Feedback on Data Structures Section MEGA Issue

[ZenGround0]

This issue has a bunch of items. Feel free to check them off as they get completed or tracked in other issues. Block:

• [x] The Signature field is missing from the block data structure and should be discussed
• [x] Separate from the Ticket the block must also include an array of time delay proofs (PoST now, moving to VDF soon). One proof per null block
• [x] The Parent Weight fields must move to a single parent weight field. The data format and some reasoning about why it is good enough is captured in this recent change to go-filecoin.
• [x] We need to change both Messages and MessageReceipts to a MessageTreeRoot type
• [x] I don't see SortedCidSet defined in this section (maybe the cid spec?) it should be clear where to read about this thing.

Message:

• [x] From TODO -- discuss how method parameters get encoded
• [x] Serialization -- from @phritz we should vet our serialization process for efficiency, potentially improve it and reflect that work here. (Same comment about actor serialization which is the same.

State Tree:

• [x] There appears to be insufficient detail explaining how to use a HAMT to implement a State Tree

HAMT:

• [x] From TODO -- we need to spec this thing out, especially since this isn't really a HAMT

MessageTree:

• [ ] We need to create a spec for this thing. Likely this will look a lot like state tree and we will implement it using the same HAMT.

Thanks!

[creationix]

In https://github.com/filecoin-project/specs/blob/master/data-structures.md#filecoin-compact-serialization, it states that Message has 6 fields and the test vector towards the end matches that.

But in https://github.com/filecoin-project/specs/blob/master/data-structures.md#message there are two more fields listed (GasPrice and GasLimit)

Was the gas stuff removed at some point, but not updated in the message section?

[dignifiedquire]

* There appears to be insufficient detail explaining how to use a HAMT to implement a State Tree

solved: https://github.com/filecoin-project/specs/blob/master/data-structures.md#state-tree

* From TODO -- we need to spec this thing out, especially since this isn't really a HAMT

solved: hamt spec is being developed and close to merge: https://github.com/ipld/specs/pull/131

We need to create a spec for this thing. Likely this will look a lot like state tree and we will implement it using the same HAMT.

mostly solved in the latest spec, except the exact encoding of the sharray

[mishmosh]

9/10 of these are done. @ZenGround0 do we still need messagetree?