codekingpro/portable-devtools

1from threading import RLock2try:3    from collections.abc import Mapping as DictMixin4except ImportError:  # Python < 3.35    try:6        from UserDict import DictMixin  # Python 27    except ImportError:  # Python 3.0-3.38        from collections import Mapping as DictMixin9 10 11# With lazy loading, we might end up with multiple threads triggering12# it at the same time. We need a lock.13_fill_lock = RLock()14 15 16class LazyDict(DictMixin):17    """Dictionary populated on first use."""18    data = None19 20    def __getitem__(self, key):21        if self.data is None:22            _fill_lock.acquire()23            try:24                if self.data is None:25                    self._fill()26            finally:27                _fill_lock.release()28        return self.data[key.upper()]29 30    def __contains__(self, key):31        if self.data is None:32            _fill_lock.acquire()33            try:34                if self.data is None:35                    self._fill()36            finally:37                _fill_lock.release()38        return key in self.data39 40    def __iter__(self):41        if self.data is None:42            _fill_lock.acquire()43            try:44                if self.data is None:45                    self._fill()46            finally:47                _fill_lock.release()48        return iter(self.data)49 50    def __len__(self):51        if self.data is None:52            _fill_lock.acquire()53            try:54                if self.data is None:55                    self._fill()56            finally:57                _fill_lock.release()58        return len(self.data)59 60    def keys(self):61        if self.data is None:62            _fill_lock.acquire()63            try:64                if self.data is None:65                    self._fill()66            finally:67                _fill_lock.release()68        return self.data.keys()69 70 71class LazyList(list):72    """List populated on first use."""73 74    _props = [75        '__str__', '__repr__', '__unicode__',76        '__hash__', '__sizeof__', '__cmp__',77        '__lt__', '__le__', '__eq__', '__ne__', '__gt__', '__ge__',78        'append', 'count', 'index', 'extend', 'insert', 'pop', 'remove',79        'reverse', 'sort', '__add__', '__radd__', '__iadd__', '__mul__',80        '__rmul__', '__imul__', '__contains__', '__len__', '__nonzero__',81        '__getitem__', '__setitem__', '__delitem__', '__iter__',82        '__reversed__', '__getslice__', '__setslice__', '__delslice__']83 84    def __new__(cls, fill_iter=None):85 86        if fill_iter is None:87            return list()88 89        # We need a new class as we will be dynamically messing with its90        # methods.91        class LazyList(list):92            pass93 94        fill_iter = [fill_iter]95 96        def lazy(name):97            def _lazy(self, *args, **kw):98                _fill_lock.acquire()99                try:100                    if len(fill_iter) > 0:101                        list.extend(self, fill_iter.pop())102                        for method_name in cls._props:103                            delattr(LazyList, method_name)104                finally:105                    _fill_lock.release()106                return getattr(list, name)(self, *args, **kw)107            return _lazy108 109        for name in cls._props:110            setattr(LazyList, name, lazy(name))111 112        new_list = LazyList()113        return new_list114 115# Not all versions of Python declare the same magic methods.116# Filter out properties that don't exist in this version of Python117# from the list.118LazyList._props = [prop for prop in LazyList._props if hasattr(list, prop)]119 120 121class LazySet(set):122    """Set populated on first use."""123 124    _props = (125        '__str__', '__repr__', '__unicode__',126        '__hash__', '__sizeof__', '__cmp__',127        '__lt__', '__le__', '__eq__', '__ne__', '__gt__', '__ge__',128        '__contains__', '__len__', '__nonzero__',129        '__getitem__', '__setitem__', '__delitem__', '__iter__',130        '__sub__', '__and__', '__xor__', '__or__',131        '__rsub__', '__rand__', '__rxor__', '__ror__',132        '__isub__', '__iand__', '__ixor__', '__ior__',133        'add', 'clear', 'copy', 'difference', 'difference_update',134        'discard', 'intersection', 'intersection_update', 'isdisjoint',135        'issubset', 'issuperset', 'pop', 'remove',136        'symmetric_difference', 'symmetric_difference_update',137        'union', 'update')138 139    def __new__(cls, fill_iter=None):140 141        if fill_iter is None:142            return set()143 144        class LazySet(set):145            pass146 147        fill_iter = [fill_iter]148 149        def lazy(name):150            def _lazy(self, *args, **kw):151                _fill_lock.acquire()152                try:153                    if len(fill_iter) > 0:154                        for i in fill_iter.pop():155                            set.add(self, i)156                        for method_name in cls._props:157                            delattr(LazySet, method_name)158                finally:159                    _fill_lock.release()160                return getattr(set, name)(self, *args, **kw)161            return _lazy162 163        for name in cls._props:164            setattr(LazySet, name, lazy(name))165 166        new_set = LazySet()167        return new_set168 169# Not all versions of Python declare the same magic methods.170# Filter out properties that don't exist in this version of Python171# from the list.172LazySet._props = [prop for prop in LazySet._props if hasattr(set, prop)]173