Remove PrepareStatementStateMachine #391
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Preparing a statement is a substep of running an extended query. For this reason we should reuse the ExtendedQueryStateMachine as much as we can. This patch removes the `PrepareStatementStateMachine` and uses the `ExtendedQueryStateMachine`. As a result of this we can simplify our code in lots of other places.
fabianfett
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Additional details and impacted files@@ Coverage Diff @@
## main #391 +/- ##
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- Coverage 46.02% 44.47% -1.55%
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Files 110 109 -1
Lines 8833 8724 -109
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- Hits 4065 3880 -185
- Misses 4768 4844 +76
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| @@ -4,7 +4,7 @@ struct ExtendedQueryStateMachine { | |||
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| private enum State { | |||
| case initialized(ExtendedQueryContext) | |||
| case parseDescribeBindExecuteSyncSent(ExtendedQueryContext) | |||
| case messagesSent(ExtendedQueryContext) | |||
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Is the name messageSent intentionally generic? When I read it my first reaction was "What message? Do we have different kind of messages flying around?"
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yes. it depends on what the internal QueryContext says.
If we run an unnamed query, we sent parse, describe, bind, execute & sync.
If we prepare a statement, we sent parse, describe & sync.
If we execute a statement, we sent bind, execute & sync.
| enum RowSource { | ||
| case stream(PSQLRowsDataSource) | ||
| enum Source { | ||
| case stream([RowDescription.Column], PSQLRowsDataSource) |
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What's the difference between RowDescription and [RowDescription.Column]?
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RowDescription is a wrapper around [RowDescription.Column]. A bit stupid. This makes sense if you look at how the PostgresBackendMessages are structured.
| bufferState = .streaming(buffer: .init(), dataSource: dataSource) | ||
| case .noRows(.success(let commandTag)): | ||
| self.rowDescription = [] |
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In other parts of the codebase (e.g. in PrepareStatementStateMachine) we allowed row description to be nil. Is there any semantic difference between a RowDescription? with a nil value and an empty [RowDescription.Column]?
Preparing a statement is a substep of running an extended query. For this reason we should reuse the ExtendedQueryStateMachine as much as we can. This patch removes the
PrepareStatementStateMachineand uses theExtendedQueryStateMachine. As a result of this we can simplify our code in lots of other places.