The synchronous 'postgres' crate is just a wrapper around the async
'tokio_postgres' crate. Some places were unnecessarily using the
re-exported NoTls and Error from the synchronous 'postgres' crate, even
though they were otherwise using the 'tokio_postgres' crate. Tidy up by
using the tokio_postgres types directly.
This removes workspace hack from all libs, not from any binaries. This
does not change the behaviour of the hack.
Running
```
cargo clean
cargo build --release --bin proxy
```
Before this change took 5m16s. After this change took 3m3s. This is
because this allows the build to be parallelisable much more.
This fixes all kinds of problems related to missing params,
like broken timestamps (due to `integer_datetimes`).
This solution is not ideal, but it will help. Meanwhile,
I'm going to dedicate some time to improving connection machinery.
Note that this **does not** fix problems with passing certain parameters
in a reverse direction, i.e. **from client to compute**. This is a
separate matter and will be dealt with in an upcoming PR.
Downsides are:
* We store all components of the config separately. `Url` stores them inside a single
`String` and a bunch of ints which point to different parts of the URL, which is
probably more efficient.
* It is now impossible to pass arbitrary connection strings to the configuration file,
one has to support all components explicitly. However, we never supported anything
except for `host:port` anyway.
Upsides are:
* This significantly restricts the space of possible connection strings, some of which
may be either invalid or unsupported. E.g. Postgres' connection strings may include
a bunch of parameters as query (e.g. `connect_timeout=`, `options=`). These are nether
validated by the current implementation, nor passed to the postgres client library,
Hence, storing separate fields expresses the intention better.
* The same connection configuration may be represented as a URL in multiple ways
(e.g. either `password=` in the query part or a standard URL password).
Now we have a single canonical way.
* Escaping is provided for `options=`.
Other possibilities considered:
* `newtype` with a `String` inside and some validation on creation.
This is more efficient, but harder to log for two reasons:
* Passwords should never end up in logs, so we have to somehow
* Escaped `options=` are harder to read, especially if URL-encoded,
and we use `options=` a lot.
