mirror of
https://github.com/python/cpython.git
synced 2025-10-31 05:31:20 +00:00
91 lines
2 KiB
Python
91 lines
2 KiB
Python
|
# 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# Discard cache entries that are out of date.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
|