fastcgi客户端PHP语言实现

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fastcgi客户端PHP语言实现

发布： 2014-03-19 22:30

在一个项目中，希望使用php直接与PHP-FPM进程通信，
跳过nginx代理，减少一点中间过程的效率损耗，
同时，更重要的是把PHP-FPM当作一个PHP进程池使用，
不要受到关于nginx的超时、缓冲设置的影响，让不同处理程序之间通信更直接，
特意使用PHP语言编写了一个fastcgi客户端类，实现协议的打包、发送与接收工作。

在经过一段时间的完善之后，确定这种方式非常适用我们的需求场景，
花了一些时间，重新使用C语言编写了一个中间代理服务，
并集成了一个C版本的fastcgi客户端实现，现在已经不再需要这个PHP版本的了。

现张贴在此，给有兴趣的朋友一个示例，给需要的朋友当作参考，
在实现fastcgi类的过程中，总结下来，需要注意的一些点，
对二进制数据包的封装，像处理C语言中的不同长度的整数，字符串在PHP语言中的处理方式。
对C语言中的变长结构体类型的数据结构，在PHP中不太好表达，需要使用比较原始的分支逻辑来实现，
还可以了解网络协议的封闭数据包，解析数据包的基本模式。

如果用C语言实现，也许可以更简洁明了。
不过fastcgi协议本身非常简单，所以，PHP语言版本的实现也不算太复杂。

直接上代码，
[code type="php"]

// 内部类不会有重复包含类名冲突问题
class FastCGIClientImpl
{
const FCGI_HEADER_LEN = 0x08;
const FCGI_VERSION_1 = 0x01;

// 可用于FCGI_Header的type组件的值
const FCGI_BEGIN_REQUEST = 1;
const FCGI_ABORT_REQUEST = 2;
const FCGI_END_REQUEST = 3;
const FCGI_PARAMS = 4;
const FCGI_STDIN = 5;
const FCGI_STDOUT = 6;
const FCGI_STDERR = 7;
const FCGI_DATA = 8;
const FCGI_GET_VALUES = 9;
const FCGI_GET_VALUES_RESULT = 10;
const FCGI_UNKNOWN_TYPE = 11;
const FCGI_MAXTYPE = self::FCGI_UNKNOWN_TYPE;

//
const FCGI_NULL_REQUEST_ID = 0x00;

// 可用于FCGI_BeginRequestBody的flags组件的掩码
const FCGI_KEEP_CONN = 1;
// 可用于FCGI_BeginRequestBody的role组件的值
const FCGI_RESPONDER = 1;
const FCGI_AUTHORIZER = 2;
const FCGI_FILTER = 3;

// Values for protocolStatus component of FCGI_EndRequestBody
const FCGI_REQUEST_COMPLETE = 0;
const FCGI_CANT_MPX_CONN = 1;
const FCGI_OVERLOADED = 2;
const FCGI_UNKNOWN_ROLE = 3;

// members
public $_sock = null;
public $_app_status = 0;
public $_fcgi_status_code = -1;
public $_stderr_content = '';
public $_stdout_raw_content = '';
public $_stdout_real_content = '';
public $_response = '';
public $_http_status_code = 200;
public $_http_status_msg = 'OK';
public $_http_resp_headers = array();

// 构造函数
function __construct()
{
}

// 是否是可添加padding的协议记录类型
function isPadableRecord($appRecordType)
{
if ($appRecordType == self::FCGI_BEGIN_REQUEST
|| $appRecordType == self::FCGI_ABORT_REQUEST
|| $appRecordType == self::FCGI_END_REQUEST
|| $appRecordType == self::FCGI_STDIN
) {
return true;
}

return false;
}

// 构造fastcgi头
function fastcgiHeader($appRecordType, $contentLength)
{
assert($appRecordType >= self::FCGI_BEGIN_REQUEST);
assert($contentLength >= 0);

$hdr = '';
$hdr .= pack('C', self::FCGI_VERSION_1); // version
$hdr .= pack('C', $appRecordType); // type: self::FCGI_BEGIN_REQUEST

$hdr .= pack('n', rand(1, 65535)); // rid1,rid0

$hdr .= pack('n', $contentLength); // clen1,clen0

if ($this->isPadableRecord($appRecordType)) {
$hdr .= pack('C', rand(0, 255)); // padlen
} else {
$hdr .= pack('C', 0x00); // padlen
}
$hdr .= pack('C', 0x00); // reserved

assert(strlen($hdr) == self::FCGI_HEADER_LEN);

return $hdr;
}

// Build a FastCGI packet
function buildPacket($appRecordType, $content)
{
$hdr = $this->fastcgiHeader($appRecordType, strlen($content));
$pkt = $hdr . $content;

$padtext = '';
$padlen = unpack('C', $hdr{6})[1];
if ($this->isPadableRecord($appRecordType)) {
if ($padlen > 0) {
$padtext = str_repeat(chr(rand(0, 255)), $padlen);
$pkt .= $padtext;
assert(strlen($padtext) == $padlen);
}

// 为什么FastCGIConst:FCGI_PARAMS加padding后协议有问题
}

assert(strlen($pkt) == ($padlen + strlen($content) + self::FCGI_HEADER_LEN));
return $pkt;
}

// Build an FastCGI Name value pair
function buildNvpair($name, $value)
{
$nlen = strlen($name);
$vlen = strlen($value);

$nvpair = '';
$nvpair .= $nlen < 128 ? pack('C', $nlen) : pack('N', $nlen | (0x01 << 31));
$nvpair .= $vlen < 128 ? pack('C', $vlen) : pack('N', $vlen | (0x01 << 31));

assert(strlen($nvpair) == 2 || strlen($nvpair) == 5 || strlen($nvpair) == 8);

$nvpair .= $name . $value;
return $nvpair;
}

// 构造协议开始请求记录包
function buildBeginRequest()
{
$beginRequestBody = pack('n', self::FCGI_RESPONDER) // role1,role0
. pack('CNC', 0x00, rand(), 0x00) // flag, reserved5
;
assert(strlen($beginRequestBody) == 8);

$pkt = $this->buildPacket(self::FCGI_BEGIN_REQUEST, $beginRequestBody);
$padlen = unpack('C', $pkt{6})[1];
assert(strlen($pkt) == (self::FCGI_HEADER_LEN * 2 + $padlen));

return $pkt;
}

// 构造协议中断请求记录包
function buildAbortRequest()
{
$pkt = $this->buildPacket(self::FCGI_ABORT_REQUEST, '');
return $pkt;
}

// 构造协议参数请求记录包
function buildParamsRequest(array $params)
{
$pstr = '';
foreach ($params as $name => $value) {
$pstr .= $this->buildNvpair($name, $value);
}

$pkt = '';
$pkt .= $this->buildPacket(self::FCGI_PARAMS, $pstr);
$pkt .= $this->buildPacket(self::FCGI_PARAMS, ''); // 为什么需要构建一个空包

return $pkt;
}

// 构造协议标准输入请求记录包
function buildStdinRequest($stdin)
{
$pkt = $this->buildPacket(self::FCGI_STDIN, $stdin);
$pkt .= $this->buildPacket(self::FCGI_STDIN, ''); // 为什么需要构建一个空包
return $pkt;
}

// 构造协议结束请求记录包
function buildEndRequest()
{
$body = pack('N', 301)
. pack('C', 0x01)
. pack('C*', 0x00, 0x00, 0x00)
;
assert(strlen($body) == self::FCGI_HEADER_LEN);

$pkt = $this->buildPacket(self::FCGI_END_REQUEST, $body);

return $pkt;
}

/**
* Decode a FastCGI Packet
*
* @param String $data String containing all the packet
* @return array
*/
function decodePacketHeader($data)
{
$ret = array();
$ret['version'] = unpack('C', $data{0})[1];
$ret['type'] = unpack('C', $data{1})[1];
$ret['requestId'] = unpack('n', substr($data, 2, 2))[1];
$ret['contentLength'] = unpack('n', substr($data, 4, 2))[1];
$ret['paddingLength'] = unpack('C', $data{6})[1];
$ret['reserved'] = unpack('C', $data{7})[1];
return $ret;
}

/**
* Read a FastCGI Packet
*
* @return array
*/
function readPacket()
{
if ($packet = fread($this->_sock, self::FCGI_HEADER_LEN)) {
$resp = $this->decodePacketHeader($packet);
$resp['content'] = '';
if ($resp['contentLength']) {
$len = $resp['contentLength'];
while ($len && $buf = fread($this->_sock, $len)) {
$len -= strlen($buf);
$resp['content'] .= $buf;
$buf = '';
}
}
if ($resp['paddingLength']) {
$buf = fread($this->_sock, $resp['paddingLength']);
}
return $resp;
} else {
return false;
}
}

// 连接到FastCGI服务器
function connect($host, $port)
{
$fp = null;
if ($this->_sock == null) {
$fp = fsockopen($host, $port);
if (!$fp) {
return false;
}
}
$this->_sock = $fp;
assert($this->_sock != null);
return true;
}

// 断开到FastCGI服务器的连接
function disconnect()
{
if (is_resource($this->_sock)) {
fclose($this->_sock);
$this->_sock = null;
}
}

// 解析HTTP响应头信息
function parseHttpHeader($stdout)
{
$hdr_end_pos = strpos($stdout, "\r\n\r\n");
if ($hdr_end_pos < 0) {
return false;
}

$raw_hdr = explode("\r\n", substr($stdout, 0, $hdr_end_pos));
foreach ($raw_hdr as $lineno => $row) {
$kvpair = explode(': ', $row);
if ($lineno == 0 && $kvpair[0] == 'Status') {
$this->_http_status_code = explode(' ', trim($kvpair[1]))[0];
$this->_http_status_msg = substr($kvpair[1], strlen($this->_http_status_code)+1);
$this->_http_status_msg = trim($this->_http_status_msg);
} else {
$this->_http_resp_headers[$kvpair[0]] = $kvpair[1];
}
}

$this->_stdout_real_content = substr($stdout, $hdr_end_pos + 4);

return true;
}

// 比较全面的测试方法
public function requestFullTest(array $params, $stdin)
{
$fp = fsockopen('127.0.0.1', 9000);
var_dump($fp);
$this->_sock = $fp;

$breq = $this->buildBeginRequest();
$data = $breq;

$str = $this->buildParamsRequest($params);
$data .= $str;

$str = $this->buildStdinRequest($stdin);
$data .= $str;

$str = $this->buildAbortRequest();
$data .= $str;

$str = $this->buildEndRequest();
$data .= $str;

$ret = fwrite($fp, $data, strlen($data));
// var_dump($ret);

// $res = fread($fp, 3000);
// $res = $readPacket();
$response = '';
$stdout_content = '';
$stderr_content = '';
$cnter = 0;
do {
$btime = microtime(true);
$resp = $this->readPacket();
$now = microtime(true);
$dtime = $now - $btime;
echo "read a pkt: {$cnter} on {$now}, used: {$dtime}\n"; $cnter++;
if ($resp['type'] == self::FCGI_STDOUT || $resp['type'] == self::FCGI_STDERR) {
$response .= $resp['content'];
}
if ($resp['type'] == self::FCGI_STDOUT) {
$stdout_content .= $resp['content'];
}
if ($resp['type'] == self::FCGI_STDERR) {
$stderr_content .= $resp['content'];
}
} while ($resp && $resp['type'] != self::FCGI_END_REQUEST);

print_r($resp);
var_dump("response={$response}", "stdout={$stdout_content}", "stderr={$stderr_content}");
sleep(5);

fclose($fp);
return true;
}

// 对外执行fastcgi调用的方法
function request(array $params, $stdin)
{
$breq = $this->buildBeginRequest();
$data = $breq;

$str = $this->buildParamsRequest($params);
$data .= $str;

$str = $this->buildStdinRequest($stdin);
$data .= $str;

$ret = fwrite($this->_sock, $data, strlen($data));
if (!$ret) {
assert($ret == strlen($data));
return false;
}

$resp = null;
$cnter = 0;
do {
$btime = microtime(true);
$resp = $this->readPacket();
$now = microtime(true);
$dtime = $now - $btime;
echo "read a pkt: {$cnter} on {$now}, used: {$dtime}\n"; $cnter++;
if ($resp['type'] == self::FCGI_STDOUT || $resp['type'] == self::FCGI_STDERR) {
$this->_response .= $resp['content'];
}
if ($resp['type'] == self::FCGI_STDOUT) {
$this->_stdout_raw_content .= $resp['content'];
}
if ($resp['type'] == self::FCGI_STDERR) {
$this->_stderr_content .= $resp['content'];
}
} while ($resp && $resp['type'] != self::FCGI_END_REQUEST);

if (!$resp) {
return false;
}

assert(strlen($resp['content']) == self::FCGI_HEADER_LEN);
$this->_app_status = unpack('N', substr($resp['content'], 0, 4))[1];
$this->_fcgi_status = unpack('C', $resp['content']{4})[1];

return true;
}

}; // end class FastCGIClientImpl
?>
[/code]
测试代码：
[code type="php"]
$client = new FastCGIClientImpl();
$content = 'key123=value456&keyabc=valueefggg&中文=abcdefg&hehe=汉字utf8的';
$res = $client->__invoke(
array(
'GATEWAY_INTERFACE' => 'FastCGI/1.0',
'REQUEST_METHOD' => 'POST',
'DOCUMENT_ROOT' => '/data1/vhosts/photo.house.kitech.com.cn',
'SCRIPT_FILENAME' => '/data1/vhosts/photo.house.kitech.com.cn/index.php',
'SCRIPT_NAME' => '/index.php',
'REQUEST_URI' => '/test/test6/simpost',
'SERVER_SOFTWARE' => 'php/fastcgiclient',
'REMOTE_ADDR' => '127.0.0.1',
'REMOTE_PORT' => '9985',
'SERVER_ADDR' => '127.0.0.1',
'SERVER_PORT' => '80',
'SERVER_NAME' => 'photo.house.kitech.com.cn',
'HTTP_HOST' => 'photo.house.kitech.com.cn',
'SERVER_PROTOCOL' => 'HTTP/1.0',
'CONTENT_TYPE' => 'application/x-www-form-urlencoded',
'CONTENT_LENGTH' => strlen($content),
'kitech.com.cn_CACHE_DIR' => '',
'kitech.com.cn_DATA_DIR' => '',
'kitech.com.cn_RSYNC_SERVER' => '',
'kitech.com.cn_STORAGE_SERVER' => '',
'kitech.com.cn_RSYNC_MODULES' => '',
'kitech.com.cn_RESOURCE_URL' => '',
'kitech.com.cn_DIST_URL' => '',
'kitech.com.cn_TAAA_127' => 'DallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDall123456789012345',
'kitech.com.cn_TAAA_128' => 'DallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDallasDall1234567890123456',
),
$content
);

var_dump($res);
[/code]

通过代码，还可以看出，跳过nginx后，可以动态设置程序的DOCUMENT_ROOT目录，
能够实现一个比用nginx配置虚拟主机更快速灵活地方式，请求不同虚拟项目的程序接口。

参考资料：
http://www.fastcgi.com

原文： http://qtchina.tk/?q=node/795