Class: Perpetuity::Postgres::Connection

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Connection

Returns a new instance of Connection.



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# File 'lib/perpetuity/postgres/connection.rb', line 8

def initialize options={}
  @options = sanitize_options(options)
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/perpetuity/postgres/connection.rb', line 6

def options
  @options
end

Instance Method Details

#active? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/perpetuity/postgres/connection.rb', line 40

def active?
  !!@pg_connection
end

#connect ⇒ Object 



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# File 'lib/perpetuity/postgres/connection.rb', line 20

def connect
  @pg_connection = PG.connect(options)
  @pg_connection.exec 'SET client_min_messages TO warning'
  @pg_connection
rescue PG::ConnectionBad => e
  tries ||= 0
  connect_options = options.dup
  connect_options.delete :dbname

  conn = PG.connect connect_options
  conn.exec "CREATE DATABASE #{db}"
  conn.close

  if tries.zero?
    retry
  else
    raise e
  end
end

#db ⇒ Object 



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# File 'lib/perpetuity/postgres/connection.rb', line 12

def db
  options[:dbname]
end

#execute(sql) ⇒ Object 



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# File 'lib/perpetuity/postgres/connection.rb', line 44

def execute sql
  pg_connection.exec sql
rescue PG::AdminShutdown, PG::UnableToSend => e
  # server closed the connection unexpectedly
  # Try to reconnect 3 times in case it's just a server restart.
  unable_to_send_retries ||= 0
  if unable_to_send_retries < 3
    connect
    unable_to_send_retries += 1
    sleep 1
    retry
  else
    raise
  end
rescue PG::UndefinedFunction => e
  if e.message =~ /uuid_generate/
    use_uuid_extension
    retry
  else
    raise
  end
end

#pg_connection ⇒ Object 



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# File 'lib/perpetuity/postgres/connection.rb', line 16

def pg_connection
  @pg_connection ||= connect
end

#sanitize_options(options) ⇒ Object 



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# File 'lib/perpetuity/postgres/connection.rb', line 75

def sanitize_options options
  options = options.dup
  db = options.delete(:db)
  username = options.delete(:username)

  if db
    options[:dbname] = db
  end

  if username
    options[:user] = username
  end

  options
end

#tables ⇒ Object 



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# File 'lib/perpetuity/postgres/connection.rb', line 67

def tables
  sql = "SELECT table_name FROM information_schema.tables "
  sql << "WHERE table_schema = 'public'"

  result = execute(sql)
  result.to_a.map { |r| r['table_name'] }
end