State pruning (#216)

* Started work on state db

* Updated for a new hash type

* Pruning and tests

* Generalize on the block hash/key type

* Integrate with the client backend

* Merge w master

* CLI options

* Updated for light client refactoring

* Used IntoIterator

* Fixed invalid input hadling

substrate/substrate/runtime/council/src/lib.rs

@@ -361,7 +361,7 @@ impl<T: Trait> Module<T> {
 		let (_, _, expiring) = Self::next_finalise().ok_or("cannot present outside of presentation period")?;
 		let stakes = Self::snapshoted_stakes();
 		let voters = Self::voters();
-		let bad_presentation_punishment = Self::present_slash_per_voter() * T::Balance::sa(voters.len());
+		let bad_presentation_punishment = Self::present_slash_per_voter() * T::Balance::sa(voters.len() as u64);
 		ensure!(<staking::Module<T>>::can_slash(aux.ref_into(), bad_presentation_punishment), "presenter must have sufficient slashable funds");
 
 		let mut leaderboard = Self::leaderboard().ok_or("leaderboard must exist while present phase active")?;

substrate/substrate/runtime/democracy/src/lib.rs

@@ -117,7 +117,7 @@ impl<T: Trait> Module<T> {
 	/// Get the amount locked in support of `proposal`; `None` if proposal isn't a valid proposal
 	/// index.
 	pub fn locked_for(proposal: PropIndex) -> Option<T::Balance> {
-		Self::deposit_of(proposal).map(|(d, l)| d * T::Balance::sa(l.len()))
+		Self::deposit_of(proposal).map(|(d, l)| d * T::Balance::sa(l.len() as u64))
 	}
 
 	/// Return true if `ref_index` is an on-going referendum.

substrate/substrate/runtime/primitives/src/traits.rs

@@ -121,7 +121,7 @@ impl<T> RefInto<T> for T {
 }
 
 pub trait SimpleArithmetic:
-	Zero + One + IntegerSquareRoot + As<usize> +
+	Zero + One + IntegerSquareRoot + As<u64> +
 	Add<Self, Output = Self> + AddAssign<Self> +
 	Sub<Self, Output = Self> + SubAssign<Self> +
 	Mul<Self, Output = Self> + MulAssign<Self> +
@@ -130,7 +130,7 @@ pub trait SimpleArithmetic:
 	PartialOrd<Self> + Ord
 {}
 impl<T:
-	Zero + One + IntegerSquareRoot + As<usize> +
+	Zero + One + IntegerSquareRoot + As<u64> +
 	Add<Self, Output = Self> + AddAssign<Self> +
 	Sub<Self, Output = Self> + SubAssign<Self> +
 	Mul<Self, Output = Self> + MulAssign<Self> +
@@ -314,7 +314,7 @@ pub trait Digest {
 /// `parent_hash`, as well as a `digest` and a block `number`.
 ///
 /// You can also create a `new` one from those fields.
-pub trait Header: Clone + Send + Sync + Slicable + Eq + MaybeSerializeDebug {
+pub trait Header: Clone + Send + Sync + Slicable + Eq + MaybeSerializeDebug + 'static {
 	type Number: Member + ::rstd::hash::Hash + Copy + MaybeDisplay + SimpleArithmetic + Slicable;
 	type Hash: Member + ::rstd::hash::Hash + Copy + MaybeDisplay + Default + SimpleBitOps + Slicable + AsRef<[u8]>;
 	type Hashing: Hashing<Output = Self::Hash>;
@@ -352,7 +352,7 @@ pub trait Header: Clone + Send + Sync + Slicable + Eq + MaybeSerializeDebug {
 /// `Extrinsic` piece of information as well as a `Header`.
 ///
 /// You can get an iterator over each of the `extrinsics` and retrieve the `header`.
-pub trait Block: Clone + Send + Sync + Slicable + Eq + MaybeSerializeDebug {
+pub trait Block: Clone + Send + Sync + Slicable + Eq + MaybeSerializeDebug + 'static {
 	type Extrinsic: Member + Slicable;
 	type Header: Header<Hash=Self::Hash>;
 	type Hash: Member + ::rstd::hash::Hash + Copy + MaybeDisplay + Default + SimpleBitOps + Slicable + AsRef<[u8]>;

substrate/substrate/runtime/staking/src/lib.rs

@@ -120,12 +120,12 @@ impl<Hashing, AccountId> ContractAddressFor<AccountId> for Hashing where
 
 pub trait Trait: system::Trait + session::Trait {
 	/// The balance of an account.
-	type Balance: Parameter + SimpleArithmetic + Slicable + Default + Copy + As<Self::AccountIndex> + As<usize>;
+	type Balance: Parameter + SimpleArithmetic + Slicable + Default + Copy + As<Self::AccountIndex> + As<usize> + As<u64>;
 	/// Function type to get the contract address given the creator.
 	type DetermineContractAddress: ContractAddressFor<Self::AccountId>;
 	/// Type used for storing an account's index; implies the maximum number of accounts the system
 	/// can hold.
-	type AccountIndex: Parameter + Member + Slicable + SimpleArithmetic + As<u8> + As<u16> + As<u32> + As<usize> + Copy;
+	type AccountIndex: Parameter + Member + Slicable + SimpleArithmetic + As<u8> + As<u16> + As<u32> + As<u64> + As<usize> + Copy;
 }
 
 decl_module! {
@@ -872,7 +872,7 @@ impl<T: Trait> AuxLookup for Module<T> {
 impl<T: Trait> MakePayment<T::AccountId> for Module<T> {
 	fn make_payment(transactor: &T::AccountId, encoded_len: usize) -> Result {
 		let b = Self::free_balance(transactor);
-		let transaction_fee = Self::transaction_base_fee() + Self::transaction_byte_fee() * <T::Balance as As<usize>>::sa(encoded_len);
+		let transaction_fee = Self::transaction_base_fee() + Self::transaction_byte_fee() * <T::Balance as As<u64>>::sa(encoded_len as u64);
 		if b < transaction_fee {
 			return Err("not enough funds for transaction fee");
 		}