Compress alerts with zlib level 1 to fit in sheriff-o-matic's memcache.

Compress alerts with zlib level 1 to fit in sheriff-o-matic's memcache.

When there were 2000 failures recently the resulting alerts JSON was
~2.5MB. This is too big to fit in memcache's 1MB limit [1].

However the data compresses readily (sizes in K; level 0 is the
uncompressed size):

>>> import zlib
>>> uncompressed = open('data.json', 'r').read()
>>> for level in range(0,10):
...   compressed = zlib.compress(uncompressed, level)
...   print level, len(compressed) / 1024.0
...
0 2525.62207031
1 129.721679688
2 121.662109375
3 120.194335938
4 117.762695312
5 111.912109375
6 105.26953125
7 104.64453125
8 101.791015625
9 101.745117188

[1] https://developers.google.com/appengine/docs/python/memcache/#Python_Limits

TEST=PYTHONPATH=/usr/local/google_appengine Tools/GardeningServer/tests.py
BUG=401358
R=eseidel@chromium.org, ojan@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=180222

[dominicc (has gone to gerrit), 2014-08-14 00:02:33]

PTAL

[eseidel, 2014-08-14 00:06:48]

lgtm

Ideally we'd test.

[ojan, 2014-08-14 01:03:51]

Yay! lgtm!

https://codereview.chromium.org/469983002/diff/1/Tools/GardeningServer/alerts.py
File Tools/GardeningServer/alerts.py (right):

https://codereview.chromium.org/469983002/diff/1/Tools/GardeningServer/alerts...
Tools/GardeningServer/alerts.py:46: compressed = zlib.compress(uncompressed,
compression_level)
Nit: can you just do the following?
compressed = zlib.compress(uncompressed, level=1)

[dominicc (has gone to gerrit), 2014-08-14 02:10:16]

Added a test.

On 2014/08/14 01:03:51, ojan-only-code-yellow-reviews wrote:
> Yay! lgtm!
> 
>
https://codereview.chromium.org/469983002/diff/1/Tools/GardeningServer/alerts.py
> File Tools/GardeningServer/alerts.py (right):
> 
>
https://codereview.chromium.org/469983002/diff/1/Tools/GardeningServer/alerts...
> Tools/GardeningServer/alerts.py:46: compressed = zlib.compress(uncompressed,
> compression_level)
> Nit: can you just do the following?
> compressed = zlib.compress(uncompressed, level=1)

Unfortunately not a keyword argument [1]. I could get rid of the explaining
variable?

[1] https://docs.python.org/2/library/zlib.html#zlib.compress

[eseidel, 2014-08-14 02:37:54]

Woh.  That's crazy.  you went well above and beyond.  lgtm!

[ojan, 2014-08-14 02:40:40]

The CQ bit was checked by ojan@chromium.org

[ojan, 2014-08-14 02:40:40]

lgtm

[dominicc (has gone to gerrit), 2014-08-14 02:40:50]

Committed patchset #2 manually as 180222 (presubmit successful).

[dominicc (has gone to gerrit), 2014-08-14 02:44:01]

Thanks eseidel and ojan-only-code-yellow-reviews for reviews.

I dcommitted this because check-webkit-style does not understand that
AlertsHandler(webapp2.RequestHandler) inherits a member called 'response'... I
assume the Blink presubmit bot will squawk at that.