Class: SamplingHash::Hash

Inherits:
Object
  • Object
show all
Defined in:
lib/sampling-hash/hash.rb

Instance Method Summary collapse

Constructor Details

#initialize(size, seed = size, sampler = nil, xxhash = XXhash::XXhashInternal::StreamingHash64.new(seed)) ⇒ Hash

Returns a new instance of Hash.



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# File 'lib/sampling-hash/hash.rb', line 3

def initialize(size, seed = size, sampler = nil, xxhash = XXhash::XXhashInternal::StreamingHash64.new(seed))
  @sampler = sampler || Sampler.new(size)
  @xxhash = xxhash
  
  # Position in data stream.
  @position = 0

  # Current sample.
  @current_sample        = nil # The data.
  @current_sample_offset = 0   # The offset (within the stream).
  @current_sample_size   = 0   # The sample size.
  @next                  = 0   # The next sample index.

  # Start.
  next_sample
end

Instance Method Details

#digest ⇒ Object 



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# File 'lib/sampling-hash/hash.rb', line 30

def digest
  @xxhash.digest
end

#update(chunk) ⇒ Object 



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# File 'lib/sampling-hash/hash.rb', line 20

def update(chunk)
  pos = 0
  while pos < chunk.size
    len = chunk.size - pos
    used = advance(chunk, pos, len)
    @position += used
    pos += used
  end
end