Class: BlockchainLite::Basic::Block

Inherits:
Object
  • Object
show all
Defined in:
lib/blockchain-lite/basic/block.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(index, transactions, previous_hash, timestamp: nil) ⇒ Block

Returns a new instance of Block.



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# File 'lib/blockchain-lite/basic/block.rb', line 16

def initialize(index, transactions, previous_hash, timestamp: nil)
  @index              = index

  ## note: use coordinated universal time (utc)
  ##    auto-add timestamp for new blocks (e.g. timestamp is nil)
  @timestamp          = timestamp ? timestamp : Time.now.utc

  ## note: assumes / expects an array for transactions
  @transactions       = transactions
  @transactions_count = transactions.size

  @previous_hash      = previous_hash
  @hash               = calc_hash
end

Instance Attribute Details

#hash ⇒ Object (readonly)

Returns the value of attribute hash.



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# File 'lib/blockchain-lite/basic/block.rb', line 14

def hash
  @hash
end

#index ⇒ Object (readonly)

Returns the value of attribute index.



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# File 'lib/blockchain-lite/basic/block.rb', line 9

def index
  @index
end

#previous_hash ⇒ Object (readonly)

Returns the value of attribute previous_hash.



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# File 'lib/blockchain-lite/basic/block.rb', line 13

def previous_hash
  @previous_hash
end

#timestamp ⇒ Object (readonly)

Returns the value of attribute timestamp.



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# File 'lib/blockchain-lite/basic/block.rb', line 10

def timestamp
  @timestamp
end

#transactions ⇒ Object (readonly)

use alias - txn - why? why not?



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# File 'lib/blockchain-lite/basic/block.rb', line 12

def transactions
  @transactions
end

#transactions_count ⇒ Object (readonly)

use alias - txn_count - why? why not?



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# File 'lib/blockchain-lite/basic/block.rb', line 11

def transactions_count
  @transactions_count
end

Class Method Details

.first(*args) ⇒ Object

create genesis (big bang! first) block



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# File 'lib/blockchain-lite/basic/block.rb', line 41

def self.first( *args )    # create genesis (big bang! first) block
  ##  note: allow/support splat-* for now for convenience (auto-wraps args into array)
  if args.size == 1 && args[0].is_a?( Array )
    transactions = args[0]   ## "unwrap" array in array
  else
    transactions = args      ## use "auto-wrapped" splat array
  end
  ## uses index zero (0) and arbitrary previous_hash ('0')
  Block.new( 0, transactions, '0'  )
end

.next(previous, *args) ⇒ Object 



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# File 'lib/blockchain-lite/basic/block.rb', line 52

def self.next( previous, *args )
  ## note: allow/support splat-* for now for convenience (auto-wraps args into array)
  if args.size == 1 && args[0].is_a?( Array )
    transactions = args[0]   ## "unwrap" array in array
  else
    transactions = args      ## use "auto-wrapped" splat array
  end
  Block.new( previous.index+1, transactions, previous.hash )
end

Instance Method Details

#calc_hash ⇒ Object 



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# File 'lib/blockchain-lite/basic/block.rb', line 31

def calc_hash
  sha = Digest::SHA256.new
  sha.update( @timestamp.to_s +
              @transactions.to_s +
              @previous_hash )
  sha.hexdigest
end