Merge lp://staging/~xaav/loggerhead/export-tarball into lp://staging/loggerhead

Thanks very much, that'd be a really useful feature to have. Thanks
also for making it optional, because probably some installations would
not want it on.

This looks broadly reasonable -- I'm not deeply familiar with
loggerhead -- but I am very curious why you apparently reimplemented
the export-to-tarball feature. I'd rather reuse the bzr code and if
necessary change it to let it be reused here.

When you say "not tested" do you mean you haven't even run it, or only
that you didn't add automatic tests?

This looks very interesting.

Three isues:

1)
+class TarExporterFileObject(object):
+
+ def __init__(self):
+ self._buffer = ''
+
+ def write(self, str):
+ self._buffer += str
+
+ def get_buffer(self):
+ buffer = self._buffer
+ self._buffer = ''
+ return buffer

This is going to be somewhat inefficient. Try this:

+class TarExporterFileObject(object):
+
+ def __init__(self):
+ self._buffer = []
+
+ def write(self, str):
+ self._buffer.append(str)
+
+ def get_buffer(self):
+ try:
+ return ''.join(self._buffer)
+ finally:
+ self._buffer = []

2) There are no tests for this. the test suite is still pretty new, but its a good idea to test things - in particular in cases like this we need to be fairly confident it will be incremental and not block on the export - I can imagine the wsgi layer buffering everything, for instance. [in fact, I'll lay odds it will unless we fix a few things].

3) The export function is a copy-paste-tweak of the core from bzrlib. This will lead to bugs as that code base evolves - we should instead get a supported function in bzrlib lib that we can import and use.

I'm putting this back to WIP - but its a great start. Please keep at it and just shout if you need pointers.

> 3) The export function is a copy-paste-tweak of the core from bzrlib. This will lead to bugs as
> that code base evolves - we should instead get a supported function in bzrlib lib that we can
> import and use.

Well, there is only one problem with that. According to the WSGI spec, you must return an iterable that will export the blocks. If I were to call the provided function, it would be impossible to break the response into pieces because the provided function would export it all at once. I know that it is a copy and paste tweak, but there is really no way I can inject the 'yield' keyword into the provided function. If you have another suggestion, I would be glad to hear it.

Issue number one I will be glad to fix.

Regarding issue number two, I have not written tests before but I will try my best.

On Wed, Jun 1, 2011 at 9:46 AM, Geoff <email address hidden> wrote:
>> 3) The export function is a copy-paste-tweak of the core from bzrlib. This will lead to bugs as
>> that code base evolves - we should instead get a supported function in bzrlib lib that we can
>> import and use.
>
> Well, there is only one problem with that. According to the WSGI spec, you must return an iterable that will export the blocks. If I were to call the provided function, it would be impossible to break the response into pieces because the provided function would export it all at once. I know that it is a copy and paste tweak, but there is really no way I can inject the 'yield' keyword into the provided function. If you have another suggestion, I would be glad to hear it.

Extract the function in bzrlib into two parts - a generator (what you
have here) and a consumer than consumes it all triggering the writes.

Then we can reuse the generator.

> On Wed, Jun 1, 2011 at 9:46 AM, Geoff <email address hidden> wrote:
> >> 3) The export function is a copy-paste-tweak of the core from bzrlib. This
> will lead to bugs as
> >> that code base evolves - we should instead get a supported function in
> bzrlib lib that we can
> >> import and use.
> >
> > Well, there is only one problem with that. According to the WSGI spec, you
> must return an iterable that will export the blocks. If I were to call the
> provided function, it would be impossible to break the response into pieces
> because the provided function would export it all at once. I know that it is a
> copy and paste tweak, but there is really no way I can inject the 'yield'
> keyword into the provided function. If you have another suggestion, I would be
> glad to hear it.
>
> Extract the function in bzrlib into two parts - a generator (what you
> have here) and a consumer than consumes it all triggering the writes.
>
> Then we can reuse the generator.

Okay, I see what you mean.

See Bug #791005 for further information on this.

Okay, I think this should work, but I haven't tested it yet.

Thanks, xaav.

When you say "haven't tested" do you mean just "not written any tests", or "not even been able to run it"?

I haven't written any tests (Sorry, I'll do this ASAP.)
I also have not been able to run it because I'm lazy and it requires too much work to get loggerhead running on W1nd0w$.

Okay, I've added a simple tarfile test. However, I am not able to run the test to I would appreciate if someone would do that for me and/or try to download a tarball from their browser.

Once I'd set up a virtualenv with the right prerequisites, I got the
following error when running the test suite:

{{{
Traceback (most recent call last):
  ...
  File ".../loggerhead/tests/test_controllers.py", line 8, in <module>
    from loggerhead.apps.branch import BranchWSGIApp
  File ".../loggerhead/apps/branch.py", line 36, in <module>
    from loggerhead.controllers.download_ui import DownloadUI, DownloadTarballUI
  File ".../loggerhead/controllers/download_ui.py", line 29, in <module>
    from loggerhead.exporter import export_tarball
ImportError: cannot import name export_tarball
}}}

After fixing that I got the following error from
TestDownloadTarballUI.test_download_tarball:

{{{
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/testtools/runtest.py", line 169, in _run_user
    return fn(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/testtools/testcase.py", line 499, in _run_test_method
    return self._get_test_method()()
  File ".../loggerhead/tests/test_controllers.py", line 135, in test_download_tarball
    app = self.setUpLoggerhead()
  File ".../loggerhead/tests/test_simple.py", line 47, in setUpLoggerhead
    branch_app = BranchWSGIApp(self.tree.branch, '', **kw).app
AttributeError: 'TestDownloadTarballUI' object has no attribute 'tree'
}}}

Obviously this needs some work.

We've been talking about taking more of a "patch pilot" approach in
Launchpad. That seems to mean that one of the core team - fwiw, I
would be happy to do it - would actively help getting this landed,
rather than just reviewing it. Would you like that, or would you
prefer to iterate on your own?

Sorry, I had been gone. I will be sure and look into this right away!

On Thu, Jun 16, 2011 at 8:56 AM, Gavin Panella
<email address hidden>wrote:

> Review: Needs Fixing
> Once I'd set up a virtualenv with the right prerequisites, I got the
> following error when running the test suite:
>
> {{{
> Traceback (most recent call last):
> ...
> File ".../loggerhead/tests/test_controllers.py", line 8, in <module>
> from loggerhead.apps.branch import BranchWSGIApp
> File ".../loggerhead/apps/branch.py", line 36, in <module>
> from loggerhead.controllers.download_ui import DownloadUI,
> DownloadTarballUI
> File ".../loggerhead/controllers/download_ui.py", line 29, in <module>
> from loggerhead.exporter import export_tarball
> ImportError: cannot import name export_tarball
> }}}
>
> After fixing that I got the following error from
> TestDownloadTarballUI.test_download_tarball:
>
> {{{
> Traceback (most recent call last):
> File "/usr/lib/python2.7/dist-packages/testtools/runtest.py", line 169, in
> _run_user
> return fn(*args, **kwargs)
> File "/usr/lib/python2.7/dist-packages/testtools/testcase.py", line 499,
> in _run_test_method
> return self._get_test_method()()
> File ".../loggerhead/tests/test_controllers.py", line 135, in
> test_download_tarball
> app = self.setUpLoggerhead()
> File ".../loggerhead/tests/test_simple.py", line 47, in setUpLoggerhead
> branch_app = BranchWSGIApp(self.tree.branch, '', **kw).app
> AttributeError: 'TestDownloadTarballUI' object has no attribute 'tree'
> }}}
>
> Obviously this needs some work.
>
> We've been talking about taking more of a "patch pilot" approach in
> Launchpad. That seems to mean that one of the core team - fwiw, I
> would be happy to do it - would actively help getting this landed,
> rather than just reviewing it. Would you like that, or would you
> prefer to iterate on your own?
>
> --
> https://code.launchpad.net/~xaav/loggerhead/export-tarball/+merge/63931
> You are the owner of lp:~xaav/loggerhead/export-tarball.
>

We've been talking about taking more of a "patch pilot" approach in
Launchpad. That seems to mean that one of the core team - fwiw, I
would be happy to do it - would actively help getting this landed,
rather than just reviewing it. Would you like that, or would you
prefer to iterate on your own?

That would be great! Any help would be greatly appreciated.

Okay, I've fixed some stuff (the tests are still broken), but here is what I'm getting:

Traceback (most recent call last):
  File "C:\Python27\lib\site-packages\paste-1.7.5.1-py2.7.egg\paste\httpserver.py", l
ine 1068, in process_request_in_thread
    self.finish_request(request, client_address)
  File "C:\Python27\lib\SocketServer.py", line 323, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "C:\Python27\lib\SocketServer.py", line 639, in __init__
    self.handle()
  File "C:\Python27\lib\site-packages\paste-1.7.5.1-py2.7.egg\paste\httpserver.py", l
ine 442, in handle
    BaseHTTPRequestHandler.handle(self)
  File "C:\Python27\lib\BaseHTTPServer.py", line 337, in handle
    self.handle_one_request()
  File "C:\Python27\lib\site-packages\paste-1.7.5.1-py2.7.egg\paste\httpserver.py", l
ine 437, in handle_one_request
    self.wsgi_execute()
  File "C:\Python27\lib\site-packages\paste-1.7.5.1-py2.7.egg\paste\httpserver.py", l
ine 289, in wsgi_execute
    for chunk in result:
  File "C:\Users\Xaav\workspace\loggerhead\loggerhead\exporter.py", line 31, in e
xport_archive
    for _ in get_export_generator(tree=tree, fileobj=fileobj, format=format):
  File "C:\Python27\lib\site-packages\bzrlib\export\__init__.py", line 112, in get_ex
port_generator
    root = get_root_name(dest)
  File "C:\Python27\lib\site-packages\bzrlib\export\__init__.py", line 174, in get_ro
ot_name
    dest = os.path.basename(dest)
  File "C:\Python27\lib\ntpath.py", line 198, in basename
    return split(p)[1]
  File "C:\Python27\lib\ntpath.py", line 170, in split
    d, p = splitdrive(p)
  File "C:\Python27\lib\ntpath.py", line 125, in splitdrive
    if p[1:2] == ':':
TypeError: 'NoneType' object is not subscriptable

Any help would be appreciated.

Cool. I am busy this week, but I might get to it. If not, next week for sure.

Hi,

I almost got the test running with some additional fixes
(available at lp:~vila/loggerhead/export-tarball) only to run
into a bug in bzr itself (I think you should be able to fix that
one ;).

Note that your code requires bzr >= 2.4 (launchpad only runs
2.3.3 so far) so we'll need some support from the lp guys to
deploy a more recent version there.

Summary of my fixes:

- you need to create a branch (with some content even) before
  being able to call

         app = self.setUpLoggerhead()

  So I've added a setUp method for your class to do that. You
  probably want to add *more* tests to check that you get a valid
  tarball with the expected content (which an empty branch
  doesn't allow ;).

- you're calling get_export_generator without dest nor root and
  the code in bzrlib defaults to dest to set root. This raises an
  interesing point: which root should be used here (i.e. what do
  we want to prefix all the paths in the archive
  with). <project>-<branch nick>-<revno> may be nice (but ask
  others for feedback too).

- you used '.tar.gz' for the format but bzr expects either 'tgz'
  OR a dest file name to deduce the format from the file
  suffix. I just used 'tgz' there.

With these fixes in place we get:

======================================================================
ERROR: bzrlib.plugins.loggerhead.loggerhead.tests.test_controllers.TestDownloadTarballUI.test_download_tarball
----------------------------------------------------------------------
_StringException: Text attachment: log
------------
0.622 creating repository in file:///tmp/testbzr-KY_qfE.tmp/bzrlib.plugins.loggerhead.loggerhead.tests.test_controllers.TestDownloadTarballUI.test_download_tarball/work/.bzr/.
0.624 creating branch <bzrlib.branch.BzrBranchFormat7 object at 0x22ae990> in file:///tmp/testbzr-KY_qfE.tmp/bzrlib.plugins.loggerhead.loggerhead.tests.test_controllers.TestDownloadTarballUI.test_download_tarball/work/
0.631 trying to create missing lock '/tmp/testbzr-KY_qfE.tmp/bzrlib.plugins.loggerhead.loggerhead.tests.test_controllers.TestDownloadTarballUI.test_download_tarball/work/.bzr/checkout/dirstate'
0.631 opening working tree '/tmp/testbzr-KY_qfE.tmp/bzrlib.plugins.loggerhead.loggerhead.tests.test_controllers.TestDownloadTarballUI.test_download_tarball/work'
0.642 export version <InventoryRevisionTree instance at 29ece90, rev_id='null:'>
0.649 opening working tree '/tmp/testbzr-KY_qfE.tmp'
------------
Text attachment: traceback
------------
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/testtools/runtest.py", line 169, in _run_user
    return fn(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/testtools/testcase.py", line 499, in _run_test_method
    return self._get_test_method()()
  File "/home/vila/.bazaar/plugins/loggerhead/loggerhead/tests/test_controllers.py", line 140, in test_download_tarball
    res = app.get('/tarball')
  File "/usr/lib/pymodules/python2.7/paste/fixture.py", line 208, in get
    return self.do_request(req, status=status)
  File "/usr/lib/pymodules/python2.7/paste/fixture.py", line 389, in do_request
    **req.environ)
  File "/usr/lib/pymodules/python2.7/paste/wsgilib.py", li...