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
#!/usr/bin/env python
# Filter output by pyflakes to control which warnings we check
import sys, re, os
def makekey(message):
# "path/file:line: message"
match = re.search(r"(line \d+)", message)
line = ''
if match:
line = match.group(0)
message = re.sub(r"(line \d+)", '', message)
return re.sub(r"([^:]*):([^:]+):([^']*)('[^']*')(.*)$",
r'\3:\5:\4:\1:\2:' + line,
message)
lines = []
for line in sys.stdin:
# We whitelist tests
pats = [
r"imported but unused",
r"local variable '.*' is assigned to but never used",
r"unable to detect undefined names",
]
if not re.search('|'.join(pats), line):
continue
fn = line.split(':', 1)[0]
f = open(os.path.join(os.path.dirname(os.path.dirname(__file__)), fn))
data = f.read()
f.close()
if 'no-check-code' in data:
continue
lines.append(line)
for line in sorted(lines, key = makekey):
sys.stdout.write(line)
print