Class: Pocolog::SampleEnumerator

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/pocolog/sample_enumerator.rb

Overview

Sample enumerators are nicer interfaces for data reading built on top of a DataStream object

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(stream, read_data) ⇒ SampleEnumerator

Returns a new instance of SampleEnumerator



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# File 'lib/pocolog/sample_enumerator.rb', line 22

def initialize(stream, read_data)
    @stream = stream
    @read_data = read_data
end

Instance Attribute Details

#every_index ⇒ Object

Returns the value of attribute every_index



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# File 'lib/pocolog/sample_enumerator.rb', line 9

def every_index
  @every_index
end

#every_time ⇒ Object

Returns the value of attribute every_time



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# File 'lib/pocolog/sample_enumerator.rb', line 8

def every_time
  @every_time
end

#max_count ⇒ Object

Returns the value of attribute max_count



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# File 'lib/pocolog/sample_enumerator.rb', line 10

def max_count
  @max_count
end

#max_index ⇒ Object

Returns the value of attribute max_index



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# File 'lib/pocolog/sample_enumerator.rb', line 9

def max_index
  @max_index
end

#max_time ⇒ Object

Returns the value of attribute max_time



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# File 'lib/pocolog/sample_enumerator.rb', line 8

def max_time
  @max_time
end

#min_index ⇒ Object

Returns the value of attribute min_index



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# File 'lib/pocolog/sample_enumerator.rb', line 9

def min_index
  @min_index
end

#min_time ⇒ Object

Returns the value of attribute min_time



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# File 'lib/pocolog/sample_enumerator.rb', line 8

def min_time
  @min_time
end

#read_data ⇒ Object (readonly)

Returns the value of attribute read_data



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# File 'lib/pocolog/sample_enumerator.rb', line 21

def read_data
  @read_data
end

#sample_count ⇒ Object (readonly)

Returns the value of attribute sample_count



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# File 'lib/pocolog/sample_enumerator.rb', line 57

def sample_count
  @sample_count
end

#stream ⇒ Object (readonly)

Returns the value of attribute stream



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# File 'lib/pocolog/sample_enumerator.rb', line 21

def stream
  @stream
end

#use_rt ⇒ Object

Returns the value of attribute use_rt



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# File 'lib/pocolog/sample_enumerator.rb', line 7

def use_rt
  @use_rt
end

Instance Method Details

#at(pos) ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 42

def at(pos)
    from(pos)
    max(1)
end

#between(from, to) ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 38

def between(from, to)
    self.from(from)
    self.to(to)
end

#each(&block) ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 59

def each(&block)
    return enum_for(__method__) unless block

    raw_each do |rt, lg, raw_data|
        yield(rt, lg, Typelib.to_ruby(raw_data))
    end
end

#every(interval) ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 26

def every(interval)
    setvar('every', interval)
    self
end

#from(from) ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 30

def from(from);
    setvar("min", from)
    self
end

#max(count) ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 52

def max(count)
    @max_count = count
    self
end

#raw_each ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 67

def raw_each
    return enum_for(__method__) unless block_given?
    return if stream.empty?

    @sample_count = 0
    @next_yield_time = nil
    @next_yield_index = nil

    min_index = self.min_index
    min_time  = self.min_time

    if min_time && stream.interval_lg.first > min_time
        min_time = nil
    elsif min_index || (min_time && !use_rt)
        stream.seek(min_index || min_time)
        stream.previous
    elsif min_time && use_rt
        return unless skip_to_realtime(min_time)

        stream.previous
    end

    stream.each_block(!(min_index || min_time)) do
        sample_index = stream.sample_index
        return self if max_index && max_index < sample_index
        return self if max_count && max_count <= @sample_count

        rt, lg = stream.time
        sample_time = use_rt ? rt : lg
        return self if max_time && max_time < sample_time

        if yield_sample?(sample_time, sample_index)
            @sample_count += 1
            data_block = stream.data_header
            yield(data_block.rt, data_block.lg,
                  (stream.raw_data(data_block) if read_data))
        end
    end
    self
end

#realtime(use_rt = true) ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 47

def realtime(use_rt = true)
    @use_rt = use_rt
    self
end

#setvar(name, val) ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 11

def setvar(name, val)
    time, index = case val
                  when Integer then [nil, val]
                  when Time then [val, nil]
                  end

    send("#{name}_time=", time)
    send("#{name}_index=", index)
end

#skip_to_realtime(min_time) ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 108

def skip_to_realtime(min_time)
    stream.each_block(true) do
        sample_index = stream.sample_index
        return if max_index && max_index < sample_index

        rt, = stream.time
        return true if rt >= min_time
    end
    false
end

#to(to) ⇒ Object 



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# File 'lib/pocolog/sample_enumerator.rb', line 34

def to(to)
    setvar("max", to)
    self
end

#yield_sample?(sample_time, sample_index) ⇒ Boolean

Yield the given sample if required by our configuration

Returns:

  • (Boolean) 


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# File 'lib/pocolog/sample_enumerator.rb', line 120

def yield_sample?(sample_time, sample_index)
    if every_time
        every_time = self.every_time.to_r
        @next_yield_time ||= sample_time
        while @next_yield_time <= sample_time
            do_display = true
            @next_yield_time += every_time
        end
        do_display
    elsif every_index
        @next_yield_index ||= sample_index
        if @next_yield_index <= sample_index
            do_display = true
            @next_yield_index += every_index
        end
        do_display
    else
        true
    end
end