diff options
Diffstat (limited to 'includes/libs/CSSMin.php')
| -rw-r--r-- | includes/libs/CSSMin.php | 151 |
1 files changed, 111 insertions, 40 deletions
diff --git a/includes/libs/CSSMin.php b/includes/libs/CSSMin.php index c69e79f5..ffe26a96 100644 --- a/includes/libs/CSSMin.php +++ b/includes/libs/CSSMin.php @@ -32,12 +32,9 @@ class CSSMin { /* Constants */ /** - * Maximum file size to still qualify for in-line embedding as a data-URI - * - * 24,576 is used because Internet Explorer has a 32,768 byte limit for data URIs, - * which when base64 encoded will result in a 1/3 increase in size. + * Internet Explorer data URI length limit. See encodeImageAsDataURI(). */ - const EMBED_SIZE_LIMIT = 24576; + const DATA_URI_SIZE_LIMIT = 32768; const URL_REGEX = 'url\(\s*[\'"]?(?P<file>[^\?\)\'"]*?)(?P<query>\?[^\)\'"]*?|)[\'"]?\s*\)'; const EMBED_REGEX = '\/\*\s*\@embed\s*\*\/'; const COMMENT_REGEX = '\/\*.*?\*\/'; @@ -100,33 +97,68 @@ class CSSMin { } /** - * Encode an image file as a base64 data URI. - * If the image file has a suitable MIME type and size, encode it as a - * base64 data URI. Return false if the image type is unfamiliar or exceeds - * the size limit. + * Encode an image file as a data URI. + * + * If the image file has a suitable MIME type and size, encode it as a data URI, base64-encoded + * for binary files or just percent-encoded otherwise. Return false if the image type is + * unfamiliar or file exceeds the size limit. * * @param string $file Image file to encode. * @param string|null $type File's MIME type or null. If null, CSSMin will * try to autodetect the type. - * @param int|bool $sizeLimit If the size of the target file is greater than - * this value, decline to encode the image file and return false - * instead. If $sizeLimit is false, no limit is enforced. - * @return string|bool: Image contents encoded as a data URI or false. + * @param bool $ie8Compat By default, a data URI will only be produced if it can be made short + * enough to fit in Internet Explorer 8 (and earlier) URI length limit (32,768 bytes). Pass + * `false` to remove this limitation. + * @return string|bool Image contents encoded as a data URI or false. */ - public static function encodeImageAsDataURI( $file, $type = null, - $sizeLimit = self::EMBED_SIZE_LIMIT - ) { - if ( $sizeLimit !== false && filesize( $file ) >= $sizeLimit ) { + public static function encodeImageAsDataURI( $file, $type = null, $ie8Compat = true ) { + // Fast-fail for files that definitely exceed the maximum data URI length + if ( $ie8Compat && filesize( $file ) >= self::DATA_URI_SIZE_LIMIT ) { return false; } + if ( $type === null ) { $type = self::getMimeType( $file ); } if ( !$type ) { return false; } - $data = base64_encode( file_get_contents( $file ) ); - return 'data:' . $type . ';base64,' . $data; + + return self::encodeStringAsDataURI( file_get_contents( $file ), $type, $ie8Compat ); + } + + /** + * Encode file contents as a data URI with chosen MIME type. + * + * The URI will be base64-encoded for binary files or just percent-encoded otherwise. + * + * @since 1.25 + * + * @param string $contents File contents to encode. + * @param string $type File's MIME type. + * @param bool $ie8Compat See encodeImageAsDataURI(). + * @return string|bool Image contents encoded as a data URI or false. + */ + public static function encodeStringAsDataURI( $contents, $type, $ie8Compat = true ) { + // Try #1: Non-encoded data URI + // The regular expression matches ASCII whitespace and printable characters. + if ( preg_match( '/^[\r\n\t\x20-\x7e]+$/', $contents ) ) { + // Do not base64-encode non-binary files (sane SVGs). + // (This often produces longer URLs, but they compress better, yielding a net smaller size.) + $uri = 'data:' . $type . ',' . rawurlencode( $contents ); + if ( !$ie8Compat || strlen( $uri ) < self::DATA_URI_SIZE_LIMIT ) { + return $uri; + } + } + + // Try #2: Encoded data URI + $uri = 'data:' . $type . ';base64,' . base64_encode( $contents ); + if ( !$ie8Compat || strlen( $uri ) < self::DATA_URI_SIZE_LIMIT ) { + return $uri; + } + + // A data URI couldn't be produced + return false; } /** @@ -248,9 +280,12 @@ class CSSMin { ); if ( $embedData ) { + // Remember the occurring MIME types to avoid fallbacks when embedding some files. + $mimeTypes = array(); + $ruleWithEmbedded = preg_replace_callback( $pattern, - function ( $match ) use ( $embedAll, $local, $remote ) { + function ( $match ) use ( $embedAll, $local, $remote, &$mimeTypes ) { $embed = $embedAll || $match['embed']; $embedded = CSSMin::remapOne( $match['file'], @@ -260,21 +295,35 @@ class CSSMin { $embed ); + $url = $match['file'] . $match['query']; + $file = $local . $match['file']; + if ( + !CSSMin::isRemoteUrl( $url ) && !CSSMin::isLocalUrl( $url ) + && file_exists( $file ) + ) { + $mimeTypes[ CSSMin::getMimeType( $file ) ] = true; + } + return CSSMin::buildUrlValue( $embedded ); }, $rule ); + + // Are all referenced images SVGs? + $needsEmbedFallback = $mimeTypes !== array( 'image/svg+xml' => true ); } - if ( $embedData && $ruleWithEmbedded !== $ruleWithRemapped ) { - // Build 2 CSS properties; one which uses a base64 encoded data URI in place - // of the @embed comment to try and retain line-number integrity, and the - // other with a remapped an versioned URL and an Internet Explorer hack + if ( !$embedData || $ruleWithEmbedded === $ruleWithRemapped ) { + // We're not embedding anything, or we tried to but the file is not embeddable + return $ruleWithRemapped; + } elseif ( $embedData && $needsEmbedFallback ) { + // Build 2 CSS properties; one which uses a data URI in place of the @embed comment, and + // the other with a remapped and versioned URL with an Internet Explorer 6 and 7 hack // making it ignored in all browsers that support data URIs return "$ruleWithEmbedded;$ruleWithRemapped!ie"; } else { - // No reason to repeat twice - return $ruleWithRemapped; + // Look ma, no fallbacks! This is for files which IE 6 and 7 don't support anyway: SVG. + return $ruleWithEmbedded; } }, $source ); @@ -289,6 +338,34 @@ class CSSMin { } /** + * Is this CSS rule referencing a remote URL? + * + * @private Until we require PHP 5.5 and we can access self:: from closures. + * @param string $maybeUrl + * @return bool + */ + public static function isRemoteUrl( $maybeUrl ) { + if ( substr( $maybeUrl, 0, 2 ) === '//' || parse_url( $maybeUrl, PHP_URL_SCHEME ) ) { + return true; + } + return false; + } + + /** + * Is this CSS rule referencing a local URL? + * + * @private Until we require PHP 5.5 and we can access self:: from closures. + * @param string $maybeUrl + * @return bool + */ + public static function isLocalUrl( $maybeUrl ) { + if ( $maybeUrl !== '' && $maybeUrl[0] === '/' && !self::isRemoteUrl( $maybeUrl ) ) { + return true; + } + return false; + } + + /** * Remap or embed a CSS URL path. * * @param string $file URL to remap/embed @@ -302,22 +379,16 @@ class CSSMin { // The full URL possibly with query, as passed to the 'url()' value in CSS $url = $file . $query; - // Skip fully-qualified and protocol-relative URLs and data URIs - if ( substr( $url, 0, 2 ) === '//' || parse_url( $url, PHP_URL_SCHEME ) ) { - return $url; + // Expand local URLs with absolute paths like /w/index.php to possibly protocol-relative URL, if + // wfExpandUrl() is available. (This will not be the case if we're running outside of MW.) + if ( self::isLocalUrl( $url ) && function_exists( 'wfExpandUrl' ) ) { + return wfExpandUrl( $url, PROTO_RELATIVE ); } - // URLs with absolute paths like /w/index.php need to be expanded - // to absolute URLs but otherwise left alone - if ( $url !== '' && $url[0] === '/' ) { - // Replace the file path with an expanded (possibly protocol-relative) URL - // ...but only if wfExpandUrl() is even available. - // This will not be the case if we're running outside of MW - if ( function_exists( 'wfExpandUrl' ) ) { - return wfExpandUrl( $url, PROTO_RELATIVE ); - } else { - return $url; - } + // Pass thru fully-qualified and protocol-relative URLs and data URIs, as well as local URLs if + // we can't expand them. + if ( self::isRemoteUrl( $url ) || self::isLocalUrl( $url ) ) { + return $url; } if ( $local === false ) { |