dodb.cr/spec/test-fifo.cr

require "spec"
require "../src/fifo.cr"

describe "FIFO" do
	it "add and remove values" do
		fifo = FIFO(Int32).new 3 # Only 3 allowed entries.
		(fifo << 1).should be_nil # there is still room in the fifo
		(fifo << 2).should be_nil # there is still room in the fifo
		(fifo << 3).should be_nil # last entry without exceeding the allowed size
		(fifo << 4).should eq 1   # -> 1 (least recently used data)
		(fifo << 4).should be_nil # -> nil (already in the fifo)
		(fifo << 2).should be_nil # -> nil (already in the fifo)
		(fifo << 5).should eq 3   # -> 3 (least recently used data)
		fifo.data.should eq([5, 2, 4] of Int32)

		fifo.delete 2
		fifo.data.should eq([5, 4] of Int32)
	end
end

describe "EfficientFIFO" do
	it "add and remove values" do
		fifo = EfficientFIFO(Int32).new 3 # Only 3 allowed entries.
		(fifo << 1).should be_nil # there is still room in the fifo
		(fifo << 2).should be_nil # there is still room in the fifo
		(fifo << 3).should be_nil # last entry without exceeding the allowed size
		(fifo << 4).should eq 1   # -> 1 (least recently used data)
		(fifo << 4).should be_nil # -> nil (already in the fifo)
		(fifo << 2).should be_nil # -> nil (already in the fifo)
		(fifo << 5).should eq 3   # -> 3 (least recently used data)
		fifo.list.to_s.should eq "[ 5, 2, 4 ]"

		fifo.delete 2
		fifo.list.to_s.should eq "[ 5, 4 ]"

		(fifo << 4).should be_nil # -> nil (just a re-order)
		fifo.list.to_s.should eq "[ 4, 5 ]"

		fifo.delete 5
		(fifo << 0).should be_nil
		fifo.list.to_s.should eq "[ 0, 4 ]"

		(fifo << 1).should be_nil
		fifo.list.to_s.should eq "[ 1, 0, 4 ]"

		fifo.delete 4
		fifo.list.to_s.should eq "[ 1, 0 ]"

		fifo.delete 4
		fifo.list.to_s.should eq "[ 1, 0 ]"
		fifo.list.size.should eq 2
		fifo.hash.size.should eq 2
	end
end