feat: add AccountBalanceChange proto message (#137)

proto/tycho/evm/v1/common.proto

@@ -55,7 +55,6 @@ enum FinancialType{
   PSM = 3;
 }
 
-
 enum ImplementationType {
   VM = 0;
   CUSTOM = 1;
@@ -128,6 +127,14 @@ message ContractSlot {
   bytes value = 3;
 }
 
+// A struct for following the token balance changes for a contract.
+message AccountBalanceChange {
+  // The address of the ERC20 token whose balance changed.
+  bytes token = 1;
+  // The new balance of the token. Note: it must be a big endian encoded int.
+  bytes balance = 2;
+}
+
 // Changes made to a single contract's state.
 message ContractChange {
   // The contract's address
@@ -140,6 +147,8 @@ message ContractChange {
   repeated ContractSlot slots = 4;
   // Whether this is an update, a creation or a deletion.
   ChangeType change = 5;
+  // The new ERC20 balances of the contract.
+  repeated AccountBalanceChange token_balances = 6;
 }
 
 // Aggregate entities

substreams/crates/tycho-substreams/src/models.rs

@@ -467,6 +467,7 @@ pub struct InterimContractChange {
     code: Vec<u8>,
     slots: HashMap<Vec<u8>, SlotValue>,
     change: ChangeType,
+    token_balances: HashMap<Vec<u8>, Vec<u8>>,
 }
 
 impl InterimContractChange {
@@ -477,6 +478,7 @@ impl InterimContractChange {
             code: vec![],
             slots: Default::default(),
             change: if creation { ChangeType::Creation } else { ChangeType::Update },
+            token_balances: Default::default(),
         }
     }
 
@@ -530,6 +532,11 @@ impl From<InterimContractChange> for Option<ContractChange> {
                 .map(|(slot, value)| ContractSlot { slot, value: value.new_value })
                 .collect(),
             change: value.change.into(),
+            token_balances: value
+                .token_balances
+                .into_iter()
+                .map(|(k, v)| AccountBalanceChange { token: k, balance: v })
+                .collect(),
         };
         if contract_change.is_empty() {
             None

substreams/crates/tycho-substreams/src/pb/tycho.evm.v1.rs

@@ -38,8 +38,7 @@ pub struct Transaction {
     pub index: u64,
 }
 /// A custom struct representing an arbitrary attribute of a protocol component.
-/// This is mainly used by the native integration to track the necessary information about the
+/// This is mainly used by the native integration to track the necessary information about the protocol.
-/// protocol.
 #[allow(clippy::derive_partial_eq_without_eq)]
 #[derive(Clone, PartialEq, ::prost::Message)]
 pub struct Attribute {
@@ -66,13 +65,11 @@ pub struct ProtocolType {
     pub implementation_type: i32,
 }
 /// A struct describing a part of the protocol.
-///
+/// Note: For example this can be a UniswapV2 pair, that tracks the two ERC20 tokens used by the pair, 
-/// Note: For example this can be a UniswapV2 pair, that tracks the two ERC20 tokens used by the
+/// the component would represent a single contract. In case of VM integration, such component would 
-/// pair, the component would represent a single contract. In case of VM integration, such component
+/// not need any attributes, because all the relevant info would be tracked via storage slots and balance changes.
-/// would not need any attributes, because all the relevant info would be tracked via storage slots
+/// It can also be a wrapping contract, like WETH, that has a constant price, but it allows swapping tokens. 
-/// and balance changes. It can also be a wrapping contract, like WETH, that has a constant price,
+/// This is why the name ProtocolComponent is used instead of "Pool" or "Pair".
-/// but it allows swapping tokens. This is why the name ProtocolComponent is used instead of "Pool"
-/// or "Pair".
 #[allow(clippy::derive_partial_eq_without_eq)]
 #[derive(Clone, PartialEq, ::prost::Message)]
 pub struct ProtocolComponent {
@@ -103,10 +100,8 @@ pub struct ProtocolComponent {
     pub tx: ::core::option::Option<Transaction>,
 }
 /// A struct for following the changes of Total Value Locked (TVL) of a protocol component.
-///
+/// Note that if a ProtocolComponent contains multiple contracts, the TVL is tracked for the component as a whole.
-/// Note that if a ProtocolComponent contains multiple contracts, the TVL is tracked for the
+/// E.g. for UniswapV2 pair WETH/USDC, this tracks the USDC and WETH balance of the pair contract.
-/// component as a whole. E.g. for UniswapV2 pair WETH/USDC, this tracks the USDC and WETH balance
-/// of the pair contract.
 #[allow(clippy::derive_partial_eq_without_eq)]
 #[derive(Clone, PartialEq, ::prost::Message)]
 pub struct BalanceChange {
@@ -117,8 +112,7 @@ pub struct BalanceChange {
     #[prost(bytes="vec", tag="2")]
     pub balance: ::prost::alloc::vec::Vec<u8>,
     /// The id of the component whose TVL is tracked.  Note: This MUST be utf8 encoded.
-    /// If the protocol component includes multiple contracts, the balance change must be
+    /// If the protocol component includes multiple contracts, the balance change must be aggregated to reflect how much tokens can be traded.
-    /// aggregated to reflect how much tokens can be traded.
     #[prost(bytes="vec", tag="3")]
     pub component_id: ::prost::alloc::vec::Vec<u8>,
 }
@@ -148,6 +142,17 @@ pub struct ContractSlot {
     #[prost(bytes="vec", tag="3")]
     pub value: ::prost::alloc::vec::Vec<u8>,
 }
+/// A struct for following the token balance changes for a contract.
+#[allow(clippy::derive_partial_eq_without_eq)]
+#[derive(Clone, PartialEq, ::prost::Message)]
+pub struct AccountBalanceChange {
+    /// The address of the ERC20 token whose balance changed.
+    #[prost(bytes="vec", tag="1")]
+    pub token: ::prost::alloc::vec::Vec<u8>,
+    /// The new balance of the token. Note: it must be a big endian encoded int.
+    #[prost(bytes="vec", tag="2")]
+    pub balance: ::prost::alloc::vec::Vec<u8>,
+}
 /// Changes made to a single contract's state.
 #[allow(clippy::derive_partial_eq_without_eq)]
 #[derive(Clone, PartialEq, ::prost::Message)]
@@ -167,6 +172,9 @@ pub struct ContractChange {
     /// Whether this is an update, a creation or a deletion.
     #[prost(enumeration="ChangeType", tag="5")]
     pub change: i32,
+    /// The new ERC20 balances of the contract.
+    #[prost(message, repeated, tag="6")]
+    pub token_balances: ::prost::alloc::vec::Vec<AccountBalanceChange>,
 }
 // Aggregate entities
 
@@ -178,8 +186,7 @@ pub struct TransactionChanges {
     #[prost(message, optional, tag="1")]
     pub tx: ::core::option::Option<Transaction>,
     /// Contains the changes induced by the above transaction, aggregated on a per-contract basis.
-    /// Contains the contract changes induced by the above transaction, usually for tracking VM
+    /// Contains the contract changes induced by the above transaction, usually for tracking VM components.
-    /// components.
     #[prost(message, repeated, tag="2")]
     pub contract_changes: ::prost::alloc::vec::Vec<ContractChange>,
     /// Contains the entity changes induced by the above transaction.