### Description
This PR rewrite the backend resolve logic to support specifying multiple
EPs.
#### Backend
The first version of ONNX Runtime Web actually carried some existing
code from [ONNX.js](https://github.com/microsoft/onnxjs), which includes
the "backend" concept. The original "backend" in ONNX.js is designed in
a way assuming there is only one backend from user's backend hint list
will be used. For example, in ONNX.js, if user specify a backend hint as
`['webgl', 'wasm']`, ONNX.js will first try to use WebGL backend - if it
loads successfully (the browser supports webgl), then "webgl" backend
will be used and "wasm" will be ignored; otherwise, "webgl" will be
ignored and try to load "wasm" backend.
In short: only one backend will be used when initializing a session.
#### Execution Provider
Execution Provider, or EP, in ONNX Runtime is a different concept. One
of the differences is that users are allow to specify multiple EPs, and
if one does not support a particular kernel, it can fallback to other
EP. This is a very common case when using a GPU EP in ONNX Runtime.
#### Current Status: Backend v.s. EP
Because of the history reasons mentioned above, the current status is
quite confusing. There are **real backend**s, which means it's different
implementation in code; and there are **backend hint**s, which are used
as string names for backend hint; and there are **EP**s of the ONNX
Runtime concepts.
currently there are only 2 **backend**s in our code base: The "onnxjs
backend", and the "wasm backend". The "onnxjs backend" currently only
powers backend hint "webgl", which go into the old onnx.js code path.
All other backend hints including "wasm", "cpu"(alias to wasm), "webgpu"
and "webnn" are all powered by "wasm backend".
And because ORT Web treat "backend" as an internal concept and want to
align with ONNX Runtime, so those names of backend hints are becoming EP
names.
The following table shows today's status:
| Execution Provider Name (public) / Backend Hint (internal) | Backend |
EP in ORT
| -------- | ------- | ------- |
| "wasm"/"cpu" | WasmBackend | CPU EP
| "webgl" | OnnxjsBackend | \* technically not an EP
| "webgpu" | WasmBackend | JSEP
| "webnn" | WasmBackend | WebNN EP
#### Problem
While the API allows to specify multiple EPs, the backend resolving only
allows one backend. This causes issues when user specify multiple EP
names in session options, the backend resolve behavior and EP
registration behavior is inconsistent. Specifically, in this issue:
https://github.com/microsoft/onnxruntime/issues/15796#issuecomment-1925363908:
EP list `['webgpu', 'wasm']` on a browser without WebGPU support
resolves to 'wasm' backend, but the full EP list is passed in session
options, so JSEP is still enabled, causing the runtime error.
#### Solution
Since we still need WebGL backend, we cannot totally remove the backend
register/resolve system. In this PR I made the following changes:
- initialize every backend from the EP list, instead of only do that for
the first successful one.
- for the first resolved backend, filter all EP using the exact same
backend. Remove all EPs not using this backend from session options
- for every explicitly specified EP, if it's removed, show a warning
message in console
### Description
Following the design document:
* Added CreateTrainingSessionHandler to the Backend interface
* All existing Backend implementations throw an error for the new method
createTrainingSessionHandler
* Created TrainingSession namespace, interface, and
TrainingSessionFactory interface
* Created TrainingSessionImpl class implementation
As methods are implemented, the TrainingSession interface will be added
to or modified.
### Motivation and Context
Adding the public-facing interfaces to the onnxruntime-common package is
one of the first steps to support ORT training for web bindings.
---------
Co-authored-by: Caroline Zhu <carolinezhu@microsoft.com>
### Description
This PR contains a few changes in /js/common/ to support a coming PR for
a full implementation of webgpu IO binding.
- allows pass-through if value is already a Tensor instance in return
value of `handler.run()` called by `InferenceSession.run()`
(inference-session-impl.ts). Specifically, onnxruntime-node and
onnxruntime-react-native uses native bindings to generate a Tensor-like
object so we need to create a real Tensor instance here; for
onnxruntime-web the return value is already a Tensor instance.
- adds new types for GPU buffer supported types: `'float32'|'int32'` ->
`'float32'|'float16'|'int32'|'int64'|'uint32'|'bool'`
- exposes types `GpuBufferDataTypes` together with `CpuPinnedDataTypes`
and `TextureDataTypes` as exported
### Description
This change adds a new instance function (method) to type
`InferenceSession` to allow users to manually release an inference
session instance.
#16131 depends on this change to work correctly.
* working on re-organizing js code for ortweb
* remove dup files
* move folder
* fix common references
* fix common es5
* add webpack to common
* split interfact/impl
* use cjs for node
* add npmignore for common
* update sourcemap config for common
* update node
* adjust folder/path in CI and build
* update folder
* nit: readme
* add bundle for dev
* correct nodejs paths
* enable ORT_API_MANUAL_INIT
* set name for umd library
* correct name for commonjs export
* add priority into registerBackend()
* fix npm ci pwd
* update eslintrc
* revise code
* revert package-lock lockfileVersion 2->1
* update prebuild
* resolve comments
* update document
* revise eslint config
* update eslint for typescript rules
* revert changes by mistake in backend.ts
* add env
* resolve comments
