Class: FFI::Struct

Inherits:
Object
  • Object
show all
Defined in:
lib/ruby-libstorj/struct.rb

Instance Method Summary collapse

Instance Method Details

#map_layout ⇒ Object

convenience method for inspecting struct hierarchies



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# File 'lib/ruby-libstorj/struct.rb', line 18

def map_layout
  # NB: Hash[ [ [key, value], ... ] ] → new_hash
  Hash[members.map do |member_name|
    member = self[member_name]
    value = member.is_a?(FFI::Struct) ? member.map_layout : member
    if value.is_a? FFI::Pointer
      next [member_name, nil] if value.null?

      # attempt to read as string
      begin
        string_value = value.read_string
        # update value to string_value if it contains only printable characters
        if string_value =~ /^[[:print:]]*$/
          value = string_value
        end
      rescue
        # do nothing...
        # let value remain a pointer if an exception was raised
      end
    end
    [member_name, value]
  end]
end

#values_at(*members) ⇒ Object

allows for destructuring. NB: values_at members array order

must match assignment order!

example: “‘

bucket = ::LibStorj::Ext::Bucket.new
name, id, decrypted = bucket.values_at(:name, :id, :decrypted)
# OR name, id, decrypted = bucket.values_at([:name, :id, :decrypted])
# OR name, id, decrypted = bucket.values_at(%i[name id decrypted])
```



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# File 'lib/ruby-libstorj/struct.rb', line 13

def values_at(*members)
  members.flatten.map {|member_name| self[member_name]}
end