With the changes introduced on #6729, #6671, #6658 it seems that using java
compiler version 8 is no longer possible. We are adjusting our CI build for
Kotlin to use Java 11 as compiler, while still emiting 1.8 bytecode.
The Kotlin CI action is also being breakdown into two: Mac & Linux.
Kotlin mac will test ios & mac builds while Linux will test js and JVM.
This change will improve build times for Kotlin on CI, which is currently
taking long times.
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.
Android build was dated, using the Android.mk approach. Current
project configuration on Android encourages the usage of CMake, so we
are updating the android project as an example on how to use either the
Java/Kotlin generate code or the native C++ one.
* Add test for optional enums in Kotlin
* Rename optional_scalars2.fbs into optional_scalars.fbs
Also updated all references in the project to point to
"optional_scalars.fbs" instead of "optional_scalars2.fbs".
Added a method FlatBufferBuilder::createSharedString that
enable string sharing for building messages on java.
The shared pool will only contains strings inserted by
this methods.
Kotlin code generation was producing wrong logic for accessors
of vector of union elements. This was shadowed by the fact[1] that asserts
in Kotlin are silently ignored unless the flag "-ea" is passed to the JVM.
The tests are also updated to enable asserts.
1 - https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/assert.html
The original implementation of map access is very naive:
- Encode String to UTF8 byte[]
- Creates a new KeyVector
- Performs a binary search to find the key
- return value
So every access to the Map there was useless allocations of Keys and KeyVector
and complete encoding of the search key, which for most comparisons would be wasteful.
This changes completely removes the use of KeyVector and compute the key
positions on the spot. Besides that, it compares keys codepoint-by-codepoint,
avoiding unnecessary allocations and reducing encoding for most cases.
Some benchmarks result in a 2.75x speedup.
To read and build flexbuffers on Java, one needs to wrap the data
using ByteBuffer. But for the common case of having ByteBuffers
backed by arrays, accessing from a ByteBuffer might be inefficient.
So this change introduces two interfaces: ReadBuf and ReadWriteBuf.
It allows one to read and writes data directly on an array. It also allow
other buffer implementations to be used with flexbuffers.
Another change is that FlexBuffersBuilder backed by array allows
the buffer to grow with the increase of the message size. Something
that could not be done with ByteBuffer.
* [Java][FlexBuffers] Deprecate typed vector strings due to design flaw
It will still be possible to read buffers with this type, but the
elements will be treated as FBT_KEY and will be read as null-terminated
string.
Trying to build a vector of strings as typed will throw an exception.
More information on https://github.com/google/flatbuffers/issues/5627
Also, fix another bug on strings, where long strings were not properly
aligned.
* [Java][FlexBuffers] Make FBT_VECTOR_STRING_DEPRECATED considered typed.
The logic for FlexBuffers.isVectorType() was changed
to not consider FBT_VECTOR_STRING_DEPRECATED a typed
vector, but that can lead to missinterpretation for
existing serialized data. So we are reverting.
Kolin uses java library as dependency, which changed the way it access union vector recently
(e365c502ff).
This changes updates kotlin code generation to match Java's changes.
The condition was unnecessary and Detected by
PVS-Studio
V560 [CWE-571] A part of conditional expression is always true: !opts.use_flexbuffers. flatc.cpp 438
Empty objects that inherit from Sized would try to access internal
ByteBuffer when Sized::size was called. So we add a single byte in
the empty buffer, so when size() is called it would return 0
The real position of a string is calculated by using the indirect() method,
which should be based on parentWidth and not byteWidth, as it was implemented.
We are also fixing the flag BUILDER_FLAG_SHARE_STRINGS on FlexBuffersBuilder
that was set as '1', same value as BUILDER_FLAG_SHARE_KEYS.
* [FlexBuffers][Java] Implementation of FlexBuffers API
This is the initial attemp to implement FlexBuffer on Java.
There is some limitations as compared to the C++ implementation:
1 - No mutations implemented yet
2 - Does not parse from json
Also, this initial implementation is not focused and performance, but
get the basics write. So there is many opportunities for optimization, for instance,
remove all enums, return CharSequence instead of Strings and object pooling.
* [FlexBuffers][Java] Optimizations and simplification of the Builder API.
This change removes BitWidth enum in favor of static ints. Also
make all "reads" APIs closer to C++ implementation (try to cast or convert
as much as possible, assuming user knows what he is doing). Finally,
we remove the helper classes for building vectors and maps.
There is no official benchmarks, but the unit tests are running in less
than 50% for previous runs, which mean those optimizations are worth it.
* [FlexBuffers][Java] Fix Reference::asString behavior
There was a incorrect assumption that strings would be null-terminated, which
could lead to truncated strings. S now it relies size instead of null-termination.
Other minor improvements
* [Kotlin] Add kotlin generate code for tests and add
kotlin test to TestAll.sh
* [Kotlin] Add Kotlin generator
This change adds support for generating Kotlin classes.
The approach of this generator is to keep it as close
as possible to the java generator for now, in order
to keep the change simple.
It uses the already implemented java runtime,
so we don't support cross-platform nor js Kotlin yet.
Kotlin tests are just a copy of the java tests.
* Add optional ident support for CodeWriter
Identation is important for some languages and
different projects have different ways of ident
code, e.g. tabs vs spaces, so we are adding optional
support on CodeWriter for identation.
* [Kotlin] Add Documentation for Kotlin
* [Kotlin] Modify generated code to use experimental Unsigned types.
Paulo Pinheiro