class Dalli::Protocol::Binary::ResponseProcessor
Class that encapsulates logic for processing binary protocol responses from memcached. Includes logic for pulling data from an IO source and parsing into local values. Handles errors on unexpected values.
Constants
- RESPONSE_CODES
Response codes taken from: github.com/memcached/memcached/wiki/BinaryProtocolRevamped#response-status
Public Class Methods
# File lib/dalli/protocol/binary/response_processor.rb, line 34 def initialize(io_source, value_marshaller) @io_source = io_source @value_marshaller = value_marshaller end
Public Instance Methods
# File lib/dalli/protocol/binary/response_processor.rb, line 184 def auth_response(buf = read_header) resp_header = ResponseHeader.new(buf) body_len = resp_header.body_len validate_auth_format(resp_header.extra_len, body_len) content = read(body_len) if body_len.positive? [resp_header.status, content] end
# File lib/dalli/protocol/binary/response_processor.rb, line 150 def consume_all_responses_until_noop loop do resp_header, = read_response # This is the response to the terminating noop / end of stat return true if resp_header.ok? && resp_header.key_len.zero? end end
# File lib/dalli/protocol/binary/response_processor.rb, line 192 def contains_header?(buf) return false unless buf buf.bytesize >= ResponseHeader::SIZE end
# File lib/dalli/protocol/binary/response_processor.rb, line 103 def data_cas_response resp_header, body = read_response return [nil, resp_header.cas] if resp_header.not_found? return [nil, false] if resp_header.not_stored? raise_on_not_ok!(resp_header) return [nil, resp_header.cas] unless body [unpack_response_body(resp_header, body, true).last, resp_header.cas] end
Returns the new value for the key, if found and updated
# File lib/dalli/protocol/binary/response_processor.rb, line 115 def decr_incr body = generic_response body ? body.unpack1('Q>') : body end
# File lib/dalli/protocol/binary/response_processor.rb, line 95 def delete resp_header, = read_response return false if resp_header.not_found? || resp_header.not_stored? raise_on_not_ok!(resp_header) true end
# File lib/dalli/protocol/binary/response_processor.rb, line 138 def flush no_body_response end
# File lib/dalli/protocol/binary/response_processor.rb, line 158 def generic_response resp_header, body = read_response return false if resp_header.not_stored? # Not stored, normal status for add operation return nil if resp_header.not_found? raise_on_not_ok!(resp_header) return true unless body unpack_response_body(resp_header, body, false).last end
# File lib/dalli/protocol/binary/response_processor.rb, line 69 def get(cache_nils: false) resp_header, body = read_response return false if resp_header.not_stored? # Not stored, normal status for add operation return cache_nils ? ::Dalli::NOT_FOUND : nil if resp_header.not_found? raise_on_not_ok!(resp_header) return true unless body unpack_response_body(resp_header, body, true).last end
This method returns an array of values used in a pipelined getk process. The first value is the number of bytes by which to advance the pointer in the buffer. If the complete response is found in the buffer, this will be the response size. Otherwise it is zero.
The remaining three values in the array are the ResponseHeader
, key, and value.
# File lib/dalli/protocol/binary/response_processor.rb, line 212 def getk_response_from_buffer(buf) # There's no header in the buffer, so don't advance return [0, nil, nil, nil, nil] unless contains_header?(buf) resp_header = response_header_from_buffer(buf) body_len = resp_header.body_len # We have a complete response that has no body. # This is either the response to the terminating # noop or, if the status is not zero, an intermediate # error response that needs to be discarded. return [ResponseHeader::SIZE, resp_header.ok?, resp_header.cas, nil, nil] if body_len.zero? resp_size = ResponseHeader::SIZE + body_len # The header is in the buffer, but the body is not. As we don't have # a complete response, don't advance the buffer return [0, nil, nil, nil, nil] unless buf.bytesize >= resp_size # The full response is in our buffer, so parse it and return # the values body = buf.byteslice(ResponseHeader::SIZE, body_len) key, value = unpack_response_body(resp_header, body, true) [resp_size, resp_header.ok?, resp_header.cas, key, value] end
# File lib/dalli/protocol/binary/response_processor.rb, line 170 def no_body_response resp_header, = read_response return false if resp_header.not_stored? # Not stored, possible status for append/prepend/delete raise_on_not_ok!(resp_header) true end
# File lib/dalli/protocol/binary/response_processor.rb, line 63 def raise_on_not_ok!(resp_header) return if resp_header.ok? raise Dalli::DalliError, "Response error #{resp_header.status}: #{RESPONSE_CODES[resp_header.status]}" end
# File lib/dalli/protocol/binary/response_processor.rb, line 39 def read(num_bytes) @io_source.read(num_bytes) end
# File lib/dalli/protocol/binary/response_processor.rb, line 59 def read_header read(ResponseHeader::SIZE) || raise(Dalli::NetworkError, 'No response') end
# File lib/dalli/protocol/binary/response_processor.rb, line 43 def read_response resp_header = ResponseHeader.new(read_header) body = read(resp_header.body_len) if resp_header.body_len.positive? [resp_header, body] end
# File lib/dalli/protocol/binary/response_processor.rb, line 142 def reset generic_response end
# File lib/dalli/protocol/binary/response_processor.rb, line 198 def response_header_from_buffer(buf) ResponseHeader.new(buf) end
# File lib/dalli/protocol/binary/response_processor.rb, line 120 def stats hash = {} loop do resp_header, body = read_response # This is the response to the terminating noop / end of stat return hash if resp_header.ok? && resp_header.key_len.zero? # Ignore any responses with non-zero status codes, # such as errors from set operations. That allows # this code to be used at the end of a multi # block to clear any error responses from inside the multi. next unless resp_header.ok? key, value = unpack_response_body(resp_header, body, true) hash[key] = value end end
Response for a storage operation. Returns the cas on success. False if the value wasn’t stored. And raises an error on all other error codes from memcached.
# File lib/dalli/protocol/binary/response_processor.rb, line 86 def storage_response resp_header, = read_response return nil if resp_header.not_found? return false if resp_header.not_stored? # Not stored, normal status for add operation raise_on_not_ok!(resp_header) resp_header.cas end
# File lib/dalli/protocol/binary/response_processor.rb, line 49 def unpack_response_body(resp_header, body, parse_as_stored_value) extra_len = resp_header.extra_len key_len = resp_header.key_len bitflags = extra_len.positive? ? body.unpack1('N') : 0x0 key = body.byteslice(extra_len, key_len).force_encoding('UTF-8') if key_len.positive? value = body.byteslice((extra_len + key_len)..-1) value = parse_as_stored_value ? @value_marshaller.retrieve(value, bitflags) : value [key, value] end
# File lib/dalli/protocol/binary/response_processor.rb, line 178 def validate_auth_format(extra_len, count) return if extra_len.zero? raise Dalli::NetworkError, "Unexpected message format: #{extra_len} #{count}" end
# File lib/dalli/protocol/binary/response_processor.rb, line 146 def version generic_response end