projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| 3257aa99 DM |
1 | """Cache lines from files.\r |
| 2 | \r | |
| 3 | This is intended to read lines from modules imported -- hence if a filename\r | |
| 4 | is not found, it will look down the module search path for a file by\r | |
| 5 | that name.\r | |
| 6 | """\r | |
| 7 | \r | |
| 8 | import sys\r | |
| 9 | import os\r | |
| 10 | \r | |
| 11 | __all__ = ["getline", "clearcache", "checkcache"]\r | |
| 12 | \r | |
| 13 | def getline(filename, lineno, module_globals=None):\r | |
| 14 | lines = getlines(filename, module_globals)\r | |
| 15 | if 1 <= lineno <= len(lines):\r | |
| 16 | return lines[lineno-1]\r | |
| 17 | else:\r | |
| 18 | return ''\r | |
| 19 | \r | |
| 20 | \r | |
| 21 | # The cache\r | |
| 22 | \r | |
| 23 | cache = {} # The cache\r | |
| 24 | \r | |
| 25 | \r | |
| 26 | def clearcache():\r | |
| 27 | """Clear the cache entirely."""\r | |
| 28 | \r | |
| 29 | global cache\r | |
| 30 | cache = {}\r | |
| 31 | \r | |
| 32 | \r | |
| 33 | def getlines(filename, module_globals=None):\r | |
| 34 | """Get the lines for a file from the cache.\r | |
| 35 | Update the cache if it doesn't contain an entry for this file already."""\r | |
| 36 | \r | |
| 37 | if filename in cache:\r | |
| 38 | return cache[filename][2]\r | |
| 39 | \r | |
| 40 | try:\r | |
| 41 | return updatecache(filename, module_globals)\r | |
| 42 | except MemoryError:\r | |
| 43 | clearcache()\r | |
| 44 | return []\r | |
| 45 | \r | |
| 46 | \r | |
| 47 | def checkcache(filename=None):\r | |
| 48 | """Discard cache entries that are out of date.\r | |
| 49 | (This is not checked upon each call!)"""\r | |
| 50 | \r | |
| 51 | if filename is None:\r | |
| 52 | filenames = cache.keys()\r | |
| 53 | else:\r | |
| 54 | if filename in cache:\r | |
| 55 | filenames = [filename]\r | |
| 56 | else:\r | |
| 57 | return\r | |
| 58 | \r | |
| 59 | for filename in filenames:\r | |
| 60 | size, mtime, lines, fullname = cache[filename]\r | |
| 61 | if mtime is None:\r | |
| 62 | continue # no-op for files loaded via a __loader__\r | |
| 63 | try:\r | |
| 64 | stat = os.stat(fullname)\r | |
| 65 | except os.error:\r | |
| 66 | del cache[filename]\r | |
| 67 | continue\r | |
| 68 | if size != stat.st_size or mtime != stat.st_mtime:\r | |
| 69 | del cache[filename]\r | |
| 70 | \r | |
| 71 | \r | |
| 72 | def updatecache(filename, module_globals=None):\r | |
| 73 | """Update a cache entry and return its list of lines.\r | |
| 74 | If something's wrong, print a message, discard the cache entry,\r | |
| 75 | and return an empty list."""\r | |
| 76 | \r | |
| 77 | if filename in cache:\r | |
| 78 | del cache[filename]\r | |
| 79 | if not filename or (filename.startswith('<') and filename.endswith('>')):\r | |
| 80 | return []\r | |
| 81 | \r | |
| 82 | fullname = filename\r | |
| 83 | try:\r | |
| 84 | stat = os.stat(fullname)\r | |
| 85 | except OSError:\r | |
| 86 | basename = filename\r | |
| 87 | \r | |
| 88 | # Try for a __loader__, if available\r | |
| 89 | if module_globals and '__loader__' in module_globals:\r | |
| 90 | name = module_globals.get('__name__')\r | |
| 91 | loader = module_globals['__loader__']\r | |
| 92 | get_source = getattr(loader, 'get_source', None)\r | |
| 93 | \r | |
| 94 | if name and get_source:\r | |
| 95 | try:\r | |
| 96 | data = get_source(name)\r | |
| 97 | except (ImportError, IOError):\r | |
| 98 | pass\r | |
| 99 | else:\r | |
| 100 | if data is None:\r | |
| 101 | # No luck, the PEP302 loader cannot find the source\r | |
| 102 | # for this module.\r | |
| 103 | return []\r | |
| 104 | cache[filename] = (\r | |
| 105 | len(data), None,\r | |
| 106 | [line+'\n' for line in data.splitlines()], fullname\r | |
| 107 | )\r | |
| 108 | return cache[filename][2]\r | |
| 109 | \r | |
| 110 | # Try looking through the module search path, which is only useful\r | |
| 111 | # when handling a relative filename.\r | |
| 112 | if os.path.isabs(filename):\r | |
| 113 | return []\r | |
| 114 | \r | |
| 115 | for dirname in sys.path:\r | |
| 116 | # When using imputil, sys.path may contain things other than\r | |
| 117 | # strings; ignore them when it happens.\r | |
| 118 | try:\r | |
| 119 | fullname = os.path.join(dirname, basename)\r | |
| 120 | except (TypeError, AttributeError):\r | |
| 121 | # Not sufficiently string-like to do anything useful with.\r | |
| 122 | continue\r | |
| 123 | try:\r | |
| 124 | stat = os.stat(fullname)\r | |
| 125 | break\r | |
| 126 | except os.error:\r | |
| 127 | pass\r | |
| 128 | else:\r | |
| 129 | return []\r | |
| 130 | try:\r | |
| 131 | with open(fullname, 'rU') as fp:\r | |
| 132 | lines = fp.readlines()\r | |
| 133 | except IOError:\r | |
| 134 | return []\r | |
| 135 | if lines and not lines[-1].endswith('\n'):\r | |
| 136 | lines[-1] += '\n'\r | |
| 137 | size, mtime = stat.st_size, stat.st_mtime\r | |
| 138 | cache[filename] = size, mtime, lines, fullname\r | |
| 139 | return lines\r |