Initial decoupling of Connection, ReplSetConnection,

and networking code.
This commit is contained in:
Kyle Banker 2011-11-02 18:00:52 -04:00
parent 3655a94934
commit a5373ddb83
3 changed files with 63 additions and 331 deletions

View File

@ -65,6 +65,7 @@ require 'mongo/util/ssl_socket'
require 'mongo/util/uri_parser'
require 'mongo/collection'
require 'mongo/networking'
require 'mongo/connection'
require 'mongo/repl_set_connection'
require 'mongo/cursor'

View File

@ -25,6 +25,7 @@ module Mongo
# Instantiates and manages connections to MongoDB.
class Connection
include Mongo::Logging
include Mongo::Networking
TCPSocket = ::TCPSocket
Mutex = ::Mutex
@ -33,15 +34,11 @@ module Mongo
Thread.abort_on_exception = true
DEFAULT_PORT = 27017
STANDARD_HEADER_SIZE = 16
RESPONSE_HEADER_SIZE = 20
attr_reader :logger, :size, :auths, :primary, :safe, :host_to_try,
:pool_size, :connect_timeout, :pool_timeout,
:primary_pool, :socket_class
# Counter for generating unique request ids.
@@current_request_id = 0
# Create a connection to single MongoDB instance.
#
@ -382,126 +379,6 @@ module Mongo
@slave_ok
end
# Send a message to MongoDB, adding the necessary headers.
#
# @param [Integer] operation a MongoDB opcode.
# @param [BSON::ByteBuffer] message a message to send to the database.
#
# @option opts [Symbol] :connection (:writer) The connection to which
# this message should be sent. Valid options are :writer and :reader.
#
# @return [Integer] number of bytes sent
def send_message(operation, message, opts={})
if opts.is_a?(String)
warn "Connection#send_message no longer takes a string log message. " +
"Logging is now handled within the Collection and Cursor classes."
opts = {}
end
connection = opts.fetch(:connection, :writer)
begin
add_message_headers(message, operation)
packed_message = message.to_s
if connection == :writer
socket = checkout_writer
else
socket = checkout_reader
end
send_message_on_socket(packed_message, socket)
ensure
checkin(socket)
end
end
# Sends a message to the database, waits for a response, and raises
# an exception if the operation has failed.
#
# @param [Integer] operation a MongoDB opcode.
# @param [BSON::ByteBuffer] message a message to send to the database.
# @param [String] db_name the name of the database. used on call to get_last_error.
# @param [Hash] last_error_params parameters to be sent to getLastError. See DB#error for
# available options.
#
# @see DB#get_last_error for valid last error params.
#
# @return [Hash] The document returned by the call to getlasterror.
def send_message_with_safe_check(operation, message, db_name, log_message=nil, last_error_params=false)
docs = num_received = cursor_id = ''
add_message_headers(message, operation)
last_error_message = BSON::ByteBuffer.new
build_last_error_message(last_error_message, db_name, last_error_params)
last_error_id = add_message_headers(last_error_message, Mongo::Constants::OP_QUERY)
packed_message = message.append!(last_error_message).to_s
begin
sock = checkout_writer
send_message_on_socket(packed_message, sock)
docs, num_received, cursor_id = receive(sock, last_error_id)
ensure
checkin(sock)
end
if num_received == 1 && (error = docs[0]['err'] || docs[0]['errmsg'])
close if error == "not master"
error = "wtimeout" if error == "timeout"
raise OperationFailure.new(docs[0]['code'].to_s + ': ' + error, docs[0]['code'], docs[0])
end
docs[0]
end
# Sends a message to the database and waits for the response.
#
# @param [Integer] operation a MongoDB opcode.
# @param [BSON::ByteBuffer] message a message to send to the database.
# @param [String] log_message this is currently a no-op and will be removed.
# @param [Socket] socket a socket to use in lieu of checking out a new one.
# @param [Boolean] command (false) indicate whether this is a command. If this is a command,
# the message will be sent to the primary node.
# @param [Boolean] command (false) indicate whether the cursor should be exhausted. Set
# this to true only when the OP_QUERY_EXHAUST flag is set.
#
# @return [Array]
# An array whose indexes include [0] documents returned, [1] number of document received,
# and [3] a cursor_id.
def receive_message(operation, message, log_message=nil, socket=nil, command=false,
read=:primary, exhaust=false)
request_id = add_message_headers(message, operation)
packed_message = message.to_s
begin
if socket
sock = socket
should_checkin = false
else
if command
sock = checkout_writer
elsif read == :primary
sock = checkout_writer
elsif read == :secondary
sock = checkout_reader
else
sock = checkout_tagged(read)
end
should_checkin = true
end
result = ''
@safe_mutexes[sock].synchronize do
send_message_on_socket(packed_message, sock)
result = receive(sock, request_id, exhaust)
end
ensure
if should_checkin
checkin(sock)
end
end
result
end
def get_socket_from_thread_local
Thread.current[:socket_map] ||= {}
Thread.current[:socket_map][self] ||= {}
@ -761,212 +638,5 @@ module Mongo
@primary = [host, port]
@primary_pool = Pool.new(self, host, port, :size => @pool_size, :timeout => @pool_timeout)
end
## Low-level connection methods.
def receive(sock, cursor_id, exhaust=false)
begin
if exhaust
docs = []
num_received = 0
while(cursor_id != 0) do
receive_header(sock, cursor_id, exhaust)
number_received, cursor_id = receive_response_header(sock)
new_docs, n = read_documents(number_received, sock)
docs += new_docs
num_received += n
end
return [docs, num_received, cursor_id]
else
receive_header(sock, cursor_id, exhaust)
number_received, cursor_id = receive_response_header(sock)
docs, num_received = read_documents(number_received, sock)
return [docs, num_received, cursor_id]
end
rescue Mongo::ConnectionFailure => ex
close
raise ex
end
end
def receive_header(sock, expected_response, exhaust=false)
header = receive_message_on_socket(16, sock)
size, request_id, response_to = header.unpack('VVV')
if !exhaust && expected_response != response_to
raise Mongo::ConnectionFailure, "Expected response #{expected_response} but got #{response_to}"
end
unless header.size == STANDARD_HEADER_SIZE
raise "Short read for DB response header: " +
"expected #{STANDARD_HEADER_SIZE} bytes, saw #{header.size}"
end
nil
end
def receive_response_header(sock)
header_buf = receive_message_on_socket(RESPONSE_HEADER_SIZE, sock)
if header_buf.length != RESPONSE_HEADER_SIZE
raise "Short read for DB response header; " +
"expected #{RESPONSE_HEADER_SIZE} bytes, saw #{header_buf.length}"
end
flags, cursor_id_a, cursor_id_b, starting_from, number_remaining = header_buf.unpack('VVVVV')
check_response_flags(flags)
cursor_id = (cursor_id_b << 32) + cursor_id_a
[number_remaining, cursor_id]
end
def check_response_flags(flags)
if flags & Mongo::Constants::REPLY_CURSOR_NOT_FOUND != 0
raise Mongo::OperationFailure, "Query response returned CURSOR_NOT_FOUND. " +
"Either an invalid cursor was specified, or the cursor may have timed out on the server."
elsif flags & Mongo::Constants::REPLY_QUERY_FAILURE != 0
# Getting odd failures when a exception is raised here.
end
end
def read_documents(number_received, sock)
docs = []
number_remaining = number_received
while number_remaining > 0 do
buf = receive_message_on_socket(4, sock)
size = buf.unpack('V')[0]
buf << receive_message_on_socket(size - 4, sock)
number_remaining -= 1
docs << BSON::BSON_CODER.deserialize(buf)
end
[docs, number_received]
end
# Constructs a getlasterror message. This method is used exclusively by
# Connection#send_message_with_safe_check.
#
# Because it modifies message by reference, we don't need to return it.
def build_last_error_message(message, db_name, opts)
message.put_int(0)
BSON::BSON_RUBY.serialize_cstr(message, "#{db_name}.$cmd")
message.put_int(0)
message.put_int(-1)
cmd = BSON::OrderedHash.new
cmd[:getlasterror] = 1
if opts.is_a?(Hash)
opts.assert_valid_keys(:w, :wtimeout, :fsync)
cmd.merge!(opts)
end
message.put_binary(BSON::BSON_CODER.serialize(cmd, false).to_s)
nil
end
# Prepares a message for transmission to MongoDB by
# constructing a valid message header.
#
# Note: this method modifies message by reference.
#
# @return [Integer] the request id used in the header
def add_message_headers(message, operation)
headers = [
# Message size.
16 + message.size,
# Unique request id.
request_id = get_request_id,
# Response id.
0,
# Opcode.
operation
].pack('VVVV')
message.prepend!(headers)
request_id
end
# Increment and return the next available request id.
#
# return [Integer]
def get_request_id
request_id = ''
@id_lock.synchronize do
request_id = @@current_request_id += 1
end
request_id
end
# Low-level method for sending a message on a socket.
# Requires a packed message and an available socket,
#
# @return [Integer] number of bytes sent
def send_message_on_socket(packed_message, socket)
begin
total_bytes_sent = socket.send(packed_message, 0)
if total_bytes_sent != packed_message.size
packed_message.slice!(0, total_bytes_sent)
while packed_message.size > 0
byte_sent = socket.send(packed_message, 0)
total_bytes_sent += byte_sent
packed_message.slice!(0, byte_sent)
end
end
total_bytes_sent
rescue => ex
close
raise ConnectionFailure, "Operation failed with the following exception: #{ex}"
end
end
# Low-level method for receiving data from socket.
# Requires length and an available socket.
def receive_message_on_socket(length, socket)
begin
if @op_timeout
message = nil
Mongo::TimeoutHandler.timeout(@op_timeout, OperationTimeout) do
message = receive_data(length, socket)
end
else
message = receive_data(length, socket)
end
rescue => ex
close
if ex.class == OperationTimeout
raise OperationTimeout, "Timed out waiting on socket read."
else
raise ConnectionFailure, "Operation failed with the following exception: #{ex}"
end
end
message
end
def receive_data(length, socket)
message = new_binary_string
socket.read(length, message)
raise ConnectionFailure, "connection closed" unless message && message.length > 0
if message.length < length
chunk = new_binary_string
while message.length < length
socket.read(length - message.length, chunk)
raise ConnectionFailure, "connection closed" unless chunk.length > 0
message << chunk
end
end
message
end
if defined?(Encoding)
BINARY_ENCODING = Encoding.find("binary")
def new_binary_string
"".force_encoding(BINARY_ENCODING)
end
else
def new_binary_string
""
end
end
end
end

View File

@ -422,6 +422,67 @@ module Mongo
private
# Generic initialization code.
def setup(opts)
# Default maximum BSON object size
@max_bson_size = Mongo::DEFAULT_MAX_BSON_SIZE
@safe_mutex_lock = Mutex.new
@safe_mutexes = Hash.new {|hash, key| hash[key] = Mutex.new}
# Determine whether to use SSL.
@ssl = opts.fetch(:ssl, false)
if @ssl
@socket_class = Mongo::SSLSocket
else
@socket_class = ::TCPSocket
end
# Authentication objects
@auths = opts.fetch(:auths, [])
# Lock for request ids.
@id_lock = Mutex.new
# Pool size and timeout.
@pool_size = opts[:pool_size] || 1
if opts[:timeout]
warn "The :timeout option has been deprecated " +
"and will be removed in the 2.0 release. Use :pool_timeout instead."
end
@pool_timeout = opts[:pool_timeout] || opts[:timeout] || 5.0
# Timeout on socket read operation.
@op_timeout = opts[:op_timeout] || nil
# Timeout on socket connect.
@connect_timeout = opts[:connect_timeout] || nil
# Mutex for synchronizing pool access
# TODO: remove this.
@connection_mutex = Mutex.new
# Global safe option. This is false by default.
@safe = opts[:safe] || false
# Condition variable for signal and wait
@queue = ConditionVariable.new
# Connection pool for primay node
@primary = nil
@primary_pool = nil
@logger = opts[:logger] || nil
if @logger
@logger.debug("MongoDB logging. Please note that logging negatively impacts performance " +
"and should be disabled for high-performance production apps.")
end
should_connect = opts.fetch(:connect, true)
connect if should_connect
end
# Given a pool manager, update this connection's
# view of the replica set.
def update_config(new_manager)