log_manager.py (3605B)
1 # Copyright 2022 The Chromium Authors 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 """Reads log data from a device.""" 5 6 import os 7 import subprocess 8 import sys 9 10 from contextlib import AbstractContextManager 11 from typing import Iterable, Optional, TextIO 12 13 from common import run_continuous_ffx_command 14 from ffx_integration import run_symbolizer 15 16 17 class LogManager(AbstractContextManager): 18 """Handles opening and closing file streams for logging purposes.""" 19 20 def __init__(self, logs_dir: Optional[str]) -> None: 21 self._logs_dir = logs_dir 22 23 # A dictionary with the log file path as the key and a file stream as 24 # value. 25 self._log_files = {} 26 self._log_procs = [] 27 self._scoped_ffx_log = None 28 29 def __enter__(self): 30 return self 31 32 def is_logging_enabled(self) -> bool: 33 """Check whether logging is turned on.""" 34 35 return self._logs_dir is not None 36 37 def add_log_process(self, process: subprocess.Popen) -> None: 38 """Register a logging process to LogManager to be killed at LogManager 39 teardown.""" 40 41 self._log_procs.append(process) 42 43 def open_log_file(self, log_file_name: str) -> TextIO: 44 """Open a file stream with log_file_name in the logs directory.""" 45 46 assert self._logs_dir, 'Logging directory is not specified.' 47 log_file_path = os.path.join(self._logs_dir, log_file_name) 48 log_file = open(log_file_path, 'w', buffering=1) 49 self._log_files[log_file_path] = log_file 50 return log_file 51 52 def __exit__(self, exc_type, exc_value, traceback): 53 """Stop all active logging instances.""" 54 for proc in self._log_procs: 55 proc.kill() 56 for log in self._log_files.values(): 57 log.close() 58 return False 59 60 61 def start_system_log(log_manager: LogManager, 62 log_to_stdout: bool, 63 pkg_paths: Optional[Iterable[str]] = None, 64 log_args: Optional[Iterable[str]] = None, 65 target_id: Optional[str] = None) -> None: 66 """ 67 Start system logging. 68 69 Args: 70 log_manager: A LogManager class that manages the log file and process. 71 log_to_stdout: If set to True, print logs directly to stdout. 72 pkg_paths: Path to the packages 73 log_args: Arguments forwarded to `ffx log` command. 74 target_id: Specify a target to use. 75 """ 76 77 if not log_manager.is_logging_enabled() and not log_to_stdout: 78 return 79 symbol_paths = None 80 if pkg_paths: 81 symbol_paths = [] 82 83 # Locate debug symbols for each package. 84 for pkg_path in pkg_paths: 85 assert os.path.isfile(pkg_path), '%s does not exist' % pkg_path 86 symbol_paths.append( 87 os.path.join(os.path.dirname(pkg_path), 'ids.txt')) 88 89 if log_to_stdout: 90 system_log = sys.stdout 91 else: 92 system_log = log_manager.open_log_file('system_log') 93 log_cmd = ['log', '--symbolize', 'off', '--no-color'] 94 if log_args: 95 log_cmd.extend(log_args) 96 if symbol_paths: 97 log_proc = run_continuous_ffx_command(log_cmd, 98 target_id, 99 stdout=subprocess.PIPE) 100 log_manager.add_log_process(log_proc) 101 log_manager.add_log_process( 102 run_symbolizer(symbol_paths, log_proc.stdout, system_log)) 103 else: 104 log_manager.add_log_process( 105 run_continuous_ffx_command(log_cmd, target_id, stdout=system_log))