* VRFS-18: removed transactions from conneciton manager

This commit is contained in:
Seth Call 2012-10-22 19:59:35 -05:00
parent 331c13d858
commit e3027e831b
4 changed files with 224 additions and 141 deletions

View File

@ -5,6 +5,7 @@ require "uuidtools"
require "logging"
require "jam_ruby/errors/permission_error"
require "jam_ruby/errors/state_error"
require "jam_ruby/errors/jam_argument_error"
require "jam_ruby/mq_router"
require "jam_ruby/connection_manager"
require "jam_ruby/version"

View File

@ -13,12 +13,12 @@ module JamRuby
# Or of course we could just port the relevant methods to node-js
class ConnectionManager
attr_accessor :mq_router
attr_accessor :mq_router, :pg_conn
def initialize(conn)
def initialize(options={})
@log = Logging.logger[self]
@mq_router = MQRouter.new
@pg_conn = conn
@pg_conn = options[:conn]
@message_factory = MessageFactory.new
unless PG.threadsafe?
@ -44,24 +44,25 @@ module JamRuby
end
end
def create_connection(user_id, client_id, ip_address)
@pg_conn.transaction do |conn|
conn = @pg_conn
lock_connections(conn)
lock_connections(conn)
conn.exec("INSERT INTO connections (user_id, client_id, ip_address) VALUES ($1, $2, $3)", [user_id, client_id, ip_address]).clear
conn.exec("INSERT INTO connections (user_id, client_id, ip_address) VALUES ($1, $2, $3)", [user_id, client_id, ip_address]).clear
# we just created a new connection-if this is the first time the user has shown up, we need to send out a message to his friends
conn.exec("SELECT count(user_id) FROM connections WHERE user_id = $1", [user_id]) do |result|
count = result.getvalue(0, 0)
if count == "1"
# get all friend user_ids using the same query rails does for @user.friends
friend_update = @message_factory.friend_update(user_id, true)
friend_ids = gather_friends(conn, user_id)
@mq_router.publish_to_friends(friend_ids, friend_update, user_id)
end
# we just created a new connection-if this is the first time the user has shown up, we need to send out a message to his friends
conn.exec("SELECT count(user_id) FROM connections WHERE user_id = $1", [user_id]) do |result|
count = result.getvalue(0, 0)
if count == "1"
# get all friend user_ids using the same query rails does for @user.friends
friend_update = @message_factory.friend_update(user_id, true)
friend_ids = gather_friends(conn, user_id)
@mq_router.publish_to_friends(friend_ids, friend_update, user_id)
end
end
#end
end
@ -72,45 +73,45 @@ module JamRuby
user_id = nil
music_session_id = nil
@pg_conn.transaction do |conn|
conn = @pg_conn
lock_connections(conn)
lock_connections(conn)
previous_music_session_id = check_already_session(conn, client_id)
previous_music_session_id = check_already_session(conn, client_id)
conn.exec("DELETE FROM connections WHERE client_id = $1 RETURNING user_id, music_session_id", [client_id]) do |result|
conn.exec("DELETE FROM connections WHERE client_id = $1 RETURNING user_id, music_session_id", [client_id]) do |result|
if result.cmd_tuples == 0
# the client is already gone from the database... do nothing but log error
@log.warn("unable to delete client #{client_id}")
return
elsif result.cmd_tuples == 1
user_id = result[0]['user_id']
music_session_id = result[0]['client_id']
if result.cmd_tuples == 0
# the client is already gone from the database... do nothing but log error
@log.warn("unable to delete client #{client_id}")
return
elsif result.cmd_tuples == 1
user_id = result[0]['user_id']
music_session_id = result[0]['client_id']
else
raise Exception, 'uniqueness constraint has been lost on client_id'
end
end
session_checks(conn, previous_music_session_id, user_id)
# since we did delete a row, check and see if any more connections for that user exist
# if we are down to zero, send out user gone message
conn.exec("SELECT count(user_id) FROM connections where user_id = $1", [user_id]) do |result|
count = result.getvalue(0, 0)
if count == "0"
friend_update = @message_factory.friend_update(user_id, false)
friend_ids = gather_friends(conn, user_id)
@mq_router.publish_to_friends(friend_ids, friend_update, user_id)
end
end
# same for session-if we are down to the last participant, delete the session
unless music_session_id.nil?
conn.exec("DELETE FROM music_sessions id = $1 AND 0 = (SELECT count(music_session_id) FROM connections where music_session_id = $1)", [music_session_id]).clear
else
raise Exception, 'uniqueness constraint has been lost on client_id'
end
end
session_checks(conn, previous_music_session_id, user_id)
# since we did delete a row, check and see if any more connections for that user exist
# if we are down to zero, send out user gone message
conn.exec("SELECT count(user_id) FROM connections where user_id = $1", [user_id]) do |result|
count = result.getvalue(0, 0)
if count == "0"
friend_update = @message_factory.friend_update(user_id, false)
friend_ids = gather_friends(conn, user_id)
@mq_router.publish_to_friends(friend_ids, friend_update, user_id)
end
end
# same for session-if we are down to the last participant, delete the session
unless music_session_id.nil?
conn.exec("DELETE FROM music_sessions id = $1 AND 0 = (SELECT count(music_session_id) FROM connections where music_session_id = $1)", [music_session_id]).clear
end
# end
end
def destroy_if_empty(conn, music_session_id)
@ -161,83 +162,97 @@ module JamRuby
end
def join_music_session(user_id, client_id, music_session_id)
@pg_conn.transaction do |conn|
conn = @pg_conn
lock_connections(conn)
lock_connections(conn)
previous_music_session_id = check_already_session(conn, client_id)
previous_music_session_id = check_already_session(conn, client_id)
begin
conn.exec("UPDATE connections SET music_session_id = $1 WHERE client_id = $2", [music_session_id, client_id]) do |result|
if result.cmd_tuples == 1
@log.debug "associated music_session with connection for client=#{client_id} and music_session=#{music_session_id}"
session_checks(conn, previous_music_session_id, user_id)
elsif result.cmd_tuples == 0
@log.debug "join_music_session no connection found with client_id=#{client_id}"
raise StateError, "no connection found with client=#{client_id}"
else
@log.error "database failure or logic error; this path should be impossible if the table is locked (join_music_session)"
raise Exception, "locked table changed state"
end
end
rescue PG::Error => pg_error
if pg_error.to_s.include?("insert or update on table \"connections\" violates foreign key constraint \"connections_music_session_id_fkey\"")
# if there is no music session that exists, we will receive this message
@log.debug "music_session does not exist. music_session=#{music_session_id}"
raise StateError, "music_session does not exist"
else
raise pg_error
end
end
end
end
def leave_music_session(user_id, client_id, music_session_id)
@pg_conn.transaction do |conn|
lock_connections(conn)
previous_music_session_id = check_already_session(conn, client_id)
if previous_music_session_id == nil
@log.debug "the client is not in a session. user=#{user_id}, client=#{client_id}, music_session=#{music_session_id}"
raise StateError, "not in session"
elsif previous_music_session_id != music_session_id
@log.debug "the client is in a different session. user=#{user_id}, client=#{client_id}, music_session=#{music_session_id}"
raise StateError, "in a session different than that specified"
end
# can throw exception if the session is deleted just before this
conn.exec("UPDATE connections SET music_session_id = NULL WHERE client_id = $1", [client_id]) do |result|
begin
conn.exec("UPDATE connections SET music_session_id = $1 WHERE client_id = $2", [music_session_id, client_id]) do |result|
if result.cmd_tuples == 1
@log.debug("deassociated music_session with connection for client_id #{client_id}")
@log.debug "associated music_session with connection for client=#{client_id} and music_session=#{music_session_id}"
session_checks(conn, previous_music_session_id, user_id)
elsif result.cmd_tuples == 0
@log.debug "leave_music_session no connection found with client_id=#{client_id}"
@log.debug "join_music_session no connection found with client_id=#{client_id}"
raise StateError, "no connection found with client=#{client_id}"
else
@log.error("database failure or logic error; this path should be impossible if the table is locked (leave_music_session)")
@log.error "database failure or logic error; this path should be impossible if the table is locked (join_music_session)"
raise Exception, "locked table changed state"
end
end
rescue PG::Error => pg_error
if pg_error.to_s.include?("insert or update on table \"connections\" violates foreign key constraint \"connections_music_session_id_fkey\"")
# if there is no music session that exists, we will receive this message
@log.debug "music_session does not exist. music_session=#{music_session_id}"
raise StateError, "music_session does not exist"
else
raise pg_error
end
end
# end
end
def lock_connections(conn)
conn.exec("LOCK connections IN EXCLUSIVE MODE").clear
end
def leave_music_session(user_id, client_id, music_session_id)
conn = @pg_conn
def gather_friends(conn, user_id)
friend_ids = []
conn.exec("SELECT f1.friend_id as friend_id FROM friendships f1 WHERE f1.user_id = $1 AND f1.friend_id IN (SELECT f2.user_id FROM friendships f2 WHERE f2.friend_id = $1)", [user_id]) do |friend_results|
friend_results.each do |friend_result|
friend_ids.push(friend_result['friend_id'])
lock_connections(conn)
previous_music_session_id = check_already_session(conn, client_id)
if previous_music_session_id == nil
@log.debug "the client is not in a session. user=#{user_id}, client=#{client_id}, music_session=#{music_session_id}"
raise StateError, "not in session"
elsif previous_music_session_id != music_session_id
@log.debug "the client is in a different session. user=#{user_id}, client=#{client_id}, music_session=#{music_session_id}"
raise StateError, "in a session different than that specified"
end
# can throw exception if the session is deleted just before this
conn.exec("UPDATE connections SET music_session_id = NULL WHERE client_id = $1", [client_id]) do |result|
if result.cmd_tuples == 1
@log.debug("deassociated music_session with connection for client_id #{client_id}")
session_checks(conn, previous_music_session_id, user_id)
elsif result.cmd_tuples == 0
@log.debug "leave_music_session no connection found with client_id=#{client_id}"
raise StateError, "no connection found with client=#{client_id}"
else
@log.error("database failure or logic error; this path should be impossible if the table is locked (leave_music_session)")
raise Exception, "locked table changed state"
end
end
return friend_ids
end
end
# Creates a connection manager, and associates the connection created by active_record with ourselves
def self.active_record_transaction(&block)
connection_manager = ConnectionManager.new
ActiveRecord::Base.connection_pool.with_connection do |connection|
# create a transaction, and pass the current connection to ConnectionManager.
# this lets the entire operation work with the same transaction,
# across Rails ActiveRecord and the pg-gem based code in ConnectionManager.
connection_manager.pg_conn = connection.instance_variable_get("@connection")
block.call(connection_manager)
end
end
def lock_connections(conn)
conn.exec("LOCK connections IN EXCLUSIVE MODE").clear
end
def gather_friends(conn, user_id)
friend_ids = []
conn.exec("SELECT f1.friend_id as friend_id FROM friendships f1 WHERE f1.user_id = $1 AND f1.friend_id IN (SELECT f2.user_id FROM friendships f2 WHERE f2.friend_id = $1)", [user_id]) do |friend_results|
friend_results.each do |friend_result|
friend_ids.push(friend_result['friend_id'])
end
end
return friend_ids
end
# end
end

View File

@ -0,0 +1,7 @@
module JamRuby
# if a bad argument is supplied.
# Why not use the default one? This allows us to know our API layer threw this, versus us using some core library incorrectly
class JamArgumentError < ArgumentError
end
end

View File

@ -3,10 +3,10 @@ require 'spec_helper'
# these tests avoid the use of ActiveRecord and FactoryGirl to do blackbox, non test-instrumented tests
describe ConnectionManager do
before do
before do
@conn = PG::Connection.new(:dbname => SpecDb::TEST_DB_NAME, :user => "postgres", :password => "postgres", :host => "localhost")
@connman = ConnectionManager.new(@conn)
@connman = ConnectionManager.new(:conn => @conn)
@message_factory = MessageFactory.new
end
@ -42,30 +42,39 @@ describe ConnectionManager do
it "can't create bogus user_id" do
expect { @connman.create_connection("aeonuthaoentuh", "client_id", "1.1.1.1") }.to raise_error(PG::Error)
@conn.transaction do
expect { @connman.create_connection("aeonuthaoentuh", "client_id", "1.1.1.1") }.to raise_error(PG::Error)
end
end
it "can't create two client_ids of same value" do
client_id = "client_id1"
user_id = create_user("user1", "user1@jamkazam.com")
@connman.create_connection(user_id, client_id, "1.1.1.1")
expect { @connman.create_connection(user_id, client_id, "1.1.1.1") }.to raise_error(PG::Error)
@conn.transaction do
@connman.create_connection(user_id, client_id, "1.1.1.1")
expect { @connman.create_connection(user_id, client_id, "1.1.1.1") }.to raise_error(PG::Error)
end
end
it "create connection then delete it" do
client_id = "client_id2"
user_id = create_user("user2", "user2@jamkazam.com")
@connman.create_connection(user_id, client_id, "1.1.1.1")
@conn.transaction do
@connman.create_connection(user_id, client_id, "1.1.1.1")
end
# make sure the connection is seen
@conn.exec("SELECT count(*) FROM connections where user_id = $1", [user_id]) do |result|
result.getvalue(0, 0).should == "1"
end
@connman.delete_connection(client_id)
@conn.transaction do
@connman.delete_connection(client_id)
end
@conn.exec("SELECT count(*) FROM connections where user_id = $1", [user_id]) do |result|
result.getvalue(0, 0).should == "0"
end
@ -82,13 +91,16 @@ describe ConnectionManager do
friend_update = @message_factory.friend_update(user_id, true)
@connman.mq_router.should_receive(:publish_to_friends).with([], friend_update, user_id)
@connman.create_connection(user_id, client_id, "1.1.1.1")
@conn.transaction do
@connman.create_connection(user_id, client_id, "1.1.1.1")
end
# but a second connection from the same user should cause no such message
@connman.should_receive(:publish_to_friends).exactly(0).times
@connman.create_connection(user_id, client_id2, "1.1.1.1")
@conn.transaction do
@connman.create_connection(user_id, client_id2, "1.1.1.1")
end
end
@ -102,19 +114,29 @@ describe ConnectionManager do
# we should get a message saying that this user is online
@connman.create_connection(user_id, client_id, "1.1.1.1")
@connman.create_connection(user_id, client_id2, "1.1.1.1")
@conn.transaction do
@connman.create_connection(user_id, client_id, "1.1.1.1")
end
@conn.transaction do
@connman.create_connection(user_id, client_id2, "1.1.1.1")
end
# deleting one of the two connections should cause no messages
@connman.should_receive(:publish_to_friends).exactly(0).times
@connman.delete_connection(client_id)
@conn.transaction do
@connman.delete_connection(client_id)
end
# but deleting the final connection should cause a left message
friend_update = @message_factory.friend_update(user_id, false)
@connman.mq_router.should_receive(:publish_to_friends).with([], friend_update, user_id)
@connman.delete_connection(client_id2)
@conn.transaction do
@connman.delete_connection(client_id2)
end
end
@ -173,16 +195,22 @@ describe ConnectionManager do
user_id = create_user("user8", "user8@jamkazam.com")
@connman.create_connection(user_id, client_id, "1.1.1.1")
@conn.transaction do
@connman.create_connection(user_id, client_id, "1.1.1.1")
end
@connman.remove_stale_connections(60)
@conn.transaction do
@connman.remove_stale_connections(60)
end
assert_num_connections(client_id, 1)
sleep(1)
# this should remove the stale connection
@connman.remove_stale_connections(1)
@conn.transaction do
# this should remove the stale connection
@connman.remove_stale_connections(1)
end
assert_num_connections(client_id, 0)
end
@ -193,8 +221,10 @@ describe ConnectionManager do
user_id = create_user("user9", "user9@jamkazam.com")
music_session_id = create_music_session(user_id)
@connman.create_connection(user_id, client_id, "1.1.1.1")
@connman.join_music_session(user_id, client_id, music_session_id)
@conn.transaction do
@connman.create_connection(user_id, client_id, "1.1.1.1")
@connman.join_music_session(user_id, client_id, music_session_id)
end
assert_session_exists(music_session_id, true)
@ -202,8 +232,9 @@ describe ConnectionManager do
result.getvalue(0, 0).should == music_session_id
end
@connman.delete_connection(client_id)
@conn.transaction do
@connman.delete_connection(client_id)
end
assert_num_connections(client_id, 0)
assert_session_exists(music_session_id, false)
@ -215,7 +246,10 @@ describe ConnectionManager do
user_id = create_user("user10", "user10@jamkazam.com")
music_session_id = create_music_session(user_id)
expect { @connman.join_music_session(user_id, client_id, music_session_id)}.to raise_error(JamRuby::StateError)
@conn.transaction do
expect { @connman.join_music_session(user_id, client_id, music_session_id) }.to raise_error(JamRuby::StateError)
end
end
it "join_music_session fails if no music_session" do
@ -223,9 +257,14 @@ describe ConnectionManager do
client_id = "client_id11"
user_id = create_user("user11", "user11@jamkazam.com")
@connman.create_connection(user_id, client_id, "1.1.1.1")
@conn.transaction do
@connman.create_connection(user_id, client_id, "1.1.1.1")
end
@conn.transaction do
expect { @connman.join_music_session(user_id, client_id, "some_bogus_music_session_id") }.to raise_error(JamRuby::StateError)
end
expect { @connman.join_music_session(user_id, client_id, "some_bogus_music_session_id")}.to raise_error(JamRuby::StateError)
end
it "leave_music_session fails if no music_session" do
@ -233,9 +272,13 @@ describe ConnectionManager do
client_id = "client_id12"
user_id = create_user("user12", "user12@jamkazam.com")
@connman.create_connection(user_id, client_id, "1.1.1.1")
@conn.transaction do
@connman.create_connection(user_id, client_id, "1.1.1.1")
end
expect { @connman.leave_music_session(user_id, client_id, "some_bogus_music_session_id")}.to raise_error(JamRuby::StateError)
@conn.transaction do
expect { @connman.leave_music_session(user_id, client_id, "some_bogus_music_session_id") }.to raise_error(JamRuby::StateError)
end
end
it "leave_music_session fails if in different music_session" do
@ -244,10 +287,17 @@ describe ConnectionManager do
user_id = create_user("user13", "user13@jamkazam.com")
music_session_id = create_music_session(user_id)
@connman.create_connection(user_id, client_id, "1.1.1.1")
@connman.join_music_session(user_id, client_id, music_session_id)
@conn.transaction do
@connman.create_connection(user_id, client_id, "1.1.1.1")
end
expect { @connman.leave_music_session(user_id, client_id, "some_bogus_music_session_id")}.to raise_error(JamRuby::StateError)
@conn.transaction do
@connman.join_music_session(user_id, client_id, music_session_id)
end
@conn.transaction do
expect { @connman.leave_music_session(user_id, client_id, "some_bogus_music_session_id") }.to raise_error(JamRuby::StateError)
end
end
it "leave_music_session works" do
@ -256,8 +306,14 @@ describe ConnectionManager do
user_id = create_user("user14", "user14@jamkazam.com")
music_session_id = create_music_session(user_id)
@connman.create_connection(user_id, client_id, "1.1.1.1")
@connman.join_music_session(user_id, client_id, music_session_id)
@conn.transaction do
@connman.create_connection(user_id, client_id, "1.1.1.1")
end
@conn.transaction do
@connman.join_music_session(user_id, client_id, music_session_id)
end
assert_session_exists(music_session_id, true)
@ -265,7 +321,9 @@ describe ConnectionManager do
result.getvalue(0, 0).should == music_session_id
end
@connman.leave_music_session(user_id, client_id, music_session_id)
@conn.transaction do
@connman.leave_music_session(user_id, client_id, music_session_id)
end
@conn.exec("SELECT music_session_id FROM connections WHERE client_id = $1", [client_id]) do |result|
result.getvalue(0, 0).should == nil
@ -273,7 +331,9 @@ describe ConnectionManager do
assert_session_exists(music_session_id, false)
@connman.delete_connection(client_id)
@conn.transaction do
@connman.delete_connection(client_id)
end
assert_num_connections(client_id, 0)