From 312c66264a0267167b68883eb9050169cb33f6ad Mon Sep 17 00:00:00 2001
From: Henry de Valence <hdevalence@hdevalence.ca>
Date: Sat, 15 Aug 2020 18:36:01 -0700
Subject: [PATCH] chain: extract sprout code into sprout module.

---
 zebra-chain/src/addresses.rs                    |  1 -
 zebra-chain/src/commitments.rs                  |  3 ---
 zebra-chain/src/keys.rs                         |  1 -
 zebra-chain/src/lib.rs                          |  3 ---
 zebra-chain/src/notes.rs                        |  2 --
 zebra-chain/src/sprout.rs                       |  6 ++++++
 .../{addresses/sprout.rs => sprout/address.rs}  | 15 ++++++++-------
 .../sprout.rs => sprout/commitment.rs}          |  2 +-
 .../src/{keys/sprout.rs => sprout/keys.rs}      |  0
 .../src/{notes/sprout.rs => sprout/note.rs}     |  7 +++++--
 .../{notes/sprout => sprout/note}/arbitrary.rs  |  3 +--
 .../sprout => sprout/note}/ciphertexts.rs       |  0
 .../src/{types.rs => sprout/note/mac.rs}        |  2 --
 .../{notes/sprout => sprout/note}/nullifiers.rs |  2 +-
 .../src/{treestate/sprout.rs => sprout/tree.rs} |  0
 zebra-chain/src/transaction/joinsplit.rs        | 13 ++++++-------
 zebra-chain/src/transaction/serialize.rs        | 17 ++++++++---------
 zebra-chain/src/transaction/tests/arbitrary.rs  | 14 ++++++--------
 zebra-chain/src/treestate.rs                    |  4 ----
 19 files changed, 42 insertions(+), 53 deletions(-)
 delete mode 100644 zebra-chain/src/commitments.rs
 rename zebra-chain/src/{addresses/sprout.rs => sprout/address.rs} (91%)
 rename zebra-chain/src/{commitments/sprout.rs => sprout/commitment.rs} (97%)
 rename zebra-chain/src/{keys/sprout.rs => sprout/keys.rs} (100%)
 rename zebra-chain/src/{notes/sprout.rs => sprout/note.rs} (93%)
 rename zebra-chain/src/{notes/sprout => sprout/note}/arbitrary.rs (85%)
 rename zebra-chain/src/{notes/sprout => sprout/note}/ciphertexts.rs (100%)
 rename zebra-chain/src/{types.rs => sprout/note/mac.rs} (89%)
 rename zebra-chain/src/{notes/sprout => sprout/note}/nullifiers.rs (98%)
 rename zebra-chain/src/{treestate/sprout.rs => sprout/tree.rs} (100%)
 delete mode 100644 zebra-chain/src/treestate.rs

diff --git a/zebra-chain/src/addresses.rs b/zebra-chain/src/addresses.rs
index de5b29f7..7e200d1b 100644
--- a/zebra-chain/src/addresses.rs
+++ b/zebra-chain/src/addresses.rs
@@ -1,4 +1,3 @@
 //! Address types.
 
-pub mod sprout;
 pub mod transparent;
diff --git a/zebra-chain/src/commitments.rs b/zebra-chain/src/commitments.rs
deleted file mode 100644
index 87a6fc68..00000000
--- a/zebra-chain/src/commitments.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-//! Note and value commitments and associated types.
-
-pub mod sprout;
diff --git a/zebra-chain/src/keys.rs b/zebra-chain/src/keys.rs
index 6590557b..3601c4f0 100644
--- a/zebra-chain/src/keys.rs
+++ b/zebra-chain/src/keys.rs
@@ -1,4 +1,3 @@
 //! Key types.
 
-pub mod sprout;
 pub mod transparent;
diff --git a/zebra-chain/src/lib.rs b/zebra-chain/src/lib.rs
index 075b106b..8f982899 100644
--- a/zebra-chain/src/lib.rs
+++ b/zebra-chain/src/lib.rs
@@ -14,11 +14,8 @@ extern crate serde;
 mod merkle_tree;
 
 pub mod addresses;
-pub mod commitments;
 pub mod keys;
 pub mod notes;
-pub mod treestate;
-pub mod types;
 
 pub mod amount;
 pub mod block;
diff --git a/zebra-chain/src/notes.rs b/zebra-chain/src/notes.rs
index 4298fb20..24b15871 100644
--- a/zebra-chain/src/notes.rs
+++ b/zebra-chain/src/notes.rs
@@ -3,5 +3,3 @@
 #[cfg(test)]
 mod arbitrary;
 pub mod memo;
-
-pub mod sprout;
diff --git a/zebra-chain/src/sprout.rs b/zebra-chain/src/sprout.rs
index 8b137891..c64c4cbc 100644
--- a/zebra-chain/src/sprout.rs
+++ b/zebra-chain/src/sprout.rs
@@ -1 +1,7 @@
+//! Sprout-related functionality.
 
+pub mod address;
+pub mod commitment;
+pub mod keys;
+pub mod note;
+pub mod tree;
diff --git a/zebra-chain/src/addresses/sprout.rs b/zebra-chain/src/sprout/address.rs
similarity index 91%
rename from zebra-chain/src/addresses/sprout.rs
rename to zebra-chain/src/sprout/address.rs
index 86218998..ccdf2653 100644
--- a/zebra-chain/src/addresses/sprout.rs
+++ b/zebra-chain/src/sprout/address.rs
@@ -6,11 +6,12 @@ use std::{fmt, io};
 use proptest::{arbitrary::Arbitrary, array, prelude::*};
 
 use crate::{
-    keys::sprout,
     parameters::Network,
     serialization::{ReadZcashExt, SerializationError, ZcashDeserialize, ZcashSerialize},
 };
 
+use super::keys;
+
 /// Magic numbers used to identify what networks Sprout Shielded
 /// Addresses are associated with.
 mod magics {
@@ -24,8 +25,8 @@ mod magics {
 #[derive(Copy, Clone)]
 pub struct SproutShieldedAddress {
     network: Network,
-    paying_key: sprout::PayingKey,
-    transmission_key: sprout::TransmissionKey,
+    paying_key: keys::PayingKey,
+    transmission_key: keys::TransmissionKey,
 }
 
 impl fmt::Debug for SproutShieldedAddress {
@@ -80,8 +81,8 @@ impl ZcashDeserialize for SproutShieldedAddress {
 
         Ok(SproutShieldedAddress {
             network,
-            paying_key: sprout::PayingKey(reader.read_32_bytes()?),
-            transmission_key: sprout::TransmissionKey::from(reader.read_32_bytes()?),
+            paying_key: keys::PayingKey(reader.read_32_bytes()?),
+            transmission_key: keys::TransmissionKey::from(reader.read_32_bytes()?),
         })
     }
 }
@@ -121,8 +122,8 @@ impl Arbitrary for SproutShieldedAddress {
         )
             .prop_map(|(network, paying_key_bytes, transmission_key_bytes)| Self {
                 network,
-                paying_key: sprout::PayingKey(paying_key_bytes),
-                transmission_key: sprout::TransmissionKey::from(transmission_key_bytes),
+                paying_key: keys::PayingKey(paying_key_bytes),
+                transmission_key: keys::TransmissionKey::from(transmission_key_bytes),
             })
             .boxed()
     }
diff --git a/zebra-chain/src/commitments/sprout.rs b/zebra-chain/src/sprout/commitment.rs
similarity index 97%
rename from zebra-chain/src/commitments/sprout.rs
rename to zebra-chain/src/sprout/commitment.rs
index 2ac2ec5e..39895e99 100644
--- a/zebra-chain/src/commitments/sprout.rs
+++ b/zebra-chain/src/sprout/commitment.rs
@@ -4,7 +4,7 @@
 
 use sha2::{Digest, Sha256};
 
-use crate::notes::sprout::Note;
+use super::note::Note;
 
 /// The randomness used in the Pedersen Hash for note commitment.
 #[derive(Copy, Clone, Debug, PartialEq)]
diff --git a/zebra-chain/src/keys/sprout.rs b/zebra-chain/src/sprout/keys.rs
similarity index 100%
rename from zebra-chain/src/keys/sprout.rs
rename to zebra-chain/src/sprout/keys.rs
diff --git a/zebra-chain/src/notes/sprout.rs b/zebra-chain/src/sprout/note.rs
similarity index 93%
rename from zebra-chain/src/notes/sprout.rs
rename to zebra-chain/src/sprout/note.rs
index b48b1bc6..bbcd532e 100644
--- a/zebra-chain/src/notes/sprout.rs
+++ b/zebra-chain/src/sprout/note.rs
@@ -6,15 +6,18 @@
 #[cfg(test)]
 mod arbitrary;
 mod ciphertexts;
+mod mac;
 mod nullifiers;
 
 use crate::{
     amount::{Amount, NonNegative},
-    commitments::sprout::CommitmentRandomness,
-    keys::sprout::PayingKey,
     notes::memo::Memo,
 };
 
+use super::{commitment::CommitmentRandomness, keys::PayingKey};
+
+pub use mac::MAC;
+
 pub use ciphertexts::EncryptedCiphertext;
 
 pub use nullifiers::{Nullifier, NullifierSeed};
diff --git a/zebra-chain/src/notes/sprout/arbitrary.rs b/zebra-chain/src/sprout/note/arbitrary.rs
similarity index 85%
rename from zebra-chain/src/notes/sprout/arbitrary.rs
rename to zebra-chain/src/sprout/note/arbitrary.rs
index becdc6e4..1e6e02ad 100644
--- a/zebra-chain/src/notes/sprout/arbitrary.rs
+++ b/zebra-chain/src/sprout/note/arbitrary.rs
@@ -1,8 +1,7 @@
 use proptest::{arbitrary::any, collection::vec, prelude::*};
 
-use crate::notes::sprout;
 
-impl Arbitrary for sprout::EncryptedCiphertext {
+impl Arbitrary for super::EncryptedCiphertext {
     type Parameters = ();
 
     fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy {
diff --git a/zebra-chain/src/notes/sprout/ciphertexts.rs b/zebra-chain/src/sprout/note/ciphertexts.rs
similarity index 100%
rename from zebra-chain/src/notes/sprout/ciphertexts.rs
rename to zebra-chain/src/sprout/note/ciphertexts.rs
diff --git a/zebra-chain/src/types.rs b/zebra-chain/src/sprout/note/mac.rs
similarity index 89%
rename from zebra-chain/src/types.rs
rename to zebra-chain/src/sprout/note/mac.rs
index a006f646..20474465 100644
--- a/zebra-chain/src/types.rs
+++ b/zebra-chain/src/sprout/note/mac.rs
@@ -1,5 +1,3 @@
-//! Newtype wrappers for primitive data types with semantic meaning.
-#![allow(clippy::unit_arg)]
 use crate::serialization::{ReadZcashExt, SerializationError, ZcashDeserialize, ZcashSerialize};
 use std::io::{self, Read};
 
diff --git a/zebra-chain/src/notes/sprout/nullifiers.rs b/zebra-chain/src/sprout/note/nullifiers.rs
similarity index 98%
rename from zebra-chain/src/notes/sprout/nullifiers.rs
rename to zebra-chain/src/sprout/note/nullifiers.rs
index 6e25c859..11d0edde 100644
--- a/zebra-chain/src/notes/sprout/nullifiers.rs
+++ b/zebra-chain/src/sprout/note/nullifiers.rs
@@ -3,7 +3,7 @@
 use byteorder::{ByteOrder, LittleEndian};
 use serde::{Deserialize, Serialize};
 
-use crate::keys::sprout::SpendingKey;
+use super::super::keys::SpendingKey;
 
 /// PRF^nf is used to derive a Sprout nullifer from the receiver's
 /// spending key a_sk and a nullifier seed ρ, instantiated using the
diff --git a/zebra-chain/src/treestate/sprout.rs b/zebra-chain/src/sprout/tree.rs
similarity index 100%
rename from zebra-chain/src/treestate/sprout.rs
rename to zebra-chain/src/sprout/tree.rs
diff --git a/zebra-chain/src/transaction/joinsplit.rs b/zebra-chain/src/transaction/joinsplit.rs
index bd474778..54ef5901 100644
--- a/zebra-chain/src/transaction/joinsplit.rs
+++ b/zebra-chain/src/transaction/joinsplit.rs
@@ -2,9 +2,8 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     amount::{Amount, NonNegative},
-    notes::sprout,
+    sprout,
     primitives::{ed25519, x25519, ZkSnarkProof},
-    treestate,
 };
 
 /// A _JoinSplit Description_, as described in [protocol specification §7.2][ps].
@@ -22,25 +21,25 @@ pub struct JoinSplit<P: ZkSnarkProof> {
     /// A root of the Sprout note commitment tree at some block height in the
     /// past, or the root produced by a previous JoinSplit transfer in this
     /// transaction.
-    pub anchor: treestate::sprout::NoteTreeRootHash,
+    pub anchor: sprout::tree::NoteTreeRootHash,
     /// A nullifier for the input notes.
-    pub nullifiers: [crate::notes::sprout::Nullifier; 2],
+    pub nullifiers: [sprout::note::Nullifier; 2],
     /// A note commitment for this output note.
-    pub commitments: [crate::commitments::sprout::NoteCommitment; 2],
+    pub commitments: [sprout::commitment::NoteCommitment; 2],
     /// An X25519 public key.
     pub ephemeral_key: x25519::PublicKey,
     /// A 256-bit seed that must be chosen independently at random for each
     /// JoinSplit description.
     pub random_seed: [u8; 32],
     /// A message authentication tag.
-    pub vmacs: [crate::types::MAC; 2],
+    pub vmacs: [sprout::note::MAC; 2],
     /// A ZK JoinSplit proof, either a
     /// [`Groth16Proof`](crate::primitives::Groth16Proof) or a
     /// [`Bctv14Proof`](crate::primitives::Bctv14Proof).
     #[serde(bound(serialize = "P: ZkSnarkProof", deserialize = "P: ZkSnarkProof"))]
     pub zkproof: P,
     /// A ciphertext component for this output note.
-    pub enc_ciphertexts: [sprout::EncryptedCiphertext; 2],
+    pub enc_ciphertexts: [sprout::note::EncryptedCiphertext; 2],
 }
 
 // Because x25519_dalek::PublicKey does not impl PartialEq
diff --git a/zebra-chain/src/transaction/serialize.rs b/zebra-chain/src/transaction/serialize.rs
index 20589971..ffb679a9 100644
--- a/zebra-chain/src/transaction/serialize.rs
+++ b/zebra-chain/src/transaction/serialize.rs
@@ -9,12 +9,11 @@ use std::{
 };
 
 use crate::{
-    commitments, notes,
     primitives::{Script, ZkSnarkProof},
     serialization::{
         ReadZcashExt, SerializationError, WriteZcashExt, ZcashDeserialize, ZcashSerialize,
     },
-    treestate, types,
+    sprout,
 };
 
 use super::*;
@@ -276,25 +275,25 @@ impl<P: ZkSnarkProof> ZcashDeserialize for JoinSplit<P> {
         Ok(JoinSplit::<P> {
             vpub_old: reader.read_u64::<LittleEndian>()?.try_into()?,
             vpub_new: reader.read_u64::<LittleEndian>()?.try_into()?,
-            anchor: treestate::sprout::NoteTreeRootHash::from(reader.read_32_bytes()?),
+            anchor: sprout::tree::NoteTreeRootHash::from(reader.read_32_bytes()?),
             nullifiers: [
                 reader.read_32_bytes()?.into(),
                 reader.read_32_bytes()?.into(),
             ],
             commitments: [
-                commitments::sprout::NoteCommitment::from(reader.read_32_bytes()?),
-                commitments::sprout::NoteCommitment::from(reader.read_32_bytes()?),
+                sprout::commitment::NoteCommitment::from(reader.read_32_bytes()?),
+                sprout::commitment::NoteCommitment::from(reader.read_32_bytes()?),
             ],
             ephemeral_key: x25519_dalek::PublicKey::from(reader.read_32_bytes()?),
             random_seed: reader.read_32_bytes()?,
             vmacs: [
-                types::MAC::zcash_deserialize(&mut reader)?,
-                types::MAC::zcash_deserialize(&mut reader)?,
+                sprout::note::MAC::zcash_deserialize(&mut reader)?,
+                sprout::note::MAC::zcash_deserialize(&mut reader)?,
             ],
             zkproof: P::zcash_deserialize(&mut reader)?,
             enc_ciphertexts: [
-                notes::sprout::EncryptedCiphertext::zcash_deserialize(&mut reader)?,
-                notes::sprout::EncryptedCiphertext::zcash_deserialize(&mut reader)?,
+                sprout::note::EncryptedCiphertext::zcash_deserialize(&mut reader)?,
+                sprout::note::EncryptedCiphertext::zcash_deserialize(&mut reader)?,
             ],
         })
     }
diff --git a/zebra-chain/src/transaction/tests/arbitrary.rs b/zebra-chain/src/transaction/tests/arbitrary.rs
index dc3fcef5..d22c39e4 100644
--- a/zebra-chain/src/transaction/tests/arbitrary.rs
+++ b/zebra-chain/src/transaction/tests/arbitrary.rs
@@ -5,15 +5,13 @@ use proptest::{arbitrary::any, array, collection::vec, option, prelude::*};
 use crate::{
     amount::{Amount, NonNegative},
     block::BlockHeight,
-    commitments,
-    notes::sprout,
     primitives::{Bctv14Proof, Groth16Proof, Script, ZkSnarkProof},
     sapling,
+    sprout,
     transaction::{
         CoinbaseData, JoinSplit, JoinSplitData, LockTime, OutPoint, Output, ShieldedData, Spend,
         Transaction, TransparentInput, TransparentOutput,
     },
-    treestate,
 };
 
 impl Transaction {
@@ -125,14 +123,14 @@ impl<P: ZkSnarkProof + Arbitrary + 'static> Arbitrary for JoinSplit<P> {
         (
             any::<Amount<NonNegative>>(),
             any::<Amount<NonNegative>>(),
-            any::<treestate::sprout::NoteTreeRootHash>(),
-            array::uniform2(any::<sprout::Nullifier>()),
-            array::uniform2(any::<commitments::sprout::NoteCommitment>()),
+            any::<sprout::tree::NoteTreeRootHash>(),
+            array::uniform2(any::<sprout::note::Nullifier>()),
+            array::uniform2(any::<sprout::commitment::NoteCommitment>()),
             array::uniform32(any::<u8>()),
             array::uniform32(any::<u8>()),
-            array::uniform2(any::<crate::types::MAC>()),
+            array::uniform2(any::<sprout::note::MAC>()),
             any::<P>(),
-            array::uniform2(any::<sprout::EncryptedCiphertext>()),
+            array::uniform2(any::<sprout::note::EncryptedCiphertext>()),
         )
             .prop_map(
                 |(
diff --git a/zebra-chain/src/treestate.rs b/zebra-chain/src/treestate.rs
deleted file mode 100644
index 8cb30bd4..00000000
--- a/zebra-chain/src/treestate.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-//! Treestate representations for Sprout and Sapling
-
-// mod nullifier_set;
-pub mod sprout;