From aae6d19df9621c330761b0652e95187744883807 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Drwi=C4=99ga?= <tomusdrw@users.noreply.github.com>
Date: Thu, 22 Sep 2016 19:58:42 +0200
Subject: [PATCH] Separate path for ext code size (#2251)

* Separate path for code size

* Actually use it for EVM

* add extcodesize to TestExt
---
 ethcore/src/evm/ext.rs              |  3 +++
 ethcore/src/evm/interpreter/mod.rs  |  2 +-
 ethcore/src/evm/tests.rs            |  4 ++++
 ethcore/src/externalities.rs        |  5 +++++
 ethcore/src/json_tests/executive.rs |  4 ++++
 ethcore/src/state/mod.rs            | 10 ++++++++--
 6 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/ethcore/src/evm/ext.rs b/ethcore/src/evm/ext.rs
index 0db789507..2bbc7035b 100644
--- a/ethcore/src/evm/ext.rs
+++ b/ethcore/src/evm/ext.rs
@@ -83,6 +83,9 @@ pub trait Ext {
 	/// Returns code at given address
 	fn extcode(&self, address: &Address) -> Bytes;
 
+	/// Returns code size at given address
+	fn extcodesize(&self, address: &Address) -> usize;
+
 	/// Creates log entry with given topics and data
 	fn log(&mut self, topics: Vec<H256>, data: &[u8]);
 
diff --git a/ethcore/src/evm/interpreter/mod.rs b/ethcore/src/evm/interpreter/mod.rs
index e95fb943e..bf3062de5 100644
--- a/ethcore/src/evm/interpreter/mod.rs
+++ b/ethcore/src/evm/interpreter/mod.rs
@@ -471,7 +471,7 @@ impl<Cost: CostType> Interpreter<Cost> {
 			},
 			instructions::EXTCODESIZE => {
 				let address = u256_to_address(&stack.pop_back());
-				let len = ext.extcode(&address).len();
+				let len = ext.extcodesize(&address);
 				stack.push(U256::from(len));
 			},
 			instructions::CALLDATACOPY => {
diff --git a/ethcore/src/evm/tests.rs b/ethcore/src/evm/tests.rs
index bdb1f1ddb..ec217b6c5 100644
--- a/ethcore/src/evm/tests.rs
+++ b/ethcore/src/evm/tests.rs
@@ -140,6 +140,10 @@ impl Ext for FakeExt {
 		self.codes.get(address).unwrap_or(&Bytes::new()).clone()
 	}
 
+	fn extcodesize(&self, address: &Address) -> usize {
+		self.codes.get(address).map(|v| v.len()).unwrap_or(0)
+	}
+
 	fn log(&mut self, topics: Vec<H256>, data: &[u8]) {
 		self.logs.push(FakeLogEntry {
 			topics: topics,
diff --git a/ethcore/src/externalities.rs b/ethcore/src/externalities.rs
index 09c4b4e11..7395522c3 100644
--- a/ethcore/src/externalities.rs
+++ b/ethcore/src/externalities.rs
@@ -205,6 +205,11 @@ impl<'a, T, V> Ext for Externalities<'a, T, V> where T: 'a + Tracer, V: 'a + VMT
 		self.state.code(address).unwrap_or_else(|| vec![])
 	}
 
+	fn extcodesize(&self, address: &Address) -> usize {
+		self.state.code_size(address).unwrap_or(0)
+	}
+
+
 	#[cfg_attr(feature="dev", allow(match_ref_pats))]
 	fn ret(mut self, gas: &U256, data: &[u8]) -> evm::Result<U256>
 		where Self: Sized {
diff --git a/ethcore/src/json_tests/executive.rs b/ethcore/src/json_tests/executive.rs
index 7304f5931..1fe98acdb 100644
--- a/ethcore/src/json_tests/executive.rs
+++ b/ethcore/src/json_tests/executive.rs
@@ -131,6 +131,10 @@ impl<'a, T, V> Ext for TestExt<'a, T, V> where T: Tracer, V: VMTracer {
 		self.ext.extcode(address)
 	}
 
+	fn extcodesize(&self, address: &Address) -> usize {
+		self.ext.extcodesize(address)
+	}
+
 	fn log(&mut self, topics: Vec<H256>, data: &[u8]) {
 		self.ext.log(topics, data)
 	}
diff --git a/ethcore/src/state/mod.rs b/ethcore/src/state/mod.rs
index 78eb01c7c..e1299d1dc 100644
--- a/ethcore/src/state/mod.rs
+++ b/ethcore/src/state/mod.rs
@@ -191,10 +191,16 @@ impl State {
 		}))
 	}
 
-	/// Mutate storage of account `a` so that it is `value` for `key`.
+	/// Get the code of account `a`.
 	pub fn code(&self, a: &Address) -> Option<Bytes> {
 		self.ensure_cached(a, true,
-			|a| a.as_ref().map_or(None, |a|a.code().map(|x|x.to_vec())))
+			|a| a.as_ref().map_or(None, |a| a.code().map(|x| x.to_vec())))
+	}
+
+	/// Get the code size of account `a`.
+	pub fn code_size(&self, a: &Address) -> Option<usize> {
+		self.ensure_cached(a, true,
+			|a| a.as_ref().map_or(None, |a| a.code().map(|x| x.len())))
 	}
 
 	/// Add `incr` to the balance of account `a`.