def column_reader(self, fieldname, column=None, reverse=False,
translate=True):
if self.is_closed:
raise ReaderClosed
fieldobj = self.schema[fieldname]
column = column or fieldobj.column_type
if not column:
raise Exception("No column for field %r in %r"
% (fieldname, self))
if self._perdoc.has_column(fieldname):
creader = self._perdoc.column_reader(fieldname, column)
if reverse:
creader.set_reverse()
else:
# This segment doesn't have a column file for this field, so create
# a fake column reader that always returns the default value.
default = column.default_value(reverse)
creader = columns.EmptyColumnReader(default, self.doc_count_all())
if translate:
# Wrap the column in a Translator to give the caller
# nice values instead of sortable representations
fcv = fieldobj.from_column_value
creader = columns.TranslatingColumnReader(creader, fcv)
return creader
def column_reader(self, fieldname, column):
if not self.has_column(fieldname):
raise ValueError("No column %r" % (fieldname, ))
default = column.default_value()
colreaders = []
for r in self._readers:
if r.has_column(fieldname):
cr = r.column_reader(fieldname, column)
else:
cr = columns.EmptyColumnReader(default, r.doc_count_all())
colreaders.append(cr)
if len(colreaders) == 1:
return colreaders[0]
else:
return columns.MultiColumnReader(colreaders)
def column_reader(self, fieldname, translate=True):
column = self.schema[fieldname].column_type
if not column:
raise Exception("Field %r has no column type" % (fieldname, ))
default = column.default_value()
doccount = self.doc_count_all()
creaders = []
for r in self.readers:
if r.has_column(fieldname):
creaders.append(r.column_reader(fieldname,
translate=translate))
else:
creaders.append(columns.EmptyColumnReader(default, doccount))
return columns.MultiColumnReader(creaders)
