It also brings ToStackItem to Block and Transaction, previously this was
avoided to separate block and transaction packages from VM. But turns out
`transaction` depends on `stackitem` already, so this makes little sense (but
can be shuffled in another way if needed).
Context.Container is still a hash.Hashable because we have a number of
occasions (header or MPT root verification) where there is no ToStackItem
implementation possible. Maybe they can go with `nil` Container, but I don't
want to have this risk for now.
We shouldn't use StoragePrice from Blockchain because its dao doesn't
contain the whole set of changes from previouse transactions in the
current block. Instead, we should use an updated storage price for
each transaction and retrieve the price from cached DAO.
They never return errors, so their interface should reflect that. This allows
to remove quite a lot of useless and never tested code.
Notice that Get still does return an error. It can be made not to do that, but
usually we need to differentiate between successful/unsuccessful accesses
anyway, so this doesn't help much.
Because `Map` stores elements in arbitrary order, addition of new
element takes linear time (`Index` iterates over all keys). Thus our
`storageFind` is actually quadratic in time. Optimize this by creating
map from sorted slice.
```
name old time/op new time/op delta
StorageFind-8 157µs ± 2% 112µs ± 1% -28.60% (p=0.000 n=10+10)
name old alloc/op new alloc/op delta
StorageFind-8 69.4kB ± 0% 60.5kB ± 0% -12.90% (p=0.000 n=9+10)
name old allocs/op new allocs/op delta
StorageFind-8 2.21k ± 0% 2.00k ± 0% -9.37% (p=0.000 n=10+7)
```
Signed-off-by: Evgeniy Stratonikov <evgeniy@nspcc.ru>
But don't change the way we process/store transactions and blocks. Effectively
it's just an interface for smart contracts that replaces old syscalls.
Transaction definition is moved temporarily to runtime package and Block
definition is removed (till we solve #1691 properly).
Prices are defined in as a coefficients to `BaseExecFee` which
is defined by Policy contract (TBD later).
Native method prices are defined without need to multiply.
When calling external contracts we expect exactly 1 value to be on
stack. For methods returning nothing, `Null` value is pushed, otherwise
it is an error.`
Invoke `_initialize` method on every call if present.
In NEO3 there is no entrypoint and methods are invoked by offset,
thus `Main` function is no longer required.
We still have special `Main` method in tests to simplify them.
