This removes the inventory vector structs from `zebra-chain` (as they
are really part of the network protocol) and refactors them into a
single `InventoryHash` type. This corresponds to Bitcoin's "inventory
vector" but with a different, better name (it's not a vector, it's just
a typed hash of some other item).
This adds convenience methods to `ReadZcashExt` that read 4 and 12 byte
fixed size arrays from the `Reader`, making the actual parsing code more
legible.
Closes#10.
The core serialization logic is now in zebra-chain and consists of two
pairs of traits:
These are analogues of the Serde `Serialize` and `Deserialize` traits,
but explicitly intended for consensus-critical serialization formats.
Thus some struct `Foo` may have derived `Serialize` and `Deserialize`
implementations for (internal) use with Serde, and explicitly-written
`ZcashSerialize` and `ZcashDeserialize` implementations for use in
consensus-critical contexts. The consensus-critical implementations
provide `zcash`-prefixed `zcash_serialize` and `zcash_deserialize`
methods to make it clear in client contexts that the serialization is
consensus-critical.
These are utility traits, analogous to the `ReadBytesExt` and
`WriteBytesExt` traits provided by `byteorder`. A generic
implementation is provided for any `io::Read` or `io::Write`, so that
bringing the traits into scope adds additional Zcash-specific traits to
generic readers and writers -- for instance, writing a `u64` in the
Bitcoin "CompactSize" format.