package other_examples;

import com.google.common.base.Charsets;

import com.google.common.io.CharStreams;

import org.apache.commons.io.IOUtils;

import org.openjdk.jmh.annotations.*;

import org.openjdk.jmh.runner.Runner;

import org.openjdk.jmh.runner.options.Options;

import org.openjdk.jmh.runner.options.OptionsBuilder;

import java.io.*;

import java.nio.charset.StandardCharsets;

import java.util.Scanner;

import java.util.concurrent.TimeUnit;

import java.util.stream.Collectors;

/**

* Created by vvedenin on 2/15/2016.

*/

@BenchmarkMode(Mode.AverageTime)

@OutputTimeUnit(TimeUnit.MICROSECONDS)

@Warmup(iterations = 2, time = 1, timeUnit = TimeUnit.SECONDS)

@Measurement(iterations = 3, time = 1, timeUnit = TimeUnit.SECONDS)

@Fork(1)

@State(Scope.Benchmark)

public class ConvertInputStreamToStringBenchmark {

private final static String test1 = "test1847686128764812764876128пввпв76417826487216478216784621784672816478216784621784621786478216478216784261784621"+ "\n\r" +"782178647281647821647821697421687126784621874621786478216478216874";

private final static InputStream inputStream = IOUtils.toInputStream(test1, StandardCharsets.UTF_8);

/* 1. Using IOUtils.toString (Apache Utils) */

@Benchmark

public String test1_apacheToInputStream() throws IOException {

mark();

String result = IOUtils.toString(inputStream, StandardCharsets.UTF_8);

reset();

return result;

}

/* 2. Using CharStreams (guava) */

@Benchmark

public String test2_guavaCharStreams() throws IOException {

mark();

String result = CharStreams.toString(new InputStreamReader(inputStream, Charsets.UTF_8));

inputStream.reset();

return result;

}

/* 3. Using Scanner (JDK) */

@Benchmark

public String test3_jdkScanner() throws IOException {

mark();

Scanner s = new Scanner(inputStream).useDelimiter("\\A");

String result = s.hasNext() ? s.next() : "";

reset();

return result;

}

/* 4. Using Stream Api (Java 8) */

@Benchmark

public String test4_jdkJava8() throws IOException {

mark();

String result = new BufferedReader(new InputStreamReader(inputStream)).lines().collect(Collectors.joining("\n"));

reset();

return result;

}

/* 5. Using parallel Stream Api (Java 8) */

@Benchmark

public String test5_jdkJava8parallel() throws IOException {

mark();

String result = new BufferedReader(new InputStreamReader(inputStream)).lines().parallel().collect(Collectors.joining("\n"));

reset();

return result;

}

/* 6. Using InputStreamReader and StringBuilder (JDK) */

@Benchmark

public String test6_inputStreamReaderAndStringBuilder() throws IOException {

mark();

final int bufferSize = 1024;

final char[] buffer = new char[bufferSize];

final StringBuilder out = new StringBuilder();

Reader in = new InputStreamReader(inputStream, "UTF-8");

for (; ; ) {

int rsz = in.read(buffer, 0, buffer.length);

if (rsz < 0)

break;

out.append(buffer, 0, rsz);

}

reset();

return out.toString();

}

/* 7. Using StringWriter and IOUtils.copy (Apache Commons)*/

@Benchmark

public String test7_apacheStringWriterAndIOUtilsCopy() throws IOException {

mark();

StringWriter writer = new StringWriter();

IOUtils.copy(inputStream, writer, "UTF-8");

reset();

return writer.toString();

}

/* 8. Using ByteArrayOutputStream and inputStream.read (JDK) */

@Benchmark

public String test8_readByteArrayOutputStream() throws IOException {

mark();

ByteArrayOutputStream result = new ByteArrayOutputStream();

byte[] buffer = new byte[1024];

int length;

while ((length = inputStream.read(buffer)) != -1) {

result.write(buffer, 0, length);

}

reset();

return result.toString("UTF-8");

}

/* 9. Using BufferedReader (JDK) */

@Benchmark

public String test9_bufferedReaderReadLine() throws IOException {

mark();

String newLine = System.getProperty("line.separator");

BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));

StringBuilder result = new StringBuilder();

String line; boolean flag = false;

while ((line = reader.readLine()) != null) {

result.append(flag? newLine: "").append(line);

flag = true;

}

reset();

return result.toString();

}

/* 10. Using BufferedInputStream and ByteArrayOutputStream (JDK) */

@Benchmark

public String test10_bufferedInputStreamAndByteArrayOutputStream() throws IOException {

mark();

BufferedInputStream bis = new BufferedInputStream(inputStream);

ByteArrayOutputStream buf = new ByteArrayOutputStream();

int result = bis.read();

while(result != -1) {

buf.write((byte) result);

result = bis.read();

}

reset();

return buf.toString();

}

/* 11. Using inputStream.read() and StringBuilder (JDK) */

@Benchmark

public String test11_inputStreamReadAndStringBuilder() throws IOException {

mark();

int ch;

StringBuilder sb = new StringBuilder();

while((ch = inputStream.read()) != -1)

sb.append((char)ch);

reset();

return sb.toString();

}

/* 12. Using BufferedReader (JDK) */

@Benchmark

public String test12_bufferedReaderReadLine2() throws IOException {

mark();

String newLine = System.getProperty("line.separator");

BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));

StringBuilder result = new StringBuilder();

String line;

while ((line = reader.readLine()) != null) {

result.append(newLine).append(line);

}

reset();

return result.toString().trim();

}

private void reset() throws IOException {

inputStream.reset();

}

private void mark() {

inputStream.mark(0);

}

public static void main(String[] args) throws Exception {

ConvertInputStreamToStringBenchmark test = new ConvertInputStreamToStringBenchmark();

System.out.println();

System.out.println("1. apacheToInputStream : " + test.test1_apacheToInputStream().length());

System.out.println("2. guavaCharStreams : " + test.test2_guavaCharStreams().length());

System.out.println("3. jdkScanner : " + test.test3_jdkScanner().length());

System.out.println("4. jdkJava8 : " + test.test4_jdkJava8().length());

System.out.println("5. jdkJava8parallel : " + test.test5_jdkJava8parallel().length());

System.out.println("6. inputStreamReaderAndStringBuilder : " + test.test6_inputStreamReaderAndStringBuilder().length());

System.out.println("7. apacheStringWriterAndIOUtilsCopy : " + test.test7_apacheStringWriterAndIOUtilsCopy().length());

System.out.println("8. readByteArrayOutputStream : " + test.test8_readByteArrayOutputStream().length());

System.out.println("9. bufferedReaderReadLine : " + test.test9_bufferedReaderReadLine().length());

System.out.println("10. bufferedInputStreamAndByteArrayOutputStream : " + test.test10_bufferedInputStreamAndByteArrayOutputStream().length());

System.out.println("11. inputStreamReadAndStringBuilder : " + test.test11_inputStreamReadAndStringBuilder().length());

System.out.println("12. test12_bufferedReaderReadLine2 : " + test.test12_bufferedReaderReadLine2().length());

System.out.println();

Options opt = new OptionsBuilder()

.include(ConvertInputStreamToStringBenchmark.class.getSimpleName())

.build();

new Runner(opt).run();

}

}