Class: Mysql2postgres::Connection

Inherits:
Object
  • Object
show all
Defined in:
lib/mysql2postgres/connection.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(pg_options) ⇒ Connection

Returns a new instance of Connection.



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# File 'lib/mysql2postgres/connection.rb', line 16

def initialize(pg_options)
  @hostname = pg_options[:hostname] || 'localhost'
  @login = pg_options[:username]
  @password = pg_options[:password]
  @database = pg_options[:database]
  @port = (pg_options[:port] || 5432).to_s

  @database, @schema = database.split ':'

  @conn = open
  raise_nil_connection if conn.nil?

  @is_copying = false
  @current_statement = ''
end

Instance Attribute Details

#conn ⇒ Object (readonly)

Returns the value of attribute conn.



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# File 'lib/mysql2postgres/connection.rb', line 5

def conn
  @conn
end

#copy_manager ⇒ Object (readonly)

Returns the value of attribute copy_manager.



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# File 'lib/mysql2postgres/connection.rb', line 5

def copy_manager
  @copy_manager
end

#database ⇒ Object (readonly)

Returns the value of attribute database.



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# File 'lib/mysql2postgres/connection.rb', line 5

def database
  @database
end

#hostname ⇒ Object (readonly)

Returns the value of attribute hostname.



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# File 'lib/mysql2postgres/connection.rb', line 5

def hostname
  @hostname
end

#is_copying ⇒ Object (readonly)

Returns the value of attribute is_copying.



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# File 'lib/mysql2postgres/connection.rb', line 5

def is_copying
  @is_copying
end

#login ⇒ Object (readonly)

Returns the value of attribute login.



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# File 'lib/mysql2postgres/connection.rb', line 5

def 
  @login
end

#password ⇒ Object (readonly)

Returns the value of attribute password.



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# File 'lib/mysql2postgres/connection.rb', line 5

def password
  @password
end

#port ⇒ Object (readonly)

Returns the value of attribute port.



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# File 'lib/mysql2postgres/connection.rb', line 5

def port
  @port
end

#schema ⇒ Object (readonly)

Returns the value of attribute schema.



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# File 'lib/mysql2postgres/connection.rb', line 5

def schema
  @schema
end

#stream ⇒ Object (readonly)

Returns the value of attribute stream.



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# File 'lib/mysql2postgres/connection.rb', line 5

def stream
  @stream
end

Instance Method Details

#clear_schema ⇒ Object 



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# File 'lib/mysql2postgres/connection.rb', line 102

def clear_schema
  statements = ['DROP SCHEMA PUBLIC CASCADE', 'CREATE SCHEMA PUBLIC']
  statements.each do |statement|
    run_statement statement
  end
end

#execute(sql) ⇒ Object 



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# File 'lib/mysql2postgres/connection.rb', line 49

def execute(sql)
  if sql.match(/^COPY /) && !is_copying
    # sql.chomp!   # cHomp! cHomp!
    conn.exec sql
    @is_copying = true
  elsif sql.match(/^(ALTER|CREATE|DROP|SELECT|SET|TRUNCATE) /) && !is_copying
    @current_statement = sql
  elsif is_copying
    if sql.chomp == '\.' || sql.chomp.match(/^$/)
      flush
    else
      begin
        until conn.put_copy_data sql
          warn '  waiting for connection to be writable...'
          sleep 0.1
        end
      rescue StandardError => e
        @is_copying = false
        warn e
        raise e
      end
    end
  elsif @current_statement.length.positive?
    @current_statement << ' '
    @current_statement << sql
  end

  return unless @current_statement.match?(/;$/)

  run_statement @current_statement
  @current_statement = ''
end

#finish ⇒ Object

we’re done talking to the database, so close the connection cleanly.



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# File 'lib/mysql2postgres/connection.rb', line 83

def finish
  @conn.finish
end

#flush ⇒ Object

ensure that the copy is completed, in case we hadn’t seen a ‘.’ in the data stream.



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# File 'lib/mysql2postgres/connection.rb', line 41

def flush
  conn.put_copy_end
rescue StandardError => e
  warn e
ensure
  @is_copying = false
end

#load_file(path) ⇒ Object

given a file containing psql syntax at path, pipe it down to the database.



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# File 'lib/mysql2postgres/connection.rb', line 88

def load_file(path)
  if @conn
    File.open path, 'r:UTF-8' do |file|
      file.each_line do |line|
        execute line
      end
      flush
    end
    finish
  else
    raise_nil_connection
  end
end

#open ⇒ Object 



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# File 'lib/mysql2postgres/connection.rb', line 32

def open
  @conn = PG::Connection.open dbname: database,
                              user: ,
                              password: password,
                              host: hostname,
                              port: port
end

#raise_nil_connection ⇒ Object 



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# File 'lib/mysql2postgres/connection.rb', line 109

def raise_nil_connection
  raise 'No Connection'
end

#tables ⇒ Object 



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# File 'lib/mysql2postgres/connection.rb', line 113

def tables
  result = run_statement <<~SQL_TABLES
    SELECT table_name
    FROM information_schema.tables
    WHERE table_schema = 'public' AND table_type = 'BASE TABLE'
  SQL_TABLES

  result.map { |t| t['table_name'] }
end