Class: Px4LogReader::Reader

Inherits:
Object
  • Object
show all
Defined in:
lib/px4_log_reader/reader.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(file, options) ⇒ Reader

Returns a new instance of Reader.



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# File 'lib/px4_log_reader/reader.rb', line 122

def initialize( file, options )

	opts = {
		cache_filename: '',
	}.merge( options )

	@message_descriptors = {}
	@descriptor_cache = nil
	@context = Context.new

	@log_file = file
	@progress = Progress.new( @log_file )

	@descriptor_cache = MessageDescriptorCache.new( opts[:cache_filename] )
end

Instance Attribute Details

#context ⇒ Object (readonly)

Returns the value of attribute context.



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# File 'lib/px4_log_reader/reader.rb', line 120

def context
  @context
end

#progress ⇒ Object (readonly)

Returns the value of attribute progress.



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# File 'lib/px4_log_reader/reader.rb', line 119

def progress
  @progress
end

Instance Method Details

#descriptors(&block) ⇒ Object

Get the list of descriptors associated with the open PX4 log file. If a valid descriptor cache was specified at startup, the descriptors are loaded from the cache. Otherwise, the descriptors are parsed from the open log.

Parameters:

  • optional (block) —

    block is passed each descriptor as it is read



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# File 'lib/px4_log_reader/reader.rb', line 147

def descriptors( &block )
	if @log_file && @message_descriptors.empty?
		if @descriptor_cache && @descriptor_cache.exist?
			@message_descriptors = @descriptor_cache.read_descriptors
		else
			@message_descriptors = LogFile::read_descriptors( @log_file, @descriptor_cache, &block )
		end

		@message_descriptors[ FORMAT_MESSAGE.type ] = FORMAT_MESSAGE
	end

	return @message_descriptors
end

#each_message(options = {}, &block) ⇒ Object

Iterate over all log messages. Embedded message descriptors are skipped. If a “with” list is supplied, only messages in the list are passed to the caller-supplied block. If a “without” list supplied, all messages except those in the list are passed to the caller-supplied block. The caller must supply a block.

Parameters:

  • options (Hash) (defaults to: {}) —

    options

  • block (Block) —

    block takes message as argument



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# File 'lib/px4_log_reader/reader.rb', line 171

def each_message( options = {}, &block )

	opts ={
		with: [],        # white list - empty means all minus those in without list
		without: ['FMT'] # black list - includes types or names
	}.merge( options || {} )

	opts[:with].map! do |val|
		if val.class == String
			descriptor = descriptors.values.find { |desc| desc.name == val }
			if descriptor
				val = descriptor.type
			else
				puts "Failed to find descriptor with name '#{val}'"
			end
		end
	end

	opts[:without].map! do |val|
		if val.class == String
			descriptor = descriptors.values.find { |desc| desc.name == val }

			if descriptor
				val = descriptor.type
			else
				raise "Failed to find descriptor with name '#{val}'"
			end
		end
	end

	if block_given?

		loop do

			message, offset = LogFile::read_message( @log_file, @message_descriptors )
			break if message.nil?

			# Add message to the set of latest messages.
			@context.set( message )

			if opts[:with].empty?
				if !opts[:without].include?( message.descriptor.type )
					yield message
				end
			else
				if opts[:with].include?( message.descriptor.type )
					yield message
				end
			end

		end

	else
		raise BlockRequiredError.new
	end

end

#seek(offset) ⇒ Object

Seek to the specified file offset. If the offset is greater than the file size, seeks to the end of the file.

Parameters:

  • offset (Fixnum) —

    File offset in bytes



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# File 'lib/px4_log_reader/reader.rb', line 235

def seek( offset )
	if @log_file
		seek_offset = offset
		seek_offset = @progress.file_size if offset > @progress.file_size
		@log_file.seek( seek_offset, IO::SEEK_SET )
	end
end