Class: Crea::Stream

Inherits:
Object
  • Object
show all
Defined in:
lib/crea/stream.rb

Overview

Crea::Stream allows a live view of the CREA blockchain.

Example streaming blocks:

stream = Crea::Stream.new

stream.blocks do |block, block_num|
  puts "#{block_num} :: #{block.witness}"
end

Example streaming transactions:

stream = Crea::Stream.new

stream.transactions do |trx, trx_id, block_num|
  puts "#{block_num} :: #{trx_id} :: operations: #{trx.operations.size}"
end

Example streaming operations:

stream = Crea::Stream.new

stream.operations do |op, trx_id, block_num|
  puts "#{block_num} :: #{trx_id} :: #{op.type}: #{op.value.to_json}"
end

Allows streaming of block headers, full blocks, transactions, operations and virtual operations.

Constant Summary collapse

BLOCK_INTERVAL = 
3
MAX_BACKOFF_BLOCK_INTERVAL = 
30
MAX_RETRY_COUNT = 
10
VOP_TRX_ID = 
('0' * 40).freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {mode: :irreversible}) ⇒ Stream

Returns a new instance of Stream.

Parameters:

  • options (Hash) (defaults to: {mode: :irreversible}) —

    additional options

Options Hash (options):

  • :database_api (Crea::DatabaseApi)
  • :block_api (Crea::BlockApi)
  • :account_history_api (Crea::AccountHistoryApi || Crea::CondenserApi)
  • :mode (Symbol) —

    we have the choice between

    • :head the last block

    • :irreversible the block that is confirmed by 2/3 of all block producers and is thus irreversible!

  • :no_warn (Boolean) —

    do not generate warnings



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# File 'lib/crea/stream.rb', line 47

def initialize(options = {mode: :irreversible})
  @instance_options = options
  @database_api = options[:database_api] || Crea::DatabaseApi.new(options)
  @block_api = options[:block_api] || Crea::BlockApi.new(options)
  @account_history_api = options[:account_history_api]
  @mode = options[:mode] || :irreversible
  @no_warn = !!options[:no_warn]
end

Instance Attribute Details

#account_history_api ⇒ Object (readonly)

Returns the value of attribute account_history_api.



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# File 'lib/crea/stream.rb', line 31

def 
  @account_history_api
end

#block_api ⇒ Object (readonly)

Returns the value of attribute block_api.



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# File 'lib/crea/stream.rb', line 31

def block_api
  @block_api
end

#database_api ⇒ Object (readonly)

Returns the value of attribute database_api.



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# File 'lib/crea/stream.rb', line 31

def database_api
  @database_api
end

#mode ⇒ Object (readonly)

Returns the value of attribute mode.



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# File 'lib/crea/stream.rb', line 31

def mode
  @mode
end

Instance Method Details

#block_headers(options = {}, &block) ⇒ Object

Use this method to stream block headers. This is quite a bit faster than requesting full blocks.

Parameters:

  • options (Hash) (defaults to: {}) —

    additional options

Options Hash (options):

  • :at_block_num (Integer) —

    Starts the stream at the given block number. Default: nil.

  • :until_block_num (Integer) —

    Ends the stream at the given block number. Default: nil.



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# File 'lib/crea/stream.rb', line 74

def block_headers(options = {}, &block)
  block_objects(options.merge(object: :block_headers), block)
end

#block_numbers(options = {}, &block) ⇒ Object

Use this method to stream block numbers. This is significantly faster than requesting full blocks and even block headers. Basically, the only thing this method does is call Database#get_dynamic_global_properties at 3 second intervals.

Parameters:

  • options (Hash) (defaults to: {}) —

    additional options

Options Hash (options):

  • :at_block_num (Integer) —

    Starts the stream at the given block number. Default: nil.

  • :until_block_num (Integer) —

    Ends the stream at the given block number. Default: nil.



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# File 'lib/crea/stream.rb', line 64

def block_numbers(options = {}, &block)
  block_objects(options.merge(object: :block_numbers), block)
end

#blocks(options = {}, &block) ⇒ Object

Use this method to stream full blocks.

Parameters:

  • options (Hash) (defaults to: {}) —

    additional options

Options Hash (options):

  • :at_block_num (Integer) —

    Starts the stream at the given block number. Default: nil.

  • :until_block_num (Integer) —

    Ends the stream at the given block number. Default: nil.



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# File 'lib/crea/stream.rb', line 83

def blocks(options = {}, &block)
  block_objects(options.merge(object: :blocks), block)
end

#operations(*args, &block) ⇒ Object

Returns the latest operations from the blockchain.

stream = Crea::Stream.new
stream.operations do |op|
  puts op.to_json
end

If symbol are passed to ‘types` option, then only that operation is returned. Expected symbols are:






cancel_transfer_from_savings_operation

claim_reward_balance_operation
comment_operation
comment_options_operation
convert_operation
custom_operation
custom_json_operation
decline_voting_rights_operation
delegate_vesting_shares_operation
delete_comment_operation
escrow_approve_operation
escrow_dispute_operation
escrow_release_operation
escrow_transfer_operation
feed_publish_operation
limit_order_cancel_operation
limit_order_create_operation
limit_order_create2_operation
pow_operation
pow2_operation


set_withdraw_vesting_route_operation
transfer_operation
transfer_from_savings_operation
transfer_to_savings_operation
transfer_to_vesting_operation
vote_operation
withdraw_vesting_operation
witness_update_operation

For example, to stream only votes:

stream = Crea::Stream.new
stream.operations(types: :vote_operation) do |vote|
  puts vote.to_json
end

… Or …

stream = Crea::Stream.new
stream.operations(:vote_operation) do |vote|
  puts vote.to_json
end

You can also stream virtual operations:

stream = Crea::Stream.new
stream.operations(types: :author_reward_operation, only_virtual: true) do |vop|
  v = vop.value
  puts "#{v.author} got paid for #{v.permlink}: #{[v.cbd_payout, v.crea_payout, v.vesting_payout]}"
end

… or multiple virtual operation types;

stream = Crea::Stream.new
stream.operations(types: [:producer_reward_operation, :author_reward_operation], only_virtual: true) do |vop|
  puts vop.to_json
end

… or all types, including virtual operation types from the head block number:

stream = Crea::Stream.new(mode: :head)
stream.operations(include_virtual: true) do |op|
  puts op.to_json
end

Expected virtual operation types:

producer_reward_operation
author_reward_operation
curation_reward_operation
fill_convert_request_operation
fill_order_operation
fill_vesting_withdraw_operation
interest_operation
shutdown_witness_operation

Parameters:

  • args (Symbol || Array<Symbol> || Hash) —

    the type(s) of operation or hash of expanded options, optional.

  • block —

    the block to execute for each result. Yields: |op, trx_id, block_num|

Options Hash (*args):

  • :at_block_num (Integer) —

    Starts the stream at the given block number. Default: nil.

  • :until_block_num (Integer) —

    Ends the stream at the given block number. Default: nil.

  • :types (Symbol || Array<Symbol>) —

    the type(s) of operation, optional.

  • :only_virtual (Boolean) —

    Only stream virtual options. Setting this true will improve performance because the stream only needs block numbers to then retrieve virtual operations. Default: false.

  • :include_virtual (Boolean) —

    Also stream virtual options. Setting this true will impact performance. Default: false.



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# File 'lib/crea/stream.rb', line 211

def operations(*args, &block)
  options = {}
  types = []
  only_virtual = false
  include_virtual = false
  last_block_num = nil
  
  case args.first
  when Hash
    options = args.first
    types = transform_types(options[:types])
    only_virtual = !!options[:only_virtual] || false
    include_virtual = !!options[:include_virtual] || only_virtual || false
  when Symbol, Array then types = transform_types(args)
  end
  
  if only_virtual
    block_numbers(options) do |block_num|
      get_virtual_ops(types, block_num, block)
    end
  else
    transactions(options) do |transaction, trx_id, block_num|
      transaction.operations.each do |op|
        yield op, trx_id, block_num if types.none? || types.include?(op.type)
        
        next unless last_block_num != block_num
        
        last_block_num = block_num
        
        get_virtual_ops(types, block_num, block) if include_virtual
      end
    end
  end
end

#transactions(options = {}, &block) ⇒ Object

Use this method to stream each transaction.

Parameters:

  • options (Hash) (defaults to: {}) —

    additional options

Options Hash (options):

  • :at_block_num (Integer) —

    Starts the stream at the given block number. Default: nil.

  • :until_block_num (Integer) —

    Ends the stream at the given block number. Default: nil.



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# File 'lib/crea/stream.rb', line 92

def transactions(options = {}, &block)
  blocks(options) do |block, block_num|
    if block.nil?
      warn "Batch missing block_num: #{block_num}, retrying ..."
      
      block = block_api.get_block(block_num: block_num) do |result|
        result.block
      end
    end
    
    block.transactions.each_with_index do |transaction, index|
      trx_id = block.transaction_ids[index]
      
      yield transaction, trx_id, block_num
    end
  end
end