Make re-scanning of devices much faster by caching content hashcodes.

Make re-scanning of devices much faster by caching content hashcodes.

This CL is took over from issue 1112573005 at patchset 30001 (http://crrev.com/1112573005#ps30001)

BUG=476688
TEST=*ImportController*

Committed: https://crrev.com/e13e3de602a2b14c4481ee948fe3c0fb03064d5b
Cr-Commit-Position: refs/heads/master@{#329377}

[yawano, 2015-05-11 11:48:24]

yawano@chromium.org changed reviewers:
+ mtomasz@chromium.org

[yawano, 2015-05-11 11:48:25]

@mtomasz: PTAL. Thank you!
@smckay: I'll add you in CC since you are the original owner of this CL. Please
feel free to add comment. Thanks.

[mtomasz, 2015-05-12 00:17:27]

lgtm with an (optional) nit

https://codereview.chromium.org/1126043005/diff/20001/ui/file_manager/file_ma...
File ui/file_manager/file_manager/background/js/duplicate_finder.js (right):

https://codereview.chromium.org/1126043005/diff/20001/ui/file_manager/file_ma...
ui/file_manager/file_manager/background/js/duplicate_finder.js:56:
importer.DriveDuplicateFinder.MAX_CACHED_HASHCODES_ = 1000;
nit: Isn't it too small? WDYT?

[Steve McKay, 2015-05-12 02:16:19]

smckay@chromium.org changed reviewers:
+ smckay@chromium.org

[Steve McKay, 2015-05-12 02:16:19]

LGTM.

https://codereview.chromium.org/1126043005/diff/20001/ui/file_manager/file_ma...
File ui/file_manager/file_manager/background/js/duplicate_finder.js (right):

https://codereview.chromium.org/1126043005/diff/20001/ui/file_manager/file_ma...
ui/file_manager/file_manager/background/js/duplicate_finder.js:56:
importer.DriveDuplicateFinder.MAX_CACHED_HASHCODES_ = 1000;
On 2015/05/12 00:17:27, mtomasz wrote:
> nit: Isn't it too small? WDYT?

Yeah, a more generous number is probably a good idea. Especially because a user
with MANY files on a device is going to feel the most acute pain. So maybe 5k
maybe even 10k because there is no added cost for users with less?

[yawano, 2015-05-12 03:41:57]

Thank you for the review! Changed the cache size to 10k.

https://codereview.chromium.org/1126043005/diff/20001/ui/file_manager/file_ma...
File ui/file_manager/file_manager/background/js/duplicate_finder.js (right):

https://codereview.chromium.org/1126043005/diff/20001/ui/file_manager/file_ma...
ui/file_manager/file_manager/background/js/duplicate_finder.js:56:
importer.DriveDuplicateFinder.MAX_CACHED_HASHCODES_ = 1000;
Yes, since LRU cache expands its size automatically, we don't allocate much
memory for a user with less photos. I changed the value to 10k.

[yawano, 2015-05-12 04:03:56]

The CQ bit was checked by yawano@chromium.org

[yawano, 2015-05-12 04:03:57]

The patchset sent to the CQ was uploaded after l-g-t-m from
mtomasz@chromium.org, smckay@chromium.org
Link to the patchset: https://codereview.chromium.org/1126043005/#ps40001
(title: "Change cache size to 10k.")

[commit-bot: I haz the power, 2015-05-12 04:05:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1126043005/40001

[commit-bot: I haz the power, 2015-05-12 04:59:34]

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

[commit-bot: I haz the power, 2015-05-12 04:59:35]

Try jobs failed on following builders:
  linux_chromium_chromeos_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[yawano, 2015-05-12 08:41:27]

@mtomasz: I forgot to add an import to lru_cache.js in unit tests. Fixed it with
a new patch set. PTAL. Thank you!

[mtomasz, 2015-05-12 08:43:00]

still lgtm!

[yawano, 2015-05-12 08:47:55]

On 2015/05/12 08:43:00, mtomasz wrote:
> still lgtm!

Thank you!

[yawano, 2015-05-12 08:48:00]

The CQ bit was checked by yawano@chromium.org

[yawano, 2015-05-12 08:48:01]

The patchset sent to the CQ was uploaded after l-g-t-m from smckay@chromium.org
Link to the patchset: https://codereview.chromium.org/1126043005/#ps60001
(title: "Fix unit test.")

[commit-bot: I haz the power, 2015-05-12 08:48:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1126043005/60001

[commit-bot: I haz the power, 2015-05-12 08:51:42]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-05-12 08:52:23]

Patchset 4 (id:??) landed as
https://crrev.com/e13e3de602a2b14c4481ee948fe3c0fb03064d5b
Cr-Commit-Position: refs/heads/master@{#329377}