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Increase performance up to 15000% #98

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Merged
merged 4 commits into from
Feb 11, 2016
Merged

Increase performance up to 15000% #98

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364a897
Work with array instead of string
ossinkine Feb 11, 2016
dfd8374
Remove unnecessary peek cache
ossinkine Feb 11, 2016
9db72a0
Minor optimization
ossinkine Feb 11, 2016
c5a44a9
Fix substr with negative length
ossinkine Feb 11, 2016
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54 changes: 27 additions & 27 deletions lib/Sabberworm/CSS/Parser.php
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Original file line number Diff line number Diff line change
Expand Up @@ -26,22 +26,25 @@
*/
class Parser {

private $sText;
private $aText;
private $iCurrentPosition;
private $oParserSettings;
private $sCharset;
private $iLength;
private $peekCache = null;
private $blockRules;
private $aSizeUnits;

public function __construct($sText, Settings $oParserSettings = null) {
$this->sText = $sText;
$this->iCurrentPosition = 0;
if ($oParserSettings === null) {
$oParserSettings = Settings::create();
}
$this->oParserSettings = $oParserSettings;
if ($this->oParserSettings->bMultibyteSupport) {
$this->aText = preg_split('//u', $sText, null, PREG_SPLIT_NO_EMPTY);
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I’m not sure preg_split is multibyte-safe. Sure it supports utf-8 (if compiled in) but I don’t think it copes well with other encodings like utf-16, shift-jis. Also there is no way to pass the encoding used. I’ve never added unit tests for other encodings, though, because the identifier parsing code wasn’t actually able to match any encoding where the identifiers weren’t ASCII. Maybe I’ll just make that my next big rework project…

} else {
$this->aText = str_split($sText);
}
$this->blockRules = explode('/', AtRule::BLOCK_RULES);

foreach (explode('/', Size::ABSOLUTE_SIZE_UNITS.'/'.Size::RELATIVE_SIZE_UNITS.'/'.Size::NON_SIZE_UNITS) as $val) {
Expand All @@ -56,7 +59,7 @@ public function __construct($sText, Settings $oParserSettings = null) {

public function setCharset($sCharset) {
$this->sCharset = $sCharset;
$this->iLength = $this->strlen($this->sText);
$this->iLength = count($this->aText);
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I see a problem here: splitting should only happen after the charset is known (because it depends on the charset used).

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Also, the @charset declaration will call this method during parsing. But it should trigger a re-parse if the count is different in the new charset. Which it has never done. So, again, this is due for a rework that hasn’t necessarily got anything to do with your changeset.

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If it so, why is bMultibyteSupport flag needed? Can I pass bMultibyteSupport = false and @charset "UTF-8"?

}

public function getCharset() {
Expand Down Expand Up @@ -284,9 +287,8 @@ private function parseRuleSet($oRuleSet) {
try {
$sConsume = $this->consumeUntil(array("\n", ";", '}'), true);
// We need to “unfind” the matches to the end of the ruleSet as this will be matched later
if($this->streql($this->substr($sConsume, $this->strlen($sConsume)-1, 1), '}')) {
if($this->streql(substr($sConsume, -1), '}')) {
--$this->iCurrentPosition;
$this->peekCache = null;
} else {
$this->consumeWhiteSpace();
while ($this->comes(';')) {
Expand Down Expand Up @@ -469,8 +471,8 @@ private function parseURLValue() {
}

/**
* Tests an identifier for a given value. Since identifiers are all keywords, they can be vendor-prefixed. We need to check for these versions too.
*/
* Tests an identifier for a given value. Since identifiers are all keywords, they can be vendor-prefixed. We need to check for these versions too.
*/
private function identifierIs($sIdentifier, $sMatch) {
return (strcasecmp($sIdentifier, $sMatch) === 0)
?: preg_match("/^(-\\w+-)?$sMatch$/i", $sIdentifier) === 1;
Expand All @@ -484,38 +486,28 @@ private function comes($sString, $bCaseInsensitive = false) {
}

private function peek($iLength = 1, $iOffset = 0) {
if (($peek = (!$iOffset && ($iLength === 1))) &&
!is_null($this->peekCache)) {
return $this->peekCache;
}
$iOffset += $this->iCurrentPosition;
if ($iOffset >= $this->iLength) {
return '';
}
$iLength = min($iLength, $this->iLength-$iOffset);
$out = $this->substr($this->sText, $iOffset, $iLength);
if ($peek) {
$this->peekCache = $out;
}
$out = $this->substr($iOffset, $iLength);
return $out;
}

private function consume($mValue = 1) {
if (is_string($mValue)) {
$iLength = $this->strlen($mValue);
if (!$this->streql($this->substr($this->sText, $this->iCurrentPosition, $iLength), $mValue)) {
if (!$this->streql($this->substr($this->iCurrentPosition, $iLength), $mValue)) {
throw new UnexpectedTokenException($mValue, $this->peek(max($iLength, 5)));
}
$this->iCurrentPosition += $this->strlen($mValue);
$this->peekCache = null;
return $mValue;
} else {
if ($this->iCurrentPosition + $mValue > $this->iLength) {
throw new UnexpectedTokenException($mValue, $this->peek(5), 'count');
}
$sResult = $this->substr($this->sText, $this->iCurrentPosition, $mValue);
$sResult = $this->substr($this->iCurrentPosition, $mValue);
$this->iCurrentPosition += $mValue;
$this->peekCache = null;
return $sResult;
}
}
Expand Down Expand Up @@ -587,15 +579,23 @@ private function consumeUntil($aEnd, $bIncludeEnd = false, $consumeEnd = false)
}

private function inputLeft() {
return $this->substr($this->sText, $this->iCurrentPosition, -1);
return $this->substr($this->iCurrentPosition, -1);
}

private function substr($sString, $iStart, $iLength) {
if ($this->oParserSettings->bMultibyteSupport) {
return mb_substr($sString, $iStart, $iLength, $this->sCharset);
} else {
return substr($sString, $iStart, $iLength);
private function substr($iStart, $iLength) {
if ($iLength < 0) {
$iLength = $this->iLength - $iStart + $iLength;
}
if ($iStart + $iLength > $this->iLength) {
$iLength = $this->iLength - $iStart;
}
$out = '';
while ($iLength > 0) {
$out .= $this->aText[$iStart];
$iStart++;
$iLength--;
}
return $out;
}

private function strlen($sString) {
Expand Down