+ This is where a lot of the nitty-gritty stuff actually happens. The
+ `MyConfigParser' knows a lot about the internals of this class, which saves
+ on building a complicated interface.
+ """
+
+ def __init__(me, name, cp):
+ """Initialize a new, empty section with a given NAME and parent CP."""
+ me.name = name
+ me._itemmap = dict()
+ me._cp = cp
+
+ def _expand(me, string, resolvep):
+ """
+ Expands $(...) and (optionally) $[...] placeholders in STRING.
+
+ RESOLVEP is a boolean switch: do we bother to tax the resolver or not?
+ This is turned off by MyConfigParser's resolve() method while it's
+ collecting hostnames to be resolved.
+ """
+ string = RX_REF.sub \
+ (lambda m: me.get(m.group(1), resolvep), string)
+ if resolvep:
+ string = RX_RESOLVE.sub(lambda m: me._cp._resolver.lookup(m.group(1)),
+ string)
+ return string
+
+ def _get(me, key, map = None, path = None):
+ """
+ Low-level option-fetching method.
+
+ Fetch the value for the named KEY in this section, or maybe (recursively)
+ a section which it inherits from.
+
+ Returns a pair VALUE, PATH. The value is not expanded; nor do we check
+ for the special `name' key. The caller is expected to do these things.
+ Returns None if no value could be found.
+ """
+
+ ## If we weren't given a memoization map or path, then we'd better make
+ ## one.
+ if map is None: map = {}
+ if path is None: path = []
+
+ ## Extend the path to cover us, but remember to remove us again when
+ ## we've finished. If we need to pass the current path back upwards,
+ ## then remember to take a copy.
+ path.append(me.name)
+ try:
+
+ ## If we've been this way before on another pass through then return
+ ## the value we found then. If we're still thinking about it then
+ ## we've found a cycle.
+ try: threadp, value = map[me.name]
+ except KeyError: pass
+ else:
+ if threadp: raise InheritanceCycleError(key, path[:])
+
+ ## See whether the answer is ready waiting for us.
+ try: v = me._itemmap[key]
+ except KeyError: pass
+ else: return v, path[:]
+
+ ## No, apparently, not. Find out our list of parents.
+ try:
+ parents = [me._cp.section(p) for p in
+ me._itemmap['@inherit'].replace(',', ' ').split()]
+ except KeyError:
+ parents = []
+
+ ## Initially we have no idea.
+ value = None
+ winner = None
+
+ ## Go through our parents and ask them what they think.
+ map[me.name] = True, None
+ for p in parents:
+
+ ## See whether we get an answer. If not, keep on going.
+ v, pp = p._get(key, map, path)
+ if v is None: continue
+
+ ## If we got an answer, check that it matches any previous ones.
+ if value is None:
+ value = v
+ winner = pp
+ elif value != v:
+ raise AmbiguousOptionError(key, winner, value, pp, v)
+
+ ## That's the best we could manage.
+ map[me.name] = False, value
+ return value, winner
+
+ finally:
+ ## Remove us from the path again.
+ path.pop()
+
+ def get(me, key, resolvep = True):
+ """
+ Retrieve the value of KEY from this section.
+ """
+
+ ## Special handling for the `name' key.
+ if key == 'name':
+ value = me._itemmap.get('name', me.name)
+ else:
+ value, _ = me._get(key)
+ if value is None:
+ raise MissingKeyException(me.name, key)
+
+ ## Expand the value and return it.
+ return me._expand(value, resolvep)
+
+ def items(me, resolvep = True):
+ """
+ Return a list of (NAME, VALUE) items in this section.
+
+ This extends the default method by handling the inheritance chain.
+ """
+
+ ## Initialize for a depth-first walk of the inheritance graph.
+ d = {}
+ visited = {}
+ stack = [me.name]
+
+ ## Visit nodes, collecting their keys. Don't believe the values:
+ ## resolving inheritance is too hard to do like this.
+ while stack:
+ sec = me._cp.section(stack.pop())
+ if sec.name in visited: continue
+ visited[sec.name] = True
+
+ for key, value in sec._itemmap.iteritems():
+ if key == '@inherit': stack += value.replace(',', ' ').split()
+ else: d[key] = None
+
+ ## Now collect the values for the known keys, one by one.
+ items = []
+ for key in d: items.append((key, me.get(key, resolvep)))
+
+ ## And we're done.
+ return items
+
+class MyConfigParser (object):
~mdw / tripe / blobdiff