proofs of non-existance in ProvingBlockChainClient

ethcore/src/client/client.rs

@@ -1585,23 +1585,14 @@ impl MayPanic for Client {
 }
 
 impl ::client::ProvingBlockChainClient for Client {
-	fn prove_storage(&self, key1: H256, key2: H256, from_level: u32, id: BlockId) -> Vec<Bytes> {
+	fn prove_storage(&self, key1: H256, key2: H256, id: BlockId) -> Option<(Vec<Bytes>, H256)> {
 		self.state_at(id)
-			.and_then(move |state| state.prove_storage(key1, key2, from_level).ok())
-			.unwrap_or_else(Vec::new)
+			.and_then(move |state| state.prove_storage(key1, key2).ok())
 	}
 
-	fn prove_account(&self, key1: H256, from_level: u32, id: BlockId) -> Vec<Bytes> {
+	fn prove_account(&self, key1: H256, id: BlockId) -> Option<(Vec<Bytes>, ::types::basic_account::BasicAccount)> {
 		self.state_at(id)
-			.and_then(move |state| state.prove_account(key1, from_level).ok())
-			.unwrap_or_else(Vec::new)
-	}
-
-	fn code_by_hash(&self, account_key: H256, id: BlockId) -> Bytes {
-		self.state_at(id)
-			.and_then(move |state| state.code_by_address_hash(account_key).ok())
-			.and_then(|x| x)
-			.unwrap_or_else(Vec::new)
+			.and_then(move |state| state.prove_account(key1).ok())
 	}
 
 	fn prove_transaction(&self, transaction: SignedTransaction, id: BlockId) -> Option<Vec<DBValue>> {

ethcore/src/client/test_client.rs

@@ -38,6 +38,7 @@ use error::{ImportResult, Error as EthcoreError};
 use evm::{Factory as EvmFactory, VMType, Schedule};
 use miner::{Miner, MinerService, TransactionImportResult};
 use spec::Spec;
+use types::basic_account::BasicAccount;
 use types::mode::Mode;
 use types::pruning_info::PruningInfo;
 
@@ -754,16 +755,12 @@ impl BlockChainClient for TestBlockChainClient {
 }
 
 impl ProvingBlockChainClient for TestBlockChainClient {
-	fn prove_storage(&self, _: H256, _: H256, _: u32, _: BlockId) -> Vec<Bytes> {
-		Vec::new()
+	fn prove_storage(&self, _: H256, _: H256, _: BlockId) -> Option<(Vec<Bytes>, H256)> {
+		None
 	}
 
-	fn prove_account(&self, _: H256, _: u32, _: BlockId) -> Vec<Bytes> {
-		Vec::new()
-	}
-
-	fn code_by_hash(&self, _: H256, _: BlockId) -> Bytes {
-		Vec::new()
+	fn prove_account(&self, _: H256, _: BlockId) -> Option<(Vec<Bytes>, BasicAccount)> {
+		None
 	}
 
 	fn prove_transaction(&self, _: SignedTransaction, _: BlockId) -> Option<Vec<DBValue>> {

ethcore/src/client/traits.rs

@@ -34,6 +34,7 @@ use env_info::LastHashes;
 use block_import_error::BlockImportError;
 use ipc::IpcConfig;
 use types::ids::*;
+use types::basic_account::BasicAccount;
 use types::trace_filter::Filter as TraceFilter;
 use types::call_analytics::CallAnalytics;
 use types::blockchain_info::BlockChainInfo;
@@ -309,19 +310,12 @@ pub trait ProvingBlockChainClient: BlockChainClient {
 	///
 	/// Both provided keys assume a secure trie.
 	/// Returns a vector of raw trie nodes (in order from the root) proving the storage query.
-	/// Nodes after `from_level` may be omitted.
-	/// An empty vector indicates unservable query.
-	fn prove_storage(&self, key1: H256, key2: H256, from_level: u32, id: BlockId) -> Vec<Bytes>;
+	fn prove_storage(&self, key1: H256, key2: H256, id: BlockId) -> Option<(Vec<Bytes>, H256)>;
 
 	/// Prove account existence at a specific block id.
 	/// The key is the keccak hash of the account's address.
 	/// Returns a vector of raw trie nodes (in order from the root) proving the query.
-	/// Nodes after `from_level` may be omitted.
-	/// An empty vector indicates unservable query.
-	fn prove_account(&self, key1: H256, from_level: u32, id: BlockId) -> Vec<Bytes>;
-
-	/// Get code by address hash.
-	fn code_by_hash(&self, account_key: H256, id: BlockId) -> Bytes;
+	fn prove_account(&self, key1: H256, id: BlockId) -> Option<(Vec<Bytes>, BasicAccount)>;
 
 	/// Prove execution of a transaction at the given block.
 	fn prove_transaction(&self, transaction: SignedTransaction, id: BlockId) -> Option<Vec<DBValue>>;

ethcore/src/state/account.rs

@@ -438,18 +438,19 @@ impl Account {
 	/// trie.
 	/// `storage_key` is the hash of the desired storage key, meaning
 	/// this will only work correctly under a secure trie.
-	/// Returns a merkle proof of the storage trie node with all nodes before `from_level`
-	/// omitted.
-	pub fn prove_storage(&self, db: &HashDB, storage_key: H256, from_level: u32) -> Result<Vec<Bytes>, Box<TrieError>> {
+	pub fn prove_storage(&self, db: &HashDB, storage_key: H256) -> Result<(Vec<Bytes>, H256), Box<TrieError>> {
 		use util::trie::{Trie, TrieDB};
 		use util::trie::recorder::Recorder;
 
-		let mut recorder = Recorder::with_depth(from_level);
+		let mut recorder = Recorder::new();
 
 		let trie = TrieDB::new(db, &self.storage_root)?;
-		let _ = trie.get_with(&storage_key, &mut recorder)?;
+		let item: U256 = {
+			let query = (&mut recorder, ::rlp::decode);
+			trie.get_with(&storage_key, query)?.unwrap_or_else(U256::zero)
+		};
 
-		Ok(recorder.drain().into_iter().map(|r| r.data).collect())
+		Ok((recorder.drain().into_iter().map(|r| r.data).collect(), item.into()))
 	}
 }
 

ethcore/src/state/mod.rs

@@ -31,6 +31,7 @@ use factory::Factories;
 use trace::FlatTrace;
 use pod_account::*;
 use pod_state::{self, PodState};
+use types::basic_account::BasicAccount;
 use types::executed::{Executed, ExecutionError};
 use types::state_diff::StateDiff;
 use transaction::SignedTransaction;
@@ -857,47 +858,43 @@ impl<B: Backend> State<B> {
 // State proof implementations; useful for light client protocols.
 impl<B: Backend> State<B> {
 	/// Prove an account's existence or nonexistence in the state trie.
-	/// Returns a merkle proof of the account's trie node with all nodes before `from_level`
-	/// omitted or an encountered trie error.
+	/// Returns a merkle proof of the account's trie node omitted or an encountered trie error.
+	/// If the account doesn't exist in the trie, prove that and return defaults.
 	/// Requires a secure trie to be used for accurate results.
 	/// `account_key` == sha3(address)
-	pub fn prove_account(&self, account_key: H256, from_level: u32) -> trie::Result<Vec<Bytes>> {
-		let mut recorder = Recorder::with_depth(from_level);
+	pub fn prove_account(&self, account_key: H256) -> trie::Result<(Vec<Bytes>, BasicAccount)> {
+		let mut recorder = Recorder::new();
 		let trie = TrieDB::new(self.db.as_hashdb(), &self.root)?;
-		trie.get_with(&account_key, &mut recorder)?;
+		let maybe_account: Option<BasicAccount> = {
+			let query = (&mut recorder, ::rlp::decode);
+			trie.get_with(&account_key, query)?
+		};
+		let account = maybe_account.unwrap_or_else(|| BasicAccount {
+			balance: 0.into(),
+			nonce: self.account_start_nonce,
+			code_hash: SHA3_EMPTY,
+			storage_root: ::util::sha3::SHA3_NULL_RLP,
+		});
 
-		Ok(recorder.drain().into_iter().map(|r| r.data).collect())
+		Ok((recorder.drain().into_iter().map(|r| r.data).collect(), account))
 	}
 
 	/// Prove an account's storage key's existence or nonexistence in the state.
-	/// Returns a merkle proof of the account's storage trie with all nodes before
-	/// `from_level` omitted. Requires a secure trie to be used for correctness.
+	/// Returns a merkle proof of the account's storage trie.
+	/// Requires a secure trie to be used for correctness.
 	/// `account_key` == sha3(address)
 	/// `storage_key` == sha3(key)
-	pub fn prove_storage(&self, account_key: H256, storage_key: H256, from_level: u32) -> trie::Result<Vec<Bytes>> {
+	pub fn prove_storage(&self, account_key: H256, storage_key: H256) -> trie::Result<(Vec<Bytes>, H256)> {
 		// TODO: probably could look into cache somehow but it's keyed by
 		// address, not sha3(address).
 		let trie = TrieDB::new(self.db.as_hashdb(), &self.root)?;
 		let acc = match trie.get_with(&account_key, Account::from_rlp)? {
 			Some(acc) => acc,
-			None => return Ok(Vec::new()),
+			None => return Ok((Vec::new(), H256::new())),
 		};
 
 		let account_db = self.factories.accountdb.readonly(self.db.as_hashdb(), account_key);
-		acc.prove_storage(account_db.as_hashdb(), storage_key, from_level)
-	}
-
-	/// Get code by address hash.
-	/// Only works when backed by a secure trie.
-	pub fn code_by_address_hash(&self, account_key: H256) -> trie::Result<Option<Bytes>> {
-		let trie = TrieDB::new(self.db.as_hashdb(), &self.root)?;
-		let mut acc = match trie.get_with(&account_key, Account::from_rlp)? {
-			Some(acc) => acc,
-			None => return Ok(None),
-		};
-
-		let account_db = self.factories.accountdb.readonly(self.db.as_hashdb(), account_key);
-		Ok(acc.cache_code(account_db.as_hashdb()).map(|c| (&*c).clone()))
+		acc.prove_storage(account_db.as_hashdb(), storage_key)
 	}
 }