* [Kotlin] Introduction to Kotlin Multiplaform
The first implementation of the Kotlin code generation was made years
ago at the time Kotlin Multiplaform was not stable and Kotlin is mostly
used on JVM-based targets. For this reason the generated code uses java
based runtime.
That design decision comes with many drawbacks, leaving the code
generated more java-like and making it impossible to use more advanced
features of the Kotlin language.
In this change we are adding two parts: A pure, multi-plaform, Kotlin
runtime and a new code generator to accompany it.
* [Kotlin] Remove scalar sign cast from code generation
Now that we have a new runtime the accepts unsigned types, we don't
need to code generate casting back and from signed scalars. This
MR removes this from both code generations and adds the necessary
API to the runtime.
* [Kotlin] Use offset on public API to represent buffer position
Currently, kotlin was following Java's approach of representing objects,
vectors, tables as "Int" (the position of it in the buffer). This change
replaces naked Int with Offset<T>, offering a type-safe API. So,
instead of
fun Table.createTable(b: FlatBufferBuilder, subTable: Int)
We will have
fun Table.createTable(b: FlatBufferBuilder, subTable: Offset<SubTable>)
Making impossible to accidentally switch parameters.
The performance should be similar to use Int as we are using value
class for Offset and ArrayOffset, which most of the time translate to
Int in the bytecode.
* [Kotlin] Add builder for tables
Add builder constructor to make create of table more ergonomic.
For example the movie sample for the test set could be written as:
Movie.createMovie(fbb,
mainCharacterType = Character_.MuLan,
mainCharacter = att) {
charactersType = charsType
this.characters = characters
}
instead of:
Movie.startMovie(fbb)
Movie.addMainCharacterType(fbb, Character_.MuLan)
Movie.addMainCharacter(fbb, att as Offset<Any>)
Movie.addCharactersType(fbb, charsType)
Movie.addCharacters(fbb, charsVec)
Movie.endMovie(fbb)
* [Kotlin] Move enum types to value class
Moving to flatbuffer enums to value class adds type safety for parameters
with minimum to no performance impact.
* [Kotlin] Simplify Union parameters to avoid naked casting
Just a small change on the APIs that receive union as parameters,
creating a typealias UnionOffset to avoid using Offset<Any>. To "convert"
an table offset to an union, one just call Offset.toUnion().
* [Kotlin] Apply clang-format on kotlin code generators
* [Kotlin] Update kotlin generator to follow official naming conventions
Updating directory, package and enum naming to follow Kotlin official
convention.
https://kotlinlang.org/docs/coding-conventions.html#naming-rules
* [Kotlin] Add fixes to improve performance
1 - Add benchmark comparing serialization between Java & Kotlin
2 - ReadWriteBuffer does not auto-grow (thus avoid check size in every op)
3 - Add specialized add functions on FlatBufferBuilder to avoid boxing
offsets.
4 - Remove a few Kotlin syntax sugar that generated performance penalties.
* [Kotlin] Remove builder from Kotlin KMP and add some optimizations
to avoid boxing of Offset classes
---------
Co-authored-by: Derek Bailey <derekbailey@google.com>
* [Android] fixed build after decomission of jcenter
JCenter[1] has been removed and now is failing android build. This
change updates the configuration to remove this and few other warnings.
1 - https://developer.android.com/studio/build/jcenter-migration
* [Kotlin] fix build for latest gradle version 8.0.1
---------
Co-authored-by: Derek Bailey <derekbailey@google.com>
* [Kotlin] Update gradle to 7.4.1 and simplify config files.
* [Kotlin] Add wrapper-validation-action to Kotlin Linux
* [Kotlin] Remove benchmark actions to reduce CI time
* [Kotlin] Move CI js test to Linux action, to increase Mac action speed
* [Kotlin] Generate gradle wrapper in order to be validate
Gradle wrapper from 3.3 to 4.0 are not verifiable because those files
were dynamically generated by Gradle in a non-reproducible way.
So they are now regenerated and will be checked using gitlab action:
gradle/wrapper-validation-action@v1
Kotlinx.benchmark project just abandoned bintray and moving to maven central,
removing the artifacts from bintray and causing missing dependencies in our build.
So we are updating the dependency to point to the new version on maven central.
More information in:
53ee45d0d9 (diff-b335630551682c19a781afebcf4d07bf978fb1f8ac04c6bf87428ed5106870f5)
on the current Java Implementation.
The code dependencies related to JVM were removed and the project is able to target all available platforms.
The only requirement to implement to fully support a target is to implement functions described in `ByteArray.kt`.
Right now the code support JVM and native targets. JS port still missing, but just be trivial to introduce.
Currently, only the `jvm` and `macosX64` targets are enabled until we figure out how to enable tests on all
platforms on CI.
A submodule called "benchmark" is also introduced. It contains a series
of benchmarks comparing Java and Kotlin implementations of FlexBuffers and the UTF8 API.
Finally, this commit does not contain the scripts necessary to publish the artifacts. This will
be introduced at a later stage once the team has an agreement on how to rollout Kotlin releases.
Paulo Pinheiro