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https://issues.apache.org/jira/browse/COUCHDB-2295?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15932202#comment-15932202
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ASF GitHub Bot commented on COUCHDB-2295:
-----------------------------------------
GitHub user stevebest opened an issue:
https://github.com/apache/couchdb-nano/issues/36
Streamable multipart attachments are not supported
Consider a scenario when you want to upload a document and several
attachments to a CouchDB in a single request - a typical example would be
uploading a "Couchapp": a design doc with multiple HTML/JS/CSS attachments.
This scenario is [supported by CouchDB
API](http://docs.couchdb.org/en/1.6.1/api/document/common.html?highlight=multipart/related#creating-multiple-attachments)
using `Content-Type: multipart/related` request. Furthermore, you could expect
to leverage Node `Stream`s in order to avoid the necessity of buffering a bunch
of files in memory. Unfortunately, the combination of issues in CouchDB and
`request` prevents this.
1) CouchDB has [a nasty
bug](https://issues.apache.org/jira/browse/COUCHDB-2295) which prevents from
using `Transfer-Encoding: chunked` along with `Content-Type:
multipart/related`. It won't be fixed until `1.7`, and its status in `2.x`
branch is unknown.
2) `request` uses exactly the `Transfer-Encoding: chunked` to upload data
from `Stream`s. Uh-oh.
3) `request` could be told explicitly not to use `chunked` encoding - but
then you can't give it any `Stream`s! See [docs for a `multipart` option in
request(options,
callback)](https://github.com/request/request#requestoptions-callback). Bummer.
Technically, it should be possible to stream a bunch of attachments, in
case where one knows the length of the stream beforehand (which is not a
problem when you upload files from a disk). I attempted to add the support for
this case in dscape/nano#300, but failed miserably because `request` rightfully
thinks it's smarter than me.
----
----
> Connection hangs on document update for multipart/related and transfer
> encoding chunked request
> -----------------------------------------------------------------------------------------------
>
> Key: COUCHDB-2295
> URL: https://issues.apache.org/jira/browse/COUCHDB-2295
> Project: CouchDB
> Issue Type: Bug
> Components: HTTP Interface
> Reporter: Alexander Shorin
> Fix For: 1.7.0
>
>
> Script to reproduce:
> {code}
> import pprint
> import requests
> body = [
> b'--996713c691ec4fd5b717ef2740893b78\r\n',
> b'Content-Type: application/json\r\n',
> b'\r\n',
> b'{"_id": "test","_attachments": {"foo": {"follows": true,
> "content_type": "text/plain", "length": 12}}}\r\n',
> b'--996713c691ec4fd5b717ef2740893b78\r\n',
> b'Content-Type: text/plain\r\n'
> b'Content-Disposition: attachment;filename="foo"\r\n'
> b'Content-Length: 12\r\n'
> b'\r\n',
> b'Time to Relax!',
> b'--996713c691ec4fd5b717ef2740893b78--\r\n'
> ]
> url = 'http://localhost:5984/db/test'
> headers = {
> 'Content-Type': 'multipart/related;
> boundary="996713c691ec4fd5b717ef2740893b78"'
> }
> resp = requests.put(url, headers=headers, data=iter(body))
> pprint.pprint(resp.json())
> {code}
> This runs a request:
> {code}
> PUT /db/test HTTP/1.1
> Host: localhost:5984
> Accept-Encoding: gzip, deflate
> Transfer-Encoding: chunked
> User-Agent: python-requests/2.3.0 CPython/3.4.1 Linux/3.15.5-gentoo
> Accept: */*
> Content-Type: multipart/related; boundary="996713c691ec4fd5b717ef2740893b78"
> 24
> --996713c691ec4fd5b717ef2740893b78
> 20
> Content-Type: application/json
> 2
> 68
> {"_id": "test","_attachments": {"foo": {"follows": true, "content_type":
> "text/plain", "length": 14}}}
> 24
> --996713c691ec4fd5b717ef2740893b78
> 60
> Content-Type: text/plain
> Content-Disposition: attachment;filename="foo"
> Content-Length: 12
> e
> Time to Relax!
> 26
> --996713c691ec4fd5b717ef2740893b78--
> 0
> {code}
> But connection hangs: CouchDB thinks that there have to more data while zero
> length chunk had been send and doesn't reply with anything back to client
> which had finished the request and awaits for the response.
> The problem could be "fixed" by specifying full Content-Length of multipart
> body in request, which kills all the idea of chunked transfer.
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