Move p2p::constants::Network to crate root

The `Network` type is not a p2p construct, it is more general, used
throughout the codebase to define _which_ Bitcoin network we are
operating on.

bitcoin/examples/handshake.rs

@@ -6,7 +6,7 @@ use std::time::{SystemTime, UNIX_EPOCH};
 use std::{env, process};
 
 use bitcoin::consensus::{encode, Decodable};
-use bitcoin::p2p::{self, address, constants, message, message_network};
+use bitcoin::p2p::{self, address, message, message_network};
 use bitcoin::secp256k1;
 use bitcoin::secp256k1::rand::Rng;
 
@@ -29,7 +29,7 @@ fn main() {
     let version_message = build_version_message(address);
 
     let first_message =
-        message::RawNetworkMessage::new(constants::Network::Bitcoin.magic(), version_message);
+        message::RawNetworkMessage::new(bitcoin::Network::Bitcoin.magic(), version_message);
 
     if let Ok(mut stream) = TcpStream::connect(address) {
         // Send the message
@@ -47,7 +47,7 @@ fn main() {
                     println!("Received version message: {:?}", reply.payload());
 
                     let second_message = message::RawNetworkMessage::new(
-                        constants::Network::Bitcoin.magic(),
+                        bitcoin::Network::Bitcoin.magic(),
                         message::NetworkMessage::Verack,
                     );
 

bitcoin/src/address.rs

@@ -46,7 +46,7 @@ use crate::blockdata::script::witness_version::{self, WitnessVersion};
 use crate::blockdata::script::{self, Script, ScriptBuf};
 use crate::crypto::key::{PublicKey, TapTweak, TweakedPublicKey, UntweakedPublicKey};
 use crate::hash_types::{PubkeyHash, ScriptHash};
-use crate::p2p::constants::Network;
+use crate::network::Network;
 use crate::prelude::*;
 use crate::taproot::TapNodeHash;
 
@@ -996,7 +996,7 @@ mod tests {
 
     use super::*;
     use crate::crypto::key::PublicKey;
-    use crate::p2p::constants::Network::{Bitcoin, Testnet};
+    use crate::network::Network::{Bitcoin, Testnet};
 
     fn roundtrips(addr: &Address) {
         assert_eq!(

bitcoin/src/bip32.rs

@@ -23,7 +23,7 @@ use crate::crypto::key::{self, KeyPair, PrivateKey, PublicKey};
 use crate::hash_types::XpubIdentifier;
 use crate::internal_macros::impl_bytes_newtype;
 use crate::io::Write;
-use crate::p2p::constants::Network;
+use crate::network::Network;
 use crate::prelude::*;
 
 /// A chain code
@@ -866,7 +866,7 @@ mod tests {
     use super::ChildNumber::{Hardened, Normal};
     use super::*;
     use crate::internal_macros::hex;
-    use crate::p2p::constants::Network::{self, Bitcoin};
+    use crate::network::Network::{self, Bitcoin};
 
     #[test]
     fn test_parse_derivation_path() {

bitcoin/src/blockdata/constants.rs

@@ -20,7 +20,7 @@ use crate::blockdata::script;
 use crate::blockdata::transaction::{OutPoint, Sequence, Transaction, TxIn, TxOut};
 use crate::blockdata::witness::Witness;
 use crate::internal_macros::impl_bytes_newtype;
-use crate::p2p::constants::Network;
+use crate::network::Network;
 use crate::pow::CompactTarget;
 use crate::Amount;
 
@@ -198,7 +198,7 @@ mod test {
     use crate::blockdata::locktime::absolute;
     use crate::consensus::encode::serialize;
     use crate::internal_macros::hex;
-    use crate::p2p::constants::Network;
+    use crate::network::Network;
 
     #[test]
     fn bitcoin_genesis_first_transaction() {

bitcoin/src/blockdata/transaction.rs

@@ -68,7 +68,7 @@ impl OutPoint {
     ///
     /// ```rust
     /// use bitcoin::constants::genesis_block;
-    /// use bitcoin::p2p::constants::Network;
+    /// use bitcoin::Network;
     ///
     /// let block = genesis_block(Network::Bitcoin);
     /// let tx = &block.txdata[0];
@@ -1508,7 +1508,7 @@ mod tests {
     #[test]
     fn test_is_coinbase() {
         use crate::blockdata::constants;
-        use crate::p2p::constants::Network;
+        use crate::network::Network;
 
         let genesis = constants::genesis_block(Network::Bitcoin);
         assert!(genesis.txdata[0].is_coinbase());

bitcoin/src/consensus/params.rs

@@ -6,7 +6,7 @@
 //! chains (such as mainnet, testnet).
 //!
 
-use crate::p2p::constants::Network;
+use crate::network::Network;
 use crate::pow::Work;
 
 /// Parameters that influence chain consensus.

bitcoin/src/crypto/key.rs

@@ -18,7 +18,7 @@ pub use secp256k1::{self, constants, KeyPair, Parity, Secp256k1, Verification, X
 
 use crate::crypto::ecdsa;
 use crate::hash_types::{PubkeyHash, WPubkeyHash};
-use crate::p2p::constants::Network;
+use crate::network::Network;
 use crate::prelude::*;
 use crate::taproot::{TapNodeHash, TapTweakHash};
 use crate::{base58, io};
@@ -741,7 +741,7 @@ mod tests {
     use super::*;
     use crate::address::Address;
     use crate::io;
-    use crate::p2p::constants::Network::{Bitcoin, Testnet};
+    use crate::network::Network::{Bitcoin, Testnet};
 
     #[test]
     fn test_key_derivation() {

bitcoin/src/crypto/sighash.rs

@@ -1120,7 +1120,7 @@ mod tests {
     use crate::crypto::key::PublicKey;
     use crate::crypto::sighash::{LegacySighash, TapSighash};
     use crate::internal_macros::hex;
-    use crate::p2p::constants::Network;
+    use crate::network::Network;
     use crate::taproot::TapLeafHash;
 
     extern crate serde_json;

bitcoin/src/lib.rs

@@ -106,6 +106,7 @@ pub(crate) mod crypto;
 pub mod error;
 pub mod hash_types;
 pub mod merkle_tree;
+pub mod network;
 pub mod policy;
 pub mod pow;
 pub mod psbt;
@@ -146,7 +147,7 @@ pub use crate::hash_types::{
     BlockHash, PubkeyHash, ScriptHash, Txid, WPubkeyHash, WScriptHash, Wtxid,
 };
 pub use crate::merkle_tree::MerkleBlock;
-pub use crate::p2p::constants::Network;
+pub use crate::network::Network;
 pub use crate::pow::{CompactTarget, Target, Work};
 pub use crate::psbt::Psbt;
 

bitcoin/src/network.rs

@@ -1,22 +1,15 @@
 // SPDX-License-Identifier: CC0-1.0
 
-//! Bitcoin network constants.
+//! Bitcoin network.
 //!
-//! This module provides various constants relating to the Bitcoin network
+//! The term "network" is overloaded, here [`Network`] refers to the specific
-//! protocol, such as protocol versioning and magic header bytes.
+//! Bitcoin network we are operating on e.g., signet, regtest. The terms
-//!
+//! "network" and "chain" are often used interchangeably for this concept.
-//! The [`Network`][1] type implements the [`Decodable`][2] and
-//! [`Encodable`][3] traits and encodes the magic bytes of the given
-//! network.
-//!
-//! [1]: enum.Network.html
-//! [2]: ../../consensus/encode/trait.Decodable.html
-//! [3]: ../../consensus/encode/trait.Encodable.html
 //!
 //! # Example: encoding a network's magic bytes
 //!
 //! ```rust
-//! use bitcoin::p2p::constants::Network;
+//! use bitcoin::Network;
 //! use bitcoin::consensus::encode::serialize;
 //!
 //! let network = Network::Bitcoin;
@@ -130,7 +123,7 @@ impl Network {
     /// # Examples
     ///
     /// ```rust
-    /// use bitcoin::p2p::constants::Network;
+    /// use bitcoin::Network;
     /// use bitcoin::blockdata::constants::ChainHash;
     ///
     /// let network = Network::Bitcoin;
@@ -143,7 +136,7 @@ impl Network {
     /// # Examples
     ///
     /// ```rust
-    /// use bitcoin::p2p::constants::Network;
+    /// use bitcoin::Network;
     /// use bitcoin::blockdata::constants::ChainHash;
     /// use std::convert::TryFrom;
     ///
@@ -387,7 +380,7 @@ mod tests {
         #[derive(Serialize, Deserialize, PartialEq, Debug)]
         #[serde(crate = "actual_serde")]
         struct T {
-            #[serde(with = "crate::p2p::constants::as_core_arg")]
+            #[serde(with = "crate::network::as_core_arg")]
             pub network: Network,
         }
 

bitcoin/src/p2p/message.rs

@@ -549,8 +549,8 @@ mod test {
     use crate::blockdata::transaction::Transaction;
     use crate::consensus::encode::{deserialize, deserialize_partial, serialize};
     use crate::internal_macros::hex;
+    use crate::network::Network;
     use crate::p2p::address::{AddrV2, AddrV2Message, Address};
-    use crate::p2p::constants::Network;
     use crate::p2p::message_blockdata::{GetBlocksMessage, GetHeadersMessage, Inventory};
     use crate::p2p::message_bloom::{BloomFlags, FilterAdd, FilterLoad};
     use crate::p2p::message_compact_blocks::{GetBlockTxn, SendCmpct};

bitcoin/src/p2p/mod.rs

@@ -5,8 +5,6 @@
 //! This module defines support for (de)serialization and network transport
 //! of Bitcoin data and Bitcoin p2p network messages.
 
-pub mod constants;
-
 #[cfg(feature = "std")]
 pub mod address;
 #[cfg(feature = "std")]
@@ -33,9 +31,8 @@ use internals::{debug_from_display, write_err};
 
 use crate::consensus::encode::{self, Decodable, Encodable};
 use crate::error::impl_std_error;
-use crate::io;
-use crate::p2p::constants::Network;
 use crate::prelude::{Borrow, BorrowMut, String, ToOwned};
+use crate::{io, Network};
 
 /// Version of the protocol as appearing in network message headers.
 ///

bitcoin/src/psbt/mod.rs

@@ -823,7 +823,7 @@ mod tests {
     use crate::blockdata::transaction::{OutPoint, Sequence, Transaction, TxIn, TxOut};
     use crate::blockdata::witness::Witness;
     use crate::internal_macros::hex;
-    use crate::p2p::constants::Network::Bitcoin;
+    use crate::network::Network::Bitcoin;
     use crate::psbt::map::{Input, Output};
     use crate::psbt::raw;
     use crate::psbt::serialize::{Deserialize, Serialize};

fuzz/fuzz_targets/bitcoin/deserialize_script.rs

@@ -1,7 +1,7 @@
 use bitcoin::address::Address;
 use bitcoin::blockdata::script;
 use bitcoin::consensus::encode;
-use bitcoin::p2p::constants::Network;
+use bitcoin::Network;
 use honggfuzz::fuzz;
 
 fn do_test(data: &[u8]) {