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Diffstat (limited to 'scssphp/scssphp/src/SourceMap/Base64VLQ.php')
| -rw-r--r-- | scssphp/scssphp/src/SourceMap/Base64VLQ.php | 151 |
1 files changed, 0 insertions, 151 deletions
diff --git a/scssphp/scssphp/src/SourceMap/Base64VLQ.php b/scssphp/scssphp/src/SourceMap/Base64VLQ.php deleted file mode 100644 index d47b96a1..00000000 --- a/scssphp/scssphp/src/SourceMap/Base64VLQ.php +++ /dev/null @@ -1,151 +0,0 @@ -<?php - -/** - * SCSSPHP - * - * @copyright 2012-2020 Leaf Corcoran - * - * @license http://opensource.org/licenses/MIT MIT - * - * @link http://scssphp.github.io/scssphp - */ - -namespace ScssPhp\ScssPhp\SourceMap; - -/** - * Base 64 VLQ - * - * Based on the Base 64 VLQ implementation in Closure Compiler: - * https://github.com/google/closure-compiler/blob/master/src/com/google/debugging/sourcemap/Base64VLQ.java - * - * Copyright 2011 The Closure Compiler Authors. - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - * - * @author John Lenz <johnlenz@google.com> - * @author Anthon Pang <anthon.pang@gmail.com> - * - * @internal - */ -class Base64VLQ -{ - // A Base64 VLQ digit can represent 5 bits, so it is base-32. - const VLQ_BASE_SHIFT = 5; - - // A mask of bits for a VLQ digit (11111), 31 decimal. - const VLQ_BASE_MASK = 31; - - // The continuation bit is the 6th bit. - const VLQ_CONTINUATION_BIT = 32; - - /** - * Returns the VLQ encoded value. - * - * @param integer $value - * - * @return string - */ - public static function encode($value) - { - $encoded = ''; - $vlq = self::toVLQSigned($value); - - do { - $digit = $vlq & self::VLQ_BASE_MASK; - - //$vlq >>>= self::VLQ_BASE_SHIFT; // unsigned right shift - $vlq = (($vlq >> 1) & PHP_INT_MAX) >> (self::VLQ_BASE_SHIFT - 1); - - if ($vlq > 0) { - $digit |= self::VLQ_CONTINUATION_BIT; - } - - $encoded .= Base64::encode($digit); - } while ($vlq > 0); - - return $encoded; - } - - /** - * Decodes VLQValue. - * - * @param string $str - * @param integer $index - * - * @return integer - */ - public static function decode($str, &$index) - { - $result = 0; - $shift = 0; - - do { - $c = $str[$index++]; - $digit = Base64::decode($c); - $continuation = ($digit & self::VLQ_CONTINUATION_BIT) != 0; - $digit &= self::VLQ_BASE_MASK; - $result = $result + ($digit << $shift); - $shift = $shift + self::VLQ_BASE_SHIFT; - } while ($continuation); - - return self::fromVLQSigned($result); - } - - /** - * Converts from a two-complement value to a value where the sign bit is - * is placed in the least significant bit. For example, as decimals: - * 1 becomes 2 (10 binary), -1 becomes 3 (11 binary) - * 2 becomes 4 (100 binary), -2 becomes 5 (101 binary) - * - * @param integer $value - * - * @return integer - */ - private static function toVLQSigned($value) - { - if ($value < 0) { - return ((-$value) << 1) + 1; - } - - return ($value << 1) + 0; - } - - /** - * Converts to a two-complement value from a value where the sign bit is - * is placed in the least significant bit. For example, as decimals: - * 2 (10 binary) becomes 1, 3 (11 binary) becomes -1 - * 4 (100 binary) becomes 2, 5 (101 binary) becomes -2 - * - * @param integer $value - * - * @return integer - */ - private static function fromVLQSigned($value) - { - $negate = ($value & 1) === 1; - - //$value >>>= 1; // unsigned right shift - $value = ($value >> 1) & PHP_INT_MAX; - - if (! $negate) { - return $value; - } - - // We need to OR 0x80000000 here to ensure the 32nd bit (the sign bit) is - // always set for negative numbers. If `value` were 1, (meaning `negate` is - // true and all other bits were zeros), `value` would now be 0. -0 is just - // 0, and doesn't flip the 32nd bit as intended. All positive numbers will - // successfully flip the 32nd bit without issue, so it's a noop for them. - return -$value | 0x80000000; - } -} |