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require "bindata/base_primitive"
module BinData
# Uint8Array is a specialised type of array that only contains
# bytes (Uint8). It is a faster and more memory efficient version
# of `BinData::Array.new(:type => :uint8)`.
#
# require 'bindata'
#
# obj = BinData::Uint8Array.new(initial_length: 5)
# obj.read("abcdefg") #=> [97, 98, 99, 100, 101]
# obj[2] #=> 99
# obj.collect { |x| x.chr }.join #=> "abcde"
#
# == Parameters
#
# Parameters may be provided at initialisation to control the behaviour of
# an object. These params are:
#
# <tt>:initial_length</tt>:: The initial length of the array.
# <tt>:read_until</tt>:: May only have a value of `:eof`. This parameter
# instructs the array to read as much data from
# the stream as possible.
class Uint8Array < BinData::BasePrimitive
optional_parameters :initial_length, :read_until
mutually_exclusive_parameters :initial_length, :read_until
arg_processor :uint8_array
#---------------
private
def value_to_binary_string(val)
val.pack("C*")
end
def read_and_return_value(io)
if has_parameter?(:initial_length)
data = io.readbytes(eval_parameter(:initial_length))
else
data = io.read_all_bytes
end
data.unpack("C*")
end
def sensible_default
[]
end
end
class Uint8ArrayArgProcessor < BaseArgProcessor
def sanitize_parameters!(obj_class, params) #:nodoc:
# ensure one of :initial_length and :read_until exists
unless params.has_at_least_one_of?(:initial_length, :read_until)
params[:initial_length] = 0
end
msg = "Parameter :read_until must have a value of :eof"
params.sanitize(:read_until) { |val| raise ArgumentError, msg unless val == :eof }
end
end
end
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