Class: Roby::DRoby::Logfile::Reader

Inherits:
Object
  • Object
show all
Defined in:
lib/roby/droby/logfile/reader.rb

Overview

A class that reads log files generated by Writer

Constant Summary collapse

FORMAT_VERSION =

The current log format version

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Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(event_io, index_path: nil) ⇒ Reader

Returns a new instance of Reader.



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# File 'lib/roby/droby/logfile/reader.rb', line 16

def initialize(event_io, index_path: nil)
    @event_io = event_io
    @index_path = index_path ||
                  "#{event_io.path.gsub(/\.log$/, '')}.idx"
    event_io.rewind
    options_hash = read_header
    self.class.process_options_hash(options_hash)
end

Instance Attribute Details

#event_io ⇒ Object (readonly)

Returns the value of attribute event_io.



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# File 'lib/roby/droby/logfile/reader.rb', line 14

def event_io
  @event_io
end

#index_path ⇒ String (readonly)

The standard Roby index path, inferred from the log file’s own path

Returns:

  • (String) 


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# File 'lib/roby/droby/logfile/reader.rb', line 94

def index_path
  @index_path
end

Class Method Details

.open(path, index_path: nil) ⇒ Reader .open(path, index_path: nil) {|reader| ... } ⇒ Object

Open a reader on the file indicated by path

Overloads:

  • .open(path, index_path: nil) ⇒ Reader

    Returns:

  • .open(path, index_path: nil) {|reader| ... } ⇒ Object

    Yield the reader, and automatically closes it on return of the block

    Yield Parameters:

    Returns:

    • the value returned by the block

Parameters:

  • path (String) —

    the path to the file

  • index_path (String, nil) (defaults to: nil) —

    the path to the file’s index. If nil, the index path will be the file’s path with the ‘.log’ extension replaced by ‘.idx’



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# File 'lib/roby/droby/logfile/reader.rb', line 148

def self.open(path, index_path: nil)
    io = File.open(path)
    reader = new(File.open(path), index_path: index_path)
    return reader unless block_given?

    begin
        yield(reader)
    ensure
        reader.close unless reader.closed?
    end
rescue ::Exception => e
    io.close if io && !io.closed?
    raise
end

.process_options_hash(options_hash) ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 74

def self.process_options_hash(options_hash)
    options_hash[:plugins]&.each do |plugin_name|
        begin
            Roby.app.using plugin_name
        rescue Roby::Application::PluginsDisabled => e
            Roby.warn "the log file mentions the #{plugin_name} plugin, "\
                      "but plugins are currently disabled. "\
                      "Some information might not be displayed"
        rescue ArgumentError => e
            Roby.warn "the log file mentions the #{plugin_name} plugin, "\
                      "but it is not available on this system. "\
                      "Some information might not be displayed"
        end
    end
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 44

def close
    event_io.close
end

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/roby/droby/logfile/reader.rb', line 52

def closed?
    event_io.closed?
end

#decode_one_chunk(chunk) ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 64

def decode_one_chunk(chunk)
    Logfile.decode_one_chunk(chunk)
end

#dup ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 36

def dup
    Reader.new(event_io.dup)
end

#eof? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/roby/droby/logfile/reader.rb', line 48

def eof?
    event_io.eof?
end

#index(path = index_path, rebuild: true) ⇒ Object

Returns the index object for this event log



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# File 'lib/roby/droby/logfile/reader.rb', line 107

def index(path = index_path, rebuild: true)
    if @index
        return @index
    elsif !File.file?(path)
        unless rebuild
            raise IndexMissing, "there's no file #{path}"
        end

        rebuild_index(path)
    end

    index =
        begin Index.read(path)
        rescue Exception => e
            raise e, "while reading index file #{path}: #{e.message}", e.backtrace
        end
    if index.valid_for?(event_io.path)
        @index = index
    elsif !rebuild
        raise IndexInvalid, "#{path} is not a valid index for #{self}"
    else
        rebuild_index(path)
        @index = Index.read(path)
    end
end

#load_one_cycle ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 68

def load_one_cycle
    return unless (chunk = read_one_chunk)

    decode_one_chunk(chunk)
end

#read_header ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 25

def read_header
    Logfile.read_prologue(event_io)
    if chunk = Logfile.read_one_chunk(event_io)
        ::Marshal.load(chunk)
    else
        raise InvalidFileError,
              "expected the prologue to be followed by one chunk, "\
              "but got nothing"
    end
end

#read_one_chunk ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 60

def read_one_chunk
    Logfile.read_one_chunk(event_io)
end

#rebuild_index(path = index_path) ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 96

def rebuild_index(path = index_path)
    Logfile.warn "rebuilding index file for #{event_io.path}"
    File.open(path, "w") do |index_io|
        File.open(event_io.path) do |file_io|
            Index.rebuild(file_io, index_io)
        end
    end
    @index = nil
end

#seek(pos) ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 56

def seek(pos)
    event_io.seek(pos)
end

#tell ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 40

def tell
    event_io.tell
end