Module: EventMachine::RTMP::IOHelpers

Included in:
Buffer, Connection, ConnectionDelegate
Defined in:
lib/em-rtmp/io_helpers.rb

Instance Method Summary collapse

Instance Method Details

#read_bitfield(*widths) ⇒ Object

Read a bit field and return the mapped results

widths - Array of integers representing the size of the fields

Returns the value for each field read



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# File 'lib/em-rtmp/io_helpers.rb', line 154

def read_bitfield(*widths)
  byte = read_uint8
  shifts_and_masks(widths).map{ |shift, mask|
    (byte >> shift) & mask
  }
end

#read_double_be ⇒ Object

Read a double (big endian)

Returns the result of the read



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# File 'lib/em-rtmp/io_helpers.rb', line 88

def read_double_be
  read_safe(8).unpack('G')[0]
end

#read_int29 ⇒ Object

Read an int29

Returns the result of the stream operation



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# File 'lib/em-rtmp/io_helpers.rb', line 104

def read_int29
  count = 1
  result = 0
  byte = read_uint8

  while (byte & 0x80 != 0) && count < 4 do
    result <<= 7
    result |= (byte & 0x7f)
    byte = read_uint8
    count += 1
  end

  if count < 4
    result <<= 7
    result |= byte
  else
    result <<= 8
    result |= byte
  end

  result
end

#read_safe(length) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/em-rtmp/io_helpers.rb', line 175

def read_safe(length)
  raise ArgumentError, "cannot read nothing: #{length}" unless length && length >= 1

  if value = read(length)
    return value
  else
    Logger.error "unable to read from socket, closing connection"
    close_connection
    ""
  end
end

#read_uint16_be ⇒ Object

Read a unsigned 16-bit integer

Returns the result of the read



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# File 'lib/em-rtmp/io_helpers.rb', line 24

def read_uint16_be
  read_safe(2).unpack('n')[0]
end

#read_uint24_be ⇒ Object

Read a unsigned 24-bit integer

Returns the result of the read



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# File 'lib/em-rtmp/io_helpers.rb', line 40

def read_uint24_be
  ("\x00" + read_safe(3)).unpack('N')[0]
end

#read_uint32_be ⇒ Object

Read a unsigned 32-bit integer (big endian)

Returns the result of the read



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# File 'lib/em-rtmp/io_helpers.rb', line 56

def read_uint32_be
  read_safe(4).unpack('N')[0]
end

#read_uint32_le ⇒ Object

Read a unsigned 32-bit integer (little endian)

Returns the result of the read



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# File 'lib/em-rtmp/io_helpers.rb', line 63

def read_uint32_le
  read_safe(4).unpack('V')[0]
end

#read_uint8 ⇒ Object

Read a unsigned 8-bit integer

Returns the result of the read



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# File 'lib/em-rtmp/io_helpers.rb', line 8

def read_uint8
  read_safe(1).unpack('C')[0]
end

#write_bitfield(*values_and_widths) ⇒ Object

Write a bit field to the stream

values_and_widths - An array of arrays, each containing two values:

[0] - value to be written
[1] - width of value

Returns the value for each field read



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# File 'lib/em-rtmp/io_helpers.rb', line 168

def write_bitfield(*values_and_widths)
  sm = shifts_and_masks(values_and_widths.map{ |_,w| w })
  write_uint8 values_and_widths.zip(sm).inject(0){ |byte, ((value, width), (shift, mask))|
    byte | ((value & mask) << shift)
  }
end

#write_double_be(value) ⇒ Object

Write a double (big endian)

value - Value to write

Returns the result of the stream operation



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# File 'lib/em-rtmp/io_helpers.rb', line 97

def write_double_be(value)
  write [value].pack('G')
end

#write_int29(value) ⇒ Object

Write an int29

value - Value to write

Returns the result of the stream operation



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# File 'lib/em-rtmp/io_helpers.rb', line 132

def write_int29(value)
  value = value & 0x1fffffff
  if(value < 0x80)
    result = [value].pack('c')
    write result
  elsif(value < 0x4000)
    result = [value >> 7 & 0x7f | 0x80].pack('c') + [value & 0x7f].pack('c')
    write result
  elsif(value < 0x200000)
    result = [value >> 14 & 0x7f | 0x80].pack('c') + [value >> 7 & 0x7f | 0x80].pack('c') + [value & 0x7f].pack('c')
    write result
  else
    result = [value >> 22 & 0x7f | 0x80].pack('c') + [value >> 15 & 0x7f | 0x80].pack('c') + [value >> 8 & 0x7f | 0x80].pack('c') + [value & 0xff].pack('c')
    write result
  end
end

#write_uint16_be(value) ⇒ Object

Write an unsigned 16-bit integer

value - Value to write

Returns the result of the stream operation



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# File 'lib/em-rtmp/io_helpers.rb', line 33

def write_uint16_be(value)
  write [value].pack('n')
end

#write_uint24_be(value) ⇒ Object

Write an unsigned 24-bit integer

value - Value to write

Returns the result of the stream operation



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# File 'lib/em-rtmp/io_helpers.rb', line 49

def write_uint24_be(value)
  write [value].pack('N')[1,3]
end

#write_uint32_be(value) ⇒ Object

Write an unsigned 32-bit integer (big endian)

value - Value to write

Returns the result of the stream operation



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# File 'lib/em-rtmp/io_helpers.rb', line 72

def write_uint32_be(value)
  write [value].pack('N')
end

#write_uint32_le(value) ⇒ Object

Write an unsigned 32-bit integer (big endian)

value - Value to write

Returns the result of the stream operation



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# File 'lib/em-rtmp/io_helpers.rb', line 81

def write_uint32_le(value)
  write [value].pack('V')
end

#write_uint8(value) ⇒ Object

Write an unsigned 8-bit integer

value - Value to write

Returns the result of the stream operation



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# File 'lib/em-rtmp/io_helpers.rb', line 17

def write_uint8(value)
  write [value].pack('C')
end