#Tracing

本页面介绍 Lynx DevTool 支持的 Tracing CDP domain。

#概览

• 作用域：global-and-instance
• CDP domain：Tracing

#标准方法

• Tracing.end
• Tracing.start

#Lynx 扩展

#Tracing.getStartupTracingConfig

Returns the stored startup tracing configuration string.

• Origin: lynx-extension
• Source: devtool/lynx_devtool/agent/domain_agent/inspector_tracing_agent.cc

#参数

无参数。

#返回字段

#备注

• Dispatches through LynxGlobalDevToolMediator on the global DevTool task runner.
• Reads GlobalDevToolPlatformFacade::GetTraceController()->GetStartupTracingConfig().
• The trace controller stores the configuration as an opaque string. Lynx does not parse or validate it in this CDP method.
• Returns a CDP error with message Failed to get trace controller when no trace controller is available.
• If the global mediator has no default task runner, the current handler does not send an explicit CDP response.

#示例

Read startup tracing config

Request:

{
  "id": 1,
  "method": "Tracing.getStartupTracingConfig"
}

Response:

{
  "id": 1,
  "result": {
    "config": "{\"traceConfig\":{\"includedCategories\":[\"*\"]}}"
  }
}

#Tracing.getStartupTracingFile

Emits a Tracing.tracingComplete event for the stored startup tracing file.

• Origin: lynx-extension
• Source: devtool/lynx_devtool/agent/domain_agent/inspector_tracing_agent.cc

#参数

无参数。

#返回字段

无返回字段。

#事件

• Tracing.tracingComplete

#备注

• Dispatches through LynxGlobalDevToolMediator on the global DevTool task runner.
• Reads GlobalDevToolPlatformFacade::GetTraceController()->GetStartupTracingFilePath().
• When a startup tracing file path exists, the method first sends an empty OK response and then sends Tracing.tracingComplete.
• Tracing.tracingComplete.params.stream is a FileStream handle encoded as a string. Read it with IO.read and close it with IO.close.
• Tracing.tracingComplete.params.dataLossOccurred is true when the file cannot be opened as a stream.
• Tracing.tracingComplete.params.isStartupTracing is true for this method.
• Returns a CDP error with message Startup Tracing is running when no file is available because tracing is still active.
• Returns a CDP error with message Failed to get startup tracing file when no file is available and tracing is not active.
• Returns a CDP error with message Failed to get trace controller when no trace controller is available.

#示例

Request the startup tracing file

Request:

{
  "id": 1,
  "method": "Tracing.getStartupTracingFile"
}

Response:

{
  "id": 1,
  "result": {}
}

Startup tracing complete event

Response:

{
  "method": "Tracing.tracingComplete",
  "params": {
    "dataLossOccurred": false,
    "stream": "1",
    "isStartupTracing": true
  }
}

#Tracing.setStartupTracingConfig

Stores an opaque startup tracing configuration string.

• Origin: lynx-extension
• Source: devtool/lynx_devtool/agent/domain_agent/inspector_tracing_agent.cc

#参数

#返回字段

无返回字段。

#备注

• Dispatches through LynxGlobalDevToolMediator on the global DevTool task runner.
• Writes params.config to GlobalDevToolPlatformFacade::GetTraceController()->SetStartupTracingConfig().
• The trace controller stores the configuration as an opaque string. Lynx does not parse or validate it in this CDP method.
• Returns an empty OK response when params.config is present.
• Returns a CDP error with message Set Startup Tracing config is null when params.config is missing.
• Returns a CDP error with message Failed to get trace controller when no trace controller is available.
• If the global mediator has no default task runner, the current handler does not send an explicit CDP response.

#示例

Store startup tracing config

Request:

{
  "id": 1,
  "method": "Tracing.setStartupTracingConfig",
  "params": {
    "config": "{\"traceConfig\":{\"includedCategories\":[\"*\"]}}"
  }
}

Response:

{
  "id": 1,
  "result": {}
}

#Tracing.takeVMSnapshotByUrl

为指定 URL 对应页面的 MTS 或 BTS 虚拟机创建快照。

• 来源类型：lynx-extension
• 源码：devtool/lynx_devtool/agent/domain_agent/inspector_tracing_agent.cc

#参数

#返回字段

无返回字段。

#备注

• 通过 LynxGlobalDevToolMediator 在全局 DevTool 任务执行器上分发。
• tracing 会话处于活动状态，且提供了 params.url 和 params.type 时，返回空的成功响应。
• 缺少 url 或 type 参数时，返回 CDP 错误，消息为 Argument error。
• tracing 会话未处于活动状态时，返回 CDP 错误，消息为 Tracing is not started。
• 如果全局 mediator 没有默认任务执行器，当前处理函数不会发送显式的 CDP 响应。

#示例

为指定 URL 对应的页面创建快照

请求：

{
  "id": 1,
  "method": "Tracing.takeVMSnapshotByUrl",
  "params": {
    "config": "{\"url\":\"https://xxx/template.js\",\"type\":\"bts\"}"
  }
}

响应：

{
  "id": 1,
  "result": {}
}