feat(streams): WASM plugin support for Rust Arroyo adapter

examples/wasm_guest/.gitignore

@@ -0,0 +1,7 @@
+.venv/
+dist/
+src/wit_world/
+src/componentize_py_*/
+src/poll_loop.py
+src/componentize_py_types.py
+src/componentize_py_runtime.pyi

examples/wasm_guest/Makefile

@@ -0,0 +1,19 @@
+WIT_DIR := wit
+SRC_DIR := src
+DIST_DIR := dist
+WASM := $(DIST_DIR)/plugin.wasm
+
+.PHONY: bindings build clean
+
+bindings:
+	uv run componentize-py -d $(WIT_DIR) -w plugin bindings $(SRC_DIR)
+
+$(WASM): $(SRC_DIR)/guest_impl.py $(WIT_DIR)/processor.wit
+	@mkdir -p $(DIST_DIR)
+	$(MAKE) bindings
+	uv run componentize-py -d $(WIT_DIR) -w plugin componentize -p $(SRC_DIR) guest_impl -o $(WASM)
+
+build: $(WASM)
+
+clean:
+	rm -rf $(DIST_DIR) $(SRC_DIR)/wit_world $(SRC_DIR)/componentize_py_*

examples/wasm_guest/README.md

@@ -0,0 +1,21 @@
+# sentry_streams WASM guest example
+
+Sample [componentize-py](https://github.com/bytecodealliance/componentize-py) guest for the
+`sentry-streams:processor` WIT world used by `WasmProcessor` in the Rust Arroyo adapter.
+
+## Build
+
+```bash
+make build
+```
+
+Produces `dist/plugin.wasm`. The WIT contract lives in
+[`../../sentry_streams/wit/processor.wit`](../../sentry_streams/wit/processor.wit).
+
+## Guest behavior
+
+- `submit`: buffers the message for the next `poll`
+- `submit_watermark`: buffers the watermark for the next `poll`
+- `poll`: returns all buffered outputs (messages and watermarks), or `None` if empty
+
+Uses the host `log` import for tracing.

examples/wasm_guest/pyproject.toml

@@ -0,0 +1,11 @@
+[project]
+name = "sentry-streams-wasm-guest"
+version = "0.1.0"
+description = "Example componentize-py guest for sentry_streams WasmProcessor"
+requires-python = ">=3.11"
+dependencies = [
+    "componentize-py>=0.23.0",
+]
+
+[tool.uv]
+dev-dependencies = []

examples/wasm_guest/src/guest_impl.py

@@ -0,0 +1,31 @@
+"""Sample WASM processor guest: passthrough with host logging."""
+
+from __future__ import annotations
+
+from typing import List, Optional
+
+from wit_world.exports import Processor as ProcessorProtocol
+from wit_world.exports import processor as proc
+from wit_world.imports import log as host_log
+
+
+class Processor(ProcessorProtocol):
+    """Buffers submitted messages and watermarks; returns them on ``poll``."""
+
+    def __init__(self) -> None:
+        self._pending: List[proc.Output] = []
+
+    def submit(self, msg: proc.Message) -> None:
+        host_log.info(f"submit message len={len(msg.payload)}")
+        self._pending.append(proc.Output_Msg(value=msg))
+
+    def submit_watermark(self, wm: proc.Watermark) -> None:
+        host_log.info("submit_watermark")
+        self._pending.append(proc.Output_Wm(value=wm))
+
+    def poll(self) -> Optional[List[proc.Output]]:
+        if not self._pending:
+            return None
+        out = self._pending
+        self._pending = []
+        return out

examples/wasm_guest/wit/processor.wit

@@ -0,0 +1 @@
+../../../sentry_streams/wit/processor.wit