Motivation:
The current state of Swift does not leave room for library evolution of enum types used for `Error`.
To avoid having to increment Major SemVer to add a new error case that might be needed to fix a bug, the `enum-like struct` idiom should be used.
Ideally this idiom will disappear, when Swift provides a way for Swift Packages to have a "library evolution" capability.
See https://forums.swift.org/t/extensible-enumerations-for-non-resilient-libraries/35900
Modifications:
- Change: `RedisClientError` to be struct with private enum value
Result:
Should new error cases be necessary to add, they can be in Minor SemVer releases, rather than Major SemVer.
Motivation:
The project was moved from Mordil/swift-redi-stack to Mordil/RediStack;
some URLs still point to swift-redi-stack.
Modifications:
- Update URLs in README and CHANGELOG
Result:
More accurate URLs; fewer warnings from GitLab :)
Motivation:
The TTL and PTTL commands are missing.
Modifications:
- Add TTL and PTTL commands
- Add integration tests
Result:
- Users can query the ttl in seconds or milliseconds of a key
Motivation:
The EXISTS command was missing.
Modifications:
- Add 'EXISTS' to basic commands
- Add integration tests
Result:
The existence of a key can be checked.
Motivation:
parseInteger did not distinguish between not having enough bytes for an
integer and not being able to parse the integer that was present. This
was a bit tricky for code internally, where some call sites had extra
code looking for spooky action at a distance in order to determine if
the integer failed to parse.
This is unnecessary: parseInteger is sufficiently aware of what's going
on to address this problem itself.
Modifications:
- Added a new parser error (acceptable as we haven't tagged 1.0 yet).
- Throw it from parseInteger if the integer is invalid.
Result:
parseInteger clearly communicates if the integer failed to parse.
Motivation:
ByteBufferView is not zero indexed, but parseSimpleString assumes it is.
Modifications:
- Correctly compute on the distance between two indices.
- New, somewhat contrived, test case.
Result:
No functional change: because RediStack assumes the remote peer will
always correctly terminate with /r/n, there is no point at which this
code could misbehave in the current implementation. However, with small
changes it is possible to trigger it, as the new test demonstrates.
Motivation:
When we only want the first byte, rather than create temporary
intermediate arrays we can just ask NIO to give us the first byte. This
avoids unnecessary allocations.
Modifications:
- Replace `readBytes(length: 1).first` with `readInteger(as:
UInt8.self)`
Results:
11% performance improvement in load testing due to reduced allocator
pressure on the hot path.
Motivation:
When attempting to locate a single byte, creating a transient
ByteBufferView is an excessively heavyweight operation compared to a
simple getInteger. In particular, a BBV requires retain/release
operations to enforce the CoW invariants, as well as requires jumps
through substantial amounts of generic Collection code. While this can
be specialized, so can getInteger, and getInteger has much less code in
the way to cause costs.
Modifications:
- Replace temporary view creation with getInteger.
Results:
5% performance improvement on raw throughput tests.
Motivation:
`RESPValue` exposes a fair amount of complexity on how to intialize a single instance with the various overloads.
This aims to simplify the complexity for developers by providing a single initializer and relying on `RESPValueConvertible` to handle the complexities.
In addition, the Swift complier synthesizes a lot of default conformances that `RedisKey` has manually written, which is just unnecessary code.
Modifications:
- Rename: `RESPValue.init(_:)` to `RESPValue.init(from:)`
- Change: `RESPValue.init` `String?` and `FixedWidthInteger` overloads from `public` to `internal`
- Remove: Unnecessary code for various protocol conformances for `RedisKey`
Result:
Developers should have a direct and guided way of making instances of `RESPValue`
Motivation:
It was noticed that many of the commands are cumbersome to use with boilerplate type casting for each use that can be simplified within the library
by doing type conversion before returning the value to an end user.
Modifications:
Many APIs that return a `RESPValue` now have overloads to provide a `RESPValueConvertible` type that the value will be turned into before being returned.
For a few APIs that returned `RESPValue`, they did so as an Optional. Those APIs have been changed to always provide a `RESPValue` and return `.null` in cases where `nil` was returned.
In addition, the `@inlinable` attribute has been removed from any non-generic command API.
Result:
Developers should have less code boilerplate for turning values from `RESPValue` to their desired type with many commands.
Motivation:
SwiftPM as of Swift 5.2 introduces a new package dependency graph and package description that makes the current naming of RediStack awkward to pull in.
Modifications:
- Change: Package.name to be "RediStack"
The git repo will be renamed to "mordil/redistack" in addition to this change.
Result:
Fixes#72 and makes it seamless to pull in RediStack as a Swift package dependency.
Nathan Harris
George Barnett
Cory Benfield