流FTP下载到输出 [英] Stream FTP download to output
问题描述
我试图通过HTTP从FTP传输/管道文件到用户的浏览器。也就是说，我试图在FTP服务器上打印一个文件的内容。
这是我迄今为止的内容：
public function echo_contents（）{
$ file = fopen（'php：// output'，'w +'）;
if（！$ file）{
抛出新的异常（'Unable to open output'）;
}
尝试{
$ this-> ftp-> get（$ this-> path，$ file）;
} catch（Exception $ e）{
fclose（$ file）; // wtb finally
throw $ e;
}
fclose（$ file）;
}
$ this-> ftp-> get 看起来像这样：
public function get（$ path，$ stream）{
ftp_fget（$ this-> ftp，$ stream，$ path，FTP_BINARY）; // Line 200
}
使用这种方法，我只能发送小文件到用户的浏览器。对于较大的文件，没有打印出来，我得到一个致命的错误（从Apache日志中可读）：
PHP致命错误：允许的内存大小为16777216字节耗尽（试图分配15994881字节）在/xxx/ftpconnection.php上行200
我尝试将 php：// output with php：// stdout 没有成功（没有任何东西似乎发送到浏览器）。
如何在从FTP同时有效地下载数据的同时将数据发送到浏览器？
注意：我不想使用 file_get_contents（'ftp：// user：pass @ host：port / path / to / file'）; 或类似的名称。 / b>
创建一个套接字对（匿名管道？）。使用非阻塞
ftp_nb_fget 函数来写入管道的一端，而 echo 管道的另一端。$ b
被测试为 fast （在100Mbps连接上很容易达到10MB / s），所以没有太多的I / O开销。
确保清除任何输出缓冲区。框架通常会缓冲你的输出。
$ b
public function echo_contents（）{
/ * FTP写入[ 0]。数据从[1]传递过来。 * /
$ sockets = stream_socket_pair（STREAM_PF_UNIX，STREAM_SOCK_STREAM，STREAM_IPPROTO_IP）;
if（$ sockets === FALSE）{
抛出新的异常（'Unable to create socket pair'）;
}
stream_set_write_buffer（$ sockets [0]，0）;
stream_set_timeout（$ sockets [1]，0）;
try {
// $ this-> ftp是一个FtpConnection
$ get = $ this-> ftp-> get_non_blocking（$ this->路径， $插座[0]）; （$！get-> is_finished（））{
$ contents = stream_get_contents（$ sockets [1]）;
;
if（$ contents！== false）{
echo $ contents;
flush（）;
}
$ get-> resume（）;
}
$ contents = stream_get_contents（$ sockets [1]）;
if（$ contents！== false）{
echo $ contents;
flush（）;
}
} catch（Exception $ e）{
fclose（$ sockets [0]）; // wtb finally
fclose（$ sockets [1]）;
throw $ e;
}
fclose（$ sockets [0]）;
fclose（$ sockets [1]）;
}
// class FtpConnection
public function get_non_blocking（$ path，$ stream）{
// $ this-> ftp是返回的FTP资源ftp_connect
返回新的FtpNonBlockingRequest（$ this-> ftp，$ path，$ stream）;
}
/ * TODO错误处理。 * /
class FtpNonBlockingRequest {
protected $ ftp = NULL;
保护$ status = NULL;
公共函数__construct（$ ftp，$ path，$ stream）{
$ this-> ftp = $ ftp;
$ this-> status = ftp_nb_fget（$ this-> ftp，$ stream，$ path，FTP_BINARY）;
public function is_finished（）{
return $ this-> status！== FTP_MOREDATA; $'
$ b public function resume（）{
if（$ this-> is_finished（））{
throw BadMethodCallException（'无法继续下载;已经完成' ）;
}
$ this-> status = ftp_nb_continue（$ this-> ftp）;
}
}
I am trying to stream/pipe a file to the user's browser through HTTP from FTP. That is, I am trying to print the contents of a file on an FTP server.
This is what I have so far:
public function echo_contents() {
$file = fopen('php://output', 'w+');
if(!$file) {
throw new Exception('Unable to open output');
}
try {
$this->ftp->get($this->path, $file);
} catch(Exception $e) {
fclose($file); // wtb finally
throw $e;
}
fclose($file);
}
$this->ftp->get looks like this:
public function get($path, $stream) {
ftp_fget($this->ftp, $stream, $path, FTP_BINARY); // Line 200
}
With this approach, I am only able to send small files to the user's browser. For larger files, nothing gets printed and I get a fatal error (readable from Apache logs):
PHP Fatal error: Allowed memory size of 16777216 bytes exhausted (tried to allocate 15994881 bytes) in /xxx/ftpconnection.php on line 200
I tried replacing php://output with php://stdout without success (nothing seems to be sent to the browser).
How can I efficiently download from FTP while sending that data to the browser at the same time?
Note: I would not like to use file_get_contents('ftp://user:pass@host:port/path/to/file'); or similar.
Found a solution!
Create a socket pair (anonymous pipe?). Use the non-blocking ftp_nb_fget function to write to one end of the pipe, and echo the other end of the pipe.
Tested to be fast (easily 10MB/s on a 100Mbps connection) so there's not much I/O overhead.
Be sure to clear any output buffers. Frameworks commonly buffer your output.
public function echo_contents() {
/* FTP writes to [0]. Data passed through from [1]. */
$sockets = stream_socket_pair(STREAM_PF_UNIX, STREAM_SOCK_STREAM, STREAM_IPPROTO_IP);
if($sockets === FALSE) {
throw new Exception('Unable to create socket pair');
}
stream_set_write_buffer($sockets[0], 0);
stream_set_timeout($sockets[1], 0);
try {
// $this->ftp is an FtpConnection
$get = $this->ftp->get_non_blocking($this->path, $sockets[0]);
while(!$get->is_finished()) {
$contents = stream_get_contents($sockets[1]);
if($contents !== false) {
echo $contents;
flush();
}
$get->resume();
}
$contents = stream_get_contents($sockets[1]);
if($contents !== false) {
echo $contents;
flush();
}
} catch(Exception $e) {
fclose($sockets[0]); // wtb finally
fclose($sockets[1]);
throw $e;
}
fclose($sockets[0]);
fclose($sockets[1]);
}
// class FtpConnection
public function get_non_blocking($path, $stream) {
// $this->ftp is the FTP resource returned by ftp_connect
return new FtpNonBlockingRequest($this->ftp, $path, $stream);
}
/* TODO Error handling. */
class FtpNonBlockingRequest {
protected $ftp = NULL;
protected $status = NULL;
public function __construct($ftp, $path, $stream) {
$this->ftp = $ftp;
$this->status = ftp_nb_fget($this->ftp, $stream, $path, FTP_BINARY);
}
public function is_finished() {
return $this->status !== FTP_MOREDATA;
}
public function resume() {
if($this->is_finished()) {
throw BadMethodCallException('Cannot continue download; already finished');
}
$this->status = ftp_nb_continue($this->ftp);
}
}
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