zinc streaming post

> Hi Camillo !
>
> On 26 Feb 2013, at 15:13, Camillo Bruni <[hidden email]> wrote:
>
>> we're having our weekly git hacking session and are working on the http protocol.
>
> Great !
>
>> The smart git protocol simply runs over http, nothing too fancy once you found the
>> documentation (which is the hardest part).
>>
>> Now we want to post a request and wanted to directly stream it to the server, but
>> we only figure out on how to do it using an intermediate string. The code looks
>> something like this:
>>
>>
>> requestContents := self createGitRequestEntity.
>> client := ZnClient new
>> url: 'https://github.com/pharo-project/phar-core';
>> entity: (requestContents);
>> post.
>>
>> Now I would like to do something like this.
>>
>>
>> postStream := ZnClient new
>> url: 'https://github.com/pharo-project/phar-core';
>> postStream.
>> self writeGitRequestOn: postStream
>>
>>
>> How can I do that in Zn? I already skimmed the documentation but it only shows
>> the example of files, where we copy over from a fully existing source.
>>
>> best
>> cami
>
> OK.
>
> When you do a POST, at one point the entity is sent #writeOn: so that it gets transferred to the wire. The special thing about a ZnStreamingEntity is that is wraps an open stream and then in its #writeOn: copies from that stream to the wire. That is basically it.
>
> In the case of a file upload, you open the file stream, put it in a ZnStreamingEntity, set the content type and length (length is almost always required) and your good.
>
> Where does your input stream come from in this particular case ?

> On 2013-02-26, at 15:24, Sven Van Caekenberghe <[hidden email]> wrote:
>
>> Hi Camillo !
>>
>> On 26 Feb 2013, at 15:13, Camillo Bruni <[hidden email]> wrote:
>>
>>> we're having our weekly git hacking session and are working on the http protocol.
>>
>> Great !
>>
>>> The smart git protocol simply runs over http, nothing too fancy once you found the
>>> documentation (which is the hardest part).
>>>
>>> Now we want to post a request and wanted to directly stream it to the server, but
>>> we only figure out on how to do it using an intermediate string. The code looks
>>> something like this:
>>>
>>>
>>> requestContents := self createGitRequestEntity.
>>> client := ZnClient new
>>> url: 'https://github.com/pharo-project/phar-core';
>>> entity: (requestContents);
>>> post.
>>>
>>> Now I would like to do something like this.
>>>
>>>
>>> postStream := ZnClient new
>>> url: 'https://github.com/pharo-project/phar-core';
>>> postStream.
>>> self writeGitRequestOn: postStream
>>>
>>>
>>> How can I do that in Zn? I already skimmed the documentation but it only shows
>>> the example of files, where we copy over from a fully existing source.
>>>
>>> best
>>> cami
>>
>> OK.
>>
>> When you do a POST, at one point the entity is sent #writeOn: so that it gets transferred to the wire. The special thing about a ZnStreamingEntity is that is wraps an open stream and then in its #writeOn: copies from that stream to the wire. That is basically it.
>>
>> In the case of a file upload, you open the file stream, put it in a ZnStreamingEntity, set the content type and length (length is almost always required) and your good.
>>
>> Where does your input stream come from in this particular case ?
>
> right now we generate the git request on the fly, so it is not present as a whole
> data structure at the tim we send the request.
>
> Later we will have more issue when we upload stuff to git. We will send a lot of
> data but we generate it on the fly piece wise. So here it makes sense not to generate
> an intermediate buffer to store the full post request.