Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add function to check for state node removal. #19

Merged
merged 3 commits into from
Sep 27, 2021
Merged

Add function to check for state node removal. #19

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
b3799f3
Add function to check for state node removal.
arijitAD Sep 24, 2021
d66bef1
Update the schema.sql.
arijitAD Sep 24, 2021
d9e80c3
Update the function query.
arijitAD Sep 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
28 changes: 28 additions & 0 deletions db/migrations/00028_add_state_leaf_remove_function.sql
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,28 @@
-- +goose Up
-- +goose StatementBegin
-- returns if a state leaf node was removed within the provided block number
CREATE OR REPLACE FUNCTION was_state_leaf_removed(key character varying, hash character varying) RETURNS boolean
LANGUAGE plpgsql
AS $$
DECLARE
rec RECORD;
BEGIN
FOR rec IN SELECT state_cids.node_type
FROM eth.state_cids
INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
WHERE state_leaf_key = key
AND block_number <= (SELECT block_number FROM eth.header_cids WHERE block_hash = hash)
ORDER BY state_cids.id DESC LIMIT 1
LOOP
Copy link
Collaborator

@i-norden i-norden Sep 24, 2021 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Isn't this going to iterate over every entry for this leaf key below the provided block height (hash) before returning FALSE if the leaf was never removed below the provided height?

I think a more performant way to do this might be to simply check for a record with this state_leaf_key and node_type = 3 below the provided height, if it returns empty this contract was not deleted below the height and if such a record exists then it was (a contract can never be destroyed and then deployed to the same address/state_leaf_key, since the contract address is a function of the deploying account's address and the deploying account's nonce- which must increment each time).

Something like

SELECT exists(*) FROM eth.state_cids INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
WHERE state_leaf_key = key
AND block_number <= (SELECT block_number FROM eth.header_cids WHERE block_hash = hash)
AND node_type = 3

This type of query should, hopefully, be relatively fast now that we have a btree index on the node_type. Adding a ORDER BY block_number DESC might speed it up too for the case where a REMOVED node does exist since the REMOVED node would have to be the latest entry and that would force the query planner to search in descending order whereas, I think, otherwise it may not.

Copy link
Collaborator

@i-norden i-norden Sep 24, 2021 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Oh, an even better approach building on the train of thought at the end of the last comment: knowing that if a contract was destroyed there can never be entries for that leaf key again, we can search backwards from the provided height/hash and as soon as we find a node with that leaf key we can return TRUE if the node_type = 3 and FALSE if the node_type = 2.

So in a function we can do something like

SELECT node_type FROM eth.state_cids INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
WHERE state_leaf_key = key
AND block_number <= (SELECT block_number FROM eth.header_cids WHERE block_hash = hash)
ORDER BY block_number DESC
LIMIT 1

If the node_type we get is 3 we return TRUE, if its 2 (leaf node) we return FALSE.

Copy link
Collaborator

@i-norden i-norden Sep 24, 2021 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

And actually the knowledge about being unable to redeploy to the same address is irrelevant... even if we could redeploy, if the latest entry we see for a contract address below a height is REMOVED, then we know the contract is empty at the specified height (it would have to be empty until we saw a new LEAF entry (redeployment) at that address).

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Done

Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks, and just FYI, I am wrong and it is actually possible to deploy a contract to the same address using the CREATE2 opcode since it uses some supplied salt parameter instead of the account nonce. But in any case, that's irrelevant here as mentioned above.

IF rec.node_type = 3 THEN
RETURN TRUE;
END IF;
END LOOP;
RETURN FALSE;
END;
$$;
-- +goose StatementEnd


-- +goose Down
DROP FUNCTION was_state_leaf_removed;
26 changes: 26 additions & 0 deletions db/schema.sql
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -232,6 +232,32 @@ END
$$;


--
-- Name: was_state_leaf_removed(character varying, character varying); Type: FUNCTION; Schema: public; Owner: -
--

CREATE FUNCTION public.was_state_leaf_removed(key character varying, hash character varying) RETURNS boolean
LANGUAGE plpgsql
AS $$
DECLARE
rec RECORD;
BEGIN
FOR rec IN SELECT state_cids.node_type
FROM eth.state_cids
INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
WHERE state_leaf_key = key
AND block_number <= (SELECT block_number FROM eth.header_cids WHERE block_hash = hash)
ORDER BY state_cids.id DESC LIMIT 1
LOOP
IF rec.node_type = 3 THEN
RETURN TRUE;
END IF;
END LOOP;
RETURN FALSE;
END;
$$;


--
-- Name: was_state_removed(bytea, bigint, character varying); Type: FUNCTION; Schema: public; Owner: -
--
Expand Down