##############################################################################
#
# Copyright (c) 2001 Zope Corporation and Contributors. All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
######################################################################
# Sequence batching support
import util
__allow_access_to_unprotected_subobjects__={'batch': 1}
__roles__=None
class batch(util.Base):
"""Create a sequence batch"""
def __init__(self, sequence, size, start=0, end=0,
orphan=3, overlap=0):
start=start+1
start,end,sz=opt(start,end,size,orphan,sequence)
self._last=end-1
self._first=start-1
self._sequence=sequence
self._size=size
self._start=start
self._end=end
self._orphan=orphan
self._overlap=overlap
def previous_sequence(self): return self._first
def previous_sequence_end_number(self):
start,end,spam=opt(0, self._start-1+self._overlap,
self._size, self._orphan, self._sequence)
return end
def previous_sequence_start_number(self):
start,end,spam=opt(0, self._start-1+self._overlap,
self._size, self._orphan, self._sequence)
return start
def previous_sequence_end_item(self):
start,end,spam=opt(0, self._start-1+self._overlap,
self._size, self._orphan, self._sequence)
return self._sequence[end-1]
def previous_sequence_start_item(self):
start,end,spam=opt(0, self._start-1+self._overlap,
self._size, self._orphan, self._sequence)
return self._sequence[start-1]
def next_sequence_end_number(self):
start,end,spam=opt(self._end+1-self._overlap, 0,
self._size, self._orphan, self._sequence)
return end
def next_sequence_start_number(self):
start,end,spam=opt(self._end+1-self._overlap, 0,
self._size, self._orphan, self._sequence)
return start
def next_sequence_end_item(self):
start,end,spam=opt(self._end+1-self._overlap, 0,
self._size, self._orphan, self._sequence)
return self._sequence[end-1]
def next_sequence_start_item(self):
start,end,spam=opt(self._end+1-self._overlap, 0,
self._size, self._orphan, self._sequence)
return self._sequence[start-1]
def next_sequence(self):
try: self._sequence[self._end]
except IndexError: return 0
else: return 1
def __getitem__(self, index):
if index > self._last: raise IndexError, index
return self._sequence[index+self._first]
def opt(start,end,size,orphan,sequence):
if size < 1:
if start > 0 and end > 0 and end >= start:
size=end+1-start
else: size=7
if start > 0:
try: sequence[start-1]
except: start=len(sequence)
if end > 0:
if end < start: end=start
else:
end=start+size-1
try: sequence[end+orphan-1]
except: end=len(sequence)
elif end > 0:
try: sequence[end-1]
except: end=len(sequence)
start=end+1-size
if start - 1 < orphan: start=1
else:
start=1
end=start+size-1
try: sequence[end+orphan-1]
except: end=len(sequence)
return start,end,size
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