Module: Magicprotorb::Registrar

Defined in:
lib/magicprotorb/registrar.rb

Overview

Takes a compiled FileDescriptorSet and registers it through the stock protobuf machinery — DescriptorPool.generated_pool#add_serialized_file plus the same constant assignments a generated ‘*_pb.rb` performs. The resulting message classes are therefore indistinguishable from generated ones.

Constant Summary collapse

WELL_KNOWN_PREFIX =

The protobuf runtime already owns google/protobuf/*; never re-register or assign constants for those (it would clobber Google::Protobuf::Timestamp and friends, and add_serialized_file would reject the duplicate).

"google/protobuf/"

Class Method Summary collapse

Class Method Details

.assign_constants(pool, file) ⇒ Object

— constant assignment (mirrors protoc’s Ruby generator) —————-



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# File 'lib/magicprotorb/registrar.rb', line 46

def assign_constants(pool, file)
  package = file.package
  scope = ensure_module(Naming.package_modules(package))
  file.message_type.each { |msg| assign_message(pool, scope, package, msg) }
  file.enum_type.each { |enum| assign_enum(pool, scope, package, enum.name) }
end

.assign_enum(pool, parent, scope_fullname, enum_name) ⇒ Object 



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# File 'lib/magicprotorb/registrar.rb', line 67

def assign_enum(pool, parent, scope_fullname, enum_name)
  full_name = qualify(scope_fullname, enum_name)
  set_const(parent, Naming.constant_name(enum_name), pool.lookup(full_name).enummodule)
end

.assign_message(pool, parent, scope_fullname, msg) ⇒ Object 



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# File 'lib/magicprotorb/registrar.rb', line 53

def assign_message(pool, parent, scope_fullname, msg)
  full_name = qualify(scope_fullname, msg.name)
  klass = pool.lookup(full_name).msgclass
  set_const(parent, Naming.constant_name(msg.name), klass)

  # Synthetic map-entry messages get no constant (protoc skips them too).
  msg.nested_type.each do |nested|
    next if nested.options&.map_entry

    assign_message(pool, klass, full_name, nested)
  end
  msg.enum_type.each { |enum| assign_enum(pool, klass, full_name, enum.name) }
end

.ensure_module(segments) ⇒ Object

Walk/create a chain of modules (e.g. %w[MyCo SubPkg V1]) under Object, returning the innermost. An empty list returns Object (no-package case).



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# File 'lib/magicprotorb/registrar.rb', line 80

def ensure_module(segments)
  segments.reduce(Object) do |parent, segment|
    if parent.const_defined?(segment, false)
      parent.const_get(segment, false)
    else
      mod = Module.new
      parent.const_set(segment, mod)
      mod
    end
  end
end

.qualify(scope, name) ⇒ Object

— helpers ————————————————————–



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# File 'lib/magicprotorb/registrar.rb', line 74

def qualify(scope, name)
  scope.nil? || scope.empty? ? name : "#{scope}.#{name}"
end

.register(file_descriptor_set) ⇒ Object

Register every file in the set (dependency-ordered by the compiler), then assign Ruby constants for each non-well-known file. Idempotent.



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# File 'lib/magicprotorb/registrar.rb', line 23

def register(file_descriptor_set)
  pool = Google::Protobuf::DescriptorPool.generated_pool
  file_descriptor_set.file.each { |file| register_file(pool, file) }
end

.register_file(pool, file) ⇒ Object 



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# File 'lib/magicprotorb/registrar.rb', line 28

def register_file(pool, file)
  name = file.name
  return if @loaded_files[name]

  begin
    pool.add_serialized_file(file.to_proto)
  rescue Google::Protobuf::TypeError => e
    # Already present (a well-known type, or a shared import registered by a
    # previously imported proto). Anything else is a real error.
    raise unless e.message.include?("duplicate file name")
  end

  @loaded_files[name] = true
  assign_constants(pool, file) unless name.start_with?(WELL_KNOWN_PREFIX)
end

.set_const(parent, name, value) ⇒ Object 



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# File 'lib/magicprotorb/registrar.rb', line 92

def set_const(parent, name, value)
  parent.const_set(name, value) unless parent.const_defined?(name, false)
end