Module: Snappy::FFI

Defined in:
lib/snappy_ffi.rb

Defined Under Namespace

Modules: Lib

Constant Summary collapse

Version = 
"0.1.2"

Class Method Summary collapse

Class Method Details

.compress(input) ⇒ Object

Compresses a string, returning the compressed value



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# File 'lib/snappy_ffi.rb', line 73

def self.compress(input)
  # Set up our input
  input = input.to_s
  input_size = input.bytesize rescue input.size
  
  # Make a place to record our compressed size
  output_size = Lib::SizeT.new
  
  # Make a buffer big enough to hold the worst case
  max = Lib.max_compressed_length(input_size)
  FFI::MemoryPointer.new(max) { |output_buffer|
    # Compress
    Lib.raw_compress(input, input_size, output_buffer, output_size.pointer)

    # Get our string
    output = output_buffer.get_bytes(0, output_size[:value])

    # Return, copying taint as needed
    if input.tainted?
      return output.taint
    else
      return output
    end
  }
end

.uncompress(input) ⇒ Object

Decompresses a string, throwing ArgumentError if it’s somehow corrupt



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# File 'lib/snappy_ffi.rb', line 100

def self.uncompress(input)
  # Set up our input
  input = input.to_s
  input_size = input.bytesize rescue input.size
      
  # Make a place to record our uncompressed size
  output_size = Lib::SizeT.new
  
  # See how big our output will be
  if !Lib.get_uncompressed_length(input, input_size, output_size.pointer)
    # failure!
    raise ArgumentError, "invalid compressed data"
  end
  
  # Make the buffer
  FFI::MemoryPointer.new(output_size[:value]) { |output_buffer|
    # Decompress
    if !Lib.raw_uncompress(input, input_size, output_buffer)
      raise ArgumentError, "invalid compressed data"
    end
  
    # Get our string
    output = output_buffer.get_bytes(0, output_size[:value])
  
    # Return, copying taint as needed
    if input.tainted?
      return output.taint
    else
      return output
    end    
  }
end