Class: OpenAssets::Payload

Inherits:
Object
  • Object
show all
Defined in:
lib/openassets/payload.rb

Overview

the open assets payload

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(quantities = [], metadata = '') ⇒ Payload

Returns a new instance of Payload.



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# File 'lib/openassets/payload.rb', line 14

def initialize(quantities = [], metadata = '')
  @quantities = quantities
  @metadata = metadata
end

Instance Attribute Details

#metadata ⇒ Object

Returns the value of attribute metadata.



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# File 'lib/openassets/payload.rb', line 12

def metadata
  @metadata
end

#quantities ⇒ Object

Returns the value of attribute quantities.



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# File 'lib/openassets/payload.rb', line 11

def quantities
  @quantities
end

Class Method Details

.parse_from_payload(payload) ⇒ Payload

parse open assets payload

Returns:

  • (Payload) —

    a open assets payload object, if payload is invalid, return nil.



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# File 'lib/openassets/payload.rb', line 21

def self.parse_from_payload(payload)
  buf = StringIO.new(payload)
  marker = buf.read(2)
  version = buf.read(2)
  return nil if marker != MARKER || version != VERSION
  count = Bitcoin.unpack_var_int_from_io(buf)
  return nil unless count
  quantities = []
  count.times do
    quantities << LEB128.decode_unsigned(buf, buf.pos)
  end
  metadata_length = Bitcoin.unpack_var_int_from_io(buf)
  return nil if metadata_length.nil? || buf.length < metadata_length + buf.pos
  metadata = buf.read(metadata_length).each_byte.map(&:chr).join
  new(quantities, metadata)
rescue
  # LEB128#decode_unsigned raise 'undefined method `unpack' for nil:NilClass'
  # for invalid format such as "018f8f" (the most significant bit of the last byte should be 0)
  nil
end

Instance Method Details

#to_payload ⇒ Object

generate binary payload



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# File 'lib/openassets/payload.rb', line 43

def to_payload
  payload = String.new
  payload << MARKER
  payload << VERSION
  payload << Bitcoin.pack_var_int(quantities.size) << quantities.map{|q| LEB128.encode_unsigned(q).read }.join
  payload << Bitcoin.pack_var_int(metadata.length) << metadata.bytes.map{|b| sprintf("%02x", b)}.join.htb
  payload
end