Ruby Edition
This here is a Ruby wrapper for the official C++ implementation of Cap'n Proto.
Installing
First install libcapnp, then install the gem:
gem install capn_proto --pre
The native extension for this gem requires a C++ compiler with C++11 features, so use the same C++ compiler and flags that you used to compile libcapnp (e.g. CXX
and CXXFLAGS
). As an OSX user, having followed the instructions for installing libcapnp on OSX, the correct incantation is as follows:
CXX=$HOME/clang-3.2/bin/clang++ gem install capn_proto --pre
Example
require 'capn_proto'
module AddressBook extend CapnProto::SchemaLoader
load_schema("addressbook.capnp")
end
def write_address_book(file)
addresses = AddressBook::AddressBook.new_message
people = addresses.initPeople(2)
alice = people[0]
alice.id = 123
alice.name = 'Alice'
alice.email = 'alice@example.com'
alice_phones = alice.initPhones(1)
alice_phones[0].number = "555-1212"
alice_phones[0].type = 'mobile'
alice.employment.school = "MIT"
bob = people[1]
bob.id = 456
bob.name = 'Bob'
bob.email = 'bob@example.com'
bob_phones = bob.initPhones(2)
bob_phones[0].number = "555-4567"
bob_phones[0].type = 'home'
bob_phones[1].number = "555-7654"
bob_phones[1].type = 'work'
bob.employment.unemployed = nil
addresses.write(file)
end
def print_address_book(file)
addresses = AddressBook::AddressBook.read_from(file)
addresses.people.each do |person|
puts "#{person.name} : #{person.email}"
person.phones.each do |phone|
puts "#{phone.type} : #{phone.number}"
end
if person.employment.unemployed?
puts "unemployed"
if person.employment.employer?
puts "employer: #{person.employment.employer}"
if person.employment.school?
puts "student at: #{person.employment.school}"
if person.employment.selfEmployed?
puts "self employed"
end
end
end
if __FILE__ == $0
file = File.open("addressbook.bin", "wb")
write_address_book(file)
file = File.open("addressbook.bin", "rb")
print_address_book(file)
end
Status
What's implemented:
- Schema parsing/loading
- Message reading
- From byte string
- From file descriptor
- Message writing
- To byte string
- To file descriptor
What's to come:
- More reading/writing mechanisms:
- Packing/unpacking
- Extensive test coverage
- Proper support for JRuby
- Support for RPC