Class: OpenC3::LogWriter

Inherits:
Object show all
Defined in:
lib/openc3/logs/log_writer.rb

Overview

Creates a log. Can automatically cycle the log based on an elasped time period or when the log file reaches a predefined size.

Direct Known Subclasses

PacketLogWriter, TextLogWriter

Constant Summary collapse

CYCLE_TIME_INTERVAL =

The cycle time interval. Cycle times are only checked at this level of granularity.

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@@mutex =

Mutex protecting class variables

Mutex.new
@@instances =

Array of instances used to keep track of cycling logs

[]
@@cycle_thread =

Thread used to cycle logs across all log writers

nil
@@cycle_sleeper =

Sleeper used to delay cycle thread

nil

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(remote_log_directory, logging_enabled = true, cycle_time = nil, cycle_size = 1000000000, cycle_hour = nil, cycle_minute = nil, redis_topic: nil) ⇒ LogWriter

Returns a new instance of LogWriter.

Parameters:

  • remote_log_directory (String) —

    The s3 path to store the log files

  • logging_enabled (Boolean) (defaults to: true) —

    Whether to start with logging enabled

  • cycle_time (Integer) (defaults to: nil) —

    The amount of time in seconds before creating a new log file. This can be combined with cycle_size but is better used independently.

  • cycle_size (Integer) (defaults to: 1000000000) —

    The size in bytes before creating a new log file. This can be combined with cycle_time but is better used independently.

  • cycle_hour (Integer) (defaults to: nil) —

    The time at which to cycle the log. Combined with cycle_minute to cycle the log daily at the specified time. If nil, the log will be cycled hourly at the specified cycle_minute.

  • cycle_minute (Integer) (defaults to: nil) —

    The time at which to cycle the log. See cycle_hour for more information.

  • redis_topic (String) (defaults to: nil) —

    The key of the Redis stream to trim when files are moved to S3



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# File 'lib/openc3/logs/log_writer.rb', line 86

def initialize(
  remote_log_directory,
  logging_enabled = true,
  cycle_time = nil,
  cycle_size = 1000000000,
  cycle_hour = nil,
  cycle_minute = nil,
  redis_topic: nil
)
  @remote_log_directory = remote_log_directory
  @logging_enabled = ConfigParser.handle_true_false(logging_enabled)
  @cycle_time = ConfigParser.handle_nil(cycle_time)
  if @cycle_time
    @cycle_time = Integer(@cycle_time)
    raise "cycle_time must be >= #{CYCLE_TIME_INTERVAL}" if @cycle_time < CYCLE_TIME_INTERVAL
  end
  @cycle_size = ConfigParser.handle_nil(cycle_size)
  @cycle_size = Integer(@cycle_size) if @cycle_size
  @cycle_hour = ConfigParser.handle_nil(cycle_hour)
  @cycle_hour = Integer(@cycle_hour) if @cycle_hour
  @cycle_minute = ConfigParser.handle_nil(cycle_minute)
  @cycle_minute = Integer(@cycle_minute) if @cycle_minute
  @mutex = Mutex.new
  @file = nil
  @file_size = 0
  @filename = nil
  @start_time = Time.now.utc
  @first_time = nil
  @last_time = nil
  @cancel_threads = false
  @last_offset = nil
  @previous_file_redis_offset = nil
  @redis_topic = redis_topic

  # This is an optimization to avoid creating a new entry object
  # each time we create an entry which we do a LOT!
  @entry = String.new

  if @cycle_time or @cycle_hour or @cycle_minute
    @@mutex.synchronize do
      @@instances << self

      unless @@cycle_thread
        @@cycle_thread = OpenC3.safe_thread("Log cycle") do
          cycle_thread_body()
        end
      end
    end
  end
end

Instance Attribute Details

#cycle_hour ⇒ Object (readonly)

Returns the value of attribute cycle_hour.



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# File 'lib/openc3/logs/log_writer.rb', line 43

def cycle_hour
  @cycle_hour
end

#cycle_minute ⇒ Object (readonly)

Returns the value of attribute cycle_minute.



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# File 'lib/openc3/logs/log_writer.rb', line 47

def cycle_minute
  @cycle_minute
end

#cycle_time ⇒ Object (readonly)

Returns the value of attribute cycle_time.



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# File 'lib/openc3/logs/log_writer.rb', line 38

def cycle_time
  @cycle_time
end

#filename ⇒ String (readonly)

Returns The filename of the packet log.

Returns:

  • (String) —

    The filename of the packet log



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# File 'lib/openc3/logs/log_writer.rb', line 30

def filename
  @filename
end

#logging_enabled ⇒ true/false (readonly)

Returns Whether logging is enabled.

Returns:

  • (true/false) —

    Whether logging is enabled



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# File 'lib/openc3/logs/log_writer.rb', line 33

def logging_enabled
  @logging_enabled
end

#mutex ⇒ Mutex (readonly)

Returns Instance mutex protecting file.

Returns:

  • (Mutex) —

    Instance mutex protecting file



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# File 'lib/openc3/logs/log_writer.rb', line 53

def mutex
  @mutex
end

#start_time ⇒ Time (readonly)

Returns Time that the current log file started.

Returns:

  • (Time) —

    Time that the current log file started



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# File 'lib/openc3/logs/log_writer.rb', line 50

def start_time
  @start_time
end

Instance Method Details

#close_file(take_mutex = true) ⇒ Object

Closing a log file isn’t critical so we just log an error. NOTE: This also trims the Redis stream to keep a full file’s worth of data in the stream. This is what prevents continuous stream growth.



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# File 'lib/openc3/logs/log_writer.rb', line 251

def close_file(take_mutex = true)
  @mutex.lock if take_mutex
  begin
    if @file
      begin
        @file.close unless @file.closed?
        Logger.debug "Log File Closed : #{@filename}"
        date = first_timestamp[0..7] # YYYYMMDD
        s3_key = File.join(@remote_log_directory, date, s3_filename)
        S3Utilities.move_log_file_to_s3(@filename, s3_key)
        # Now that the file is in S3, trim the Redis stream up until the previous file.
        # This keeps one file worth of data in Redis as a safety buffer
        Topic.trim_topic(@redis_topic, @previous_file_redis_offset) if @redis_topic and @previous_file_redis_offset
        @previous_file_redis_offset = @last_offset
      rescue Exception => err
        Logger.instance.error "Error closing #{@filename} : #{err.formatted}"
      end

      @file = nil
      @file_size = 0
      @filename = nil
    end
  ensure
    @mutex.unlock if take_mutex
  end
end

#create_unique_filename(ext = extension) ⇒ Object

implementation details



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# File 'lib/openc3/logs/log_writer.rb', line 168

def create_unique_filename(ext = extension)
  # Create a filename that doesn't exist
  attempt = nil
  while true
    filename_parts = [attempt]
    filename_parts.unshift @label if @label
    filename = File.join(Dir.tmpdir, File.build_timestamped_filename([@label, attempt], ext))
    if File.exist?(filename)
      attempt ||= 0
      attempt += 1
    else
      return filename
    end
  end
end

#cycle_thread_body ⇒ Object 



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# File 'lib/openc3/logs/log_writer.rb', line 184

def cycle_thread_body
  @@cycle_sleeper = Sleeper.new
  while true
    start_time = Time.now
    @@mutex.synchronize do
      @@instances.each do |instance|
        # The check against start_time needs to be mutex protected to prevent a packet coming in between the check
        # and closing the file
        instance.mutex.synchronize do
          utc_now = Time.now.utc
          # Logger.debug("start:#{@start_time.to_f} now:#{utc_now.to_f} cycle:#{@cycle_time} new:#{(utc_now - @start_time) > @cycle_time}")
          if instance.logging_enabled and
            (
              # Cycle based on total time logging
              (instance.cycle_time and (utc_now - instance.start_time) > instance.cycle_time) or

              # Cycle daily at a specific time
              (instance.cycle_hour and instance.cycle_minute and utc_now.hour == instance.cycle_hour and utc_now.min == instance.cycle_minute and instance.start_time.yday != utc_now.yday) or

              # Cycle hourly at a specific time
              (instance.cycle_minute and not instance.cycle_hour and utc_now.min == instance.cycle_minute and instance.start_time.hour != utc_now.hour)
            )
            instance.close_file(false)
          end
        end
      end
    end

    # Only check whether to cycle at a set interval
    run_time = Time.now - start_time
    sleep_time = CYCLE_TIME_INTERVAL - run_time
    sleep_time = 0 if sleep_time < 0
    break if @@cycle_sleeper.sleep(sleep_time)
  end
end

#extension ⇒ Object 



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# File 'lib/openc3/logs/log_writer.rb', line 282

def extension
  '.log'.freeze
end

#first_time ⇒ Object 



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# File 'lib/openc3/logs/log_writer.rb', line 286

def first_time
  Time.from_nsec_from_epoch(@first_time)
end

#first_timestamp ⇒ Object 



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# File 'lib/openc3/logs/log_writer.rb', line 294

def first_timestamp
  first_time().to_timestamp # "YYYYMMDDHHmmSSNNNNNNNNN"
end

#graceful_kill ⇒ Object 



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# File 'lib/openc3/logs/log_writer.rb', line 162

def graceful_kill
  @cancel_threads = true
end

#last_time ⇒ Object 



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# File 'lib/openc3/logs/log_writer.rb', line 290

def last_time
  Time.from_nsec_from_epoch(@last_time)
end

#last_timestamp ⇒ Object 



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# File 'lib/openc3/logs/log_writer.rb', line 298

def last_timestamp
  last_time().to_timestamp # "YYYYMMDDHHmmSSNNNNNNNNN"
end

#prepare_write(time_nsec_since_epoch, data_length, redis_offset) ⇒ Object 



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# File 'lib/openc3/logs/log_writer.rb', line 241

def prepare_write(time_nsec_since_epoch, data_length, redis_offset)
  # This check includes logging_enabled again because it might have changed since we acquired the mutex
  if @logging_enabled and (!@file or (@cycle_size and (@file_size + data_length) > @cycle_size))
    start_new_file()
  end
  @last_offset = redis_offset # This is needed for the redis offset marker entry at the end of the log file
end

#s3_filename ⇒ Object 



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# File 'lib/openc3/logs/log_writer.rb', line 278

def s3_filename
  "#{first_timestamp}__#{last_timestamp}" + extension
end

#shutdown ⇒ Object

Stop all logging, close the current log file, and kill the logging threads.



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# File 'lib/openc3/logs/log_writer.rb', line 150

def shutdown
  stop()
  @@mutex.synchronize do
    @@instances.delete(self)
    if @@instances.length <= 0
      @@cycle_sleeper.cancel if @@cycle_sleeper
      OpenC3.kill_thread(self, @@cycle_thread) if @@cycle_thread
      @@cycle_thread = nil
    end
  end
end

#start ⇒ Object

Starts a new log file by closing the existing log file. New log files are not created until packets are written by #write so this does not immediately create a log file on the filesystem.



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# File 'lib/openc3/logs/log_writer.rb', line 140

def start
  @mutex.synchronize { close_file(false); @logging_enabled = true }
end

#start_new_file ⇒ Object

Starting a new log file is a critical operation so the entire method is wrapped with a rescue and handled with handle_critical_exception Assumes mutex has already been taken



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# File 'lib/openc3/logs/log_writer.rb', line 223

def start_new_file
  close_file(false)

  # Start log file
  @filename = create_unique_filename()
  @file = File.new(@filename, 'wb')
  @file_size = 0

  @start_time = Time.now.utc
  @first_time = nil
  @last_time = nil
  Logger.debug "Log File Opened : #{@filename}"
rescue => err
  Logger.error "Error starting new log file: #{err.formatted}"
  @logging_enabled = false
  OpenC3.handle_critical_exception(err)
end

#stop ⇒ Object

Stops all logging and closes the current log file.



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# File 'lib/openc3/logs/log_writer.rb', line 145

def stop
  @mutex.synchronize { @logging_enabled = false; close_file(false) }
end