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-rw-r--r--cloudinit/mergers/__init__.py104
-rw-r--r--cloudinit/mergers/dict.py33
-rw-r--r--cloudinit/mergers/list.py41
-rw-r--r--cloudinit/mergers/str.py28
4 files changed, 206 insertions, 0 deletions
diff --git a/cloudinit/mergers/__init__.py b/cloudinit/mergers/__init__.py
new file mode 100644
index 00000000..b3e728b0
--- /dev/null
+++ b/cloudinit/mergers/__init__.py
@@ -0,0 +1,104 @@
+# vi: ts=4 expandtab
+#
+# Copyright (C) 2012 Yahoo! Inc.
+#
+# Author: Joshua Harlow <harlowja@yahoo-inc.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3, as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+from cloudinit import importer
+from cloudinit import log as logging
+from cloudinit import util
+
+LOG = logging.getLogger(__name__)
+
+
+class UnknownMerger(object):
+ # Named differently so auto-method finding
+ # doesn't pick this up if there is ever a type
+ # named "unknown"
+ def _handle_unknown(self, meth_wanted, value, merge_with):
+ return value
+
+ def merge(self, source, merge_with):
+ type_name = util.obj_name(source)
+ type_name = type_name.lower()
+ method_name = "_on_%s" % (type_name)
+ meth = None
+ args = [source, merge_with]
+ if hasattr(self, method_name):
+ meth = getattr(self, method_name)
+ if not meth:
+ meth = self._handle_unknown
+ args.insert(0, method_name)
+ return meth(*args)
+
+
+class LookupMerger(UnknownMerger):
+ def __init__(self, lookups=None):
+ UnknownMerger.__init__(self)
+ if lookups is None:
+ self._lookups = []
+ else:
+ self._lookups = lookups
+
+ def _handle_unknown(self, meth_wanted, value, merge_with):
+ meth = None
+ for merger in self._lookups:
+ if hasattr(merger, meth_wanted):
+ # First one that has that method/attr gets to be
+ # the one that will be called
+ meth = getattr(merger, meth_wanted)
+ break
+ if not meth:
+ return UnknownMerger._handle_unknown(self, meth_wanted,
+ value, merge_with)
+ return meth(value, merge_with)
+
+
+def _extract_merger_names(merge_how):
+ names = []
+ for m_name in merge_how.split("+"):
+ # Canonicalize the name (so that it can be found
+ # even when users alter it in various ways...
+ m_name = m_name.lower().strip()
+ m_name = m_name.replace(" ", "_")
+ m_name = m_name.replace("\t", "_")
+ m_name = m_name.replace("-", "_")
+ if not m_name:
+ continue
+ names.append(m_name)
+ return names
+
+
+def construct(merge_how, default_classes=None):
+ mergers = []
+ merger_classes = []
+ root = LookupMerger(mergers)
+ for m_name in _extract_merger_names(merge_how):
+ merger_locs = importer.find_module(m_name,
+ [__name__],
+ ['Merger'])
+ if not merger_locs:
+ msg = "Could not find merger named %s" % (m_name)
+ raise ImportError(msg)
+ else:
+ mod = importer.import_module(merger_locs[0])
+ cls = getattr(mod, 'Merger')
+ merger_classes.append(cls)
+ if not merger_classes and default_classes:
+ merger_classes = default_classes
+ for m_class in merger_classes:
+ mergers.append(m_class(root))
+ return root \ No newline at end of file
diff --git a/cloudinit/mergers/dict.py b/cloudinit/mergers/dict.py
new file mode 100644
index 00000000..a0ffaa33
--- /dev/null
+++ b/cloudinit/mergers/dict.py
@@ -0,0 +1,33 @@
+# vi: ts=4 expandtab
+#
+# Copyright (C) 2012 Yahoo! Inc.
+#
+# Author: Joshua Harlow <harlowja@yahoo-inc.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3, as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+class Merger(object):
+ def __init__(self, merger):
+ self._merger = merger
+
+ def _on_dict(self, value, merge_with):
+ if not isinstance(merge_with, (dict)):
+ return value
+ merged = dict(value)
+ for (k, v) in merge_with.items():
+ if k in merged:
+ merged[k] = self._merger.merge(merged[k], v)
+ else:
+ merged[k] = v
+ return merged
diff --git a/cloudinit/mergers/list.py b/cloudinit/mergers/list.py
new file mode 100644
index 00000000..ad1b9793
--- /dev/null
+++ b/cloudinit/mergers/list.py
@@ -0,0 +1,41 @@
+# vi: ts=4 expandtab
+#
+# Copyright (C) 2012 Yahoo! Inc.
+#
+# Author: Joshua Harlow <harlowja@yahoo-inc.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3, as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+class Merger(object):
+ def __init__(self, merger):
+ self._merger = merger
+
+ def _on_tuple(self, value, merge_with):
+ return self._on_list(list(value), merge_with)
+
+ def _on_list(self, value, merge_with):
+ if isinstance(merge_with, (tuple, list)):
+ new_value = list(value)
+ for m_v in merge_with:
+ m_am = 0
+ for (i, o_v) in enumerate(new_value):
+ if m_v == o_v:
+ new_value[i] = self._merger.merge(o_v, m_v)
+ m_am += 1
+ if m_am == 0:
+ new_value.append(m_v)
+ else:
+ new_value = list(value)
+ new_value.append(merge_with)
+ return new_value
diff --git a/cloudinit/mergers/str.py b/cloudinit/mergers/str.py
new file mode 100644
index 00000000..7c3fa585
--- /dev/null
+++ b/cloudinit/mergers/str.py
@@ -0,0 +1,28 @@
+# vi: ts=4 expandtab
+#
+# Copyright (C) 2012 Yahoo! Inc.
+#
+# Author: Joshua Harlow <harlowja@yahoo-inc.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3, as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+class Merger(object):
+ def __init__(self, merger):
+ pass
+
+ def _on_unicode(self, value, merge_with):
+ return self._on_str(value, merge_with)
+
+ def _on_str(self, value, merge_with):
+ return value