Commit Graph

3 Commits

Author SHA1 Message Date
Jacek Sieka 822c339607
e2store: avoid uint48 (#4625)
In SSZ, `uint32` is used for offsets, effectively limiting the size of
an SSZ entry to 2**32 bytes.

Also, `uint48` isn't a valid SSZ type, so the header was not correctly
defined according to the SSZ spec - the extra 2 bytes are left for
future expansion instead.
2023-02-15 14:51:17 +01:00
Jacek Sieka ba99c8fe4f
update era file documentation / impl (#3226)
Overhaul of era files, including documentation and reference
implementations

* store blocks, then state, then slot indices for easy lookup at low
cost
* document era file rationale
* altair+ support in era writer
2022-01-07 11:13:19 +01:00
Jacek Sieka aabdd34704
e2store: add era format (#2382)
Era files contain 8192 blocks and a state corresponding to the length of
the array holding block roots in the state, meaning that each block is
verifiable using the pubkeys and block roots from the state. Of course,
one would need to know the root of the state as well, which is available
in the first block of the _next_ file - or known from outside.

This PR also adds an implementation to write e2s, e2i and era files, as
well as a python script to inspect them.

All in all, the format is very similar to what goes on in the network
requests meaning it can trivially serve as a backing format for serving
said requests.

Mainnet, up to the first 671k slots, take up 3.5gb - in each era file,
the BeaconState contributes about 9mb at current validator set sizes, up
from ~3mb in the early blocks, for a grand total of ~558mb for the 82 eras
tested - this overhead could potentially be calculated but one would lose
the ability to verify individual blocks (eras could still be verified using
historical roots).

```
-rw-rw-r--. 1 arnetheduck arnetheduck   16  5 mar 11.47 ethereum2-mainnet-00000000-00000001.e2i
-rw-rw-r--. 1 arnetheduck arnetheduck 1,8M  5 mar 11.47 ethereum2-mainnet-00000000-00000001.e2s
-rw-rw-r--. 1 arnetheduck arnetheduck  65K  5 mar 11.47 ethereum2-mainnet-00000001-00000001.e2i
-rw-rw-r--. 1 arnetheduck arnetheduck  18M  5 mar 11.47 ethereum2-mainnet-00000001-00000001.e2s
...
-rw-rw-r--. 1 arnetheduck arnetheduck  65K  5 mar 11.52 ethereum2-mainnet-00000051-00000001.e2i
-rw-rw-r--. 1 arnetheduck arnetheduck  68M  5 mar 11.52 ethereum2-mainnet-00000051-00000001.e2s
-rw-rw-r--. 1 arnetheduck arnetheduck  61K  5 mar 11.11 ethereum2-mainnet-00000052-00000001.e2i
-rw-rw-r--. 1 arnetheduck arnetheduck  62M  5 mar 11.11 ethereum2-mainnet-00000052-00000001.e2s
```
2021-03-15 11:31:39 +01:00