From 1fa8f108d920f4890f440de7af04650dd26cc782 Mon Sep 17 00:00:00 2001
From: Gav Wood <gavin@ethcore.io>
Date: Mon, 6 Jun 2016 00:24:21 +0200
Subject: [PATCH] StateDiff uses serde preprocessor.

---
 rpc/src/v1/impls/traces.rs | 11 +++---
 rpc/src/v1/types/bytes.rs  |  6 ++++
 rpc/src/v1/types/mod.rs.in |  2 +-
 rpc/src/v1/types/trace.rs  | 71 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 82 insertions(+), 8 deletions(-)

diff --git a/rpc/src/v1/impls/traces.rs b/rpc/src/v1/impls/traces.rs
index 745f1c036..817420f3c 100644
--- a/rpc/src/v1/impls/traces.rs
+++ b/rpc/src/v1/impls/traces.rs
@@ -20,15 +20,12 @@ use std::sync::{Weak, Arc};
 use jsonrpc_core::*;
 use std::collections::BTreeMap;
 use util::{H256, U256, FixedHash, Uint};
-use serde;
 use ethcore::client::{BlockChainClient, CallAnalytics, TransactionID, TraceId};
 use ethcore::trace::VMTrace;
 use ethcore::miner::MinerService;
-use ethcore::state_diff::StateDiff;
-use ethcore::account_diff::{Diff, Existance};
 use ethcore::transaction::{Transaction as EthTransaction, SignedTransaction, Action};
 use v1::traits::Traces;
-use v1::types::{TraceFilter, LocalizedTrace, Trace, BlockNumber, Index, CallRequest, Bytes};
+use v1::types::{TraceFilter, LocalizedTrace, Trace, BlockNumber, Index, CallRequest, Bytes, StateDiff};
 
 /// Traces api implementation.
 pub struct TracesClient<C, M> where C: BlockChainClient, M: MinerService {
@@ -108,7 +105,7 @@ fn vm_trace_to_object(t: &VMTrace) -> Value {
 	ret.insert("ops".to_owned(), Value::Array(ops));
 	Value::Object(ret)
 }
-
+/*
 fn diff_to_object<T>(d: &Diff<T>) -> Value where T: serde::Serialize + Eq {
 	let mut ret = BTreeMap::new();
 	match *d {
@@ -149,7 +146,7 @@ fn state_diff_to_object(t: &StateDiff) -> Value {
 		]))
 	}).collect::<BTreeMap<_, _>>())
 }
-
+*/
 impl<C, M> Traces for TracesClient<C, M> where C: BlockChainClient + 'static, M: MinerService + 'static {
 	fn filter(&self, params: Params) -> Result<Value, Error> {
 		from_params::<(TraceFilter,)>(params)
@@ -217,7 +214,7 @@ impl<C, M> Traces for TracesClient<C, M> where C: BlockChainClient + 'static, M:
 						ret.insert("vmTrace".to_owned(), vm_trace_to_object(&vm_trace));
 					}
 					if let Some(state_diff) = executed.state_diff {
-						ret.insert("stateDiff".to_owned(), state_diff_to_object(&state_diff));
+						ret.insert("stateDiff".to_owned(), to_value(&StateDiff::from(state_diff)).unwrap());
 					}
 					return Ok(Value::Object(ret))
 				}
diff --git a/rpc/src/v1/types/bytes.rs b/rpc/src/v1/types/bytes.rs
index 76d84d0dd..1bf5deb75 100644
--- a/rpc/src/v1/types/bytes.rs
+++ b/rpc/src/v1/types/bytes.rs
@@ -36,6 +36,12 @@ impl Bytes {
 	}
 }
 
+impl From<Vec<u8>> for Bytes {
+	fn from(bytes: Vec<u8>) -> Bytes {
+		Bytes(bytes)
+	}
+}
+
 impl Serialize for Bytes {
 	fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
 	where S: Serializer {
diff --git a/rpc/src/v1/types/mod.rs.in b/rpc/src/v1/types/mod.rs.in
index ba10fbe18..fc2a19987 100644
--- a/rpc/src/v1/types/mod.rs.in
+++ b/rpc/src/v1/types/mod.rs.in
@@ -41,5 +41,5 @@ pub use self::transaction::Transaction;
 pub use self::transaction_request::{TransactionRequest, TransactionConfirmation, TransactionModification};
 pub use self::call_request::CallRequest;
 pub use self::receipt::Receipt;
-pub use self::trace::{Trace, LocalizedTrace};
+pub use self::trace::{Trace, LocalizedTrace, StateDiff};
 pub use self::trace_filter::TraceFilter;
diff --git a/rpc/src/v1/types/trace.rs b/rpc/src/v1/types/trace.rs
index 070b7d7d0..ede99b448 100644
--- a/rpc/src/v1/types/trace.rs
+++ b/rpc/src/v1/types/trace.rs
@@ -14,11 +14,82 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
+use std::collections::BTreeMap;
 use util::{Address, U256, H256};
+use serde::{Serialize, Serializer};
 use ethcore::trace::trace;
 use ethcore::trace::{Trace as EthTrace, LocalizedTrace as EthLocalizedTrace};
+use ethcore::state_diff;
+use ethcore::account_diff;
 use v1::types::Bytes;
 
+#[derive(Debug, Serialize)]
+/// Aux type for Diff::Changed.
+pub struct ChangedType<T> where T: Serialize {
+	from: T,
+	to: T,
+}
+
+#[derive(Debug, Serialize)]
+/// Serde-friendly `Diff` shadow.
+pub enum Diff<T> where T: Serialize {
+	#[serde(rename="=")]
+	Same,
+	#[serde(rename="+")]
+	Born(T),
+	#[serde(rename="-")]
+	Died(T),
+	#[serde(rename="*")]
+	Changed(ChangedType<T>),
+}
+
+impl<T, U> From<account_diff::Diff<T>> for Diff<U> where T: Eq, U: Serialize + From<T> {
+	fn from(c: account_diff::Diff<T>) -> Self {
+		match c {
+			account_diff::Diff::Same => Diff::Same,
+			account_diff::Diff::Born(t) => Diff::Born(t.into()),
+			account_diff::Diff::Died(t) => Diff::Died(t.into()),
+			account_diff::Diff::Changed(t, u) => Diff::Changed(ChangedType{from: t.into(), to: u.into()}),
+		}
+	}
+}
+
+#[derive(Debug, Serialize)]
+/// Serde-friendly `AccountDiff` shadow.
+pub struct AccountDiff {
+	pub balance: Diff<U256>,
+	pub nonce: Diff<U256>,
+	pub code: Diff<Bytes>,
+	pub storage: BTreeMap<H256, Diff<H256>>,
+}
+
+impl From<account_diff::AccountDiff> for AccountDiff {
+	fn from(c: account_diff::AccountDiff) -> Self {
+		AccountDiff {
+			balance: c.balance.into(),
+			nonce: c.nonce.into(),
+			code: c.code.into(),
+			storage: c.storage.into_iter().map(|(k, v)| (k, v.into())).collect(),
+		}
+	}
+}
+
+/// Serde-friendly `StateDiff` shadow.
+pub struct StateDiff(BTreeMap<Address, AccountDiff>);
+
+impl Serialize for StateDiff {
+	fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+	where S: Serializer {
+		Serialize::serialize(&self.0, serializer)
+	}
+}
+
+impl From<state_diff::StateDiff> for StateDiff {
+	fn from(c: state_diff::StateDiff) -> Self {
+		StateDiff(c.0.into_iter().map(|(k, v)| (k, v.into())).collect())
+	}
+}
+
 /// Create response
 #[derive(Debug, Serialize)]
 pub struct Create {