qetag.php

<?php 

/**
 * 最新版本 在 https://github.com/qiniu/php-sdk/blob/master/src/Qiniu/Etag.php
 */
define('BLOCK_BITS', 22);
define('BLOCK_SIZE', 1 << BLOCK_BITS);


error_reporting(E_ERROR | E_WARNING | E_PARSE);


function PackArray($v, $a) {
    return call_user_func_array('pack', array_merge(array($v),(array)$a));
}


function BlockCount($fsize) {
    return (($fsize + (BLOCK_SIZE - 1)) >> BLOCK_BITS);
}


function URLSafeBase64Encode($str) // URLSafeBase64Encode
{
    $find = array('+', '/');
    $replace = array('-', '_');
    return str_replace($find, $replace, base64_encode($str));
}


function CalSha1($fhandler) {
    $fdata = fread($fhandler, BLOCK_SIZE);
    $sha1Str = sha1($fdata, true);
    $err = error_get_last();
    if ($err != null) {
        return array(null, $err);
    }
    $byteArray = unpack('C*', $sha1Str);
    return array($byteArray, null);
}


function GetEtag($filename) {
    if (!is_file($filename)) {
        $err = array ('message' => 'Can not open ' . $filename . ' as a file.');
        return array(null, $err);
    }
    $fhandler = fopen($filename, 'r');
    $err = error_get_last();
    if ($err != null) {
        return array(null, $err);
    }

    $fstat = fstat($fhandler);
    $fsize = $fstat['size'];
    $blockCnt = BlockCount($fsize);
    $sha1Buf = array();

    if ($blockCnt <= 1) {
        $sha1Buf[] = 0x16;
        list($sha1Code, $err) = CalSha1($fhandler);
        if ($err != null) {
            return array(null, $err);
        }
        fclose($fhandler);
        $sha1Buf = array_merge($sha1Buf, $sha1Code);
    } else {
        $sha1Buf[] = 0x96;
        $sha1BlockBuf = array();
        for ($i=0; $i < $blockCnt; $i++) {
            list($sha1Code, $err) = CalSha1($fhandler);
            if ($err != null) {
                return array(null, $err);
            }
            $sha1BlockBuf = array_merge($sha1BlockBuf, $sha1Code);
        }
        $tmpData = PackArray('C*', $sha1BlockBuf);
        $tmpFhandler = tmpfile();
        fwrite($tmpFhandler, $tmpData);
        fseek($tmpFhandler, 0);
        list($sha1Final, $_err) = CalSha1($tmpFhandler);
        $sha1Buf = array_merge($sha1Buf, $sha1Final);
    }
    $etag = URLSafeBase64Encode(PackArray('C*', $sha1Buf));
    return array($etag, null);
}


function isCmd () {
    $selfName = basename($_SERVER['PHP_SELF']);
    $cwd = getcwd();
    $fullPath = $cwd . '/' . $selfName;
    $isCmd = __file__ == $fullPath ? true : false;
    return $isCmd;
}


function run () {
    if ($_SERVER["argc"] < 2) {
        echo 'Usage: php qetag.php <filename>' . "\n";
        exit();
    }
    $filename = $_SERVER["argv"][1];
    list($ret, $err) = GetEtag($filename);
    if ($err != null) {
        echo $err['message'] . "\n";
        exit();
    }
    echo $ret . "\n";
    exit();
}

if (isCmd()) {
    run();
}

?>