A kotlin multiplatform library that allows you to allocate and modify byte[] natively using an API similar to Java's ByteBuffer API.
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Allocating and managing a chunk of memory can be slightly different based on each platform. This project aims to make it easier to manage buffers in a cross platform way using kotlin multiplatform. This was originally created as a side project for a kotlin multiplatform mqtt data sync solution.
Implementation notes:
JVM+Androiddelegate to direct ByteBuffers to avoid memory copies when possible.- Apple targets use NSData or NSMutableData
JStargets use Uint8Array.Nativeplatforms use standard byte arrays to manage memory.
- None
- All Kotlin Multiplatform supported OS's.
| Platform | Wrapped Type |
|---|---|
JVM 1.8 |
ByteBuffer |
Node.js |
Uint8Array including SharedArrayBuffer |
Browser (Chrome) |
Uint8Array including SharedArrayBuffer |
Android |
ByteBuffer including SharedMemory |
iOS |
NSData |
WatchOS |
NSData |
TvOS |
NSData |
MacOS |
NSData |
Linux X64 |
kotlin ByteArray |
Windows X64 |
TODO |
val buffer = PlatformBuffer.allocate(
byteSize,
zone = AllocationZone.Direct,
byteOrder = ByteOrder.BIG_ENDIAN
)val byteArray = byteArrayOf(1, 2, 3, 4, 5)
val buffer = PlatformBuffer.wrap(byteArray, byteOrder = ByteOrder.BIG_ENDIAN)Allocation zones allow you to change where the buffer is allocated.
AllocationZone.Custom-> Allows you to override the underlying buffer. This can be helpful for memory mapped structures.AllocationZone.Heap-> On JVM platforms, allocates a HeapByteBuffer, otherwise a native byte arrayAllocationZone.Direct-> On JVM platforms, allocates a DirectByteBuffer, otherwise a native byte arrayAllocationZone.SharedMemory-> On JS Platforms this will populate thesharedArrayBufferparameter inJsBuffer. On API 27+ it allocates a Shared Memory instance, otherwise will pipe the data during parcel using ParcelFileDescriptor and java.nio.Channel api. ForJSplatforms it will allocate aSharedArrayBuffer. If the proper security requirements are not set, it will fallback to a standardArrayBuffer.
Android: All
JvmBuffers areParcelable. To avoid extra memory copies when using IPC, always chooseAllocationZone.SharedMemory.
Browser JS: To enable SharedArrayBuffer, add the appropriate headers for the JS server in a gradle project by adding any file to a directory
webpack.config.dnext to thesrcdirectory containing:if (config.devServer != null) { config.devServer.headers = { "Cross-Origin-Opener-Policy": "same-origin", "Cross-Origin-Embedder-Policy": "require-corp" } }
Byte order defaults to big endian but can be specified when creating the buffer
with ByteOrder.BIG_ENDIAN
or ByteOrder.LITTLE_ENDIAN
The byte order of a buffer can be checked with buffer.byteOrder
val buffer: WriteBuffer
// write signed byte
buffer.writeByte(5.toByte())
// write unsigned byte
buffer.writeUByte(5.toUByte())
// write short
buffer.writeShort(5.toShort())
// write unsigned short
buffer.writeUShort(5.toUShort())
// write int
buffer.writeInt(5)
// write unsigned int
buffer.writeUInt(5.toUInt())
// write long
buffer.writeLong(5L)
// write unsigned long
buffer.writeULong(5uL)
// write float
buffer.writeFloat(123.456f)
// write double
buffer.writeDouble(123.456)
// write text
buffer.writeString("5", Charset.UTF8)
// copy buffer into this one
buffer.write(otherBuffer)
// write byte array
buffer.writeBytes(byteArrayOf(1, 2, 3, 4))
// write partial byte array
buffer.writeBytes(byteArrayOf(1, 2, 3, 4, 5), offset, length)val buffer: WriteBuffer
// set signed byte
buffer[index] = 5.toByte()
// set unsigned byte
buffer[index] = 5.toUByte()
// set short
buffer[index] = 5.toByte()
// set unsigned short
buffer[index] = 5.toUShort()
// set int
buffer[index] = 5
// set unsigned int
buffer[index] = 5.toUInt()
// set long
buffer[index] = 5L
// set unsigned long
buffer[index] = 5uL
// set float
buffer[index] = 123.456f
// set double
buffer[index] = 123.456val buffer: ReadBuffer
// read signed byte
val b = buffer.readByte()
// read unsigned byte
val uByte = buffer.readUnsignedByte()
// read short
val short = buffer.readShort()
// read unsigned short
val uShort = buffer.readUnsignedShort()
// read int
val intValue = buffer.readInt()
// read unsigned int
val uIntValue = buffer.readUnsignedInt()
// read long
val longValue = buffer.readLong()
// read unsigned long
val uLongValue = buffer.readUnsignedLong()
// read float
val float = buffer.readFloat()
// read double
val double = buffer.readDouble()
// read text
val string = buffer.readUtf8(numOfBytesToRead)
// read byte array
val byteArray = buffer.readByteArray(numOfBytesToRead)
// read a shared subsequence read buffer (changes to the original reflect here)
val readBuffer = buffer.readBytes(numOfBytesForBuffer)val buffer: ReadBuffer
// get signed byte
val b = buffer.get(index) // or buffer[index]
// get unsigned byte
val uByte = buffer.getUnsignedByte(index)
// get short
val short = buffer.getShort(index)
// get unsigned short
val uShort = buffer.getUnsignedShort(index)
// get int
val intValue = buffer.getInt(index)
// get unsigned int
val uIntValue = buffer.getUnsignedInt(index)
// get long
val longValue = buffer.getLong(index)
// get unsigned long
val uLongValue = buffer.getUnsignedLong(index)
// get float
val float = buffer.getFloat(index)
// get double
val double = buffer.getDouble(index)
// slice the buffer without adjusting the position or limit (changes to the original reflect here)
val slicedBuffer = buffer.slice()git clone [email protected]:DitchOoM/buffer.git- Open cloned directory with Intellij IDEA.
- Be sure to open with gradle
See the open issues for a list of proposed features ( and known issues).
Contributions are what make the open source community such an amazing place to be learn, inspire, and create. Any contributions you make are greatly appreciated.
- Fork the Project
- Create your Feature Branch (
git checkout -b feature/AmazingFeature) - Commit your Changes (
git commit -m 'Add some AmazingFeature') - Push to the Branch (
git push origin feature/AmazingFeature) - Open a Pull Request
Distributed under the Apache 2.0 License. See LICENSE for more information.