assert('$j >= 0 && !$other_changed[$j]');
}
}
}
}