diff options
Diffstat (limited to 'cloudinit/mergers/m_list.py')
| -rw-r--r-- | cloudinit/mergers/m_list.py | 86 |
1 files changed, 61 insertions, 25 deletions
diff --git a/cloudinit/mergers/m_list.py b/cloudinit/mergers/m_list.py index a56ff007..76591bea 100644 --- a/cloudinit/mergers/m_list.py +++ b/cloudinit/mergers/m_list.py @@ -16,35 +16,71 @@ # You should have received a copy of the GNU General Public License # along with this program. If not, see <http://www.gnu.org/licenses/>. +DEF_MERGE_TYPE = 'replace' +MERGE_TYPES = ('append', 'prepend', DEF_MERGE_TYPE, 'no_replace') + +def _has_any(what, *keys): + for k in keys: + if k in what: + return True + return False + class Merger(object): def __init__(self, merger, opts): self._merger = merger - self._discard_non = 'discard_non_list' in opts - self._extend = 'extend' in opts + # Affects merging behavior... + self._method = DEF_MERGE_TYPE + for m in MERGE_TYPES: + if m in opts: + self._method = m + break + # Affect how recursive merging is done on other primitives + self._recurse_str = _has_any(opts, 'recurse_str') + self._recurse_dict = _has_any(opts, 'recurse_dict') + self._recurse_array = _has_any(opts, 'recurse_array', 'recurse_list') + + def __str__(self): + return ('ListMerger: (method=%s,recurse_str=%s,' + 'recurse_dict=%s,recurse_array=%s)') % (self._method, + self._recurse_str, + self._recurse_dict, + self._recurse_array) def _on_tuple(self, value, merge_with): - return self._on_list(list(value), merge_with) - - # On encountering a list or tuple type this action will be applied - # a new list will be returned, if the value to merge with is itself - # a list and we have been told to 'extend', then the value here will - # be extended with the other list. If in 'extend' mode then we will - # attempt to merge instead, which means that values from the list - # to merge with will replace values in te original list (they will - # also be merged recursively). - # - # If the value to merge with is not a list, and we are set to discared - # then no modifications will take place, otherwise we will just append - # the value to merge with onto the end of our own list. + return tuple(self._on_list(list(value), merge_with)) + def _on_list(self, value, merge_with): - new_value = list(value) - if isinstance(merge_with, (tuple, list)): - if self._extend: - new_value.extend(merge_with) - else: - return new_value - else: - if not self._discard_non: - new_value.append(merge_with) - return new_value + if (self._method == 'replace' and + not isinstance(merge_with, (tuple, list))): + return merge_with + + # Ok we now know that what we are merging with is a list or tuple. + merged_list = [] + if self._method == 'prepend': + merged_list.extend(merge_with) + merged_list.extend(value) + return merged_list + elif self._method == 'append': + merged_list.extend(value) + merged_list.extend(merge_with) + return merged_list + + def merge_same_index(old_v, new_v): + if self._method == 'no_replace': + # Leave it be... + return old_v + if isinstance(new_v, (list, tuple)) and self._recurse_array: + return self._merger.merge(old_v, new_v) + if isinstance(new_v, (str, basestring)) and self._recurse_str: + return self._merger.merge(old_v, new_v) + if isinstance(new_v, (dict)) and self._recurse_dict: + return self._merger.merge(old_v, new_v) + return new_v + + # Ok now we are replacing same indexes + merged_list.extend(value) + common_len = min(len(merged_list), len(merge_with)) + for i in xrange(0, common_len): + merged_list[i] = merge_same_index(merged_list[i], merge_with[i]) + return merged_list |