posix, windows: introduce cachestat
This class contains a stat result, and possibly other file info to reliably
determine between two points in time whether a file has changed.
Uniquely identifying a file gives us that reliability because we either
atomic rename or append. So one of two will happen: the file 'id' will change,
or the size of the file will change.
posix implements it simply by calling os.stat() and checking if the result
has st_ino.
For now on Windows we always assume the path is uncacheable. This can be
improved on NTFS due to file IDs: http://msdn.microsoft.com/en-us/library/
aa363788(v=vs.85).aspx
So we need to find out if a file path is on an NTFS drive, for that we have:
- GetVolumeInformation, which unfortunately only works with a root path (but is available on XP)
- GetVolumeInformationByHandleW, works on a full file path but requires Vista or higher
[('string', 'string value'), ('bool1', 'true'), ('bool2', 'false'), ('boolinvalid', 'foo'), ('int1', '42'), ('int2', '-42'), ('intinvalid', 'foo')]
[('list1', 'foo'), ('list2', 'foo bar baz'), ('list3', 'alice, bob'), ('list4', 'foo bar baz alice, bob'), ('list5', 'abc d"ef"g "hij def"'), ('list6', '"hello world", "how are you?"'), ('list7', 'Do"Not"Separate'), ('list8', '"Do"Separate'), ('list9', '"Do\\"NotSeparate"'), ('list10', 'string "with extraneous" quotation mark"'), ('list11', 'x, y'), ('list12', '"x", "y"'), ('list13', '""" key = "x", "y" """'), ('list14', ',,,, '), ('list15', '" just with starting quotation'), ('list16', '"longer quotation" with "no ending quotation'), ('list17', 'this is \\" "not a quotation mark"'), ('list18', '\n \n\nding\ndong')]
---
'string value'
'true'
'false'
None
---
values.string is not a boolean ('string value')
True
False
False
False
True
---
42
-42
---
['foo']
['foo', 'bar', 'baz']
['alice', 'bob']
['foo', 'bar', 'baz', 'alice', 'bob']
['foo', 'bar', 'baz', 'alice', 'bob']
['abc', 'd"ef"g', 'hij def']
['hello world', 'how are you?']
['Do"Not"Separate']
['Do', 'Separate']
['Do"NotSeparate']
['string', 'with extraneous', 'quotation', 'mark"']
['x', 'y']
['x', 'y']
['', ' key = ', 'x"', 'y', '', '"']
[]
['"', 'just', 'with', 'starting', 'quotation']
['longer quotation', 'with', '"no', 'ending', 'quotation']
['this', 'is', '"', 'not a quotation mark']
['ding', 'dong']
[]
[]
['foo']
['foo']
['foo', 'bar']
['foo', 'bar']
['foo bar']
['foo', 'bar']
None
True
boolinvalid
intinvalid