Migrate to Swift Atomics

This patch was authored by @fatto and released by @0xTim.

Fix deprecation warnings from NIOAtomic and migrate any uses to swift-atomics

Add locking clause syntax to dialect

This patch was authored and released by @gwynne.

Leverages the new functionality in vapor/sql-kit#154 to provide the correct syntax for both shared and exclusive locking clauses in PostgreSQL.

1.7.0

What's Changed

• Ignore ParamaterStatus messages when handling response by @baarde in #218

Full Changelog: 1.6.0...1.7.0

Allow `backendKeyData` to be set

This patch was authored by @rausnitz and released by @0xTim.

This change provides access to the new functionality provided in this postgres-nio PR: vapor/postgres-nio#296. In short, apps can enable integration with Amazon RDS Proxy by setting requireBackendKeyData to false. See the postgres-nio PR for more details.

Drop support for Swift 5.2/5.3 + Yet another CI overhaul

This patch was authored and released by @gwynne.

This removes support for Swift 5.2 and Swift 5.3, making Swift 5.4 the earliest supported version as announced

Improve row decoding performance

This patch was authored and released by @gwynne.

• Leverage new APIs available in PostgresNIO to improve row decoding performance, making up for some speed regressions and then some, especially for queries with lots of result fields.
• Minor improvements to connection handling, also partially courtesy of improved APIs in PostgresNIO.

Note: No new APIs, but marked semver-minor due to requiring an updated minor release of postgres-nio.

Version bump postgres-nio dependency to prevent build error against swift-nio

This patch was authored by @eob and released by @gwynne.

Hi folks!

I'm not sure what this project's process for version-bumping is, but the current vapor/postgres-nio@1.4.0 dependency can't build against the more current swift-nio versions because of a duplicate addition of writeNullTerminatedString to ByteBuffer by extension:

/path/to/.build/checkouts/postgres-nio/Sources/PostgresNIO/New/Extensions/ByteBuffer+PSQL.swift:4:19: note: found this candidate
    mutating func writeNullTerminatedString(_ string: String) {
                  ^
/path/to/.build/checkouts/swift-nio/Sources/NIOCore/ByteBuffer-aux.swift:100:26: note: found this candidate
    public mutating func writeNullTerminatedString(_ string: String) -> Int { 

The postgres-nio project has since removed the duplicate method definition, so rolling forward the dependency to 1.7.2 (in this PR) fixes the build error.

Declare supported UNION features

This patch was authored and released by @gwynne.

Leverages the new dialect flags from vapor/sql-kit#144 to enable full UNION queries according to PostgreSQL's support.

The increased SQLKit version requirement makes this a semver-minor change.

Declare UPSERT support for PostgreSQL

This patch was authored and released by @gwynne.

semver-minor because the new SQLKit version requirement is a semver-minor bump.

Address issues in decoding data from the database

This patch was authored and released by @gwynne.

Basically this just cleans up PostgresDataDecoder quite a bit, along with the PostgresKit unit tests, such as they are. It's difficult to say whether this will have any performance impact (probably not).