bitbake: compat, event: use OrderedDict from py2.7 for the event handlers

This ensures that our event handlers get run in registration order, making the
behavior more deterministic. I pulled in the python2.7 OrderedDict to avoid
essentially reimplementing a version of it ourselves, figuring we can drop it
when we bump our required python version next.

(Bitbake rev: 44aa0b0537d3fbd1272015e7677948f84d8c0607)

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 215 insertions, 1 deletions

diff --git a/bitbake/lib/bb/compat.py b/bitbake/lib/bb/compat.py
index c6978fccc5..1466da2379 100644
--- a/bitbake/lib/bb/compat.py
+++ b/bitbake/lib/bb/compat.py
@@ -1,5 +1,11 @@
 """Code pulled from future python versions, here for compatibility"""
 
+from collections import MutableMapping, KeysView, ValuesView, ItemsView
+try:
+    from thread import get_ident as _get_ident
+except ImportError:
+    from dummy_thread import get_ident as _get_ident
+
 def total_ordering(cls):
     """Class decorator that fills in missing ordering methods"""
     convert = {
@@ -26,3 +32,210 @@ def total_ordering(cls):
             opfunc.__doc__ = getattr(int, opname).__doc__
             setattr(cls, opname, opfunc)
     return cls
+
+class OrderedDict(dict):
+    'Dictionary that remembers insertion order'
+    # An inherited dict maps keys to values.
+    # The inherited dict provides __getitem__, __len__, __contains__, and get.
+    # The remaining methods are order-aware.
+    # Big-O running times for all methods are the same as regular dictionaries.
+
+    # The internal self.__map dict maps keys to links in a doubly linked list.
+    # The circular doubly linked list starts and ends with a sentinel element.
+    # The sentinel element never gets deleted (this simplifies the algorithm).
+    # Each link is stored as a list of length three:  [PREV, NEXT, KEY].
+
+    def __init__(self, *args, **kwds):
+        '''Initialize an ordered dictionary.  The signature is the same as
+        regular dictionaries, but keyword arguments are not recommended because
+        their insertion order is arbitrary.
+
+        '''
+        if len(args) > 1:
+            raise TypeError('expected at most 1 arguments, got %d' % len(args))
+        try:
+            self.__root
+        except AttributeError:
+            self.__root = root = []                     # sentinel node
+            root[:] = [root, root, None]
+            self.__map = {}
+        self.__update(*args, **kwds)
+
+    def __setitem__(self, key, value, PREV=0, NEXT=1, dict_setitem=dict.__setitem__):
+        'od.__setitem__(i, y) <==> od[i]=y'
+        # Setting a new item creates a new link at the end of the linked list,
+        # and the inherited dictionary is updated with the new key/value pair.
+        if key not in self:
+            root = self.__root
+            last = root[PREV]
+            last[NEXT] = root[PREV] = self.__map[key] = [last, root, key]
+        dict_setitem(self, key, value)
+
+    def __delitem__(self, key, PREV=0, NEXT=1, dict_delitem=dict.__delitem__):
+        'od.__delitem__(y) <==> del od[y]'
+        # Deleting an existing item uses self.__map to find the link which gets
+        # removed by updating the links in the predecessor and successor nodes.
+        dict_delitem(self, key)
+        link_prev, link_next, key = self.__map.pop(key)
+        link_prev[NEXT] = link_next
+        link_next[PREV] = link_prev
+
+    def __iter__(self):
+        'od.__iter__() <==> iter(od)'
+        # Traverse the linked list in order.
+        NEXT, KEY = 1, 2
+        root = self.__root
+        curr = root[NEXT]
+        while curr is not root:
+            yield curr[KEY]
+            curr = curr[NEXT]
+
+    def __reversed__(self):
+        'od.__reversed__() <==> reversed(od)'
+        # Traverse the linked list in reverse order.
+        PREV, KEY = 0, 2
+        root = self.__root
+        curr = root[PREV]
+        while curr is not root:
+            yield curr[KEY]
+            curr = curr[PREV]
+
+    def clear(self):
+        'od.clear() -> None.  Remove all items from od.'
+        for node in self.__map.itervalues():
+            del node[:]
+        root = self.__root
+        root[:] = [root, root, None]
+        self.__map.clear()
+        dict.clear(self)
+
+    # -- the following methods do not depend on the internal structure --
+
+    def keys(self):
+        'od.keys() -> list of keys in od'
+        return list(self)
+
+    def values(self):
+        'od.values() -> list of values in od'
+        return [self[key] for key in self]
+
+    def items(self):
+        'od.items() -> list of (key, value) pairs in od'
+        return [(key, self[key]) for key in self]
+
+    def iterkeys(self):
+        'od.iterkeys() -> an iterator over the keys in od'
+        return iter(self)
+
+    def itervalues(self):
+        'od.itervalues -> an iterator over the values in od'
+        for k in self:
+            yield self[k]
+
+    def iteritems(self):
+        'od.iteritems -> an iterator over the (key, value) pairs in od'
+        for k in self:
+            yield (k, self[k])
+
+    update = MutableMapping.update
+
+    __update = update # let subclasses override update without breaking __init__
+
+    __marker = object()
+
+    def pop(self, key, default=__marker):
+        '''od.pop(k[,d]) -> v, remove specified key and return the corresponding
+        value.  If key is not found, d is returned if given, otherwise KeyError
+        is raised.
+
+        '''
+        if key in self:
+            result = self[key]
+            del self[key]
+            return result
+        if default is self.__marker:
+            raise KeyError(key)
+        return default
+
+    def setdefault(self, key, default=None):
+        'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od'
+        if key in self:
+            return self[key]
+        self[key] = default
+        return default
+
+    def popitem(self, last=True):
+        '''od.popitem() -> (k, v), return and remove a (key, value) pair.
+        Pairs are returned in LIFO order if last is true or FIFO order if false.
+
+        '''
+        if not self:
+            raise KeyError('dictionary is empty')
+        key = next(reversed(self) if last else iter(self))
+        value = self.pop(key)
+        return key, value
+
+    def __repr__(self, _repr_running={}):
+        'od.__repr__() <==> repr(od)'
+        call_key = id(self), _get_ident()
+        if call_key in _repr_running:
+            return '...'
+        _repr_running[call_key] = 1
+        try:
+            if not self:
+                return '%s()' % (self.__class__.__name__,)
+            return '%s(%r)' % (self.__class__.__name__, self.items())
+        finally:
+            del _repr_running[call_key]
+
+    def __reduce__(self):
+        'Return state information for pickling'
+        items = [[k, self[k]] for k in self]
+        inst_dict = vars(self).copy()
+        for k in vars(OrderedDict()):
+            inst_dict.pop(k, None)
+        if inst_dict:
+            return (self.__class__, (items,), inst_dict)
+        return self.__class__, (items,)
+
+    def copy(self):
+        'od.copy() -> a shallow copy of od'
+        return self.__class__(self)
+
+    @classmethod
+    def fromkeys(cls, iterable, value=None):
+        '''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S.
+        If not specified, the value defaults to None.
+
+        '''
+        self = cls()
+        for key in iterable:
+            self[key] = value
+        return self
+
+    def __eq__(self, other):
+        '''od.__eq__(y) <==> od==y.  Comparison to another OD is order-sensitive
+        while comparison to a regular mapping is order-insensitive.
+
+        '''
+        if isinstance(other, OrderedDict):
+            return len(self)==len(other) and self.items() == other.items()
+        return dict.__eq__(self, other)
+
+    def __ne__(self, other):
+        'od.__ne__(y) <==> od!=y'
+        return not self == other
+
+    # -- the following methods support python 3.x style dictionary views --
+
+    def viewkeys(self):
+        "od.viewkeys() -> a set-like object providing a view on od's keys"
+        return KeysView(self)
+
+    def viewvalues(self):
+        "od.viewvalues() -> an object providing a view on od's values"
+        return ValuesView(self)
+
+    def viewitems(self):
+        "od.viewitems() -> a set-like object providing a view on od's items"
+        return ItemsView(self)
diff --git a/bitbake/lib/bb/event.py b/bitbake/lib/bb/event.py
index ab62d4d055..7ee28fcfcb 100644
--- a/bitbake/lib/bb/event.py
+++ b/bitbake/lib/bb/event.py
@@ -32,6 +32,7 @@ import logging
 import atexit
 import traceback
 import bb.utils
+import bb.compat
 
 # This is the pid for which we should generate the event. This is set when
 # the runqueue forks off.
@@ -53,7 +54,7 @@ Registered        = 10
 AlreadyRegistered = 14
 
 # Internal
-_handlers = {}
+_handlers = bb.compat.OrderedDict()
 _ui_handlers = {}
 _ui_handler_seq = 0