# -*- coding: utf-8 -*-
########################################################################
#
# License: BSD
# Created: June 02, 2004
# Author: Francesc Alted - faltet@pytables.com
#
# $Source: /cvsroot/pytables/pytables/tables/indexes.py $
# $Id$
#
########################################################################
"""Here is defined the IndexArray class."""
from bisect import bisect_left, bisect_right
from tables.node import NotLoggedMixin
from tables.carray import CArray
from tables.earray import EArray
from tables import indexesextension
from tables._past import previous_api, previous_api_property
# Declarations for inheriting
class CacheArray(NotLoggedMixin, EArray, indexesextension.CacheArray):
"""Container for keeping index caches of 1st and 2nd level."""
# Class identifier.
_c_classid = 'CACHEARRAY'
_c_classId = previous_api_property('_c_classid')
class LastRowArray(NotLoggedMixin, CArray, indexesextension.LastRowArray):
"""Container for keeping sorted and indices values of last row of an
index."""
# Class identifier.
_c_classid = 'LASTROWARRAY'
_c_classId = previous_api_property('_c_classid')
[docs]class IndexArray(NotLoggedMixin, EArray, indexesextension.IndexArray):
"""Represent the index (sorted or reverse index) dataset in HDF5 file.
All NumPy typecodes are supported except for complex datatypes.
Parameters
----------
parentnode
The Index class from which this object will hang off.
.. versionchanged:: 3.0
Renamed from *parentNode* to *parentnode*.
name : str
The name of this node in its parent group.
atom
An Atom object representing the shape and type of the atomic objects to
be saved. Only scalar atoms are supported.
title
Sets a TITLE attribute on the array entity.
filters : Filters
An instance of the Filters class that provides information about the
desired I/O filters to be applied during the life of this object.
byteorder
The byteroder of the data on-disk.
"""
# Class identifier.
_c_classid = 'INDEXARRAY'
_c_classId = previous_api_property('_c_classid')
# Properties
# ~~~~~~~~~~
chunksize = property(
lambda self: self.chunkshape[1], None, None,
"""The chunksize for this object.""")
slicesize = property(
lambda self: self.shape[1], None, None,
"""The slicesize for this object.""")
# Other methods
# ~~~~~~~~~~~~~
def __init__(self, parentnode, name,
atom=None, title="",
filters=None, byteorder=None):
"""Create an IndexArray instance."""
self._v_pathname = parentnode._g_join(name)
if atom is not None:
# The shape and chunkshape needs to be fixed here
if name == "sorted":
reduction = parentnode.reduction
shape = (0, parentnode.slicesize // reduction)
chunkshape = (1, parentnode.chunksize // reduction)
else:
shape = (0, parentnode.slicesize)
chunkshape = (1, parentnode.chunksize)
else:
# The shape and chunkshape will be read from disk later on
shape = None
chunkshape = None
super(IndexArray, self).__init__(
parentnode, name, atom, shape, title, filters,
chunkshape=chunkshape, byteorder=byteorder)
# This version of searchBin uses both ranges (1st level) and
# bounds (2nd level) caches. It uses a cache for boundary rows,
# but not for 'sorted' rows (this is only supported for the
# 'optimized' types).
def _search_bin(self, nrow, item):
item1, item2 = item
result1 = -1
result2 = -1
hi = self.shape[1]
ranges = self._v_parent.rvcache
boundscache = self.boundscache
# First, look at the beginning of the slice
begin = ranges[nrow, 0]
# Look for items at the beginning of sorted slices
if item1 <= begin:
result1 = 0
if item2 < begin:
result2 = 0
if result1 >= 0 and result2 >= 0:
return (result1, result2)
# Then, look for items at the end of the sorted slice
end = ranges[nrow, 1]
if result1 < 0:
if item1 > end:
result1 = hi
if result2 < 0:
if item2 >= end:
result2 = hi
if result1 >= 0 and result2 >= 0:
return (result1, result2)
# Finally, do a lookup for item1 and item2 if they were not found
# Lookup in the middle of slice for item1
chunksize = self.chunksize # Number of elements/chunksize
nchunk = -1
# Try to get the bounds row from the LRU cache
nslot = boundscache.getslot(nrow)
if nslot >= 0:
# Cache hit. Use the row kept there.
bounds = boundscache.getitem(nslot)
else:
# No luck with cached data. Read the row and put it in the cache.
bounds = self._v_parent.bounds[nrow]
size = bounds.size * bounds.itemsize
boundscache.setitem(nrow, bounds, size)
if result1 < 0:
# Search the appropriate chunk in bounds cache
nchunk = bisect_left(bounds, item1)
chunk = self._read_sorted_slice(nrow, chunksize * nchunk,
chunksize * (nchunk + 1))
result1 = indexesextension._bisect_left(chunk, item1, chunksize)
result1 += chunksize * nchunk
# Lookup in the middle of slice for item2
if result2 < 0:
# Search the appropriate chunk in bounds cache
nchunk2 = bisect_right(bounds, item2)
if nchunk2 != nchunk:
chunk = self._read_sorted_slice(nrow, chunksize * nchunk2,
chunksize * (nchunk2 + 1))
result2 = indexesextension._bisect_right(chunk, item2, chunksize)
result2 += chunksize * nchunk2
return (result1, result2)
_searchBin = previous_api(_search_bin)
def __str__(self):
"A compact representation of this class"
return "IndexArray(path=%s)" % self._v_pathname
def __repr__(self):
"""A verbose representation of this class."""
return """%s
atom = %r
shape = %s
nrows = %s
chunksize = %s
slicesize = %s
byteorder = %r""" % (self, self.atom, self.shape, self.nrows,
self.chunksize, self.slicesize, self.byteorder)
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