add tx_output type conversion to byte array

README.md

@@ -13,6 +13,7 @@ First, we're going to implement a thin-client wallet.
 
 - Should consider creating object types (e.g., addresses with metadata; wallets; etc)
 - Clean up tests to make more consistent
+- Different nets (e.g., https://github.com/haskoin/haskoin/blob/master/prodnet/Network/Haskoin/Constants.hs)
 
 ### Public key distribution
 - See [ref](https://github.com/danielsuo/Crypto.jl)

src/Coin.jl

@@ -26,7 +26,8 @@ export
        reverse_endian,
        get_checksum,
        hex_string_to_array,
-       to_varint
+       to_varint,
+       bytearray
 
 export magic_mainnet,
        magic_testnet,

src/messages.jl

@@ -101,20 +101,34 @@ end
 
 type Tx_Output
   # ERROR: does Uint64 exist on 32-bit OS?
-  value::Uint64               # Transaction value
-  scriptPubKey_length::Int    # Variable length integer: length of scriptPubKey
-  scriptPubKey::Array{Uint8}  # Script to set up cond'ns to claim tx output
+  value::Uint64                         # Transaction value
+  scriptPubKey_length::Array{Uint8}     # Variable length int: scriptPubKey len
+  scriptPubKey::Array{Uint8}            # Script for claiming tx output
 
   # value: transaction value in Satoshi
   # scriptPubKey: script as hex string
   function Tx_Output(value, scriptPubKey::String)
     value = uint64(value)
     scriptPubKey = hex_string_to_array(scriptPubKey)
-    scriptPubKey_length = length(scriptPubKey)
+    scriptPubKey_length = to_varint(length(scriptPubKey))
     new(value, scriptPubKey_length, scriptPubKey)
   end
 end
 
+function convert(::Type{Array{Uint8}}, tx_out::Tx_Output)
+  result = Array(Uint8, 0)
+
+  # TODO: This is a really terrible way to get little
+  # endian byte array
+  append!(result, reverse(convert(Array{Uint8}, tx_out.value)))
+
+  append!(result, reverse(tx_out.scriptPubKey_length))
+
+  append!(result, tx_out.scriptPubKey)
+
+  return result
+end
+
 type Tx
   version::Uint32             # Transaction data format version
   num_inputs::Int             # Variable length integer: number of input tx

src/utils.jl

@@ -5,6 +5,9 @@ import Base.convert
 #
 # Only providing convenience functions to and from Array{Uint8} because varint
 # seems like its primarily a transport structure
+#
+# VarInt are created as big-endian here, but are sent little-endian as per
+# https://bitcoin.org/en/developer-reference#compactsize-unsigned-integers
 function to_varint(x::Integer)
   result = Array(Uint8, 0)
 
@@ -73,4 +76,10 @@ function hex_string_to_array(hex_string::String)
   hex_length = div(hex_length, 2)
 
   return [uint8(parseint(hex_string[2i-1:2i], 16)) for i in 1:hex_length]
+end
+
+# Convenience function for converting to Array{Uint8}
+# Must be defined for given types
+function bytearray(x)
+  convert(Array{Uint8}, x)
 end

test/runtests.jl

@@ -61,6 +61,12 @@ public_key = Coin.get_public_key(secret_key)
 payload = "0100000001484d40d45b9ea0d652fca8258ab7caa42541eb52975857f96fb50cd732c8b481000000008a47304402202cb265bf10707bf49346c3515dd3d16fc454618c58ec0a0ff448a676c54ff71302206c6624d762a1fcef4618284ead8f08678ac05b13c84235f1654e6ad168233e8201410414e301b2328f17442c0b8310d787bf3d8a404cfbd0704f135b6ad4b2d3ee751310f981926e53a6e8c39bd7d3fefd576c543cce493cbac06388f2651d1aacbfcdffffffff0162640100000000001976a914c8e90996c7c6080ee06284600c684ed904d14c5c88ac00000000"
 # @test Coin.create_header(magic_mainnet, "tx", payload) == "f9beb4d9747800000000000000000000df000000ea0f5494"
 
+# Transaction output
+tx_out = Coin.Tx_Output(123, "abc")
+@test bytearray(tx_out) == Uint8[123,0,0,0,0,0,0,0,2,10,188]
+tx_out = Coin.Tx_Output(5000000, "76A9141AA0CD1CBEA6E7458A7ABAD512A9D9EA1AFB225E88AC")
+@test bytearray(tx_out) == Uint8[64,75,76,0,0,0,0,0,25,118,169,20,26,160,205,28,190,166,231,69,138,122,186,213,18,169,217,234,26,251,34,94,136,172]
+
 ##############################################################################
 ##
 ## Utility tests