[DO NOT COMMIT] Refactor systrace to support new clock sync design

systrace/systrace/agents/ftrace_agent_unittest.py

-#!/usr/bin/env python
-
-# Copyright (c) 2015 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-import unittest
-
-from systrace import systrace
-from systrace.agents import ftrace_agent
-
-SYSTRACE_HOST_CMD_DEFAULT = ['./systrace.py', '--target=linux']
-FT_DIR = "/sys/kernel/debug/tracing/"
-FT_EVENT_DIR = FT_DIR + "events/"
-FT_TRACE_ON = FT_DIR + "tracing_on"
-FT_TRACE = FT_DIR + "trace"
-FT_BUFFER_SIZE = FT_DIR + "buffer_size_kb"
-
-
-def make_test_io_interface(permitted_files):
-  class TestIoImpl(object):
-
-    @staticmethod
-    def writeFile(path, data):
-      permitted_files[path] = data
-
-    @staticmethod
-    def readFile(path):
-      if path in permitted_files:
-        return permitted_files[path]
-      else:
-        return ""
-
-    @staticmethod
-    def haveWritePermissions(path):
-      return path in permitted_files
-  return TestIoImpl
-
-
-class FtraceAgentTest(unittest.TestCase):
-
-  def test_avail_categories(self):
-    # sched only has required events
-    permitted_files = {
-      FT_EVENT_DIR + "sched/sched_switch/enable": "0",
-      FT_EVENT_DIR + "sched/sched_wakeup/enable": "0"
-    }
-    io_interface = make_test_io_interface(permitted_files)
-    options, categories = systrace.parse_options(SYSTRACE_HOST_CMD_DEFAULT)
-    agent = ftrace_agent.FtraceAgent(options, categories, io_interface)
-    self.assertEqual(['sched'], agent._avail_categories())
-
-    # check for no available categories
-    permitted_files = {}
-    io_interface = make_test_io_interface(permitted_files)
-    options, categories = systrace.parse_options(SYSTRACE_HOST_CMD_DEFAULT)
-    agent = ftrace_agent.FtraceAgent(options, categories, io_interface)
-    self.assertEqual([], agent._avail_categories())
-
-    # block has some required, some optional events
-    permitted_files = {
-      FT_EVENT_DIR + "block/block_rq_complete/enable": "0",
-      FT_EVENT_DIR + "block/block_rq_issue/enable": "0"
-    }
-    io_interface = make_test_io_interface(permitted_files)
-    options, categories = systrace.parse_options(SYSTRACE_HOST_CMD_DEFAULT)
-    agent = ftrace_agent.FtraceAgent(options, categories, io_interface)
-    self.assertEqual(['disk'], agent._avail_categories())
-
-  def test_tracing_bootstrap(self):
-    workq_event_path = FT_EVENT_DIR + "workqueue/enable"
-    permitted_files = {
-      workq_event_path: "0",
-      FT_TRACE: "x"
-    }
-    io_interface = make_test_io_interface(permitted_files)
-    systrace_cmd = SYSTRACE_HOST_CMD_DEFAULT + ["workq"]
-    options, categories = systrace.parse_options(systrace_cmd)
-    agent = ftrace_agent.FtraceAgent(options, categories, io_interface)
-    self.assertEqual(['workq'], agent._avail_categories())
-
-    # confirm tracing is enabled, buffer is cleared
-    agent.start()
-    self.assertEqual(permitted_files[FT_TRACE_ON], "1")
-    self.assertEqual(permitted_files[FT_TRACE], "")
-
-    # fill in file with dummy contents
-    dummy_trace = "trace_contents"
-    permitted_files[FT_TRACE] = dummy_trace
-
-    # confirm tracing is disabled
-    agent.collect_result()
-    self.assertEqual(permitted_files[FT_TRACE_ON], "0")
-
-    # confirm trace is expected, and read from fs
-    self.assertTrue(agent.expect_trace())
-    self.assertEqual(agent.get_trace_data(), dummy_trace)
-
-    # confirm buffer size is reset to 1
-    self.assertEqual(permitted_files[FT_BUFFER_SIZE], "1")
-
-  def test_tracing_event_enable_disable(self):
-    # turn on irq tracing
-    ipi_event_path = FT_EVENT_DIR + "ipi/enable"
-    irq_event_path = FT_EVENT_DIR + "irq/enable"
-    permitted_files = {
-      ipi_event_path: "0",
-      irq_event_path: "0"
-    }
-    io_interface = make_test_io_interface(permitted_files)
-    systrace_cmd = SYSTRACE_HOST_CMD_DEFAULT + ["irq"]
-    options, categories = systrace.parse_options(systrace_cmd)
-    agent = ftrace_agent.FtraceAgent(options, categories, io_interface)
-    self.assertEqual(['irq'], agent._avail_categories())
-
-    # confirm all the event nodes are turned on during tracing
-    agent.start()
-    self.assertEqual(permitted_files[irq_event_path], "1")
-    self.assertEqual(permitted_files[ipi_event_path], "1")
-
-    # and then turned off when completed.
-    agent.collect_result()
-    self.assertEqual(permitted_files[irq_event_path], "0")
-    self.assertEqual(permitted_files[ipi_event_path], "0")
-
-  def test_trace_time(self):
-    systrace_cmd = SYSTRACE_HOST_CMD_DEFAULT + ['-t', '10']
-    options, categories = systrace.parse_options(systrace_cmd)
-    agent = ftrace_agent.FtraceAgent(options, categories)
-    self.assertEqual(agent._get_trace_time(), 10)
-
-  def test_buffer_size(self):
-    systrace_cmd = SYSTRACE_HOST_CMD_DEFAULT + ['-b', '16000']
-    options, categories = systrace.parse_options(systrace_cmd)
-    agent = ftrace_agent.FtraceAgent(options, categories)
-    self.assertEqual(agent._get_trace_buffer_size(), 16000)