<?php
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);
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;
}
$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;
}
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;
}
$this->_compareseq(0, count($this->xv), 0, count($this->yv));
$this->_shiftBoundaries($from_lines, $this->xchanged, $this->ychanged);
$this->_shiftBoundaries($to_lines, $this->ychanged, $this->xchanged);
$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]);
$copy = array();
while ($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);
}
$delete = array();
while ($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 $edits;
}
function _diag($xoff, $xlim, $yoff, $ylim, $nchunks)
{
$flip = false;
if ($xlim - $xoff > $ylim - $yoff) {
$flip = true;
list($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]);
$this->in_seq[$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 $end;
}
function _compareseq($xoff, $xlim, $yoff, $ylim)
{
while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) {
++$xoff;
++$yoff;
}
while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) {
--$xlim;
--$ylim;
}
if ($xoff == $xlim || $yoff == $ylim) {
$lcs = 0;
} else {
$nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1;
list($lcs, $seps) = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks);
}
if ($lcs == 0) {
while ($yoff < $ylim) {
$this->ychanged[$this->yind[$yoff++]] = 1;
}
while ($xoff < $xlim) {
$this->xchanged[$this->xind[$xoff++]] = 1;
}
} else {
reset($seps);
$pt1 = $seps[0];
while ($pt2 = next($seps)) {
$this->_compareseq($pt1[0], $pt2[0], $pt1[1], $pt2[1]);
$pt1 = $pt2;
}
}
}
function _shiftBoundaries($lines, &$changed, $other_changed)
{
$i = 0;
$j = 0;
assert('count($lines) == count($changed)');
$len = count($lines);
$other_len = count($other_changed);
while (1) {
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 = $i;
while (++$i < $len && $changed[$i]) {
continue;
}
do {
$runlength = $i - $start;
while ($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]');
}
$corresponding = $j < $other_len ? $i : $len;
while ($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 - $start);
while ($corresponding < $i) {
$changed[--$start] = 1;
$changed[--$i] = 0;
assert('$j > 0');
while ($other_changed[--$j]) {
continue;
}
assert('$j >= 0 && !$other_changed[$j]');
}
}
}
}
class Text_Diff
{
var $_edits;
function Text_Diff($engine, $params)
{
if (!is_string($engine)) {
$params = array(
$engine,
$params
);
$engine = 'auto';
}
if ($engine == 'auto') {
$engine = extension_loaded('xdiff') ? 'xdiff' : 'native';
} else {
$engine = basename($engine);
}
$class = 'Text_Diff_Engine_' . $engine;
$diff_engine = new $class();
$this->_edits = call_user_func_array(array(
$diff_engine,
'diff'
), $params);
}
function getDiff()
{
return $this->_edits;
}
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;
}
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;
}
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 $rev;
}
function isEmpty()
{
foreach ($this->_edits as $edit) {
if (!is_a($edit, 'Text_Diff_Op_copy')) {
return false;
}
}
return true;
}
function lcs()
{
$lcs = 0;
foreach ($this->_edits as $edit) {
if (is_a($edit, 'Text_Diff_Op_copy')) {
$lcs += count($edit->orig);
}
}
return $lcs;
}
function getOriginal()
{
$lines = array();
foreach ($this->_edits as $edit) {
if ($edit->orig) {
array_splice($lines, count($lines), 0, $edit->orig);
}
}
return $lines;
}
function getFinal()
{
$lines = array();
foreach ($this->_edits as $edit) {
if ($edit->final) {
array_splice($lines, count($lines), 0, $edit->final);
}
}
return $lines;
}
static function trimNewlines(&$line, $key)
{
$line = str_replace(array(
"\n",
"\r"
), '', $line);
}
function _getTempDir()
{
$tmp_locations = array(
'/tmp',
'/var/tmp',
'c:\WUTemp',
'c:\temp',
'c:\windows\temp',
'c:\winnt\temp'
);
$tmp = ini_get('upload_tmp_dir');
if (!strlen($tmp)) {
$tmp = getenv('TMPDIR');
}
while (!strlen($tmp) && count($tmp_locations)) {
$tmp_check = array_shift($tmp_locations);
if (@is_dir($tmp_check)) {
$tmp = $tmp_check;
}
}
return strlen($tmp) ? $tmp : false;
}
function _check($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;
}
}
class Text_MappedDiff extends Text_Diff
{
function Text_MappedDiff($from_lines, $to_lines, $mapped_from_lines, $mapped_to_lines)
{
assert(count($from_lines) == count($mapped_from_lines));
assert(count($to_lines) == count($mapped_to_lines));
parent::Text_Diff($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);
}
}
}
}
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;
}
}
class Text_Diff_Op_copy extends Text_Diff_Op
{
function Text_Diff_Op_copy($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 $reverse;
}
}
class Text_Diff_Op_delete extends Text_Diff_Op
{
function Text_Diff_Op_delete($lines)
{
$this->orig = $lines;
$this->final = false;
}
function &reverse()
{
$reverse =& new Text_Diff_Op_add($this->orig);
return $reverse;
}
}
class Text_Diff_Op_add extends Text_Diff_Op
{
function Text_Diff_Op_add($lines)
{
$this->final = $lines;
$this->orig = false;
}
function &reverse()
{
$reverse =& new Text_Diff_Op_delete($this->final);
return $reverse;
}
}
class Text_Diff_Op_change extends Text_Diff_Op
{
function Text_Diff_Op_change($orig, $final)
{
$this->orig = $orig;
$this->final = $final;
}
function &reverse()
{
$reverse =& new Text_Diff_Op_change($this->final, $this->orig);
return $reverse;
}
}