Class: BlockchainLite::ProofOfWork::Block

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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

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

Returns a new instance of Block.



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# File 'lib/blockchain-lite/proof_of_work/block.rb', line 18

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

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

  ## todo: add empty array check to merkletree.compute why? why not?
  @transactions_hash  = transactions.empty? ? '0' : MerkleTree.compute_root_for( transactions )

  @previous_hash = previous_hash

  ## note: use coordinated universal time (utc)
  @timestamp = timestamp ? timestamp : Time.now.utc

  if nonce     ## restore pre-computed/mined block (from disk/cache/db/etc.)
     ## todo: check timestamp MUST NOT be nil
     @nonce = nonce
     @hash  = calc_hash
  else   ## new block  (mine! e.g. find nonce - "lucky" number used once)
     @nonce, @hash = compute_hash_with_proof_of_work
  end
end

Instance Attribute Details

#hash ⇒ Object (readonly)

Returns the value of attribute hash.



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

def hash
  @hash
end

#index ⇒ Object (readonly)

Returns the value of attribute index.



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

def index
  @index
end

#nonce ⇒ Object (readonly)

(“lucky” number used once) - proof of work if hash starts with leading zeros (00)



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# File 'lib/blockchain-lite/proof_of_work/block.rb', line 15

def nonce
  @nonce
end

#previous_hash ⇒ Object (readonly)

Returns the value of attribute previous_hash.



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

def previous_hash
  @previous_hash
end

#timestamp ⇒ Object (readonly)

Returns the value of attribute timestamp.



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

def transactions_count
  @transactions_count
end

#transactions_hash ⇒ Object (readonly)

use alias - merkle_root - why? why not?



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

def transactions_hash
  @transactions_hash
end

Class Method Details

.first(*args, **opts) ⇒ Object

create genesis (big bang! first) block



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# File 'lib/blockchain-lite/proof_of_work/block.rb', line 48

def self.first( *args, **opts )    # 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')
  ##  note: pass along (optional) custom timestamp (e.g. used for 1637 etc.)
  Block.new( 0, transactions, '0', timestamp: opts[:timestamp] )
end

.next(previous, *args, **opts) ⇒ Object 



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# File 'lib/blockchain-lite/proof_of_work/block.rb', line 60

def self.next( previous, *args, **opts )
  ## 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, timestamp: opts[:timestamp] )
end

Instance Method Details

#calc_hash ⇒ Object 



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# File 'lib/blockchain-lite/proof_of_work/block.rb', line 42

def calc_hash
  calc_hash_with_nonce( @nonce )
end