Don't use SSZ in RPC request/response wrappers

This commit is contained in:
Matthew Slipper 2019-04-20 17:26:07 -07:00
parent 75fae6f311
commit f7ef9a1ba5
1 changed files with 23 additions and 19 deletions

View File

@ -39,32 +39,36 @@ To facilitate RPC-over-`libp2p`, a single protocol name is used: `/eth/serenity/
Remote method calls are wrapped in a "request" structure:
```
(
id: uint64
method_id: uint16
body: Request
)
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ id (uint64) +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| method_id (uint16) | body_len (uint32) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | body (body_len bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
```
and their corresponding responses are wrapped in a "response" structure:
```
(
id: uint64
response_code: uint16
result: bytes
)
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ id (uint64) +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| response_code (uint16) | result_len (uint32) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | result (result_len bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
```
If an error occurs, a variant of the response structure is returned:
```
(
id: uint64
response_code: uint16
result: bytes
)
```
Note that the above structures are NOT encoded as SSZ but rather as sequences of bytes according to the packet diagrams above. This is because SSZ does not support structures without an explicit schema. Since the `body` and `result` fields depend on the value of `method_id` and `response_code`, a schema for the above structure cannot be known beforehand.
The details of the RPC-Over-`libp2p` protocol are similar to [JSON-RPC 2.0](https://www.jsonrpc.org/specification). Specifically: