Try fast-fetch rather than full fetch if drive::FileSystem::GetEntryInfo failed.

Try fast-fetch rather than full fetch if drive::FileSystem::GetEntryInfo failed.

GetEntryInfoByPath is not only used for querying an entry info,
but also for just testing the existence of an entry.
So, it is not always desirable to start full fetch when
it does not exist locally.

The new implementation falls back to full fetch after all
when the parent directory's entry is not ready either.
This should not be an issue, however.
Existence testing most typically happens when user tries to
put a new file in a folder, in which case, the folder is
already opened in UI and hence loaded.

BUG=236708
TEST=the steps explained in BUG.
R=satorux@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=198671

[satorux1, 2013-05-02 04:42:38]

looks like a great change. would it be possible to write a test?

https://codereview.chromium.org/14838003/diff/1/chrome/browser/chromeos/drive...
File chrome/browser/chromeos/drive/file_system.cc (right):

https://codereview.chromium.org/14838003/diff/1/chrome/browser/chromeos/drive...
chrome/browser/chromeos/drive/file_system.cc:750: // If we don't know about the
directory, start loading full feed.
full feed -> full resource list.

[kinaba, 2013-05-02 06:21:28]

On 2013/05/02 04:42:38, satorux1 wrote:
> looks like a great change. would it be possible to write a test?

I think I need some preparation for writing a test. Just a moment...

[kinaba, 2013-05-02 08:35:54]

On 2013/05/02 06:21:28, kinaba wrote:
> On 2013/05/02 04:42:38, satorux1 wrote:
> > looks like a great change. would it be possible to write a test?
> 
> I think I need some preparation for writing a test. Just a moment...

Actually it turned out to be breaking existing tests,
let me reconsider more (for most of the cases I should change the
test expectation, but the tricky case is "drive/other/foo")

[kinaba, 2013-05-02 11:31:34]

Added tests for the new flow, and fixed failure in existing tests.

(Sorry I contaminated rebasing changes..., the actual changes
are the ones in _unittest.cc and at the point I commented.)

https://codereview.chromium.org/14838003/diff/14001/chrome/browser/chromeos/d...
File chrome/browser/chromeos/drive/file_system.cc (right):

https://codereview.chromium.org/14838003/diff/14001/chrome/browser/chromeos/d...
chrome/browser/chromeos/drive/file_system.cc:773: entry->resource_id() ==
util::kDriveOtherDirSpecialResourceId) {
Special case for handling "drive/other/exist.txt".
Fast-fetching "drive/other" doesn't make sense, so we need 
to load the full resource list.

[kinaba, 2013-05-02 11:32:11]

https://codereview.chromium.org/14838003/diff/1/chrome/browser/chromeos/drive...
File chrome/browser/chromeos/drive/file_system.cc (right):

https://codereview.chromium.org/14838003/diff/1/chrome/browser/chromeos/drive...
chrome/browser/chromeos/drive/file_system.cc:750: // If we don't know about the
directory, start loading full feed.
On 2013/05/02 04:42:38, satorux1 wrote:
> full feed -> full resource list.

Done.

[satorux1, 2013-05-07 06:29:45]

LGTM with nits.

hashimoto@, could you land this patch on behalf of kinaba who'll be ooo this
week?

https://codereview.chromium.org/14838003/diff/14001/chrome/browser/chromeos/d...
File chrome/browser/chromeos/drive/file_system_unittest.cc (right):

https://codereview.chromium.org/14838003/diff/14001/chrome/browser/chromeos/d...
chrome/browser/chromeos/drive/file_system_unittest.cc:311: bool
SaveTestFileSystem(SaveTestFileSystemParam param) {
This looks like a misnomer. I think this function was named when we were saving
a giant serialized proto file.

Maybe: SetUpTestFileSystem() ?

https://codereview.chromium.org/14838003/diff/14001/chrome/browser/chromeos/d...
chrome/browser/chromeos/drive/file_system_unittest.cc:910: // Enter the
"refreshing" state.
Enter the "refreshing" state so the fast fetch will be performed.

[hashimoto, 2013-05-07 06:49:01]

Uploading a new patch

https://codereview.chromium.org/14838003/diff/14001/chrome/browser/chromeos/d...
File chrome/browser/chromeos/drive/file_system_unittest.cc (right):

https://codereview.chromium.org/14838003/diff/14001/chrome/browser/chromeos/d...
chrome/browser/chromeos/drive/file_system_unittest.cc:311: bool
SaveTestFileSystem(SaveTestFileSystemParam param) {
On 2013/05/07 06:29:45, satorux1 wrote:
> This looks like a misnomer. I think this function was named when we were
saving
> a giant serialized proto file.
> 
> Maybe: SetUpTestFileSystem() ?

Done.

https://codereview.chromium.org/14838003/diff/14001/chrome/browser/chromeos/d...
chrome/browser/chromeos/drive/file_system_unittest.cc:910: // Enter the
"refreshing" state.
On 2013/05/07 06:29:45, satorux1 wrote:
> Enter the "refreshing" state so the fast fetch will be performed.

Done for ReadDirectoryWhileRefreshing and
GetEntryInfoNonExistentWhileRefreshing.

[kinaba, 2013-05-07 06:52:34]

lgtm

[hashimoto, 2013-05-07 08:28:10]

Committed patchset #5 manually as r198671 (presubmit successful).