home *** CD-ROM | disk | FTP | other *** search
- # 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 *
-
- def getline(filename, lineno):
- lines = getlines(filename)
- if 1 <= lineno <= len(lines):
- return lines[lineno-1]
- else:
- return ''
-
-
- # The cache
-
- cache = {} # The cache
-
-
- # Clear the cache entirely
-
- def clearcache():
- global cache
- cache = {}
-
-
- # Get the lines for a file from the cache.
- # Update the cache if it doesn't contain an entry for this file already.
-
- def getlines(filename):
- if cache.has_key(filename):
- return cache[filename][2]
- else:
- return updatecache(filename)
-
-
- # Discard cache entries that are out of date.
- # (This is not checked upon each call!)
-
- def checkcache():
- 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]
-
-
- # 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.
-
- def updatecache(filename):
- 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:
- fullname = os.path.join(dirname, basename)
- 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
-