You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
101 lines
2.7 KiB
101 lines
2.7 KiB
"""Cache lines from files. |
|
|
|
This is intended to read lines from modules imported -- hence if a filename |
|
is not found, it will look down the module search path for a file by |
|
that name. |
|
""" |
|
|
|
import sys |
|
import os |
|
from stat import * |
|
|
|
__all__ = ["getline","clearcache","checkcache"] |
|
|
|
def getline(filename, lineno): |
|
lines = getlines(filename) |
|
if 1 <= lineno <= len(lines): |
|
return lines[lineno-1] |
|
else: |
|
return '' |
|
|
|
|
|
# The cache |
|
|
|
cache = {} # The cache |
|
|
|
|
|
def clearcache(): |
|
"""Clear the cache entirely.""" |
|
|
|
global cache |
|
cache = {} |
|
|
|
|
|
def getlines(filename): |
|
"""Get the lines for a file from the cache. |
|
Update the cache if it doesn't contain an entry for this file already.""" |
|
|
|
if cache.has_key(filename): |
|
return cache[filename][2] |
|
else: |
|
return updatecache(filename) |
|
|
|
|
|
def checkcache(): |
|
"""Discard cache entries that are out of date. |
|
(This is not checked upon each call!)""" |
|
|
|
for filename in cache.keys(): |
|
size, mtime, lines, fullname = cache[filename] |
|
try: |
|
stat = os.stat(fullname) |
|
except os.error: |
|
del cache[filename] |
|
continue |
|
if size != stat[ST_SIZE] or mtime != stat[ST_MTIME]: |
|
del cache[filename] |
|
|
|
|
|
def updatecache(filename): |
|
"""Update a cache entry and return its list of lines. |
|
If something's wrong, print a message, discard the cache entry, |
|
and return an empty list.""" |
|
|
|
if cache.has_key(filename): |
|
del cache[filename] |
|
if not filename or filename[0] + filename[-1] == '<>': |
|
return [] |
|
fullname = filename |
|
try: |
|
stat = os.stat(fullname) |
|
except os.error, msg: |
|
# Try looking through the module search path. |
|
basename = os.path.split(filename)[1] |
|
for dirname in sys.path: |
|
# When using imputil, sys.path may contain things other than |
|
# strings; ignore them when it happens. |
|
try: |
|
fullname = os.path.join(dirname, basename) |
|
except (TypeError, AttributeError): |
|
# Not sufficiently string-like to do anything useful with. |
|
pass |
|
else: |
|
try: |
|
stat = os.stat(fullname) |
|
break |
|
except os.error: |
|
pass |
|
else: |
|
# No luck |
|
## print '*** Cannot stat', filename, ':', msg |
|
return [] |
|
try: |
|
fp = open(fullname, 'r') |
|
lines = fp.readlines() |
|
fp.close() |
|
except IOError, msg: |
|
## print '*** Cannot open', fullname, ':', msg |
|
return [] |
|
size, mtime = stat[ST_SIZE], stat[ST_MTIME] |
|
cache[filename] = size, mtime, lines, fullname |
|
return lines
|
|
|