view tests/test-propertycache.py.out @ 27430:e240e914d226 stable

revlog: seek to end of file before writing (issue4943)

Revlogs were recently refactored to open file handles in "a+" and use a
persistent file handle for reading and writing. This drastically
reduced the number of file handles being opened.

Unfortunately, it appears that some versions of Solaris lose the file
offset when performing a write after the handle has been seeked.

The simplest workaround is to seek to EOF on files opened in a+ mode
before writing to them, which is what this patch does.

Ideally, this code would exist in the vfs layer. However, this would
require creating a proxy class for file objects in order to provide a
custom implementation of write(). This would add overhead. Since
revlogs are the only files we open in a+ mode, the one-off workaround
in revlog.py should be sufficient.

This patch appears to have little to no impact on performance on my
Linux machine.

=== property cache ===

calllog: []
cached value (unfiltered): NOCACHE

= first access on unfiltered, should do a call
access: 0
calllog: [0]
cached value (unfiltered): 0

= second access on unfiltered, should not do call
access 0
calllog: [0]
cached value (unfiltered): 0

= first access on "visible" view, should do a call
cached value ("visible" view): NOCACHE
access: 7
calllog: [0, 7]
cached value (unfiltered): 0
cached value ("visible" view): 7

= second access on "visible view", should not do call
access: 7
calllog: [0, 7]
cached value (unfiltered): 0
cached value ("visible" view): 7

= no effect on other view
cached value ("immutable" view): NOCACHE
access: 9
calllog: [0, 7, 9]
cached value (unfiltered): 0
cached value ("visible" view): 7
cached value ("immutable" view): 9


=== unfiltered property cache ===

unficalllog: []
cached value (unfiltered):       NOCACHE
cached value ("visible" view):   NOCACHE
cached value ("immutable" view): NOCACHE

= first access on unfiltered, should do a call
access (unfiltered): 100
unficalllog: [100]
cached value (unfiltered):       100

= second access on unfiltered, should not do call
access (unfiltered): 100
unficalllog: [100]
cached value (unfiltered):       100

= access on view should use the unfiltered cache
access (unfiltered):       100
access ("visible" view):   100
access ("immutable" view): 100
unficalllog: [100]
cached value (unfiltered):       100
cached value ("visible" view):   NOCACHE
cached value ("immutable" view): NOCACHE

= even if we clear the unfiltered cache
cached value (unfiltered):       NOCACHE
cached value ("visible" view):   NOCACHE
cached value ("immutable" view): NOCACHE
unficalllog: [100]
access ("visible" view):   100
unficalllog: [100, 100]
cached value (unfiltered):       100
cached value ("visible" view):   NOCACHE
cached value ("immutable" view): NOCACHE
access ("immutable" view): 100
unficalllog: [100, 100]
cached value (unfiltered):       100
cached value ("visible" view):   NOCACHE
cached value ("immutable" view): NOCACHE
access (unfiltered):       100
unficalllog: [100, 100]
cached value (unfiltered):       100
cached value ("visible" view):   NOCACHE
cached value ("immutable" view): NOCACHE