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-rw-r--r--lib/python2.7/linecache.py135
1 files changed, 135 insertions, 0 deletions
diff --git a/lib/python2.7/linecache.py b/lib/python2.7/linecache.py
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+++ b/lib/python2.7/linecache.py
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+"""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
+
+__all__ = ["getline", "clearcache", "checkcache"]
+
+def getline(filename, lineno, module_globals=None):
+ lines = getlines(filename, module_globals)
+ 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, module_globals=None):
+ """Get the lines for a file from the cache.
+ Update the cache if it doesn't contain an entry for this file already."""
+
+ if filename in cache:
+ return cache[filename][2]
+ else:
+ return updatecache(filename, module_globals)
+
+
+def checkcache(filename=None):
+ """Discard cache entries that are out of date.
+ (This is not checked upon each call!)"""
+
+ if filename is None:
+ filenames = cache.keys()
+ else:
+ if filename in cache:
+ filenames = [filename]
+ else:
+ return
+
+ for filename in filenames:
+ size, mtime, lines, fullname = cache[filename]
+ if mtime is None:
+ continue # no-op for files loaded via a __loader__
+ 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, module_globals=None):
+ """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 filename in cache:
+ del cache[filename]
+ if not filename or (filename.startswith('<') and filename.endswith('>')):
+ return []
+
+ fullname = filename
+ try:
+ stat = os.stat(fullname)
+ except OSError:
+ basename = filename
+
+ # Try for a __loader__, if available
+ if module_globals and '__loader__' in module_globals:
+ name = module_globals.get('__name__')
+ loader = module_globals['__loader__']
+ get_source = getattr(loader, 'get_source', None)
+
+ if name and get_source:
+ try:
+ data = get_source(name)
+ except (ImportError, IOError):
+ pass
+ else:
+ if data is None:
+ # No luck, the PEP302 loader cannot find the source
+ # for this module.
+ return []
+ cache[filename] = (
+ len(data), None,
+ [line+'\n' for line in data.splitlines()], fullname
+ )
+ return cache[filename][2]
+
+ # Try looking through the module search path, which is only useful
+ # when handling a relative filename.
+ if os.path.isabs(filename):
+ return []
+
+ 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.
+ continue
+ try:
+ stat = os.stat(fullname)
+ break
+ except os.error:
+ pass
+ else:
+ return []
+ try:
+ with open(fullname, 'rU') as fp:
+ lines = fp.readlines()
+ except IOError:
+ return []
+ if lines and not lines[-1].endswith('\n'):
+ lines[-1] += '\n'
+ size, mtime = stat.st_size, stat.st_mtime
+ cache[filename] = size, mtime, lines, fullname
+ return lines