def paginate_resources(cls, request, resources, on_fail_status):
"""Truncates a list of resources based on ClientPagingControls
Args:
request (object): The parsed protobuf request object
resources (list of objects): The resources to be paginated
Returns:
list: The paginated list of resources
object: The ClientPagingResponse to be sent back to the client
"""
if not resources:
return (resources,
client_list_control_pb2.ClientPagingResponse(
total_resources=0))
paging = request.paging
count = min(paging.count, MAX_PAGE_SIZE) or MAX_PAGE_SIZE
# Find the start index from the location marker sent
try:
if paging.start_id:
start_index = cls.index_by_id(paging.start_id, resources)
elif paging.end_id:
end_index = cls.index_by_id(paging.end_id, resources)
start_index = end_index + 1 - count
else:
start_index = paging.start_index
if start_index < 0 or start_index >= len(resources):
raise AssertionError
except AssertionError:
raise _ResponseFailed(on_fail_status)
paged_resources = resources[start_index:start_index + count]
paging_response = client_list_control_pb2.ClientPagingResponse(
next_id=cls.id_by_index(start_index + count, resources),
previous_id=cls.id_by_index(start_index - 1, resources),
start_index=start_index,
total_resources=len(resources))
return paged_resources, paging_response
def paginate_resources(cls, request, resources, on_fail_status):
"""Truncates a list of resources based on ClientPagingControls
Args:
request (object): The parsed protobuf request object
resources (list of objects): The resources to be paginated
Returns:
list: The paginated list of resources
object: The ClientPagingResponse to be sent back to the client
"""
if not resources:
return (resources, client_list_control_pb2.ClientPagingResponse())
paging = request.paging
limit = min(paging.limit, MAX_PAGE_SIZE) or DEFAULT_PAGE_SIZE
# Find the start index from the location marker sent
try:
if paging.start:
start_index = cls.index_by_id(paging.start, resources)
else:
start_index = 0
if start_index < 0 or start_index >= len(resources):
raise AssertionError
except AssertionError:
raise _ResponseFailed(on_fail_status)
paged_resources = resources[start_index: start_index + limit]
if start_index + limit < len(resources):
paging_response = client_list_control_pb2.ClientPagingResponse(
next=cls.id_by_index(start_index + limit, resources),
start=cls.id_by_index(start_index, resources),
limit=limit)
else:
paging_response = client_list_control_pb2.ClientPagingResponse(
start=cls.id_by_index(start_index, resources),
limit=limit)
return paged_resources, paging_response
def _respond(self, request):
head_block = self._get_head_block(request)
self._validate_ids(request.block_ids)
blocks = None
paging_response = None
if request.block_ids:
blocks = self._block_store.get_blocks(request.block_ids)
blocks = itertools.filterfalse(
lambda block: block.block_num > head_block.block_num, blocks)
# realize the iterator
blocks = list(map(lambda blkw: blkw.block, blocks))
paging_response = client_list_control_pb2.ClientPagingResponse()
else:
paging = request.paging
sort_reverse = BlockListRequest.is_reverse(
request.sorting, self._status.INVALID_SORT)
limit = min(paging.limit, MAX_PAGE_SIZE) or DEFAULT_PAGE_SIZE
iterargs = {'reverse': not sort_reverse}
if paging.start:
iterargs['start_block_num'] = paging.start
elif not sort_reverse:
iterargs['start_block'] = head_block
block_iter = None
try:
block_iter = self._block_store.get_block_iter(**iterargs)
blocks = block_iter
if sort_reverse:
blocks = itertools.takewhile(
lambda block: block.block_num <= head_block.block_num,
blocks)
blocks = itertools.islice(blocks, limit)
# realize the result list, which will evaluate the underlying
# iterator
blocks = list(map(lambda blkw: blkw.block, blocks))
next_block = next(block_iter, None)
if next_block:
next_block_num = block_num_to_hex(next_block.block_num)
else:
next_block_num = None
block_id = blocks[0].header_signature
start = self._block_store[block_id].block_num
except ValueError:
if paging.start:
return self._status.INVALID_PAGING
return self._status.NO_ROOT
except KeyError:
if paging.start:
return self._status.INVALID_PAGING
return self._status.NO_ROOT
paging_response = client_list_control_pb2.ClientPagingResponse(
next=next_block_num,
limit=limit,
start=block_num_to_hex(start))
if not blocks:
return self._wrap_response(self._status.NO_RESOURCE,
head_id=head_block.identifier,
paging=paging_response)
return self._wrap_response(head_id=head_block.identifier,
paging=paging_response,
blocks=blocks)
def _respond(self, request):
head_block = self._get_head_block(request)
blocks = None
paging_response = None
if request.block_ids:
blocks = self._block_store.get_blocks(request.block_ids)
blocks = itertools.filterfalse(
lambda block: block.block_num > head_block.block_num, blocks)
# realize the iterator
blocks = list(map(lambda blkw: blkw.block, blocks))
paging_response = client_list_control_pb2.ClientPagingResponse(
total_resources=len(blocks))
else:
paging = request.paging
sort_reverse = BlockListRequest.is_reverse(
request.sorting, self._status.INVALID_SORT)
count = min(paging.count, MAX_PAGE_SIZE) or MAX_PAGE_SIZE
iterargs = {'reverse': not sort_reverse}
if paging.start_id:
iterargs['start_block_num'] = paging.start_id
elif not sort_reverse:
iterargs['start_block'] = head_block
block_iter = None
try:
block_iter = self._block_store.get_block_iter(**iterargs)
blocks = block_iter
if sort_reverse:
blocks = itertools.takewhile(
lambda block: block.block_num <= head_block.block_num,
blocks)
blocks = itertools.islice(blocks, count)
# realize the result list, which will evaluate the underlying
# iterator
blocks = list(map(lambda blkw: blkw.block, blocks))
next_block = next(block_iter, None)
if next_block:
next_block_num = BlockStore.block_num_to_hex(
next_block.block_num)
else:
next_block_num = None
except ValueError:
if paging.start_id:
return self._status.INVALID_PAGING
return self._status.NO_ROOT
paging_response = client_list_control_pb2.ClientPagingResponse(
next_id=next_block_num,
total_resources=head_block.block_num + 1)
if not blocks:
return self._wrap_response(self._status.NO_RESOURCE,
head_id=head_block.identifier,
paging=paging_response)
return self._wrap_response(head_id=head_block.identifier,
paging=paging_response,
blocks=blocks)
