def __init__(self, *parts):
self.parts = parts
+ small = object()
+ large = object()
+ def minim(self, *parts):
+ return parts + tuple([self.small] * (len(self.parts) - len(parts)))
+ def maxim(self, *parts):
+ return parts + tuple([self.large] * (len(self.parts) - len(parts)))
+
def encode(self, obs):
if len(obs) != len(self.parts):
raise ValueError("invalid length of compound data: " + str(len(obs)) + ", rather than " + len(self.parts))
buf = bytearray()
for ob, part in zip(obs, self.parts):
- dat = part.encode(ob)
- if len(dat) < 128:
- buf.append(0x80 | len(dat))
- buf.extend(dat)
+ if ob is self.small:
+ buf.append(0x01)
+ elif ob is self.large:
+ buf.append(0x02)
else:
- buf.extend(struct.pack(">i", len(dat)))
- buf.extend(dat)
+ dat = part.encode(ob)
+ if len(dat) < 128:
+ buf.append(0x80 | len(dat))
+ buf.extend(dat)
+ else:
+ buf.extend(struct.pack(">BI", 0, len(dat)))
+ buf.extend(dat)
return bytes(buf)
def decode(self, dat):
ret = []
off = 0
for part in self.parts:
- if dat[off] & 0x80:
- ln = dat[off] & 0x7f
- off += 1
+ fl = dat[off]
+ off += 1
+ if fl & 0x80:
+ ln = fl & 0x7f
+ elif fl == 0x01:
+ ret.append(self.small)
+ continue
+ elif fl == 0x02:
+ ret.append(self.large)
+ continue
else:
- ln = struct.unpack(">i", dat[off:off + 4])[0]
+ ln = struct.unpack(">I", dat[off:off + 4])[0]
off += 4
- ret.append(part.decode(dat[off:off + len]))
- off += len
+ ret.append(part.decode(dat[off:off + ln]))
+ off += ln
return tuple(ret)
def compare(self, al, bl):
if (len(al) != len(self.parts)) or (len(bl) != len(self.parts)):
raise ValueError("invalid length of compound data: " + str(len(al)) + ", " + str(len(bl)) + ", rather than " + len(self.parts))
for a, b, part in zip(al, bl, self.parts):
+ if a in (self.small, self.large) or b in (self.small, self.large):
+ if a is b:
+ return 0
+ if a is self.small:
+ return -1
+ elif b is self.small:
+ return 1
+ elif a is self.large:
+ return 1
+ elif b is self.large:
+ return -1
c = part.compare(a, b)
if c != 0:
return c
def _decode(self, d):
k, v = d
- k = self.type.decode(k)
+ k = self.typ.decode(k)
v = struct.unpack(">Q", v)[0]
return k, v
@dloopfun
def first(self):
try:
- if self.fd is None:
+ if self.fd is missing:
self.item = self._decode(self.cur.first())
else:
k, v = self._decode(self.cur.set_range(self.typ.encode(self.fd)))
@dloopfun
def last(self):
try:
- if self.fd is None:
+ if self.ld is missing:
self.item = self._decode(self.cur.last())
else:
- k, v = self._decode(self.cur.set_range(self.typ.encode(self.ld)))
- if self.fi:
- while self.typ.compare(k, self.fd) == 0:
+ try:
+ k, v = self._decode(self.cur.set_range(self.typ.encode(self.ld)))
+ except notfound:
+ k, v = self._decode(self.cur.last())
+ if self.li:
+ while self.typ.compare(k, self.ld) == 0:
k, v = self._decode(self.cur.next())
- k, v = self._decode(self.cur.prev())
+ while self.typ.compare(k, self.ld) > 0:
+ k, v = self._decode(self.cur.prev())
else:
- while self.typ.compare(k, self.fd) >= 0:
+ while self.typ.compare(k, self.ld) >= 0:
k, v = self._decode(self.cur.prev())
self.item = k, v
except notfound:
def next(self):
try:
k, v = self.item = self._decode(self.cur.next())
- if ((self.li and self.typ.compare(k, self.ld) > 0) or
- (not self.li and self.typ.compare(k, self.ld) >= 0)):
+ if (self.ld is not missing and
+ ((self.li and self.typ.compare(k, self.ld) > 0) or
+ (not self.li and self.typ.compare(k, self.ld) >= 0))):
self.item = StopIteration
except notfound:
self.item = StopIteration
def prev(self):
try:
self.item = self._decode(self.cur.prev())
- if ((self.fi and self.typ.compare(k, self.fd) < 0) or
- (not self.fi and self.typ.compare(k, self.fd) <= 0)):
+ if (self.fd is not missing and
+ ((self.fi and self.typ.compare(k, self.fd) < 0) or
+ (not self.fi and self.typ.compare(k, self.fd) <= 0))):
self.item = StopIteration
except notfound:
self.item = StopIteration
def __next__(self):
- if self.item is StopIteration:
- raise StopIteration()
if self.item is None:
if not self.rev:
self.next()
else:
self.prev()
+ if self.item is StopIteration:
+ raise StopIteration()
ret, self.item = self.item, None
return ret
def get(self, *, match=missing, ge=missing, gt=missing, lt=missing, le=missing, all=False, reverse=False):
if all:
- cur = self.cursor(self, None, True, None, True, reverse)
+ cur = self.cursor(self, missing, True, missing, True, reverse)
elif match is not missing:
cur = self.cursor(self, match, True, match, True, reverse)
elif ge is not missing or gt is not missing or lt is not missing or le is not missing:
elif gt is not missing:
fd, fi = gt, False
else:
- fd, fi = None, True
+ fd, fi = missing, True
if le is not missing:
ld, li = le, True
elif lt is not missing:
ld, li = lt, False
else:
- ld, li = None, True
+ ld, li = missing, True
cur = self.cursor(self, fd, fi, ld, li, reverse)
else:
raise NameError("invalid get() specification")