gecko/tools/profiler/SaveProfileTask.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef PROFILER_SAVETASK_H_
#define PROFILER_SAVETASK_H_

#include "platform.h"
#include "nsThreadUtils.h"
#include "nsIXULRuntime.h"
#include "nsDirectoryServiceUtils.h"
#include "nsDirectoryServiceDefs.h"
#include "nsXULAppAPI.h"
#include "nsIJSRuntimeService.h"

#ifdef XP_WIN
 #include <windows.h>
 #define getpid GetCurrentProcessId
#else
 #include <unistd.h>
#endif

static JSBool
WriteCallback(const jschar *buf, uint32_t len, void *data)
{
  std::ofstream& stream = *static_cast<std::ofstream*>(data);
  nsAutoCString profile = NS_ConvertUTF16toUTF8(buf, len);
  stream << profile.Data();
  return JS_TRUE;
}

/**
 * This is an event used to save the profile on the main thread
 * to be sure that it is not being modified while saving.
 */
class SaveProfileTask : public nsRunnable {
public:
  SaveProfileTask() {}

  NS_IMETHOD Run() {
    // Get file path
#   if defined(SPS_PLAT_arm_android)
    nsCString tmpPath;
    tmpPath.AppendPrintf("/sdcard/profile_%i_%i.txt", XRE_GetProcessType(), getpid());
#   else
    nsCOMPtr<nsIFile> tmpFile;
    nsAutoCString tmpPath;
    if (NS_FAILED(NS_GetSpecialDirectory(NS_OS_TEMP_DIR, getter_AddRefs(tmpFile)))) {
      LOG("Failed to find temporary directory.");
      return NS_ERROR_FAILURE;
    }
    tmpPath.AppendPrintf("profile_%i_%i.txt", XRE_GetProcessType(), getpid());

    nsresult rv = tmpFile->AppendNative(tmpPath);
    if (NS_FAILED(rv))
      return rv;

    rv = tmpFile->GetNativePath(tmpPath);
    if (NS_FAILED(rv))
      return rv;
#   endif

    // Create a JSContext to run a JSObjectBuilder :(
    // Based on XPCShellEnvironment
    JSRuntime *rt;
    JSContext *cx;
    nsCOMPtr<nsIJSRuntimeService> rtsvc 
      = do_GetService("@mozilla.org/js/xpc/RuntimeService;1");
    if (!rtsvc || NS_FAILED(rtsvc->GetRuntime(&rt)) || !rt) {
      LOG("failed to get RuntimeService");
      return NS_ERROR_FAILURE;;
    }

    cx = JS_NewContext(rt, 8192);
    if (!cx) {
      LOG("Failed to get context");
      return NS_ERROR_FAILURE;
    }

    {
      JSAutoRequest ar(cx);
      static JSClass c = {
          "global", JSCLASS_GLOBAL_FLAGS,
          JS_PropertyStub, JS_PropertyStub, JS_PropertyStub, JS_StrictPropertyStub,
          JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub
      };
      JSObject *obj = JS_NewGlobalObject(cx, &c, NULL);

      std::ofstream stream;
      stream.open(tmpPath.get());
      if (stream.is_open()) {
        JSAutoCompartment autoComp(cx, obj);
        JSObject* profileObj = profiler_get_profile_jsobject(cx);
        jsval val = OBJECT_TO_JSVAL(profileObj);
        JS_Stringify(cx, &val, nullptr, JSVAL_NULL, WriteCallback, &stream);
        stream.close();
        LOGF("Saved to %s", tmpPath.get());
      } else {
        LOG("Fail to open profile log file.");
      }
    }
    JS_EndRequest(cx);
    JS_DestroyContext(cx);

    return NS_OK;
  }
};

#endif