Stream you content

With Restkit you can easily stream your content to an from a server.

Stream to

To stream a content to a server, pass to your request a file (or file-like object) or an iterator as body. If you use an iterator or a file-like object and Restkit can’t determine its size (by reading Content-Length header or fetching the size of the file), sending will be chunked and Restkit add Transfer-Encoding: chunked header to the list of headers.

Here is a quick snippet with a file:

from restkit import request

with open("/some/file", "r") as f:
  request("/some/url", 'POST', body=f)

Here restkit will put the file size in Content-Length header. Another example with an iterator:

from restkit import request

myiterator = ['line 1', 'line 2']
request("/some/url", 'POST', body=myiterator)

Sending will be chunked. If you want to send without TE: chunked, you need to add the Content-Length header:

request("/some/url", 'POST', body=myiterator,
    headers={'content-Length': 12})

Stream from

Each requests return a restkit.client.HttpResponse object. If you want to receive the content in a streaming fashion you just have to use the body_stream member of the response. You can iter on it or just use as a file-like object (read, readline, readlines, ...).

Attention: Since 2.0, response.body are just streamed and aren’t persistent. In previous version, the implementation may cause problem with memory or storage usage.

Quick snippet with iteration:

import os
from restkit import request
import tempfile

r = request("http://e-engura.com/images/logo.gif")
fd, fname = tempfile.mkstemp(suffix='.gif')

with r.body_stream() as body:
  with os.fdopen(fd, "wb") as f:
    for block in body:
        f.write(block)

Or if you just want to read:

with r.body_stream() as body:
  with os.fdopen(fd, "wb") as f:
    while True:
        data = body.read(1024)
        if not data:
            break
        f.write(data)

Tee input

While with body_stream you can only consume the input until the end, you may want to reuse this body later in your application. For that, restkit since the 3.0 version offer the tee method. It copy response input to standard output or a file if length > sock.MAX_BODY. When all the input has been read, connection is released:

from restkit import request
import tempfile

r = request("http://e-engura.com/images/logo.gif")
fd, fname = tempfile.mkstemp(suffix='.gif')
fd1, fname1 = tempfile.mkstemp(suffix='.gif')

body = t.tee()
# save first file
with os.fdopen(fd, "wb") as f:
   for chunk in body: f.write(chunk)

# reset
body.seek(0)
# save second file.
with os.fdopen(fd1, "wb") as f:
   for chunk in body: f.write(chunk)

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