Add background-wide file metadata cache.

Add background-wide file metadata cache.

Several background classes needs file metadata to perform their tasks.
However, Metadata cache was only available to foreground classes. Also,
lifetime of foreground metadata cache is tied to windows, so we have to
maintain separate Least Recently Used cache in the background.
As having separate cache for several background classes is inefficient,
we are going to have global cache class that is shared among them.
This has huge performance impact on slow storage devices such as MTP
conencted ones.

TEST=manually tested.
BUG=716309, 712121
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2856533003
Cr-Commit-Position: refs/heads/master@{#476228}
Committed: https://chromium.googlesource.com/chromium/src/+/e32d7951cd631cbeccd84b0ce874a41c9ee12faa

[tetsui, 2017-05-01 08:30:24]

Description was changed from

==========
WIP DO NOT MERGE: Add background-wide file metadata cache.

Several background classes needs file metadata to perform their tasks.
However, Metadata cache was only available to foreground classes. Also,
lifetime of foreground metadata cache is tied to windows, so we have to
maintain separate Least Recently Used cache in the background.
As having separate cache for several background classes is inefficient,
we are going to have global cache class that is shared among them.
This has huge performance impact on slow storage devices such as MTP
conencted ones.

TEST=manually tested.
BUG=716309,712121
==========

to

==========
WIP DO NOT MERGE: Add background-wide file metadata cache.

Several background classes needs file metadata to perform their tasks.
However, Metadata cache was only available to foreground classes. Also,
lifetime of foreground metadata cache is tied to windows, so we have to
maintain separate Least Recently Used cache in the background.
As having separate cache for several background classes is inefficient,
we are going to have global cache class that is shared among them.
This has huge performance impact on slow storage devices such as MTP
conencted ones.

TEST=manually tested.
BUG=716309,712121
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation
==========

[tetsui, 2017-05-31 07:00:40]

Description was changed from

==========
WIP DO NOT MERGE: Add background-wide file metadata cache.

Several background classes needs file metadata to perform their tasks.
However, Metadata cache was only available to foreground classes. Also,
lifetime of foreground metadata cache is tied to windows, so we have to
maintain separate Least Recently Used cache in the background.
As having separate cache for several background classes is inefficient,
we are going to have global cache class that is shared among them.
This has huge performance impact on slow storage devices such as MTP
conencted ones.

TEST=manually tested.
BUG=716309,712121
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation
==========

to

==========
Add background-wide file metadata cache.

Several background classes needs file metadata to perform their tasks.
However, Metadata cache was only available to foreground classes. Also,
lifetime of foreground metadata cache is tied to windows, so we have to
maintain separate Least Recently Used cache in the background.
As having separate cache for several background classes is inefficient,
we are going to have global cache class that is shared among them.
This has huge performance impact on slow storage devices such as MTP
conencted ones.

TEST=manually tested.
BUG=716309,712121
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation
==========

[tetsui, 2017-05-31 07:01:16]

The CQ bit was checked by tetsui@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-31 07:01:34]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-31 08:03:14]

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

[commit-bot: I haz the power, 2017-05-31 08:03:15]

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

[tetsui, 2017-05-31 08:13:10]

The CQ bit was unchecked by tetsui@chromium.org

[tetsui, 2017-05-31 09:04:57]

The CQ bit was checked by tetsui@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-31 09:05:11]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-31 09:31:29]

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

[commit-bot: I haz the power, 2017-05-31 09:31:30]

Dry run: This issue passed the CQ dry run.

[tetsui, 2017-05-31 10:43:57]

tetsui@chromium.org changed reviewers:
+ fukino@chromium.org

[tetsui, 2017-05-31 10:43:58]

fukino@: Please take a look! Thank you!

[fukino, 2017-06-01 03:37:46]

https://codereview.chromium.org/2856533003/diff/60001/ui/file_manager/file_ma...
File ui/file_manager/file_manager/background/js/global_metadata_cache.js
(right):

https://codereview.chromium.org/2856533003/diff/60001/ui/file_manager/file_ma...
ui/file_manager/file_manager/background/js/global_metadata_cache.js:11: var
MAX_CACHED_METADATA = 10000;
Name it as MAX_CACHED_METADATA_ as it is private.

https://codereview.chromium.org/2856533003/diff/60001/ui/file_manager/file_ma...
ui/file_manager/file_manager/background/js/global_metadata_cache.js:16: var
metadataCache = new LRUCache(MAX_CACHED_METADATA);
ditto

https://codereview.chromium.org/2856533003/diff/60001/ui/file_manager/file_ma...
File ui/file_manager/file_manager/background/js/import_history.js (right):

https://codereview.chromium.org/2856533003/diff/60001/ui/file_manager/file_ma...
ui/file_manager/file_manager/background/js/import_history.js:1030: * @param
{!Object} metadata
Correct the indentation.

[tetsui, 2017-06-01 04:45:57]

The CQ bit was checked by tetsui@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-06-01 04:46:07]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[tetsui, 2017-06-01 04:46:59]

Thank you! How about the naming of global_metadata_cache?

https://codereview.chromium.org/2856533003/diff/60001/ui/file_manager/file_ma...
File ui/file_manager/file_manager/background/js/global_metadata_cache.js
(right):

https://codereview.chromium.org/2856533003/diff/60001/ui/file_manager/file_ma...
ui/file_manager/file_manager/background/js/global_metadata_cache.js:11: var
MAX_CACHED_METADATA = 10000;
On 2017/06/01 03:37:46, fukino wrote:
> Name it as MAX_CACHED_METADATA_ as it is private.

Done.

https://codereview.chromium.org/2856533003/diff/60001/ui/file_manager/file_ma...
ui/file_manager/file_manager/background/js/global_metadata_cache.js:16: var
metadataCache = new LRUCache(MAX_CACHED_METADATA);
On 2017/06/01 03:37:46, fukino wrote:
> ditto

Done.

https://codereview.chromium.org/2856533003/diff/60001/ui/file_manager/file_ma...
File ui/file_manager/file_manager/background/js/import_history.js (right):

https://codereview.chromium.org/2856533003/diff/60001/ui/file_manager/file_ma...
ui/file_manager/file_manager/background/js/import_history.js:1030: * @param
{!Object} metadata
On 2017/06/01 03:37:46, fukino wrote:
> Correct the indentation.

Done.

[commit-bot: I haz the power, 2017-06-01 05:10:43]

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

[commit-bot: I haz the power, 2017-06-01 05:10:44]

Dry run: This issue passed the CQ dry run.

[fukino, 2017-06-01 07:01:31]

On 2017/06/01 04:46:59, tetsui wrote:
> Thank you! How about the naming of global_metadata_cache?

It sounds OK, but maybe it's better to have consistent name between the filename
and the module we provide.
How about naming it as metadata_proxy.js, and move the getEntryMetadata function
and other variables inside metadataProxy namespace, and call the function by
metadataProxy.getEntryMetadata(entry) from other background scripts?

[tetsui, 2017-06-01 07:52:00]

The CQ bit was checked by tetsui@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-06-01 07:52:25]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-06-01 08:20:08]

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

[commit-bot: I haz the power, 2017-06-01 08:20:09]

Dry run: This issue passed the CQ dry run.

[tetsui, 2017-06-01 08:21:41]

Thanks!

[fukino, 2017-06-01 08:27:18]

LGTM. Thank you!

[tetsui, 2017-06-01 08:27:50]

The CQ bit was checked by tetsui@chromium.org

[commit-bot: I haz the power, 2017-06-01 08:28:00]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-06-01 08:31:56]

CQ is committing da patch.

Bot data: {"patchset_id": 100001, "attempt_start_ts": 1496305670733250,
"parent_rev": "c769afbfff90770510b20c2c070e370bf915ac5e", "commit_rev":
"e32d7951cd631cbeccd84b0ce874a41c9ee12faa"}

[commit-bot: I haz the power, 2017-06-01 08:32:05]

Description was changed from

==========
Add background-wide file metadata cache.

Several background classes needs file metadata to perform their tasks.
However, Metadata cache was only available to foreground classes. Also,
lifetime of foreground metadata cache is tied to windows, so we have to
maintain separate Least Recently Used cache in the background.
As having separate cache for several background classes is inefficient,
we are going to have global cache class that is shared among them.
This has huge performance impact on slow storage devices such as MTP
conencted ones.

TEST=manually tested.
BUG=716309,712121
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation
==========

to

==========
Add background-wide file metadata cache.

Several background classes needs file metadata to perform their tasks.
However, Metadata cache was only available to foreground classes. Also,
lifetime of foreground metadata cache is tied to windows, so we have to
maintain separate Least Recently Used cache in the background.
As having separate cache for several background classes is inefficient,
we are going to have global cache class that is shared among them.
This has huge performance impact on slow storage devices such as MTP
conencted ones.

TEST=manually tested.
BUG=716309,712121
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2856533003
Cr-Commit-Position: refs/heads/master@{#476228}
Committed:
https://chromium.googlesource.com/chromium/src/+/e32d7951cd631cbeccd84b0ce874...
==========

[commit-bot: I haz the power, 2017-06-01 08:32:07]

Committed patchset #6 (id:100001) as
https://chromium.googlesource.com/chromium/src/+/e32d7951cd631cbeccd84b0ce874...