class FDB::Database

def self.finalize(ptr)
  proc do
    # puts "Destroying database #{ptr}"
    FDBC.fdb_database_destroy(ptr)
  end
end

def clear(key)
  transact do |tr|
    tr.clear(key)
  end
end

def clear_and_watch(key)
  transact do |tr|
    tr.clear(key)
    tr.watch(key)
  end
end

def clear_range(bkey, ekey)
  transact do |tr|
    tr.clear_range(bkey, ekey)
  end
end

def clear_range_start_with(prefix)
  transact do |tr|
    tr.clear_range_start_with(prefix)
  end
end

def create_transaction
  tr = FFI::MemoryPointer.new :pointer
  FDBC.check_error FDBC.fdb_database_create_transaction(@dpointer, tr)
  Transaction.new(tr.read_pointer, self)
end

def get(key)
  transact do |tr|
    tr[key].value
  end
end

def get_and_watch(key)
  transact do |tr|
    value = tr.get(key)
    watch = tr.watch(key)
    [value.value, watch]
  end
end

def get_key(keysel)
  transact do |tr|
    tr.get_key(keysel).value
  end
end

def get_range(bkeysel, ekeysel, options={}, &block)
  transact do |tr|
    a = tr.get_range(bkeysel, ekeysel, options).to_a
    if block_given?
      a.each &block
    else
      a
    end
  end
end

def get_range_start_with(prefix, options={}, &block)
  transact do |tr|
    a = tr.get_range_start_with(prefix, options).to_a
    if block_given?
      a.each &block
    else
      a
    end
  end
end

def initialize(dpointer)
  @dpointer = dpointer
  @options = DatabaseOptions.new lambda { |code, param|
    FDBC.check_error FDBC.fdb_database_set_option(dpointer, code, param, param.nil? ? 0 : param.bytesize)
  }
  ObjectSpace.define_finalizer(self, self.class.finalize(@dpointer))
end

def set(key, value)
  transact do |tr|
    tr[key] = value
  end
end

def set_and_watch(key, value)
  transact do |tr|
    tr.set(key, value)
    tr.watch(key)
  end
end

def transact
  tr = create_transaction
  committed = false
  begin
    ret = yield tr
    # puts ret
    tr.commit.wait
    committed = true
  rescue Error => e
    # puts "Rescued #{e}"
    tr.on_error(e).wait
  end until committed
  ret
end

def watch(key)
  transact do |tr|
    tr.watch(key)
  end
end