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) ⇒ Reader 



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

def initialize(event_io)
    @event_io = event_io
    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 12

def event_io
  @event_io
end

Class Method Details

.open(path) ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 123

def self.open(path)
    io = new(File.open(path))
    if block_given?
        begin
            yield(io)
        ensure
            io.close unless io.closed?
        end
    else
        io
    end
end

.process_options_hash(options_hash) ⇒ Object 



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

def self.process_options_hash(options_hash)
    if options_hash[:plugins]
        options_hash[:plugins].each do |plugin_name|
            begin
                Roby.app.using plugin_name
            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
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 38

def close
    event_io.close
end

#closed? ⇒ Boolean 



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# File 'lib/roby/droby/logfile/reader.rb', line 46

def closed?
    event_io.closed?
end

#dup ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 30

def dup
    Reader.new(event_io.dup)
end

#eof? ⇒ Boolean 



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# File 'lib/roby/droby/logfile/reader.rb', line 42

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 98

def index(path = index_path, rebuild: true)
    if @index
        return @index
    elsif !File.file?(path)
        if !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

#index_path ⇒ String

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



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# File 'lib/roby/droby/logfile/reader.rb', line 84

def index_path
    event_io.path.gsub(/\.log$/, '') + ".idx"
end

#load_one_cycle ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 54

def load_one_cycle
    if chunk = Logfile.read_one_chunk(event_io)
        begin ::Marshal.load_with_missing_constants(chunk)
        rescue ArgumentError => e
            if e.message == "marshal data too short"
                raise TruncatedFileError, "marshal data invalid"
            else raise
            end
        end
    end
rescue Exception => e
    raise e, "#{e.message}, running roby-log repair might repair the file", e.backtrace
end

#read_header ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 21

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

#rebuild_index(path = index_path) ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 88

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

#seek(pos) ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 50

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

#tell ⇒ Object 



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# File 'lib/roby/droby/logfile/reader.rb', line 34

def tell
    event_io.tell
end