Rust的TraceLogging

tracelogging crate提供了一个简单高效的系统，用于在编译时已知事件模式的情况下记录TraceLogging事件。

这类似于Windows SDK中C/C++的TraceLoggingProvider.h实现。

use tracelogging as tlg;

// Define a static variable for the "MyCompany.MyComponent" provider.
// Note that provider variable is not pub so it is not visible outside the
// module. To share the variable with multiple modules, put the define_provider
// in the parent module, e.g. in lib.rs.
tlg::define_provider!(
    MY_PROVIDER,              // The static symbol to use for this provider.
    "MyCompany.MyComponent"); // The provider's name (string literal).

// Register the provider at module initialization. If you don't register (or if
// register fails) then MY_PROVIDER.enabled() will always return false, the
// write_event macro will be a no-op, and MY_PROVIDER.unregister() will be a no-op.
// Safety: MUST call MY_PROVIDER.unregister() before module unload.
unsafe { MY_PROVIDER.register(); }

// As necessary, call write_event to send events to ETW.
let field1_value = "String Value";
let field2_value = 42u32;
tlg::write_event!(
    MY_PROVIDER,                    // The provider to use for the event.
    "MyEventName",                  // The event's name (string literal).
    level(Warning),                 // Event's severity level.
    keyword(0x23),                  // Event category bits.
    str8("Field1", field1_value),   // Add a string field to the event.
    u32("Field2", &field2_value),   // Add an integer field to the event.
);

// Before module unload, unregister the provider.
MY_PROVIDER.unregister();

配置

此crate支持以下可配置功能

• etw：使用Windows ETW API来记录事件。如果未启用，所有日志操作都将为空操作。默认启用。
• kernel_mode：使用内核模式ETW API（例如EtwWriteTransfer）而不是用户模式ETW API（例如EventWriteTransfer）。
• macros：重新导出来自tracelogging_macros crate的define_provider!和write_event!宏。默认启用。

此外，此包仅当编译为Windows操作系统时才会记录事件。如果编译为非Windows操作系统，所有日志操作都将不执行。