StringBuilderArray

The version of StringBuilder built on an array of strings string[]: uses less memory.

Benchmark:

        [Benchmark(Baseline = true, Description = "StringBuilder")]
        public void StringBuilder()
        {
            var sb = new System.Text.StringBuilder();
            for (int i = 0; i < 1000; i++)
            {
                sb.AppendLine(_str);
            }

            var result = sb.ToString();
        }

        [Benchmark(Description = "StringBuilderArray")]
        public void StringBuilderArray()
        {
            var sb = new StringBuilderArray.StringBuilderArray();
            for (int i = 0; i < 1000; i++)
            {
                sb.AppendLine(_str);
            }

            var result = sb.ToString();
        }

Method	StrLength	Mean	Ratio	Gen0	Gen1	Gen2	Allocated	Alloc Ratio
System.Text.StringBuilder	5	17.97 μs	1.00	-	-	-	30.98 KB	1.00
StringBuilderArray	5	31.92 μs	1.77	-	-	-	34.77 KB	1.12
System.Text.StringBuilder	7	19.56 μs	1.00	-	-	-	50.59 KB	1.00
StringBuilderArray	7	31.61 μs	1.64	-	-	-	38.67 KB	0.76
System.Text.StringBuilder	10	18.31 μs	1.00	-	-	-	56.45 KB	1.00
StringBuilderArray	10	32.29 μs	1.76	-	-	-	44.53 KB	0.79
System.Text.StringBuilder	50	28.05 μs	1.00	-	-	-	206.36 KB	1.00
StringBuilderArray	50	34.38 μs	1.39	-	-	-	122.66 KB	0.59
System.Text.StringBuilder	100	29.47 μs	1.00	-	-	-	413.8 KB	1.00
StringBuilderArray	100	37.92 μs	1.28	-	-	-	220.31 KB	0.53
System.Text.StringBuilder	1000	747.71 μs	1.00	-	-	-	3935.53 KB	1.00
StringBuilderArray	1000	550.49 μs	0.78	-	-	-	1978.13 KB	0.50
System.Text.StringBuilder	2500	1,869.84 μs	1.00	-	-	-	9804.08 KB	1.00
StringBuilderArray	2500	1,348.66 μs	0.73	-	-	-	4907.81 KB	0.50
System.Text.StringBuilder	5000	5,274.39 μs	1.00	1000.0000	-	-	19583.76 KB	1.00
StringBuilderArray	5000	2,672.41 μs	0.51	-	-	-	9790.63 KB	0.50
System.Text.StringBuilder	10000	10,141.16 μs	1.00	2000.0000	1000.0000	-	39162.77 KB	1.00
StringBuilderArray	10000	5,112.69 μs	0.50	-	-	-	19556.25 KB	0.50
System.Text.StringBuilder	100000	54,063.39 μs	1.00	4000.0000	4000.0000	3000.0000	390802.44 KB	1.00
StringBuilderArray	100000	20,596.38 μs	0.38	-	-	-	195337.5 KB	0.50
System.Text.StringBuilder	500000	210,668.68 μs	1.00	5000.0000	4000.0000	4000.0000	1953310.77 KB	1.00
StringBuilderArray	500000	105,116.28 μs	0.50	-	-	-	976587.5 KB	0.50
System.Text.StringBuilder	1071741	289,865.89 μs	1.00	5000.0000	4000.0000	4000.0000	4186664.2 KB	1.00
StringBuilderArray	1071741	152,856.84 μs	0.53	-	-	-	2093269.14 KB	0.50

Reuse instance benchmark

        [Benchmark(Baseline = true, Description = "StringBuilder")]
        public void StringBuilder()
        {
            var sb = new System.Text.StringBuilder();
            for (int i = 0; i < 1000; i++)
            {
                sb.AppendLine(_str);
            }

            sb.Clear();
            for (int i = 0; i < 1000; i++)
            {
                sb.AppendLine(_str);
            }

            var result = sb.ToString();
        }

        [Benchmark(Description = "StringBuilderArray")]
        public void StringBuilderArray()
        {
            var sb = new StringBuilderArray.StringBuilderArray();
            for (int i = 0; i < 1000; i++)
            {
                sb.AppendLine(_str);
            }

            sb.Clear();
            for (int i = 0; i < 1000; i++)
            {
                sb.AppendLine(_str);
            }

            var result = sb.ToString();
        }

Method	StrLength	Mean	Ratio	Gen0	Gen1	Gen2	Allocated	Alloc Ratio
System.Text.StringBuilder	5	22.54 μs	1.00	-	-	-	47.01 KB	1.00
StringBuilderArray	5	39.13 μs	1.75	-	-	-	45.12 KB	0.96
System.Text.StringBuilder	7	21.42 μs	1.00	-	-	-	71.7 KB	1.00
StringBuilderArray	7	38.15 μs	1.78	-	-	-	49.02 KB	0.68
System.Text.StringBuilder	10	22.49 μs	1.00	-	-	-	84.59 KB	1.00
StringBuilderArray	10	39.34 μs	1.77	-	-	-	54.88 KB	0.65
System.Text.StringBuilder	50	29.06 μs	1.00	-	-	-	309.51 KB	1.00
StringBuilderArray	50	41.42 μs	1.42	-	-	-	133.01 KB	0.43
System.Text.StringBuilder	100	96.25 μs	1.00	-	-	-	626.33 KB	1.00
StringBuilderArray	100	49.48 μs	0.56	-	-	-	230.66 KB	0.37
System.Text.StringBuilder	1000	1,109.48 μs	1.00	-	-	-	5904.3 KB	1.00
StringBuilderArray	1000	542.58 μs	0.50	-	-	-	1988.48 KB	0.34
System.Text.StringBuilder	2500	3,839.15 μs	1.00	1000.0000	1000.0000	1000.0000	14698.94 KB	1.00
StringBuilderArray	2500	1,378.40 μs	0.36	-	-	-	4918.16 KB	0.33
System.Text.StringBuilder	5000	8,019.07 μs	1.00	2000.0000	1000.0000	1000.0000	29353.62 KB	1.00
StringBuilderArray	5000	2,711.04 μs	0.36	-	-	-	9800.98 KB	0.33
System.Text.StringBuilder	10000	13,084.87 μs	1.00	3000.0000	2000.0000	1000.0000	58702.15 KB	1.00
StringBuilderArray	10000	5,610.82 μs	0.42	-	-	-	19566.6 KB	0.33
System.Text.StringBuilder	100000	95,966.62 μs	1.00	5000.0000	5000.0000	4000.0000	586134.84 KB	1.00
StringBuilderArray	100000	20,813.11 μs	0.25	-	-	-	195347.85 KB	0.33
System.Text.StringBuilder	500000	284,075.06 μs	1.00	7000.0000	6000.0000	4000.0000	2930037.34 KB	1.00
StringBuilderArray	500000	105,142.19 μs	0.37	-	-	-	976597.85 KB	0.33
System.Text.StringBuilder	1071741	370,876.76 μs	1.00	7000.0000	6000.0000	4000.0000	6280013.72 KB	1.00
StringBuilderArray	1071741	152,671.59 μs	0.41	-	-	-	2093279.49 KB	0.33