[PATCH] Adding RecipePath module to handle both local and http paths

[Jan Tluka]

RecipePath module is an abstraction over paths that can be specified on
command line and inside recipe files. Currently module supports local
files and HTTP urls but it's possible to extend the functionality for 
other, e.g. FTP.

Signed-off-by: Jan Tluka <jtluka(a)redhat.com&gt;
---
 Common/RecipePath.py |  115 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 115 insertions(+), 0 deletions(-)
 create mode 100644 Common/RecipePath.py

diff --git a/Common/RecipePath.py b/Common/RecipePath.py
new file mode 100644
index 0000000..b5f650c
--- /dev/null
+++ b/Common/RecipePath.py
@@ -0,0 +1,115 @@
+"""
+This module contains code code for LNST recipe paths and references.
+
+Copyright 2012 Red Hat, Inc.
+Licensed under the GNU General Public License, version 2 as
+published by the Free Software Foundation; see COPYING for details.
+"""
+
+__author__ = """
+jtluka(a)redhat.com (Jan Tluka)
+"""
+
+import os
+from urlparse import urljoin
+from urllib2 import urlopen
+
+def get_recipepath_class(root, path):
+    if root == None:
+        if path.startswith('http'):
+            return HttpRecipePath(root, path)
+        else:
+            if os.access(path, os.R_OK):
+                return FileRecipePath(root, path)
+            else:
+                raise Exception("Recipe path does not exist \"%s\"!"
% path)
+
+    if root.startswith('http'):
+        return HttpRecipePath(root, path)
+    elif os.access(root, os.R_OK):
+        return FileRecipePath(root, path)
+    else:
+        raise Exception("Could not recognize recipe path type \"%s\""
% path)
+
+class RecipePath:
+    def __init__(self, root, path):
+        self._recipepath_class = get_recipepath_class(root, path)
+
+    def get_root(self):
+        return self._recipepath_class.get_root()
+
+    def abs_path(self):
+        return self._recipepath_class.abs_path()
+
+    def to_str(self):
+        return self._recipepath_class.to_str()
+
+class RecipePathGeneric:
+    def __init__(self, root, path):
+        self._root = root
+        self._path = path
+        self._data = None
+
+    def get_root(self):
+        pass
+
+    def abs_path(self):
+        pass
+
+    def to_str(self):
+        pass
+
+class FileRecipePath(RecipePathGeneric):
+    def _load_file(self):
+        f = open(self.abs_path(),'r')
+        self._data = f.read()
+        f.close()
+
+    def to_str(self):
+        if not self._data:
+            self._load_file()
+
+        return self._data
+
+    def _append_path(self, path):
+        basedir = os.path.dirname(self._path)
+        return os.path.join(basedir, path)
+
+    def abs_path(self):
+        if self._root:
+            return os.path.normpath(os.path.join(self._root,
+                                    os.path.expanduser(self._path)))
+        else:
+            return os.path.normpath(os.path.expanduser(self._path))
+
+    def get_root(self):
+        return os.path.dirname(self.abs_path())
+
+class HttpRecipePath(RecipePathGeneric):
+    def _get_url(self):
+        url = self.abs_path()
+
+        try:
+            f = urlopen(url)
+            self._data = f.read()
+        except IOError, err:
+            msg = "Unable to resolve path: %s (%s)" % (url, str(err))
+            raise Exception(msg)
+
+        f.close()
+
+    def to_str(self):
+        if not self._data:
+            self._get_url()
+
+        return self._data
+
+    def abs_path(self):
+        if self._root:
+            return urljoin(self._root + '/', self._path)
+        else:
+            return self._path
+
+    def get_root(self):
+        url = self.abs_path()
+        return url.rpartition('/')[0]
-- 
1.7.7.6