Log forwarding support (#413)

Fixes #311

temporalio/bridge/Cargo.toml

@@ -8,13 +8,15 @@ name = "temporal_sdk_bridge"
 crate-type = ["cdylib"]
 
 [dependencies]
+futures = "0.3"
 log = "0.4"
 once_cell = "1.16.0"
 parking_lot = "0.12"
 prost = "0.11"
 prost-types = "0.11"
-pyo3 = { version = "0.18", features = ["extension-module", "abi3-py37"] }
-pyo3-asyncio = { version = "0.18", features = ["tokio-runtime"] }
+pyo3 = { version = "0.19", features = ["extension-module", "abi3-py37"] }
+pyo3-asyncio = { version = "0.19", features = ["tokio-runtime"] }
+pythonize = "0.19"
 temporal-client = { version = "0.1.0", path = "./sdk-core/client" }
 temporal-sdk-core = { version = "0.1.0", path = "./sdk-core/core", features = ["ephemeral-server"] }
 temporal-sdk-core-api = { version = "0.1.0", path = "./sdk-core/core-api" }

temporalio/bridge/runtime.py

@@ -6,7 +6,9 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Any, Mapping, Optional, Sequence, Type
+from typing import Any, Callable, Dict, Mapping, Optional, Sequence, Type
+
+from typing_extensions import Protocol
 
 import temporalio.bridge.temporal_sdk_bridge
 
@@ -29,13 +31,21 @@ def retrieve_buffered_metrics(self) -> Sequence[Any]:
         """Get buffered metrics."""
         return self._ref.retrieve_buffered_metrics()
 
+    def write_test_info_log(self, message: str, extra_data: str) -> None:
+        """Write a test core log at INFO level."""
+        self._ref.write_test_info_log(message, extra_data)
+
+    def write_test_debug_log(self, message: str, extra_data: str) -> None:
+        """Write a test core log at DEBUG level."""
+        self._ref.write_test_debug_log(message, extra_data)
+
 
 @dataclass(frozen=True)
 class LoggingConfig:
     """Python representation of the Rust struct for logging config."""
 
     filter: str
-    forward: bool
+    forward_to: Optional[Callable[[Sequence[BufferedLogEntry]], None]]
 
 
 @dataclass(frozen=True)
@@ -75,3 +85,42 @@ class TelemetryConfig:
 
     logging: Optional[LoggingConfig]
     metrics: Optional[MetricsConfig]
+
+
+# WARNING: This must match Rust runtime::BufferedLogEntry
+class BufferedLogEntry(Protocol):
+    """A buffered log entry."""
+
+    @property
+    def target(self) -> str:
+        """Target category for the log entry."""
+        ...
+
+    @property
+    def message(self) -> str:
+        """Log message."""
+        ...
+
+    @property
+    def time(self) -> float:
+        """Time as from ``time.time`` since Unix epoch."""
+        ...
+
+    @property
+    def level(self) -> int:
+        """Python log level, with trace as 9."""
+        ...
+
+    @property
+    def fields(self) -> Dict[str, Any]:
+        """Additional log entry fields.
+        Requesting this property performs a conversion from the internal
+        representation to the Python representation on every request. Therefore
+        callers should store the result instead of repeatedly calling.
+
+        Raises:
+            Exception: If the internal representation cannot be converted. This
+                should not happen and if it does it is considered a bug in the
+                SDK and should be reported.
+        """
+        ...

temporalio/bridge/src/lib.rs

@@ -26,6 +26,7 @@ fn temporal_sdk_bridge(py: Python, m: &PyModule) -> PyResult<()> {
 
     // Runtime stuff
     m.add_class::<runtime::RuntimeRef>()?;
+    m.add_class::<runtime::BufferedLogEntry>()?;
     m.add_function(wrap_pyfunction!(init_runtime, m)?)?;
     m.add_function(wrap_pyfunction!(raise_in_thread, m)?)?;