Everything

php

Pass file handle in XMLReader

php.internals

Aimeos | Norbert Sendetzky

5 years ago

Hi internals

The XMLReader object only allows a file name in the constructor and the
open() method. While this is OK most of the time, files stored at cloud
services not accessible via an URL must be downloaded first. For big
files (e.g 100MB to 1GB and more), this requires a lot of time and
resources.

If the XMLReader would be able accept a file handle too, we could pass
the handle of a stream to the methods and the XMLReader could process
the XML data on the fly without the need of a local copy.

Is it possible to allow a file handle in the existing methods or is a
new one required due to type or other constraints like implementation
difficulties?

The open() method is implemented here:

https://github.com/php/php-src/blob/faea5ab837ab6393c8821f85cf8abe2723593e8e/ext/xmlreader/php_xmlreader.c#L835-L887

Not sure where the constructor is implemented.

Thanks


Norbert

Christoph Becker

5 years ago

On 02.12.2020 at 18:17, Aimeos | Norbert Sendetzky wrote:

> The XMLReader object only allows a file name in the constructor and the
> open() method. While this is OK most of the time, files stored at cloud
> services not accessible via an URL must be downloaded first. For big
> files (e.g 100MB to 1GB and more), this requires a lot of time and
> resources.
>
> If the XMLReader would be able accept a file handle too, we could pass
> the handle of a stream to the methods and the XMLReader could process
> the XML data on the fly without the need of a local copy.
>
> Is it possible to allow a file handle in the existing methods or is a
> new one required due to type or other constraints like implementation
> difficulties?
>
> The open() method is implemented here:
>
> https://github.com/php/php-src/blob/faea5ab837ab6393c8821f85cf8abe2723593e8e/ext/xmlreader/php_xmlreader.c#L835-L887

For clarity, it might be preferable to introduce a new static creation
method for this.  The implementation could probably use
xmlReaderForIO()[1], instead of xmlReaderForFile().

[1]
<http://www.xmlsoft.org/html/libxml-xmlreader.html#xmlReaderForIOhttp://www.xmlsoft.org/html/libxml-xmlreader.html#xmlReaderForIO

Regards,
Christoph

Aimeos | Norbert Sendetzky

5 years ago

Am 04.12.20 um 13:23 schrieb Christoph M. Becker:

> For clarity, it might be preferable to introduce a new static creation
> method for this.  The implementation could probably use
> xmlReaderForIO()[1], instead of xmlReaderForFile().

Wouldn't xmlReaderForFd() be more suitable or is this only for file
handles, not for streams?

What would be a good name for the new method? XMLReader::stream()?

Best,

Norbert

Christoph Becker

5 years ago

On 04.12.2020 at 13:35, Aimeos | Norbert Sendetzky wrote:

> Am 04.12.20 um 13:23 schrieb Christoph M. Becker:
>
>> For clarity, it might be preferable to introduce a new static creation
>> method for this.  The implementation could probably use
>> xmlReaderForIO()[1], instead of xmlReaderForFile().
>
> Wouldn't xmlReaderForFd() be more suitable or is this only for file
> handles, not for streams?

xmlReaderForFd() is only for file descriptors; PHP streams are more general.

> What would be a good name for the new method? XMLReader::stream()?

Maybe XMLReader::createForStream(), but I think the name is secondary;
someone would have to come up at least with a draft implementation first.

Regards,
Christoph