[telemetry] Add ability to read data previously written to HTML

[telemetry] Add ability to read data previously written to HTML

This lets telemetry read the data that was previously put into an
html viewer file.

BUG=340096
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=255582

[nduca, 2014-03-04 08:33:10]

small one ptal

[tonyg, 2014-03-05 03:33:48]

https://codereview.chromium.org/183973020/diff/1/tools/telemetry/telemetry/we...
File tools/telemetry/telemetry/web_components/viewer.py (right):

https://codereview.chromium.org/183973020/diff/1/tools/telemetry/telemetry/we...
tools/telemetry/telemetry/web_components/viewer.py:72: def
ReadDataObjectFromViewerFile(f):
We do the same thing in
https://code.google.com/p/chromium/codesearch#chromium/src/tools/telemetry/te...
, except it looks for a '<script id="foo" type="application/json"> instead of an
HTML comment. What if we just have one helper that returns the json of all
application/json scripts in an html document.

[nduca, 2014-03-05 19:28:45]

I'd like to keep it simple basically. This i know works.

[nduca, 2014-03-05 19:32:00]

(i'll make the change haha)

[nduca, 2014-03-06 02:07:57]

Oh, I remember now: the existing one requires you read the results file into
memory ... this new one does a streaming read. Good for big files. I could
change it to not rely on the before/after script tag but tbh, I think I'd rather
leave it alone. So, seeking lg on patch as is. :$

[dtu, 2014-03-06 21:50:57]

https://codereview.chromium.org/183973020/diff/1/tools/telemetry/telemetry/we...
File tools/telemetry/telemetry/web_components/viewer.py (right):

https://codereview.chromium.org/183973020/diff/1/tools/telemetry/telemetry/we...
tools/telemetry/telemetry/web_components/viewer.py:59: output_file.write('%s\n'
% _BEGIN_VIEWER_DATA_MARKER)
Alternatively,
print >> output_file, _BEGIN_VIEWER_DATA_MARKER

https://codereview.chromium.org/183973020/diff/1/tools/telemetry/telemetry/we...
tools/telemetry/telemetry/web_components/viewer.py:101: assert
lines[0].strip().startswith("<script")
Now that I look at it, a script tag with id "viewer-data" also serves as a begin
marker. (And its matching </script> serves as an end marker.)

I guess that's consistent with tonyg's comment above.

Also I think this method would be shorter/clearer if you use HTMLParser (which
does support incomplete data, so you can do a streaming read).

[dtu, 2014-03-06 22:14:02]

On 2014/03/06 21:50:57, dtu wrote:
>
https://codereview.chromium.org/183973020/diff/1/tools/telemetry/telemetry/we...
> File tools/telemetry/telemetry/web_components/viewer.py (right):
> 
>
https://codereview.chromium.org/183973020/diff/1/tools/telemetry/telemetry/we...
> tools/telemetry/telemetry/web_components/viewer.py:59:
output_file.write('%s\n'
> % _BEGIN_VIEWER_DATA_MARKER)
> Alternatively,
> print >> output_file, _BEGIN_VIEWER_DATA_MARKER
> 
>
https://codereview.chromium.org/183973020/diff/1/tools/telemetry/telemetry/we...
> tools/telemetry/telemetry/web_components/viewer.py:101: assert
> lines[0].strip().startswith("<script")
> Now that I look at it, a script tag with id "viewer-data" also serves as a
begin
> marker. (And its matching </script> serves as an end marker.)
> 
> I guess that's consistent with tonyg's comment above.
> 
> Also I think this method would be shorter/clearer if you use HTMLParser (which
> does support incomplete data, so you can do a streaming read).


class MyHTMLParser(HTMLParser):
  def __init__(self):
    super(MyHTMLParser, self).__init__()
    self._data_tag = False
    self._data = ''

  def handle_starttag(self, tag, attrs):
    if attrs['id'] == 'viewer-data':
      self._data_tag = True

  def handle_endtag(self, tag):
    self._data_tag = False

  def handle_data(self, data):
    if self._data_tag:
      self._data += data

  @property
  def data(self):
    return json.loads(self._data)

parser = MyHTMLParser()
for line in f:
  parser.feed(line)
return parser.data

[nduca, 2014-03-06 22:33:18]

fixed, ptal

[dtu, 2014-03-06 23:14:50]

Ok, sorry, I don't know if that was any better.


lgtm

https://codereview.chromium.org/183973020/diff/20001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/web_components/viewer.py (right):

https://codereview.chromium.org/183973020/diff/20001/tools/telemetry/telemetr...
tools/telemetry/telemetry/web_components/viewer.py:85: 
dict(attrs)['id']

[nduca, 2014-03-06 23:50:23]

The CQ bit was checked by nduca@chromium.org

[commit-bot: I haz the power, 2014-03-06 23:59:06]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/nduca@chromium.org/183973020/40001

[commit-bot: I haz the power, 2014-03-07 06:23:11]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-07 06:23:11]

Retried try job too often on mac_rel for step(s) telemetry_perf_unittests,
telemetry_unittests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_rel&nu...

[nduca, 2014-03-07 08:35:45]

The CQ bit was checked by nduca@chromium.org

[commit-bot: I haz the power, 2014-03-07 08:40:09]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/nduca@chromium.org/183973020/40001

[commit-bot: I haz the power, 2014-03-07 11:29:49]

Change committed as 255582