**Stack 4/5** — base #4125. Part of the #4096 split; see #4096 for the
overall picture.
> Review after #4123, #4124 and #4125.
## What this is
The generic OPC UA to OpenUSD binding, scene materialization, and the
connector that drives a live stage from a running server.
## Contents
**Binding (Part 1)** — `Opc.Ua.OpenUsd` and `Opc.Ua.OpenUsd.Server`. A
server describes how its Variables drive USD prims, and serves the USD
layers it refers to as Part 5 files with a content digest.
**Scene materialization (Part 2)** — `Opc.Ua.OpenUsdScene` and
`Opc.Ua.OpenUsdScene.Server`, including the USDA writer.
- **Escaping fix**: string values, composition-arc references, variant
set names and selections, `doc` and prim names were all emitted
unescaped, so a value carrying a quote or a newline could author its own
layer syntax. Every emit site now goes through the escapers. The tests
assert the right property — not that the payload is absent (it
legitimately survives inside the escaped literal) but that no payload
becomes its own line of layer syntax.
**Client** — `Opc.Ua.OpenUsd.Client` streams live values into an
`IUsdSink`. `CompositeUsdSink` fans out to several sinks; the file sink
interpolates between server samples so motion is continuous rather than
stepped at the publishing interval.
**Connector** — `tools/Opc.Ua.OpenUsd.Connector` composes a stage from a
live server. The optional in-process viewport lives in a separate
assembly probed at run time, so the connector still runs — and says why
— when it is absent.
- **Fix**: the asset cache and PKI root moved off the shared temp
directory to `LocalApplicationData`.
**Sample** — `PumpDeviceIntegrationServer` gains an OpenUSD
representation of the pump.
## Notes for the reviewer
- The viewport assembly is net10.0-only. It is what exercises the
`Directory.Build.targets` change from 1/5: without it, the `net8.0` leg
of the per-TFM CI build fails with `CS0433` because the
`System.Threading.Lock` polyfill collides with the real type.
- `UsdAssetDelivery` hashes through `SHA256.Create` rather than the
static `HashData`, which does not exist on the net472/net48 targets this
test project also builds for.
## Validation
`dotnet build UA.slnx` — 0 errors, 0 warnings.
| Suite | Result |
| --- | --- |
| Opc.Ua.OpenUsd.Tests | 621 / 0 |
| Opc.Ua.Di.Tests | 321 / 0 |
---------
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 8cbb8cd0-f0cb-4ab0-bea2-6202fbf69485
This change adds a **new Opc.Ua.Types** nuget that contains core types that do not rely on generated code. Why the name? Because almost all code that was in the Types subfolder is part of it, and because we do not want to change the name of the Opc.Ua.Core nuget/assembly because code relies on it. Any other name like base or bootstrap felt out of place due to the current structure already defining the name "types". Key design is to depend on only a small set of libraries with limited transitive dependencies, that includes hashcode, logging.abstraction, and for non standard20 builds System.Text.Json (needed for localizedText mul parsing). Also, key is to support .netstd 2.0 to support source generators and to allow removal of EEC_SUPPORT defines by removing std2.0 from core and all libraries.
The changes are mostly restructuring, and thus small but contain some key changes:
- **Status code** struct now comes with a Symbol field, which is used to carry symbols in case the code is not generated. Currently (until generated) the status code struct must be manually created with a symbol or the ToSymbolicId extension must be called in the core project. Future will generate Status code constants just like NodeId that contain the symbol which also removes the reflection-based lookup. Several tests needed to be adjusted as they checked the status code symbol strings instead of the code.
- **Core identifiers** are copied as they were needed for code to compile, that includes attributes, a subset of status codes and node identifiers. These will never change so no need to generate them.
- The types folder now contains **encoders**, except for json which is still in core. Once the json encoder is ported to system.text.json it will also be included and Newtonsoft.Json dropped as dependency (-> #3329).
- Since types relies on **IOperationContext** and **ISystemContext**, and these export IUserIdentity which relies on crypto, these were split and extended in core with ISessionOperationContext and ISessionSystemContext, which mean changes to ServerSystemContext and introduction of SessionOperationContext and SessionSystemContext classes that extend OperationContext and SystemContext. Some runtime checks in the server are therefore needed to get at the session and auth info, however, those are anyway optional fields and are not on the critical paths, and thus a type check is in order (and was done in the past already, but against OperationContext class).
- **Manifest resources** are now split between Core (nodeset zip, some generated resoures) and Types (built in bsd/xsds). This needs to be revisited later if the bsd/xsd need to be regenerated during type generation. Note that the embedded resource names changed as a result. Since these are only used internally and do not constitute public API this feels reasonable vs duplication of resources in 2 assemblies.
- Reflection however now needs to load not just the built in **encodeables** from Opc.Ua.Types assembly, but also the generated encodeables from Opc.Ua.Core assembly. For this a new helper Utils method was added to get the Core assembly when linked against Opc.Ua.Core otherwise null.
- Whatever utils methods needed to be split out into the new Opc.Ua.Types assembly, they are now in **CoreUtils** static class in Opc.Ua.Types, and Utils.xxxx forwards to them to ensure minimal changes. Later we would want to obsolete them in favor of CoreUtils, although it might make sense to split them again into domain specific utilities, such as networking, files, etc
Marc Schier