Module: BTC::Data

Extended by:
Data
Included in:
BTC, Data
Defined in:
lib/btc/data.rb,
lib/btc/data.rb

Overview

This allows doing ‘BTC.to_hex(…)`

Constant Summary collapse

HEX_PACK_CODE = 
'H*'
BYTE_PACK_CODE = 
'C*'

Instance Method Summary collapse

Instance Method Details

#bytes_from_data(data, offset: 0, limit: nil, range: nil) ⇒ Object

Converts a binary string to an array of bytes (list of integers). Returns a much more efficient slice of bytes if offset/limit or range are specified. That is, avoids converting the entire buffer to byte array.

Note 1: if range is specified, it takes precedence over offset/limit.

Note 2: byteslice(…).bytes is less efficient as it creates

an intermediate shorter string.

Raises:

  • (ArgumentError) 


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# File 'lib/btc/data.rb', line 56

def bytes_from_data(data, offset: 0, limit: nil, range: nil)
  raise ArgumentError, 'Data is missing' unless data
  return data.bytes if offset == 0 && limit.nil? && range.nil?
  if range
    offset = range.begin
    limit  = range.size
  end
  bytes = []
  data.each_byte do |byte|
    if offset > 0
      offset -= 1
    else
      if !limit || limit > 0
        bytes << byte
        limit -= 1 if limit
      else
        break
      end
    end
  end
  bytes
end

#data_from_bytes(bytes) ⇒ Object

Converts binary string to an array of bytes (list of integers).

Raises:

  • (ArgumentError) 


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# File 'lib/btc/data.rb', line 80

def data_from_bytes(bytes)
  raise ArgumentError, 'Bytes are missing' unless bytes
  bytes.pack(BYTE_PACK_CODE)
end

#data_from_hex(hex_string) ⇒ Object

Converts hexadecimal string to a binary data string.

Raises:

  • (ArgumentError) 


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# File 'lib/btc/data.rb', line 23

def data_from_hex(hex_string)
  raise ArgumentError, 'Hex string is missing' unless hex_string
  hex_string = hex_string.strip
  data = [hex_string].pack(HEX_PACK_CODE)
  if hex_from_data(data) != hex_string.downcase # invalid hex string was detected
    raise FormatError, "Hex string is invalid: #{hex_string.inspect}"
  end
  data
end

#ensure_ascii_compatible_encoding(string, options = nil) ⇒ Object

Returns string as-is if it is ASCII-compatible (that is, if you are interested in 7-bit characters exposed as #bytes). If it is not, attempts to transcode to UTF8 replacing invalid characters if there are any. If options are not specified, uses safe default that replaces unknown characters with standard character. If options are specified, they are used as-is for String#encode method.



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# File 'lib/btc/data.rb', line 90

def ensure_ascii_compatible_encoding(string, options = nil)
  if string.encoding.ascii_compatible?
    string
  else
    string.encode(Encoding::UTF_8, options || { invalid: :replace, undef: :replace })
  end
end

#ensure_binary_encoding(string) ⇒ Object

Returns string as-is if it is already encoded in binary encoding (aka BINARY or ASCII-8BIT). If it is not, converts to binary by calling stdlib’s method #b.

Raises:

  • (ArgumentError) 


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# File 'lib/btc/data.rb', line 100

def ensure_binary_encoding(string)
  raise ArgumentError, 'String is missing' unless string
  if string.encoding == Encoding::BINARY
    string
  else
    string.b
  end
end

#from_hex(hex) ⇒ Object 



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# File 'lib/btc/data.rb', line 43

def from_hex(hex)
  data_from_hex(hex)
end

#hex_from_data(data) ⇒ Object

Converts binary string to lowercase hexadecimal representation.

Raises:

  • (ArgumentError) 


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# File 'lib/btc/data.rb', line 34

def hex_from_data(data)
  raise ArgumentError, 'Data is missing' unless data
  data.unpack(HEX_PACK_CODE).first
end

#random_data(length = 32) ⇒ Object

Generates a secure random number of a given length



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# File 'lib/btc/data.rb', line 18

def random_data(length = 32)
  SecureRandom.random_bytes(length)
end

#to_hex(data) ⇒ Object 



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# File 'lib/btc/data.rb', line 39

def to_hex(data)
  hex_from_data(data)
end