Mercurial > repos > bcclaywell > argo_navis

comparison venv/lib/python2.7/linecache.py @ 0:d67268158946 draft

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planemo upload commit a3f181f5f126803c654b3a66dd4e83a48f7e203b
author bcclaywell
date Mon, 12 Oct 2015 17:43:33 -0400
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-1:000000000000 0:d67268158946
1 """Cache lines from files.
2
3 This is intended to read lines from modules imported -- hence if a filename
4 is not found, it will look down the module search path for a file by
5 that name.
6 """
7
8 import sys
9 import os
10
11 __all__ = ["getline", "clearcache", "checkcache"]
12
13 def getline(filename, lineno, module_globals=None):
14 lines = getlines(filename, module_globals)
15 if 1 <= lineno <= len(lines):
16 return lines[lineno-1]
17 else:
18 return ''
19
20
21 # The cache
22
23 cache = {} # The cache
24
25
26 def clearcache():
27 """Clear the cache entirely."""
28
29 global cache
30 cache = {}
31
32
33 def getlines(filename, module_globals=None):
34 """Get the lines for a file from the cache.
35 Update the cache if it doesn't contain an entry for this file already."""
36
37 if filename in cache:
38 return cache[filename][2]
39
40 try:
41 return updatecache(filename, module_globals)
42 except MemoryError:
43 clearcache()
44 return []
45
46
47 def checkcache(filename=None):
48 """Discard cache entries that are out of date.
49 (This is not checked upon each call!)"""
50
51 if filename is None:
52 filenames = cache.keys()
53 else:
54 if filename in cache:
55 filenames = [filename]
56 else:
57 return
58
59 for filename in filenames:
60 size, mtime, lines, fullname = cache[filename]
61 if mtime is None:
62 continue # no-op for files loaded via a __loader__
63 try:
64 stat = os.stat(fullname)
65 except os.error:
66 del cache[filename]
67 continue
68 if size != stat.st_size or mtime != stat.st_mtime:
69 del cache[filename]
70
71
72 def updatecache(filename, module_globals=None):
73 """Update a cache entry and return its list of lines.
74 If something's wrong, print a message, discard the cache entry,
75 and return an empty list."""
76
77 if filename in cache:
78 del cache[filename]
79 if not filename or (filename.startswith('<') and filename.endswith('>')):
80 return []
81
82 fullname = filename
83 try:
84 stat = os.stat(fullname)
85 except OSError:
86 basename = filename
87
88 # Try for a __loader__, if available
89 if module_globals and '__loader__' in module_globals:
90 name = module_globals.get('__name__')
91 loader = module_globals['__loader__']
92 get_source = getattr(loader, 'get_source', None)
93
94 if name and get_source:
95 try:
96 data = get_source(name)
97 except (ImportError, IOError):
98 pass
99 else:
100 if data is None:
101 # No luck, the PEP302 loader cannot find the source
102 # for this module.
103 return []
104 cache[filename] = (
105 len(data), None,
106 [line+'\n' for line in data.splitlines()], fullname
107 )
108 return cache[filename][2]
109
110 # Try looking through the module search path, which is only useful
111 # when handling a relative filename.
112 if os.path.isabs(filename):
113 return []
114
115 for dirname in sys.path:
116 # When using imputil, sys.path may contain things other than
117 # strings; ignore them when it happens.
118 try:
119 fullname = os.path.join(dirname, basename)
120 except (TypeError, AttributeError):
121 # Not sufficiently string-like to do anything useful with.
122 continue
123 try:
124 stat = os.stat(fullname)
125 break
126 except os.error:
127 pass
128 else:
129 return []
130 try:
131 with open(fullname, 'rU') as fp:
132 lines = fp.readlines()
133 except IOError:
134 return []
135 if lines and not lines[-1].endswith('\n'):
136 lines[-1] += '\n'
137 size, mtime = stat.st_size, stat.st_mtime
138 cache[filename] = size, mtime, lines, fullname
139 return lines