Add alternate network support to `Blockchain`, `UtxoSet`, `Socket`

Still need to do alternate diffchange rules..

src/blockdata/blockchain.rs

@@ -30,7 +30,8 @@ use std::kinds::marker;
 
 use blockdata::block::{Block, BlockHeader};
 use blockdata::transaction::Transaction;
-use blockdata::constants::{DIFFCHANGE_INTERVAL, DIFFCHANGE_TIMESPAN, max_target};
+use blockdata::constants::{DIFFCHANGE_INTERVAL, DIFFCHANGE_TIMESPAN, max_target, genesis_block};
+use network::constants::Network;
 use network::serialize::{Serializable, SerializeIter};
 use util::BitArray;
 use util::error::{BitcoinResult, BlockNotFound, DuplicateHash, PrevHashNotFound};
@@ -134,6 +135,7 @@ impl Serializable for Rc<BlockchainNode> {
 
 /// The blockchain
 pub struct Blockchain {
+  network: Network,
   tree: BlockTree,
   best_tip: Rc<BlockchainNode>,
   best_hash: Sha256dHash,
@@ -143,6 +145,7 @@ pub struct Blockchain {
 impl Serializable for Blockchain {
   fn serialize(&self) -> Vec<u8> {
     let mut ret = vec![];
+    ret.extend(self.network.serialize().move_iter());
     ret.extend(self.tree.serialize().move_iter());
     ret.extend(self.best_hash.serialize().move_iter());
     ret.extend(self.genesis_hash.serialize().move_iter());
@@ -152,7 +155,8 @@ impl Serializable for Blockchain {
   fn serialize_iter<'a>(&'a self) -> SerializeIter<'a> {
     SerializeIter {
       data_iter: None,
-      sub_iter_iter: box vec![ &self.tree as &Serializable,
+      sub_iter_iter: box vec![ &self.network as &Serializable,
+                               &self.tree as &Serializable,
                                &self.best_hash as &Serializable,
                                &self.genesis_hash as &Serializable ].move_iter(),
       sub_iter: None,
@@ -161,6 +165,7 @@ impl Serializable for Blockchain {
   }
 
   fn deserialize<I: Iterator<u8>>(mut iter: I) -> IoResult<Blockchain> {
+    let network: Network = try!(prepend_err("network", Serializable::deserialize(iter.by_ref())));
     let tree: BlockTree = try!(prepend_err("tree", Serializable::deserialize(iter.by_ref())));
     let best_hash: Sha256dHash = try!(prepend_err("best_hash", Serializable::deserialize(iter.by_ref())));
     let genesis_hash: Sha256dHash = try!(prepend_err("genesis_hash", Serializable::deserialize(iter.by_ref())));
@@ -201,6 +206,7 @@ impl Serializable for Blockchain {
     } else {
       // Return the chain
       Ok(Blockchain {
+        network: network,
         tree: tree,
         best_tip: best.clone(),
         best_hash: best_hash,
@@ -367,7 +373,8 @@ fn satoshi_the_precision(n: &Uint256) -> Uint256 {
 
 impl Blockchain {
   /// Constructs a new blockchain
-  pub fn new(genesis: Block) -> Blockchain {
+  pub fn new(network: Network) -> Blockchain {
+    let genesis = genesis_block(network);
     let genhash = genesis.header.hash();
     let rc_gen = Rc::new(BlockchainNode {
       total_work: Zero::zero(),
@@ -379,6 +386,7 @@ impl Blockchain {
       next: RefCell::new(None)
     });
     Blockchain {
+      network: network,
       tree: {
         let mut pat = PatriciaTree::new();
         pat.insert(&genhash.as_uint256(), 256, rc_gen.clone());
@@ -479,7 +487,7 @@ impl Blockchain {
             target = target.mul_u32(timespan);
             target = target / FromPrimitive::from_u64(DIFFCHANGE_TIMESPAN as u64).unwrap();
             // Clamp below MAX_TARGET (difficulty 1)
-            let max = max_target();
+            let max = max_target(self.network);
             if target > max { target = max };
             // Compactify (make expressible in the 8+24 nBits float format
             satoshi_the_precision(&target)
@@ -601,12 +609,14 @@ mod tests {
 
   use blockdata::blockchain::Blockchain;
   use blockdata::constants::genesis_block;
+  use network::constants::Bitcoin;
   use network::serialize::Serializable;
 
   #[test]
   fn blockchain_serialize_test() {
-    let empty_chain = Blockchain::new(genesis_block());
-    assert_eq!(empty_chain.best_tip.hash().serialize(), genesis_block().header.hash().serialize());
+    let empty_chain = Blockchain::new(Bitcoin);
+    assert_eq!(empty_chain.best_tip.hash().serialize(),
+               genesis_block(Bitcoin).header.hash().serialize());
 
     let serial = empty_chain.serialize();
     assert_eq!(serial, empty_chain.serialize_iter().collect());
@@ -614,7 +624,8 @@ mod tests {
     let deserial: IoResult<Blockchain> = Serializable::deserialize(serial.iter().map(|n| *n));
     assert!(deserial.is_ok());
     let read_chain = deserial.unwrap();
-    assert_eq!(read_chain.best_tip.hash().serialize(), genesis_block().header.hash().serialize());
+    assert_eq!(read_chain.best_tip.hash().serialize(),
+               genesis_block(Bitcoin).header.hash().serialize());
   }
 }
 

src/blockdata/constants.rs

@@ -19,6 +19,8 @@
 //! single transaction
 //!
 
+use network::constants::{Network, Bitcoin, BitcoinTestnet};
+
 use std::num::from_u64;
 
 use blockdata::opcodes;
@@ -35,12 +37,12 @@ pub static DIFFCHANGE_INTERVAL: u32 = 2016;
 pub static DIFFCHANGE_TIMESPAN: u32 = 14 * 24 * 3600;
 
 /// In Bitcoind this is insanely described as ~((u256)0 >> 32)
-pub fn max_target() -> Uint256 {
+pub fn max_target(_: Network) -> Uint256 {
   from_u64::<Uint256>(0xFFFF).unwrap() << 208u
 }
 
-/// Constructs and returns the coinbase (and only) transaction of the genesis block
-pub fn genesis_tx() -> Transaction {
+/// Constructs and returns the coinbase (and only) transaction of the Bitcoin genesis block
+fn bitcoin_genesis_tx() -> Transaction {
   // Base
   let mut ret = Transaction {
     version: 1,
@@ -75,34 +77,51 @@ pub fn genesis_tx() -> Transaction {
 }
 
 /// Constructs and returns the genesis block
-pub fn genesis_block() -> Block {
-  let txdata = vec![genesis_tx()];
-  let header = BlockHeader {
-    version: 1,
-    prev_blockhash: zero_hash(),
-    merkle_root: merkle_root(txdata.as_slice()),
-    time: 1231006505,
-    bits: 0x1d00ffff,
-    nonce: 2083236893
-  };
-
-  Block {
-    header: header,
-    txdata: txdata
+pub fn genesis_block(network: Network) -> Block {
+  match network {
+    Bitcoin => {
+      let txdata = vec![bitcoin_genesis_tx()];
+      Block {
+        header: BlockHeader {
+          version: 1,
+          prev_blockhash: zero_hash(),
+          merkle_root: merkle_root(txdata.as_slice()),
+          time: 1231006505,
+          bits: 0x1d00ffff,
+          nonce: 2083236893
+        },
+        txdata: txdata
+      }
+    }
+    BitcoinTestnet => {
+      let txdata = vec![bitcoin_genesis_tx()];
+      Block {
+        header: BlockHeader {
+          version: 1,
+          prev_blockhash: zero_hash(),
+          merkle_root: merkle_root(txdata.as_slice()),
+          time: 1296688602,
+          bits: 0x1d00ffff,
+          nonce: 414098458
+        },
+        txdata: txdata
+      }
+    }
   }
 }
 
 #[cfg(test)]
 mod test {
   use network::serialize::Serializable;
-  use blockdata::constants::{genesis_block, genesis_tx};
+  use network::constants::{Bitcoin, BitcoinTestnet};
+  use blockdata::constants::{genesis_block, bitcoin_genesis_tx};
   use blockdata::constants::{MAX_SEQUENCE, COIN_VALUE};
   use util::misc::hex_bytes;
   use util::hash::zero_hash;
 
   #[test]
-  fn genesis_first_transaction() {
-    let gen = genesis_tx();
+  fn bitcoin_genesis_first_transaction() {
+    let gen = bitcoin_genesis_tx();
 
     assert_eq!(gen.version, 1);
     assert_eq!(gen.input.len(), 1);
@@ -123,18 +142,32 @@ mod test {
   }
 
   #[test]
-  fn genesis_full_block() {
-    let gen = genesis_block();
+  fn bitcoin_genesis_full_block() {
+    let gen = genesis_block(Bitcoin);
 
     assert_eq!(gen.header.version, 1);
     assert_eq!(gen.header.prev_blockhash.as_slice(), zero_hash().as_slice());
-    assert_eq!(gen.header.merkle_root.serialize().iter().rev().map(|n| *n).collect::<Vec<u8>>(),
-               hex_bytes("4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b").unwrap());
+    assert_eq!(gen.header.merkle_root.le_hex_string(),
+               "4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b".to_string());
     assert_eq!(gen.header.time, 1231006505);
     assert_eq!(gen.header.bits, 0x1d00ffff);
     assert_eq!(gen.header.nonce, 2083236893);
-    assert_eq!(gen.header.hash().serialize().iter().rev().map(|n| *n).collect::<Vec<u8>>(),
-               hex_bytes("000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f").unwrap());
+    assert_eq!(gen.header.hash().le_hex_string(),
+               "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f".to_string());
+  }
+
+  #[test]
+  fn testnet_genesis_full_block() {
+    let gen = genesis_block(BitcoinTestnet);
+    assert_eq!(gen.header.version, 1);
+    assert_eq!(gen.header.prev_blockhash.as_slice(), zero_hash().as_slice());
+    assert_eq!(gen.header.merkle_root.le_hex_string(),
+               "4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b".to_string());
+    assert_eq!(gen.header.time, 1296688602);
+    assert_eq!(gen.header.bits, 0x1d00ffff);
+    assert_eq!(gen.header.nonce, 414098458);
+    assert_eq!(gen.header.hash().le_hex_string(),
+               "000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943".to_string());
   }
 }
 

src/blockdata/utxoset.rs

@@ -22,7 +22,9 @@ use std::io::IoResult;
 use std::mem;
 
 use blockdata::transaction::{Transaction, TxOut};
+use blockdata::constants::genesis_block;
 use blockdata::block::Block;
+use network::constants::Network;
 use network::serialize::{Serializable, SerializeIter};
 use util::hash::Sha256dHash;
 use util::uint::Uint128;
@@ -51,14 +53,14 @@ impl_serializable!(UtxoSet, last_hash, n_utxos, spent_txos, spent_idx, tree)
 
 impl UtxoSet {
   /// Constructs a new UTXO set
-  pub fn new(genesis: Block, rewind_limit: uint) -> UtxoSet {
+  pub fn new(network: Network, rewind_limit: uint) -> UtxoSet {
     // There is in fact a transaction in the genesis block, but the Bitcoin
     // reference client does not add its sole output to the UTXO set. We
     // must follow suit, otherwise we will accept a transaction spending it
     // while the reference client won't, causing us to fork off the network.
     UtxoSet {
       tree: PatriciaTree::new(),
-      last_hash: genesis.header.hash(),
+      last_hash: genesis_block(network).header.hash(),
       spent_txos: Vec::from_elem(rewind_limit, vec![]),
       spent_idx: 0,
       n_utxos: 0
@@ -270,14 +272,14 @@ mod tests {
   use std::io::IoResult;
   use serialize::hex::FromHex;
 
-  use blockdata::constants::genesis_block;
   use blockdata::block::Block;
   use blockdata::utxoset::UtxoSet;
+  use network::constants::Bitcoin;
   use network::serialize::Serializable;
 
   #[test]
   fn utxoset_serialize_test() {
-    let mut empty_set = UtxoSet::new(genesis_block(), 100);
+    let mut empty_set = UtxoSet::new(Bitcoin, 100);
 
     let new_block: Block = Serializable::deserialize("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".from_hex().unwrap().iter().map(|n| *n)).unwrap();
 

src/lib.rs

@@ -62,4 +62,3 @@ pub mod network;
 pub mod blockdata;
 pub mod util;
 
-

src/network/constants.rs

@@ -18,10 +18,47 @@
 //! protocol, such as protocol versioning and magic header bytes.
 //!
 
-pub static MAGIC_BITCOIN: u32       = 0xD9B4BEF9;
-pub static MAGIC_TESTNET: u32       = 0x0709110B;
+use std::io::{IoResult, InvalidInput, standard_error};
+
+use network::serialize::Serializable;
+use util::misc::prepend_err;
+
+/// The cryptocurrency to operate on
+#[deriving(PartialEq, Eq, Clone, Show)]
+pub enum Network {
+  /// Classic Bitcoin
+  Bitcoin,
+  /// Bitcoin's testnet
+  BitcoinTestnet,
+}
 
 pub static PROTOCOL_VERSION: u32    = 70001;
 pub static SERVICES: u64            = 0;
 pub static USER_AGENT: &'static str = "bitcoin-rust v0.1";
 
+/// Return the network magic bytes, which should be encoded little-endian
+/// at the start of every message
+pub fn magic(network: Network) -> u32 {
+  match network {
+    Bitcoin => 0xD9B4BEF9,
+    BitcoinTestnet => 0x0709110B
+    // Note: any new entries here must be added to `deserialize` below
+  }
+}
+
+// This affects the representation of the `Network` in text files
+impl Serializable for Network {
+  fn serialize(&self) -> Vec<u8> {
+    magic(*self).serialize()
+  }
+
+  fn deserialize<I: Iterator<u8>>(iter: I) -> IoResult<Network> {
+    let magic: u32 = try!(prepend_err("magic", Serializable::deserialize(iter)));
+    match magic {
+      0xD9B4BEF9 => Ok(Bitcoin),
+      0x0709110B => Ok(BitcoinTestnet),
+      _ => Err(standard_error(InvalidInput))
+    }
+  }
+}
+

src/network/listener.rs

@@ -21,6 +21,7 @@
 use std::io::{IoResult, standard_error, ConnectionFailed};
 use std::io::timer;
 
+use network::constants::Network;
 use network::message::{NetworkMessage, Verack};
 use network::socket::Socket;
 
@@ -30,12 +31,12 @@ pub trait Listener {
   fn peer<'a>(&'a self) -> &'a str;
   /// Return the port we have connected to the peer on
   fn port(&self) -> u16;
-  /// Return the network magic
-  fn magic(&self) -> u32;
+  /// Return the network this `Listener` is operating on
+  fn network(&self) -> Network;
   /// Main listen loop
   fn start(&self) -> IoResult<(Receiver<NetworkMessage>, Socket)> {
     // Open socket
-    let mut ret_sock = Socket::new(self.magic());
+    let mut ret_sock = Socket::new(self.network());
     match ret_sock.connect(self.peer(), self.port()) {
       Ok(_) => {},
       Err(_) => return Err(standard_error(ConnectionFailed))

src/network/serialize.rs

@@ -76,9 +76,6 @@ impl<'a> Iterator<u8> for SerializeIter<'a> {
   }
 }
 
-/// A string which must be encoded as 12 bytes, used in network message headers
-
-
 #[deriving(PartialEq, Clone, Show)]
 /// Data which must be preceded by a 4-byte checksum
 pub struct CheckedData(pub Vec<u8>);

src/network/socket.rs

@@ -61,14 +61,14 @@ pub struct Socket {
 impl Socket {
   // TODO: we fix services to 0
   /// Construct a new socket
-  pub fn new(magic: u32) -> Socket {
+  pub fn new(network: constants::Network) -> Socket {
     let mut rng = task_rng();
     Socket {
       stream: None,
       services: 0,
       version_nonce: rng.gen(),
       user_agent: String::from_str(constants::USER_AGENT),
-      magic: magic
+      magic: constants::magic(network)
     }
   }