jni-java wrapper for pytorchScript api (#25084)
Summary:
TLDR; initial commit of android java-jni wrapper of pytorchscript c++ api
The main idea is to provide java interface for android developers to use pytorchscript modules.
java API tries to repeat semantic of c++ and python pytorchscript API
org.pytorch.Module (wrapper of torch::jit::script::Module)
- static Module load(String path)
- IValue forward(IValue... inputs)
- IValue runMethod(String methodName, IValue... inputs)
org.pytorch.Tensor (semantic of at::Tensor)
- newFloatTensor(long[] dims, float[] data)
- newFloatTensor(long[] dims, FloatBuffer data)
- newIntTensor(long[] dims, int[] data)
- newIntTensor(long[] dims, IntBuffer data)
- newByteTensor(long[] dims, byte[] data)
- newByteTensor(long[] dims, ByteBuffer data)
org.pytorch.IValue (semantic of at::IValue)
- static factory methods to create pytorchscript supported types
Examples of usage api could be found in PytorchInstrumentedTests.java:
Module module = Module.load(path);
IValue input = IValue.tensor(Tensor.newByteTensor(new long[]{1}, Tensor.allocateByteBuffer(1)));
IValue output = module.forward(input);
Tensor outputTensor = output.getTensor();
ThreadSafety:
Api is not thread safe, all synchronization must be done on caller side.
Mutability:
org.pytorch.Tensor buffer is DirectBuffer with native byte order, can be created with static factory methods specifing DirectBuffer.
At the moment org.pytorch.Tensor does not hold at::Tensor on jni side, it has: long[] dimensions, type, DirectByteBuffer blobData
Input tensors are mutable (can be modified and used for the next inference),
Uses values from buffer on the momment of Module#forward or Module#runMethod calls.
Buffers of input tensors is used directly by input at::Tensor
Output is copied from output at::Tensor and is immutable.
Dependencies:
Jni level is implemented with usage of fbjni library, that was developed in Facebook,
and was already used and opensourced in several opensource projects,
added to the repo as submodule from personal account to be able to switch submodule
when fbjni will be opensourced separately.
ghstack-source-id: b39c848359a70d717f2830a15265e4aa122279c0
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25084
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25105
Reviewed By: dreiss
Differential Revision: D16988107
Pulled By: IvanKobzarev
fbshipit-source-id: 41ca7c9869f8370b8504c2ef8a96047cc16516d4