AppPkg/Applications/Python/Python-2.7.10: Initial Checkin part 4/5.

The Lib directory from the cPython 2.7.10 distribution.
These files are unchanged and set the baseline for subsequent commits.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Daryl McDaniel <edk2-lists@mc2research.org>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18740 6f19259b-4bc3-4df7-8a09-765794883524

AppPkg/Applications/Python/Python-2.7.10/Lib/linecache.py

@@ -0,0 +1,139 @@
+"""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]
+
+    try:
+        return updatecache(filename, module_globals)
+    except MemoryError:
+        clearcache()
+        return []
+
+
+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+    """Discard cache entries that are out of date.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