def get_by_filters(cls,
context,
filters,
sort_key='created_at',
sort_dir='desc',
limit=None,
marker=None,
expected_attrs=None,
use_slave=False,
sort_keys=None,
sort_dirs=None):
if sort_keys or sort_dirs:
db_inst_list = db.instance_get_all_by_filters_sort(
context,
filters,
limit=limit,
marker=marker,
columns_to_join=_expected_cols(expected_attrs),
use_slave=use_slave,
sort_keys=sort_keys,
sort_dirs=sort_dirs)
else:
db_inst_list = db.instance_get_all_by_filters(
context,
filters,
sort_key,
sort_dir,
limit=limit,
marker=marker,
columns_to_join=_expected_cols(expected_attrs),
use_slave=use_slave)
return _make_instance_list(context, cls(), db_inst_list,
expected_attrs)
def get_by_filters(self, ctx, filters, limit, marker, **kwargs):
return db.instance_get_all_by_filters_sort(
ctx,
filters,
limit=limit,
marker=marker,
sort_keys=self.sort_ctx.sort_keys,
sort_dirs=self.sort_ctx.sort_dirs,
**kwargs)
def _get_by_filters_impl(cls, context, filters,
sort_key='created_at', sort_dir='desc', limit=None,
marker=None, expected_attrs=None, use_slave=False,
sort_keys=None, sort_dirs=None):
if sort_keys or sort_dirs:
db_inst_list = db.instance_get_all_by_filters_sort(
context, filters, limit=limit, marker=marker,
columns_to_join=_expected_cols(expected_attrs),
sort_keys=sort_keys, sort_dirs=sort_dirs)
else:
db_inst_list = db.instance_get_all_by_filters(
context, filters, sort_key, sort_dir, limit=limit,
marker=marker, columns_to_join=_expected_cols(expected_attrs))
return _make_instance_list(context, cls(), db_inst_list,
expected_attrs)
def do_query(ctx):
"""Generate InstanceWrapper(Instance) objects from a cell.
We do this inside the thread (created by
scatter_gather_all_cells()) so that we return wrappers and
avoid having to iterate the combined result list in the caller
again. This is run against each cell by the scatter_gather
routine.
"""
# The local marker is a uuid of an instance in a cell that is found
# by the special method instance_get_by_sort_filters(). It should
# be the next instance in order according to the sort provided,
# but after the marker instance which may have been in another cell.
local_marker = None
# Since the regular DB query routines take a marker and assume that
# the marked instance was the last entry of the previous page, we
# may need to prefix it to our result query if we're not the cell
# that had the actual marker instance.
local_marker_prefix = []
if marker:
# FIXME(danms): If we knew which cell we were in here, we could
# avoid looking up the marker again. But, we don't currently.
local_marker = db.instance_get_by_sort_filters(
ctx, sort_keys, sort_dirs, global_marker_values)
if local_marker:
if local_marker != marker:
# We did find a marker in our cell, but it wasn't
# the global marker. Thus, we will use it as our
# marker in the main query below, but we also need
# to prefix that result with this marker instance
# since the result below will not return it and it
# has not been returned to the user yet. Note that
# we do _not_ prefix the marker instance if our
# marker was the global one since that has already
# been sent to the user.
local_marker_filters = copy.copy(filters)
if 'uuid' not in local_marker_filters:
# If a uuid filter was provided, it will
# have included our marker already if this instance
# is desired in the output set. If it wasn't, we
# specifically query for it. If the other filters would
# have excluded it, then we'll get an empty set here
# and not include it in the output as expected.
local_marker_filters['uuid'] = [local_marker]
local_marker_prefix = db.instance_get_all_by_filters_sort(
ctx,
local_marker_filters,
limit=1,
marker=None,
columns_to_join=columns_to_join,
sort_keys=sort_keys,
sort_dirs=sort_dirs)
else:
# There was a global marker but everything in our cell is
# _before_ that marker, so we return nothing. If we didn't
# have this clause, we'd pass marker=None to the query below
# and return a full unpaginated set for our cell.
return []
main_query_result = db.instance_get_all_by_filters_sort(
ctx,
filters,
limit=limit,
marker=local_marker,
columns_to_join=columns_to_join,
sort_keys=sort_keys,
sort_dirs=sort_dirs)
return (InstanceWrapper(sort_ctx, inst) for inst in itertools.chain(
local_marker_prefix, main_query_result))
