Class: ZeevexCluster::Coordinator::Mysql

Inherits:
BaseKeyValStore show all
Defined in:
lib/zeevex_cluster/coordinator/mysql.rb

Defined Under Namespace

Classes: Literal

Constant Summary collapse

ERR_DUPLICATE_KEY = 
1062

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from BaseKeyValStore

#with_connection_retry

Methods included from Util::Logging

#logger

Constructor Details

#initialize(options = {}) ⇒ Mysql

Returns a new instance of Mysql.



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# File 'lib/zeevex_cluster/coordinator/mysql.rb', line 38

def initialize(options = {})
  super
  @table = @options[:table] || 'kvstore'
  @logger = @options[:logger] || Logger.new(STDOUT)
  @namespace = @options.fetch(:namespace, '')
  @client ||= Mysql2::Client.new(:host => options[:server] || 'localhost',
                                 :port => options[:port] | 3306,
                                 :database => options[:database] || 'zcluster',
                                 :username => options[:username],
                                 :password => options[:password],
                                 :reconnect => true,
                                 :symbolize_keys => true,
                                 :cache_rows => false,
                                 :application_timezone => :utc,
                                 :database_timezone => :utc)
end

Class Method Details

.setup ⇒ Object 



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# File 'lib/zeevex_cluster/coordinator/mysql.rb', line 29

def self.setup
  unless @setup
    require 'mysql2'
    BaseKeyValStore.setup

    @setup = true
  end
end

Instance Method Details

#add(key, value, options = {}) ⇒ Object

Add the value for a key to the DB if there is no existing entry Serializes unless :raw => true

Returns true if key was added, false if key already had a value



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# File 'lib/zeevex_cluster/coordinator/mysql.rb', line 61

def add(key, value, options = {})
  key = to_key(key)
  value = serialize_value(value, is_raw?(options))
  res = do_insert_row({:keyname => key, :value => value, :namespace => @namespace},
                       :expiration => options.fetch(:expiration, @expiration))
  res[:affected_rows] == 1
rescue Mysql2::Error => e
  case e.error_number
    # duplicate key
    # see http://www.briandunning.com/error-codes/?source=MySQL
    when ERR_DUPLICATE_KEY
      false
    else
      raise  ZeevexCluster::Coordinator::ConnectionError.new, "Unhandled mysql error: #{e.errno} #{e.message}", e
  end
rescue
  raise ZeevexCluster::Coordinator::ConnectionError.new 'Connection error', $!
end

#append(key, str, options = {}) ⇒ Object

append string vlaue to an entry does NOT serialize



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# File 'lib/zeevex_cluster/coordinator/mysql.rb', line 157

def append(key, str, options = {})
  newval = Literal.new %{CONCAT(value, #{qval str})}
  do_update_row({:keyname => to_key(key)}, {:value => newval})
rescue ::Mysql2::Error
  raise ZeevexCluster::Coordinator::ConnectionError.new 'Connection error', $!
end

#cas(key, options = {}) ⇒ Object

Block is passed the current value, and returns the updated value.

Block can raise DontChange to simply exit the block without updating.

returns nil for no value returns false for failure (somebody else set) returns true for success



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# File 'lib/zeevex_cluster/coordinator/mysql.rb', line 111

def cas(key, options = {})
  key = to_key(key)

  orig_row = do_get_first(key)
  return nil unless orig_row

  expiration = options.fetch(:expiration, @expiration)

  newval = serialize_value(yield(deserialize_value(orig_row[:value], is_raw?(options))), is_raw?(options))
  updates = {:value => newval}
  res = do_update_row(simple_cond(orig_row), updates, :expiration => options.fetch(:expiration, @expiration))
  case res
    when false then false
    when true then true
    else
      raise ZeevexCluster::Coordinator::ConnectionError, "Unhandled return value from do_update_row - #{res.inspect}"
  end
rescue ZeevexCluster::Coordinator::DontChange => e
  false
rescue ::Mysql2::Error
  logger.error "got error in cas: #{$!.inspect}"
  raise ZeevexCluster::Coordinator::ConnectionError.new 'Connection error', $!
rescue
  logger.error "got general error in cas: #{$!.inspect}"
  raise
end

#delete(key, options = {}) ⇒ Object

Delete key from database; true if key existed beforehand



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# File 'lib/zeevex_cluster/coordinator/mysql.rb', line 97

def delete(key, options = {})
  res = do_delete_row(:keyname => to_key(key))
  res[:success]
end

#get(key, options = {}) ⇒ Object

Fetch the value for a key, deserializing unless :raw => true



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# File 'lib/zeevex_cluster/coordinator/mysql.rb', line 141

def get(key, options = {})
  key = to_key(key)
  row = do_get_first key
  return nil if row.nil?

  if !is_raw?(options)
    deserialize_value(row[:value])
  else
    row[:value]
  end
rescue ::Mysql2::Error
  raise ZeevexCluster::Coordinator::ConnectionError.new 'Connection error', $!
end

#prepend(key, str, options = {}) ⇒ Object

prepend string value to an entry does NOT serialize



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# File 'lib/zeevex_cluster/coordinator/mysql.rb', line 166

def prepend(key, str, options = {})
  newval = Literal.new %{CONCAT(#{qval str}, value)}
  do_update_row({:keyname => to_key(key)}, {:value => newval})
rescue ::Mysql2::Error
  raise ZeevexCluster::Coordinator::ConnectionError.new 'Connection error', $!
end

#set(key, value, options = {}) ⇒ Object

Set the value for a key, serializing unless :raw => true



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# File 'lib/zeevex_cluster/coordinator/mysql.rb', line 83

def set(key, value, options = {})
  key = to_key(key)
  value = serialize_value(value, is_raw?(options))
  row = {:keyname => key, :value => value}

  res = do_upsert_row(row, :expiration => options.fetch(:expiration, @expiration), :skip_locking => true)
  res[:success]
rescue ::Mysql2::Error
  raise ZeevexCluster::Coordinator::ConnectionError.new 'Connection error', $!
end