Class: PostgresPR::Connection

Inherits:
Object
  • Object
show all
Defined in:
lib/postgres-pr/connection.rb

Defined Under Namespace

Classes: Result

Constant Summary collapse

DEFAULT_PORT =
5432
DEFAULT_HOST =
'localhost'
DEFAULT_PATH =
'/tmp'
DEFAULT_URI =
if RUBY_PLATFORM.include?('win')
  'tcp://' + DEFAULT_HOST + ':' + DEFAULT_PORT.to_s 
else
  'unix:' + File.join(DEFAULT_PATH, '.s.PGSQL.' + DEFAULT_PORT.to_s)  
end

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(database, user, password = nil, uri = nil) ⇒ Connection

Returns a new instance of Connection.


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# File 'lib/postgres-pr/connection.rb', line 49

def initialize(database, user, password=nil, uri = nil)
  uri ||= DEFAULT_URI

  @transaction_status = nil
  @params = {}
  establish_connection(uri)

  @conn << StartupMessage.new(PROTO_VERSION, 'user' => user, 'database' => database).dump

  loop do
    msg = Message.read(@conn)

    case msg
    when AuthentificationClearTextPassword
      raise ArgumentError, "no password specified" if password.nil?
      @conn << PasswordMessage.new(password).dump

    when AuthentificationCryptPassword
      raise ArgumentError, "no password specified" if password.nil?
      @conn << PasswordMessage.new(password.crypt(msg.salt)).dump

    when AuthentificationMD5Password
      raise ArgumentError, "no password specified" if password.nil?
      require 'digest/md5'

      m = Digest::MD5.hexdigest(password + user) 
      m = Digest::MD5.hexdigest(m + msg.salt)
      m = 'md5' + m
      @conn << PasswordMessage.new(m).dump

    when AuthentificationKerberosV4, AuthentificationKerberosV5, AuthentificationSCMCredential
      raise "unsupported authentification"

    when AuthentificationOk
    when ErrorResponse
      raise msg.field_values.join("\t")
    when NoticeResponse
      @notice_processor.call(msg) if @notice_processor
    when ParameterStatus
      @params[msg.key] = msg.value
    when BackendKeyData
      # TODO
      #p msg
    when ReadyForQuery
      @transaction_status = msg.backend_transaction_status_indicator
      break
    else
      raise "unhandled message type"
    end
  end
end

Instance Attribute Details

#notice_processorObject

A block which is called with the NoticeResponse object as parameter.


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# File 'lib/postgres-pr/connection.rb', line 22

def notice_processor
  @notice_processor
end

Instance Method Details

#closeObject


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# File 'lib/postgres-pr/connection.rb', line 101

def close
  raise "connection already closed" if @conn.nil?
  @conn.shutdown
  @conn = nil
end

#query(sql) ⇒ Object

Raises:


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# File 'lib/postgres-pr/connection.rb', line 114

def query(sql)
  @conn << Query.dump(sql)

  result = Result.new
  errors = []

  loop do
    msg = Message.read(@conn)
    case msg
    when DataRow
      result.rows << msg.columns
    when CommandComplete
      result.cmd_tag = msg.cmd_tag
    when ReadyForQuery
      @transaction_status = msg.backend_transaction_status_indicator
      break
    when RowDescription
      result.fields = msg.fields
    when CopyInResponse
    when CopyOutResponse
    when EmptyQueryResponse
    when ErrorResponse
      # TODO
      errors << msg
    when NoticeResponse
      @notice_processor.call(msg) if @notice_processor
    else
      # TODO
    end
  end

  raise DatabaseError.new(errors.map{|e| e.field_values.join("\t") }.join("\n")) unless errors.empty?

  result
end

#transaction_statusObject

Returns one of the following statuses:

PQTRANS_IDLE    = 0 (connection idle)
PQTRANS_INTRANS = 2 (idle, within transaction block)
PQTRANS_INERROR = 3 (idle, within failed transaction)
PQTRANS_UNKNOWN = 4 (cannot determine status)

Not yet implemented is:

PQTRANS_ACTIVE  = 1 (command in progress)

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# File 'lib/postgres-pr/connection.rb', line 36

def transaction_status
  case @transaction_status
  when ?I
    0
  when ?T
    2
  when ?E
    3
  else
    4
  end
end