Refactor database utils into a class

[marcocastignoli]

See #1653

[kuzdogan]

Couple things:

I've noticed the schema env var was not documented in https://github.com/ethereum/sourcify/pull/1652/files Please add documentation for that including the env var and that it defaults to public.

I see we are no longer passing this.schema but we still pass the client in the Database functions. Can't we also remove that? node-postgres says: "In fact, pool.query delegates directly to client.query internally": https://node-postgres.com/features/queries unless we are using a transaction: https://node-postgres.com/apis/pool#poolquery Maybe we can move the client acquisition and handling all inside the Database and remove this from the DatabaseServices.

As a side note, turns out we could pass this.schema in the SQL query with pg-format: https://node-postgres.com/features/queries#parameterized-query The docs say it can be vulnerable for injection. In our case it should be fine because this.schema is not a user input, right? So we don't need to change that part of the code now.

Can you also check the "Prepared statements" docs if this is something we can take advantage of? https://node-postgres.com/features/queries#prepared-statements

[marcocastignoli]

I've noticed the schema env var was not documented in https://github.com/ethereum/sourcify/pull/1652/files Please add documentation for that including the env var and that it defaults to public.

Right

unless we are using a transaction

That's exactly why we are using it... "Maybe we can move the client acquisition and handling all inside the Database and remove this from the DatabaseServices." we can do this.

The docs say it can be vulnerable for injection. In our case it should be fine because this.schema is not a user input, right? So we don't need to change that part of the code now.

Yes, everything is passed via arguments except this.schema, I don't think we should care about this.schema being vulnerable because it's not passed by the users

Can you also check the "Prepared statements" docs if this is something we can take advantage of? https://node-postgres.com/features/queries#prepared-statements

Good idea

[marcocastignoli]

Maybe we can move the client acquisition and handling all inside the Database and remove this from the DatabaseServices

Actually regarding this it's not that straightforward because multiple transactions can be initialized from a Pool. We cannot remove the PoolClient parameter from the insert/updates functions because all of them need to be executed within the PoolClient that starter the transaction. The only improvement that we can do is the following

let client: PoolClient;
try {
  client = await this.database.beginTransaction();
  onchainCreationCodeInsertResult = await this.database.insertCode(
      client,
      databaseColumns.onchainCreationCode,
    );
} catch(e) {
    await this.database.rollbackTransaction(client!);
} finally {
    this.database.releaseClient(client!)
}

Personally I don't think this is much better than before... @kuzdogan wdyt?

[kuzdogan]

Ok yes, I see. Moving the client acquisition inside Database.ts doesn't seem possible.

[marcocastignoli]

@kuzdogan I added SOURCIFY_POSTGRES_SCHEMA and ALLIANCE_POSTGRES_SCHEMA in .env.dev.