Class: Runar::SDK::RunarContract

Inherits:
Object
  • Object
show all
Defined in:
lib/runar/sdk/contract.rb

Overview

rubocop:disable Naming/AccessorMethodName, Naming/PredicatePrefix

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(artifact, constructor_args) ⇒ RunarContract

Returns a new instance of RunarContract.

Parameters:

  • artifact (RunarArtifact) —

    compiled contract artifact

  • constructor_args (Array) —

    constructor argument values

Raises:

  • (ArgumentError) —

    when arg count does not match the ABI



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# File 'lib/runar/sdk/contract.rb', line 56

def initialize(artifact, constructor_args)
  expected = artifact.abi.constructor_params.length
  actual   = constructor_args.length
  if actual != expected
    raise ArgumentError,
          "RunarContract: expected #{expected} constructor args for " \
          "#{artifact.contract_name}, got #{actual}"
  end

  @artifact         = artifact
  @constructor_args = constructor_args.dup
  @state            = {}
  @code_script      = ''
  @current_utxo     = nil
  @provider         = nil
  @signer           = nil

  init_state_from_constructor_args
end

Instance Attribute Details

#artifact ⇒ Object (readonly)

Returns the value of attribute artifact.



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# File 'lib/runar/sdk/contract.rb', line 51

def artifact
  @artifact
end

Class Method Details

.from_txid(artifact, txid, output_index, provider) ⇒ RunarContract

Reconnect to an existing deployed contract by looking up the transaction on-chain.

rubocop:disable Metrics/AbcSize, Metrics/MethodLength

Parameters:

  • artifact (RunarArtifact)
  • txid (String) —

    txid of the deploy transaction

  • output_index (Integer) —

    index of the contract output

  • provider (Provider)

Returns:



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# File 'lib/runar/sdk/contract.rb', line 432

def self.from_txid(artifact, txid, output_index, provider)
  tx = provider.get_transaction(txid)
  if output_index >= tx.outputs.length
    raise ArgumentError,
          "RunarContract.from_txid: output index #{output_index} out of range " \
          "(tx has #{tx.outputs.length} outputs)"
  end

  output     = tx.outputs[output_index]
  dummy_args = Array.new(artifact.abi.constructor_params.length, 0)
  contract   = new(artifact, dummy_args)

  stateful = !artifact.state_fields.empty?
  code_script = if stateful
                  last_or = State.find_last_op_return(output.script)
                  last_or != -1 ? output.script[0, last_or] : output.script
                else
                  output.script
                end

  contract.instance_variable_set(:@code_script, code_script)
  contract.instance_variable_set(
    :@current_utxo,
    Utxo.new(txid: txid, output_index: output_index, satoshis: output.satoshis, script: output.script)
  )

  if stateful
    state = State.extract_state_from_script(artifact, output.script)
    contract.instance_variable_set(:@state, state) if state
  end

  contract
end

Instance Method Details

#build_code_script ⇒ String

Build the code script (artifact script with constructor args spliced in).

For each constructor slot, the 1-byte placeholder at byte_offset in the artifact script is replaced with the encoded arg value. Slots are processed in descending byte_offset order so earlier substitutions do not shift the offsets of later ones.

rubocop:disable Metrics/AbcSize, Metrics/MethodLength

Returns:

  • (String) —

    hex-encoded code script



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# File 'lib/runar/sdk/contract.rb', line 509

def build_code_script
  script = @artifact.script.dup

  if @artifact.constructor_slots.any?
    sorted_slots = @artifact.constructor_slots.sort_by { |s| -s.byte_offset }
    sorted_slots.each do |slot|
      encoded    = encode_arg(@constructor_args[slot.param_index])
      hex_offset = slot.byte_offset * 2
      script     = "#{script[0, hex_offset]}#{encoded}#{script[hex_offset + 2..]}"
    end
  elsif @artifact.state_fields.empty?
    # Backward compatibility: stateless artifacts without constructorSlots.
    @constructor_args.each { |arg| script += encode_arg(arg) }
  end

  script
end

#build_unlocking_script(method_name, args) ⇒ String

Build the unlocking script for a method call without broadcasting.

Parameters:

  • method_name (String)
  • args (Array)

Returns:

  • (String) —

    hex-encoded unlocking script



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# File 'lib/runar/sdk/contract.rb', line 486

def build_unlocking_script(method_name, args)
  script              = args.map { |a| encode_arg(a) }.join
  public_methods_list = get_public_methods

  if public_methods_list.length > 1
    method_index = public_methods_list.index { |m| m.name == method_name }
    raise ArgumentError, "build_unlocking_script: public method '#{method_name}' not found" unless method_index

    script += State.encode_script_int(method_index)
  end

  script
end

#call(method_name, args = [], provider = nil, signer = nil, options = nil) ⇒ Array(String, TransactionData)

Invoke a public method (spend the contract UTXO).

For stateful contracts, the preimage and k=1 OP_PUSH_TX signature are computed automatically. For methods with Sig params, a 72-byte placeholder is substituted during transaction construction then replaced with a real signature.

Parameters:

  • method_name (String) —

    ABI method name

  • args (Array) (defaults to: []) —

    user-supplied arguments

  • provider (Provider, nil) (defaults to: nil) —

    overrides connected provider

  • signer (Signer, nil) (defaults to: nil) —

    overrides connected signer

  • options (CallOptions, nil) (defaults to: nil)

Returns:



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# File 'lib/runar/sdk/contract.rb', line 166

def call(method_name, args = [], provider = nil, signer = nil, options = nil)
  provider = resolve_provider(provider, 'call')
  signer   = resolve_signer(signer, 'call')

  prepared   = prepare_call(method_name, args, provider, signer, options)
  signatures = {}
  prepared.sig_indices.each do |idx|
    subscript = prepared.contract_utxo.script
    if prepared.is_stateful && prepared.code_sep_idx >= 0
      trim_pos  = (prepared.code_sep_idx + 1) * 2
      subscript = subscript[trim_pos..] if trim_pos <= subscript.length
    end
    signatures[idx] = signer.sign(
      prepared.tx_hex, 0,
      subscript,
      prepared.contract_utxo.satoshis
    )
  end

  finalize_call(prepared, signatures, provider)
end

#connect(provider, signer) ⇒ Object

Store provider and signer for use by subsequent deploy/call invocations.

Parameters:



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# File 'lib/runar/sdk/contract.rb', line 87

def connect(provider, signer)
  @provider = provider
  @signer   = signer
end

#deploy(provider = nil, signer = nil, options = nil) ⇒ Array(String, TransactionData)

Deploy the contract to the blockchain.

Builds the locking script (code + optional state), selects UTXOs, constructs and signs the transaction, broadcasts it, and begins tracking the contract UTXO.

Parameters:

  • provider (Provider, nil) (defaults to: nil) —

    overrides connected provider

  • signer (Signer, nil) (defaults to: nil) —

    overrides connected signer

  • options (DeployOptions, nil) (defaults to: nil) —

    deployment parameters

Returns:



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# File 'lib/runar/sdk/contract.rb', line 102

def deploy(provider = nil, signer = nil, options = nil)
  provider = resolve_provider(provider, 'deploy')
  signer   = resolve_signer(signer, 'deploy')
  opts     = options || DeployOptions.new

  address        = signer.get_address
  change_address = opts.change_address.to_s.empty? ? address : opts.change_address
  locking_script = get_locking_script

  fee_rate  = provider.get_fee_rate
  all_utxos = provider.get_utxos(address)

  raise "RunarContract.deploy: no UTXOs found for #{address}" if all_utxos.empty?

  utxos         = SDK.select_utxos(all_utxos, opts.satoshis, locking_script.length / 2, fee_rate: fee_rate)
  change_script = SDK.build_p2pkh_script(change_address)

  tx_hex, input_count = SDK.build_deploy_transaction(
    locking_script, utxos, opts.satoshis, change_address, change_script, fee_rate: fee_rate
  )

  # Sign all P2PKH funding inputs.
  signed_tx = tx_hex
  pub_key   = signer.get_public_key
  input_count.times do |i|
    utxo      = utxos[i]
    sig       = signer.sign(signed_tx, i, utxo.script, utxo.satoshis)
    unlock    = State.encode_push_data(sig) + State.encode_push_data(pub_key)
    signed_tx = SDK.insert_unlocking_script(signed_tx, i, unlock)
  end

  txid = provider.broadcast(signed_tx)

  @current_utxo = Utxo.new(
    txid: txid, output_index: 0,
    satoshis: opts.satoshis, script: locking_script
  )

  tx = begin
    provider.get_transaction(txid)
  rescue StandardError
    TransactionData.new(
      txid: txid, version: 1,
      outputs: [TxOutput.new(satoshis: opts.satoshis, script: locking_script)],
      raw: signed_tx
    )
  end

  [txid, tx]
end

#finalize_call(prepared, signatures, provider = nil) ⇒ Array(String, TransactionData)

Complete a prepared call by injecting external signatures and broadcasting.

rubocop:disable Metrics/MethodLength

Parameters:

  • prepared (PreparedCall) —

    result of prepare_call

  • signatures (Hash<Integer, String>) —

    map from arg index to hex signature

  • provider (Provider, nil) (defaults to: nil) —

    overrides connected provider

Returns:



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# File 'lib/runar/sdk/contract.rb', line 401

def finalize_call(prepared, signatures, provider = nil)
  provider = resolve_provider(provider, 'finalize_call')

  resolved_args = prepared.resolved_args.dup
  prepared.sig_indices.each { |idx| resolved_args[idx] = signatures[idx] if signatures.key?(idx) }

  primary_unlock = assemble_primary_unlock(prepared, resolved_args)
  final_tx       = SDK.insert_unlocking_script(prepared.tx_hex, 0, primary_unlock)
  txid           = provider.broadcast(final_tx)

  update_tracked_utxo(txid, prepared)

  tx = begin
    provider.get_transaction(txid)
  rescue StandardError
    TransactionData.new(txid: txid, version: 1, raw: final_tx)
  end

  [txid, tx]
end

#get_locking_script ⇒ String

Return the full locking script hex (code script + optional OP_RETURN + state).

Returns:

  • (String) 


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# File 'lib/runar/sdk/contract.rb', line 470

def get_locking_script
  script = @code_script.empty? ? build_code_script : @code_script

  unless @artifact.state_fields.empty?
    state_hex = State.serialize_state(@artifact.state_fields, @state)
    script    = "#{script}6a#{state_hex}" unless state_hex.empty? # OP_RETURN
  end

  script
end

#get_state ⇒ Hash

Return a copy of the current state.

Returns:

  • (Hash) 


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# File 'lib/runar/sdk/contract.rb', line 531

def get_state
  @state.dup
end

#get_utxo ⇒ Utxo?

Return the UTXO currently tracked by this contract, or nil if not deployed.

Returns:



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# File 'lib/runar/sdk/contract.rb', line 79

def get_utxo
  @current_utxo
end

#prepare_call(method_name, args = [], provider = nil, signer = nil, options = nil) ⇒ PreparedCall

Prepare a method call without signing the primary contract input’s Sig params. Returns a PreparedCall struct for use with finalize_call.

P2PKH funding inputs ARE signed. Only the primary contract input’s Sig params are left as 72-byte placeholders.

rubocop:disable Metrics/AbcSize, Metrics/MethodLength, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity

Parameters:

  • method_name (String)
  • args (Array, nil) (defaults to: [])
  • provider (Provider, nil) (defaults to: nil)
  • signer (Signer, nil) (defaults to: nil)
  • options (CallOptions, nil) (defaults to: nil)

Returns:



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# File 'lib/runar/sdk/contract.rb', line 201

def prepare_call(method_name, args = [], provider = nil, signer = nil, options = nil)
  provider = resolve_provider(provider, 'prepare_call')
  signer   = resolve_signer(signer, 'prepare_call')
  args     = Array(args)

  method = find_method(method_name)
  unless method
    raise ArgumentError,
          "RunarContract.prepare_call: method '#{method_name}' not found in #{@artifact.contract_name}"
  end

  is_stateful = !@artifact.state_fields.empty?

  method_needs_change     = method.params.any? { |p| p.name == '_changePKH' }
  method_needs_new_amount = method.params.any? { |p| p.name == '_newAmount' }

  user_params = if is_stateful
                  method.params.reject do |p|
                    p.type == 'SigHashPreimage' ||
                      p.name == '_changePKH' ||
                      p.name == '_changeAmount' ||
                      p.name == '_newAmount'
                  end
                else
                  method.params
                end

  if user_params.length != args.length
    raise ArgumentError,
          "RunarContract.prepare_call: method '#{method_name}' expects " \
          "#{user_params.length} args, got #{args.length}"
  end

  unless @current_utxo
    raise 'RunarContract.prepare_call: contract is not deployed. Call deploy() or from_txid() first.'
  end

  contract_utxo = Utxo.new(
    txid: @current_utxo.txid, output_index: @current_utxo.output_index,
    satoshis: @current_utxo.satoshis, script: @current_utxo.script
  )
  address        = signer.get_address
  opts           = options || CallOptions.new
  change_address = opts.change_address.to_s.empty? ? address : opts.change_address

  extra_input_count = Array(opts.additional_contract_inputs).length
  estimated_inputs  = 1 + extra_input_count + 1
  resolved_args, sig_indices, preimage_index, prevouts_indices =
    resolve_method_args(args, user_params, signer, estimated_inputs: estimated_inputs)

  needs_op_push_tx    = preimage_index >= 0 || is_stateful
  method_selector_hex = compute_method_selector(method_name, is_stateful)
  code_sep_idx        = get_code_sep_index(find_method_index(method_name))

  change_pkh_hex = compute_change_pkh(signer, is_stateful, method_needs_change)

  # Auto-compute new state via ANF interpreter when artifact has ANF IR and
  # no explicit new_state was provided. This mirrors the Python SDK behavior:
  # compute_new_state is called here (where method_name and args are available),
  # not in build_continuation (which has neither).
  if is_stateful && @artifact.anf && opts.new_state.nil?
    named_args = build_named_args(user_params, resolved_args)
    opts = opts.dup
    opts.new_state = ANFInterpreter.compute_new_state(
      @artifact.anf, method_name, @state, named_args
    )
  end

  # Terminal call path: build a transaction with exact outputs, no funding inputs.
  if opts.terminal_outputs && !opts.terminal_outputs.empty?
    return prepare_terminal(
      method_name, resolved_args, signer, opts,
      is_stateful, needs_op_push_tx, method_needs_change,
      sig_indices, preimage_index,
      method_selector_hex, change_pkh_hex, contract_utxo, code_sep_idx
    )
  end

  # Multi-output path: build contract_outputs from opts.outputs when present.
  # Single-output path: fall through to build_continuation.
  has_multi_output = is_stateful && opts.outputs && !Array(opts.outputs).empty?
  contract_outputs = nil
  new_locking_script = ''
  new_satoshis = 0

  if has_multi_output
    code_script = @code_script.empty? ? build_code_script : @code_script
    contract_outputs = Array(opts.outputs).map do |out_spec|
      state_dict = out_spec.is_a?(OutputSpec) ? out_spec.state : (out_spec['state'] || out_spec[:state])
      sats = out_spec.is_a?(OutputSpec) ? out_spec.satoshis : (out_spec['satoshis'] || out_spec[:satoshis] || 1)
      state_hex = State.serialize_state(@artifact.state_fields, state_dict)
      { script: "#{code_script}6a#{state_hex}", satoshis: sats }
    end
  else
    new_locking_script, new_satoshis = build_continuation(is_stateful, opts)
  end

  # Normalise additional contract inputs to Utxo objects.
  extra_contract_utxos = Array(opts.additional_contract_inputs).map do |item|
    case item
    when Utxo then item
    when Hash
      Utxo.new(
        txid: item[:txid] || item['txid'],
        output_index: item[:output_index] || item['output_index'],
        satoshis: item[:satoshis] || item['satoshis'],
        script: item[:script] || item['script']
      )
    else item
    end
  end

  # Resolve per-input args for additional contract inputs.
  raw_per_input_args = Array(opts.additional_contract_input_args)
  resolved_per_input_args = extra_contract_utxos.each_with_index.map do |_, i|
    input_args = (raw_per_input_args[i] || resolved_args).dup
    user_params.each_with_index do |param, j|
      case param.type
      when 'Sig'    then input_args[j] = '00' * 72 if input_args[j].nil?
      when 'PubKey' then input_args[j] = signer.get_public_key if input_args[j].nil?
      end
    end
    input_args
  end

  fee_rate          = provider.get_fee_rate
  change_script     = SDK.build_p2pkh_script(change_address)
  all_funding_utxos = provider.get_utxos(address)
  additional_utxos  = all_funding_utxos.reject do |u|
    u.txid == @current_utxo.txid && u.output_index == @current_utxo.output_index
  end

  unlocking_script = if needs_op_push_tx
                       build_stateful_prefix('00' * 72, method_needs_change) +
                         build_unlocking_script(method_name, resolved_args)
                     else
                       build_unlocking_script(method_name, resolved_args)
                     end

  # Build placeholder unlocking scripts for extra contract inputs.
  extra_unlock_placeholders = extra_contract_utxos.each_with_index.map do |_, i|
    args_for_placeholder = resolved_per_input_args[i] || resolved_args
    build_stateful_prefix('00' * 72, method_needs_change) +
      build_unlocking_script(method_name, args_for_placeholder)
  end

  call_options = {}
  call_options[:contract_outputs] = contract_outputs if contract_outputs
  if extra_contract_utxos.any?
    call_options[:additional_contract_inputs] = extra_contract_utxos.each_with_index.map do |utxo, i|
      { utxo: utxo, unlocking_script: extra_unlock_placeholders[i] }
    end
  end

  tx_hex, _input_count, change_amount = SDK.build_call_transaction(
    contract_utxo, unlocking_script, new_locking_script,
    new_satoshis, change_address, change_script,
    additional_utxos.empty? ? nil : additional_utxos,
    fee_rate: fee_rate,
    options: call_options.empty? ? nil : call_options
  )

  p2pkh_start_idx = 1 + extra_contract_utxos.length
  signed_tx = sign_funding_inputs(tx_hex, additional_utxos, signer, p2pkh_start_idx)

  signed_tx, change_amount, final_op_push_tx_sig, final_preimage =
    compute_preimage_passes(
      signed_tx, contract_utxo, resolved_args, sig_indices,
      method_name, method_needs_change, method_needs_new_amount,
      change_pkh_hex, method_selector_hex, code_sep_idx,
      change_amount, new_satoshis, new_locking_script,
      change_address, change_script, additional_utxos, fee_rate, signer,
      is_stateful, needs_op_push_tx, preimage_index,
      contract_outputs: contract_outputs,
      extra_contract_utxos: extra_contract_utxos,
      resolved_per_input_args: resolved_per_input_args,
      prevouts_indices: prevouts_indices
    )

  sighash = final_preimage.empty? ? '' : Digest::SHA256.hexdigest([final_preimage].pack('H*'))

  build_prepared_call(
    sighash, final_preimage, final_op_push_tx_sig, signed_tx,
    sig_indices, method_name, resolved_args, method_selector_hex,
    is_stateful, needs_op_push_tx, method_needs_change, change_pkh_hex,
    change_amount, method_needs_new_amount, new_satoshis, preimage_index,
    contract_utxo, new_locking_script, code_sep_idx,
    has_multi_output: has_multi_output,
    contract_outputs: contract_outputs || []
  )
end

#set_state(new_state) ⇒ Object

Update state values directly (useful for testing).

Parameters:

  • new_state (Hash) 


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# File 'lib/runar/sdk/contract.rb', line 538

def set_state(new_state)
  @state.merge!(new_state)
end