elements: Environment with generic transaction ref

A generic transaction reference is more flexible and will prevent us
from cloning transactions in the upcoming sighash.

Because we changed jet/init/elements.rs, we need to update the Haskell
code that generated the original file.

Author: uncomputable

jets-bench/benches/elements/env.rs

@@ -28,12 +28,12 @@ pub enum EnvSampling {
 
 impl EnvSampling {
     /// Obtain a random environment without any annex
-    pub fn env(&self) -> ElementsEnv {
+    pub fn env(&self) -> ElementsEnv<Arc<Transaction>> {
         self.env_with_annex(None)
     }
 
     /// Obtains a env with annex
-    pub fn env_with_annex(&self, annex: Option<Vec<u8>>) -> ElementsEnv {
+    pub fn env_with_annex(&self, annex: Option<Vec<u8>>) -> ElementsEnv<Arc<Transaction>> {
         let ((txin, spent_utxo), n_in, n_out) = match self {
             EnvSampling::Null => return null_env(),
             EnvSampling::Issuance(n_in, n_out) => (txin_utils::issuance(), n_in, n_out),
@@ -81,7 +81,7 @@ fn env_with_spent_utxos(
     tx: Transaction,
     utxos: Vec<ElementsUtxo>,
     annex: Option<Vec<u8>>,
-) -> ElementsEnv {
+) -> ElementsEnv<Arc<Transaction>> {
     let ctrl_blk: [u8; 33] = [
         0xc0, 0xeb, 0x04, 0xb6, 0x8e, 0x9a, 0x26, 0xd1, 0x16, 0x04, 0x6c, 0x76, 0xe8, 0xff, 0x47,
         0x33, 0x2f, 0xb7, 0x1d, 0xda, 0x90, 0xff, 0x4b, 0xef, 0x53, 0x70, 0xf2, 0x52, 0x26, 0xd3,
@@ -98,7 +98,7 @@ fn env_with_spent_utxos(
     )
 }
 
-fn null_env() -> ElementsEnv {
+fn null_env() -> ElementsEnv<Arc<Transaction>> {
     let tx = Transaction {
         version: u32::default(),
         lock_time: LockTime::ZERO,

jets-bench/benches/elements/main.rs

@@ -59,7 +59,7 @@ enum ElementsBenchEnvType {
 }
 
 impl ElementsBenchEnvType {
-    fn env(&self) -> ElementsEnv {
+    fn env(&self) -> ElementsEnv<Arc<elements::Transaction>> {
         let n_in = NUM_TX_INPUTS;
         let n_out = NUM_TX_OUTPUTS;
         let env_sampler = match self {

src/jet/elements/environment.rs

@@ -16,7 +16,7 @@ use crate::merkle::cmr::Cmr;
 use elements::confidential;
 use elements::taproot::ControlBlock;
 use simplicity_sys::c_jets::c_env::CElementsTxEnv;
-use std::sync::Arc;
+use std::ops::Deref;
 
 use super::c_env;
 
@@ -58,11 +58,11 @@ impl From<elements::TxOut> for ElementsUtxo {
 // Similar story if we tried to use a &'a elements::Transaction rather than
 // an Arc: we'd have a lifetime parameter <'a> that would cause us trouble.
 #[allow(dead_code)]
-pub struct ElementsEnv {
+pub struct ElementsEnv<T: Deref<Target = elements::Transaction>> {
     /// The CTxEnv struct
     c_tx_env: CElementsTxEnv,
     /// The elements transaction
-    tx: Arc<elements::Transaction>,
+    tx: T,
     /// the current index of the input
     ix: u32,
     /// Control block used to spend this leaf script
@@ -73,9 +73,12 @@ pub struct ElementsEnv {
     genesis_hash: elements::BlockHash,
 }
 
-impl ElementsEnv {
+impl<T> ElementsEnv<T>
+where
+    T: Deref<Target = elements::Transaction>,
+{
     pub fn new(
-        tx: Arc<elements::Transaction>,
+        tx: T,
         utxos: Vec<ElementsUtxo>,
         ix: u32,
         script_cmr: Cmr,
@@ -128,7 +131,7 @@ impl ElementsEnv {
 }
 
 #[cfg(test)]
-impl ElementsEnv {
+impl ElementsEnv<std::sync::Arc<elements::Transaction>> {
     /// Return a dummy Elements environment
     pub fn dummy() -> Self {
         Self::dummy_with(elements::LockTime::ZERO, elements::Sequence::MAX)
@@ -146,7 +149,7 @@ impl ElementsEnv {
         ];
 
         ElementsEnv::new(
-            Arc::new(elements::Transaction {
+            std::sync::Arc::new(elements::Transaction {
                 version: 2,
                 lock_time,
                 // Enable locktime in dummy txin

src/jet/init/elements.rs

@@ -12,6 +12,7 @@ use std::io::Write;
 use std::{fmt, str};
 use crate::jet::elements::ElementsEnv;
 use simplicity_sys::CElementsTxEnv;
+use std::sync::Arc;
 
 /// Elements jet family
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
@@ -313,7 +314,7 @@ pub enum Elements {
 
 impl Jet for Elements {
 
-    type Environment = ElementsEnv;
+    type Environment = ElementsEnv<Arc<elements::Transaction>>;
     type CJetEnvironment = CElementsTxEnv;
 
     fn c_jet_env<'env>(&self, env: &'env Self::Environment) -> &'env Self::CJetEnvironment {

src/policy/satisfy.rs

@@ -249,7 +249,9 @@ mod tests {
         }
     }
 
-    fn get_satisfier(env: &ElementsEnv) -> PolicySatisfier<XOnlyPublicKey> {
+    fn get_satisfier(
+        env: &ElementsEnv<Arc<elements::Transaction>>,
+    ) -> PolicySatisfier<XOnlyPublicKey> {
         let mut preimages = HashMap::new();
 
         for i in 0..3 {
@@ -283,7 +285,10 @@ mod tests {
         }
     }
 
-    fn execute_successful(program: Arc<RedeemNode<Elements>>, env: &ElementsEnv) {
+    fn execute_successful(
+        program: Arc<RedeemNode<Elements>>,
+        env: &ElementsEnv<Arc<elements::Transaction>>,
+    ) {
         let mut mac = BitMachine::for_program(&program);
         assert!(mac.exec(&program, env).is_ok());
     }

src/policy/serialize.rs

@@ -255,7 +255,12 @@ mod tests {
     use hashes::{sha256, Hash};
     use std::sync::Arc;
 
-    fn compile(policy: Policy<XOnlyPublicKey>) -> (Arc<ConstructNode<Elements>>, ElementsEnv) {
+    fn compile(
+        policy: Policy<XOnlyPublicKey>,
+    ) -> (
+        Arc<ConstructNode<Elements>>,
+        ElementsEnv<Arc<elements::Transaction>>,
+    ) {
         let commit = policy.serialize_no_witness();
         let env = ElementsEnv::dummy();
 
@@ -265,7 +270,7 @@ mod tests {
     fn execute_successful(
         commit: &ConstructNode<Elements>,
         witness: Vec<Value>,
-        env: &ElementsEnv,
+        env: &ElementsEnv<Arc<elements::Transaction>>,
     ) -> bool {
         let finalized = commit
             .finalize_types()